Biological and Pharmaceutical Bulletin
Online ISSN : 1347-5215
Print ISSN : 0918-6158
ISSN-L : 0918-6158
Volume 18 , Issue 1
Showing 1-41 articles out of 41 articles from the selected issue
  • Shinji MIURA, Junichi WATANABE, Mitsuaki SANO, Takako TOMITA, Toshihik ...
    1995 Volume 18 Issue 1 Pages 1-4
    Published: January 15, 1995
    Released: April 10, 2008
    JOURNALS FREE ACCESS
    We have reported in our previous paper that several flavan-3-ol derivatives (tea polyphenols) inhibited the Cu2+-mediated low density lipoprotein (LDL) oxidation in vitro. (-)-Epigallocatechin gallate (EGCG), in particular, exhibited strong inhibition. In this study, we have compared the antioxidative effects of EGCG with those of other natural antioxidants, such as flavonols, sesaminol, curcuminoid derivatives, tocopherol analogues, and theaflavins. The antioxidative effects were monitored by conjugated diene formation in LDL which was carried out at 37°C with 5 μM CuSO4 with or without antioxidants. Dibutyl hydroxytoluene (BHT) was used as a reference compound. The lag-time before the onset of conjugated diene formation was more than 100 min in the presence of 0.5 μM EGCG, theaflavin, myricetin, quercetin, and sesaminol. The ability to prolong the lag-time was in the order of sesaminol>quercetin>EGCG>theaflavin≥myricetin>BHT>α-tocopherol. Among the 4 tocopherol analogues used, α-tocopherol showed the strongest antioxidative activity. We have also studied the effects of EGCG, BHT, and α-tocopherol on cholesteryl ester (CE) degradation and apolipoprotein B 100 (apo B 100) fragmentation in the Cu2+-mediated oxidative modification of LDL. EGCG was the most effective inhibitor of CE degradation and apo B 100 fragmentation.
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  • Masahito IKAWA, Xing YING, Keiichi TANAKA, Kazutomo OHASHI, Fumitaka S ...
    1995 Volume 18 Issue 1 Pages 5-8
    Published: January 15, 1995
    Released: April 10, 2008
    JOURNALS FREE ACCESS
    A conditioned medium (CM) was prepared by culturing human sperm at 3.0×106 sperm/ml for 12 h. The fusion index increased significantly when the sperm penetration assay (SPA) was performed with CM (0.6 without CM to 2.0 with CM). The conditioned medium was also effective on the sperm from 11 patients who showed a low or zero value in SPA and who's in vitro fertilization treatment failed. When CM from the sperm of healthy donors was added to these patients'sperm, the fusing ability to zona free hamster eggs was significantly restored.
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  • Yoshiyuki MIYABE, Tetsuya AMANO, Yoshihiro DEYASHIKI, Akira HARA, Fumi ...
    1995 Volume 18 Issue 1 Pages 9-12
    Published: January 15, 1995
    Released: April 10, 2008
    JOURNALS FREE ACCESS
    We have investigated the steady-state kinetics for a cytosolic 3α-hydroxysteroid/dihydrodiol dehydrogenase isozyme of human liver and its inhibition by several bile acids and anti-inflammatory drugs such as indomethacin, flufemanic acid and naproxen. Initial velocity and product inhibition studies performed in the NADP+-linked (S)-1-indanol oxidation at pH 7.4 were consistent with a sequential ordered mechanism in which NADP+ binds first and leaves last. The bile acids and drugs, competitive inhibitors with respect to the alcohol substrate, exhibited uncompetitive inhibition with respect to the coenzyme, with Ki values less than 1 μM, whereas indomethacin exhibited noncompetitive inhibition (Ki<24 μM). The kinetics of the inhibition by a mixture of the two inhibitors suggests that bile acids and drugs, except indomethacin, bind to overlapping sites at the active center of the enzyme-coenzyme binary complex.
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  • Yasuhiro KIMURA, Kenji KIHIRA, Katsushi MIYAKE, Teruaki KITAURA, Hiros ...
    1995 Volume 18 Issue 1 Pages 13-17
    Published: January 15, 1995
    Released: April 10, 2008
    JOURNALS FREE ACCESS
    We investigated the changes in cholecystokinin octapeptide (CCK8) tissue levels after the intraperitoneal administration of L-3, 4-dihydroxyphenylalanine (L-DOPA) in normal and 6-hydroxydopamine (6-OHDA) treated rat brains to clarify the interaction between CCK8 and dopamine (DA). The administration of L-DOPA to the normal rats elevated the regional CCK8-like immunoreactivity (CCK8LI) tissue levels in a dose dependent manner in the frontal cortex, striatum, and nucleus accumbens where CCK neurons were closely associated with DA neurons but not in the hippocampus where CCK neurons were identified as local circuit neurons. Moreover, coadministration of D2-selective antagonist, L-sulpiride, with L-DOPA inhibited the elevation of CCK8LI levels in several brain regions. This evidence indicates that CCK8 release was inhibited by exogenous DA converted from L-DOPA via D2 receptor stimulation. In the 6-OHDA treated rats on the 3rd day after the treatment, the L-DOPA administration elevated the CCK8 levels in several regions. However, the elevation of CCK8LI levels was not observed on the 7th day after the 6-OHDA treatment. These results suggest that there would be a great difference in the effect of L-DOPA on CCK8LI levels between the 3rd day and 7th day after 6-OHDA treatment. It was concluded that the changes in CCK8LI levels would be due to changes in CCK8 release, and that the CCK8 release would be regulated by extracellular DA via D2 receptor.
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  • Hiroshi OKUMURA, Naoki ASHIZAWA, Rieko ASAKURA, Tomoji AOTSUKA, Fujio ...
    1995 Volume 18 Issue 1 Pages 18-23
    Published: January 15, 1995
    Released: April 10, 2008
    JOURNALS FREE ACCESS
    The effects of diltiazem and phosphoramidon on sudden death induced by endothelin (ET)-1 and by big ET-1 were compared in rodents. Diltiazem (2 mg/kg, i. v.) remarkably diminished the lethal toxicity of ET-1 with a reduction in the extent of the rise in plasma immunoreactive ET-1-like activity (IR-ET-1), tissue IR-ET-1 accumulation in the heart and the rise in plasma potassium concentration. In big ET-1-induced lethality, diltiazem only slightly prolonged the latency and did not reduce the mortality. Although diltiazem moderately inhibited the rise in plasma IR-ET-1 and potassium concentration in these mice, it did not affect the accumulation of IR-ET-1 in the heart, lung or kidney. Phosphoramidon (2 mg/kg, i. v.) decreased the lethality of big ET-1 with the decrement in elevation of IR-ET-1 in the heart, lung and plasma as well as with the decrease in plasma potassium concentration, but it failed to improve any parameters in ET-1-induced lethality. In anesthetized rats, ET-1 (5 nmol/kg, i. v.) elevated ST-segment of electromyocardiograms, and diltiazem (2 mg/kg, i. v.) significantly reversed this change. Big ET-1 (25 nmol/kg, i. v.) also induced the ST-segment elevation, which was significantly inhibited by phosphoramidon but not by diltiazem. These findings suggest that accumulation of ET-1 in the heart, which may lead to lethal cardiac ischemia, is an important factor in the lethality of ET-1, while additional factors (such as hemoconcentration and bronchoconstriction) may be involved in big ET-1-induced lethality.
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  • JoungHoon KIM, YoungKeun AHN, Motoyasu OHSAWA
    1995 Volume 18 Issue 1 Pages 24-27
    Published: January 15, 1995
    Released: April 10, 2008
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    The effects of diphenyl dimethyl dicarboxylate (PMC) on serum antibody production were investigated in BALB/c mice. PMC (3 and 6 mg/kg/d, respectively) was orally administered to the mice for 14 consecutive days. The effects on antibody production were assessed by enzyme-linked immunosorbant assay (ELISA) of immunoglobulin (Ig) subset levels in serum, collected at week 2 from mice with or without immunization by an i. p. injection of 0.1 mg ovalbumin (OVA) in complete Freund's adjuvant (CFA) at week 1 after the first oral administration of PMC. PMC showed a significant enhancement of the levels of total serum IgG, IgG1, IgG2a and IgA without the immunization, while total IgE levels were not affected. When mice were immunized with OVA after the oral administration of PMC, moreover, a marked stimulation of antibody production was observed in mice fed 6 mg/kg/d PMC, hardly accompanied with increase of IgE levels. In these mice, additionally, PMC significantly elevated anti-OVA IgG (including both IgG1 and IgG2a mediated by different T-helper cells) levels. These findings indicate that PMC enhances antibody production in mice with therapeutic concentrations that have shown great promise in the treatment of chronic hepatitis virus of type B.
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  • Hideki SHIMIZU, Michiko YOSHII, Masako YANO, Masako TANI, Takahiko HOS ...
    1995 Volume 18 Issue 1 Pages 28-32
    Published: January 15, 1995
    Released: April 10, 2008
    JOURNALS FREE ACCESS
    We studied the effect of 5β-cholane-3α, 7β, 24-triol-24-sulfate (UDC-O-sulfate) on ileal active transport of cholyltaurine, on hepatic cholesterol 7α-hydroxylase activity, on serum and liver cholesterol levels, on intestinal absorption of cholesterol, and on bile salt composition of gallbladder bile in hamsters. Experiments using the everted gut sacs show that UDC-O-sulfate inhibits the ileal active transport of cholyltaurine. In experiments feeding the diets with either UDC-O-sulfate, cholesterol, or both to hamsters, the addition of UDC-O-sulfate to the cholesterolenriched diet reduced the elevation of serum and liver cholesterol levels caused by cholesterol feeding. Supplementation with UDC-O-sulfate to the standard diet was likely to reduce serum and liver cholesterol levels. Cholesterol 7α-hydroxylase activity was higher in the two UDC-O-sulfate supplemented groups than in the two corresponding groups, the standard diet group and the cholesterol enriched diet group, respectively. Addition of UDC-O-sulfate to the standard and cholesterol diets did not change intestinal absorption of cholesterol. The change of the bile salt composition in hamsters fed UDC-O-sulfate may also suggest that the bile alcohol sulfate inhibits the intestinal absorption of endogenous bile salts. Hence the hypocholesterolemic activity of dietary UDC-O-sulfate is thought to be the effect of the partial interruption of the enterohepatic circulation of endogenous bile salts.
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  • Wantana REANMONGKOL, Kinzo MATSUMOTO, Hiroshi WATANABE, Sanan SUBHADHI ...
    1995 Volume 18 Issue 1 Pages 33-36
    Published: January 15, 1995
    Released: April 10, 2008
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    The effects of crude alkaloids extracted from the stem bark of Hunteria zeylanica GARD. (H. zeylanica) on acute inflammatory responses such as carrageenin-induced paw edema in rats and croton oil- and arachidonic acid-induced ear edema in mice were investigated. Oral administration of H. zeylanica alkaloid extract (200-400 mg/kg) significantly suppressed the paw swelling induced by carrageenin. In the croton oil-induced ear edema, topically applied H. zeylanica alkaloid extract, at doses of 200 and 400 mg/ml, also significantly reduced ear edema. Moreover, the extract (50-200 mg/kg, p. o.) reduced in a dose-dependent manner the ear swelling induced by topically applied arachidonic acid (2 mg/ear). These results suggest that the inhibitory effects of H. zeylanica alkaloid extract on acute edema formation are partly due to inhibition of 5-lipoxygenase and cyclooxygenase activity.
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  • Hiroichi NAGAI, Takehisa IWAMA, Hiroshi MORI, Hiroyuki NISHIDA, Kiyosh ...
    1995 Volume 18 Issue 1 Pages 37-41
    Published: January 15, 1995
    Released: April 10, 2008
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    We have developed an experimental model for exercise-induced asthma (EIA) using conscious guinea pigs. Respiratory resistance (Rrs) was measured before and after exercise (running). When a 0.05% lipopolysaccharide (LPS) was inhaled by guinea pigs which had been pretreated with a corticosteroid biosynthesis inhibitor metyrapone (50 mg/kg, i. v.), Rrs significantly increased 24 h after exercise. Metyrapone had no effect, however, on the LPS-induced increase in the numbers of macrophages, eosinophils, neutrophils and lymphocytes in bronchoalveolar lavage fluid (BALF). In order to examine the role of airway inflammation, the effects of murine recombinant interleukin-5 (mrIL-5) and platelet activating factor (PAF) were investigated in guinea pigs. The exercise-elicited increase in Rrs was observed 24 h later than the treatment with mrIL-5 in metyrapone-treated animals. The number of macrophages, eosinophils and neutrophils increased in the BALF of mrIL-5-treated animals. In contrast, a 0.05% PAF aerosol caused an increased number of eosinophils in BALF, but did not affect Rrs after exercise in either metyrapone-treated or non-treated animals. Moreover, to evaluate the value of this model as a pharmacological tool, the effect of ketotifen and prednisolone on the exercise-induced increase in Rrs was investigated. Prior administration of ketotifen and prednisolone showed a tendency to prevent, or clearly inhibited, the exercise-induced increase in Rrs in animals treated with the combination with LPS and metopyrone.
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  • Kazuhiko OKANO, Yasushi KURAISHI, Masamichi SATOH
    1995 Volume 18 Issue 1 Pages 42-44
    Published: January 15, 1995
    Released: April 10, 2008
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    To determine the role of NK-1 substance P receptors and N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptors in the spinal dorsal horn in the hyperalgesia induced by repeated cold stress (RCS), we examined the effects of intrathecal injections of antagonists to NK-1, NMDA and non-NMDA receptors on the nociceptive threshold of RCS rats for paw-pressure stimulation. Intrathecal injections of the NK-1 antagonist (2S, 3S)-cis-2-(diphenylmethyl)-N-[(2-methoxyphenyl)-methyl]-1-azabicyclo [2. 2. 2] octan-3-amine (CP-96, 345, 0.3-3 nmol/rat), the NMDA antagonist 2-amino-5-phosphonovaleric acid (APV, 1-10 nmol/rat), and the non-NMDA antagonist 6-cyano-7-nitroquinoxaline-2, 3-dione (CNQX, 1-10 nmol/rat) suppressed RCS-induced hyperalgesia in a dose-dependent manner, without affecting the nociceptive threshold of normal rats. Combinations of any two of CP-96, 345 (3 nmol/rat), APV (10 nmol/rat), and CNQX (10 nmol/rat) did not produce a larger inhibition than that produced by their single doses. The present results suggest that the enhancement of the substance P-NK-1 receptor system and glutamate-NMDA and non-NMDA receptor systems in the spinal dorsal horn is at least partly involved in the RCS-induced hyperalgesia.
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  • Ken RIN, Kenji KAWAGUCHI, Kenzo YAMANAKA, Masakatsu TEZUKA, Naoto OKU, ...
    1995 Volume 18 Issue 1 Pages 45-48
    Published: January 15, 1995
    Released: April 10, 2008
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    We previously reported that dimethylarsinic acid (DMAA), a major metabolite of inorganic arsenics, induced DNA single-strand breaks (ssb) both in vivo and in cultured alveolar type II (L-132) cells in vitro, possibly via the production of dimethylarsenic peroxyl radicals. Here, the interaction of superoxide anion radicals (O-2) in the induction of ssb in L-132 cells was investigated using paraquat, an O-2-producing agent. A significant enhancement of ssb formation was observed in the DMAA-exposed cells when coexposed to paraquat. This enhancement occurred even when post-exposed to DMAA after washing, suggesting that the DMAA exposure caused some modification of DNA such as DNA-adducts, which was recognized by active oxygens to form ssb. An experiment with UV-irradiation, which was likely to induce ssb at the modified region, supported the possibility of DNA modification by DMAA exposure. An ESR study indicated that O-2 produced by paraquat in DMAA-exposed cells was more consumed than in non-exposed cells, assumingly through the reaction with the dimethylarsenic-modified region of DNA. The species of active oxygens were estimated by using diethyldithiocarbamate, aminotriazole, diethylmaleate, hydrogen peroxide (H2O2), γ-irradiation and ethanol. O-2 but neither H2O2 nor hydroxyl radicals was very likely to contribute to the ssb-enhancing action of paraquat.
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  • Eriko OKOCHI, Eri NAMAI, Masataka MOCHIZUKI, Kei ITO
    1995 Volume 18 Issue 1 Pages 49-52
    Published: January 15, 1995
    Released: April 10, 2008
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    N-Nitrosodialkylamines are environmental alkylating carcinogens which are metabolically activated to α-hydroxy nitrosamines by cytochrome P450. The precise mechanism of their activation is not well understood, and a simplified chemical model for cytochrome P450 as a non-enzymatic system is useful for investigating the mechanism. In the present study, a chemical model was used in a bacterial mutation assay as a substitute of S9 mix, and its ability in the activation of N-nitrosodialkylamines was elucidated. In the presence of tetrakis (pentafluorophenyl) porphyrinatoiron (III) chloride and tert-butyl hydroperoxide, the mutagenicity of N-nitrosodialkylamines [alkyl=methyl (NDM), ethyl (NDE), propyl (NDP) and butyl (NDB)] in Salmonella typhimurium YG7108 was detected. The mutagenicity increased by the pre-incubation and was dependent on the concentration of mutagens. The mutagenic activity of N-nitrosodialkylamines in Salmonella typhimurium YG7108 was in the following order : NDB>NDM>NDE&ap;NDP. The formation of aldehydes derived from dealkylation in the present model was exemplified by the formation of acetaldehyde from NDE. These results showed that N-nitrosodialkylamines were activated by the model system, and consequent mutagenicity was observed. The oxidation by the model can mimic the metabolic activation of chemical carcinogens by cytochrome P450, and the biomimetic catalyst is useful in investigating the mechanisms of the metabolic pathway of N-nitrosodialkylamines.
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  • Kiyoshi SUGIYAMA, Harumi UEDA, Yoshimasa ICHIO, Masami YOKOTA
    1995 Volume 18 Issue 1 Pages 53-58
    Published: January 15, 1995
    Released: April 10, 2008
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    The effects of oral treatment with 1-, 5-, 10- and 20-fold the usual daily dose of Juzen-taiho-to on the nephrotoxicity, immunosuppression, hepatic toxicity and gastrointestinal toxicity caused by i. p. administration of 3.0 mg/kg cisplatin (CDDP) 9 times (on days 3, 4, 5, 6, 7, 8, 10, 11, and 12) were examined in ddY mice inoculated with sarcoma 180 (S-180) cells on day 1. The increase in blood urea nitrogen, serum creatinine, serum glutamic-oxaloacetic transaminase, serum glutamic-pyruvic transaminases and relative stomach weight and decrease in white blood cell count, platelet count, relative spleen and thymus weight, food intake and body weight caused by CDDP were inhibited to nearly the control levels without reducing the antitumor activity of CDDP against S-180 by the oral treatment with either 10-fold (1.7 g/kg) or 20-fold (3.4 g/kg) the usual daily dose of Juzen-taiho-to 12 times (on days 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, and 15). All the mice receiving 4.5, 6.0, 7.5, 9.0, and 12.0 mg/kg CDDP died by day 12, while treatment with 3.4 g/kg Juzen-taiho-to efficiently prolonged the survival time. These findings indicate that Juzen-taiho-to may provide protection against most clinical toxicity caused by CDDP, and Juzen-taiho-to may allow us to administer a much higher dose of CDDP in clinical therapy.
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  • Hitoshi MASAKI, Takamasa ATSUMI, Hiromu SAKURAI
    1995 Volume 18 Issue 1 Pages 59-63
    Published: January 15, 1995
    Released: April 10, 2008
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    Previously we demonstrated that hamamelitannin (2', 5-di-O-galloyl hamamelose) in Hamamelis virginiana L. exhibits potent superoxide-anion scavenging activity. We then examined the physiological and pharmacological activities of hamamelitannin as well as its functional homologues, gallic acid and syringic acid. The following results were obtained : (1) Hamamelitannin has a higher protective activity against cell damages induced by superoxide anions than gallic acid which is the functional moiety of hamamelitannin. The protective activity of hamamelitannin on murine fibroblast-damage induced by superoxide anions was found at a minimum concentration of 50 μM, while the corresponding figure for gallic acid was 100 μM. (2) Pre-treatment of fibroblasts with hamamelitannin enhances cell survival. (3) The superoxide-anion scavenging activity of the compound in terms of its IC50 value (50% inhibition concentration of superoxide anion radicals generated) was evaluated by ESR spin-trapping. Both hamamelitannin (IC50=1.31±0.06 μM) and gallic acid (IC50=1.01±0.03 μM) exhibited high superoxide-anion scavenging activity followed by syringic acid (IC50=13.90±2.38 μM). (4) When hamamelitannin was treated with superoxide anions generated by a KO2-crown ether system, HPLC analysis showed the disappearance of hamamelitannin and the concomitant formation of hamamelitannin-derived radicals (g=2.005, ΔH1=2.16 G, ΔH2=4.69 G) was detected by ESR spectrometry. From these observations, we concluded that (i) a compound with polyphenolic hydroxyl groups, especially the galloyl group (3, 4, 5-trihydroxy-), has potent scavenging activity against superoxide anions, and (ii) hamamelitannin is superior to gallic acid in protecting against cell damage induced by superoxide anions, suggesting that the high affinity of hamamelitannin for cells or membranes may be an important factor for protecting cells against active oxygen species.
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  • Kozo TAGAWA, Masakazu MIZOBE, Kazuo NODA
    1995 Volume 18 Issue 1 Pages 64-69
    Published: January 15, 1995
    Released: April 10, 2008
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    In order to obtain a rational explanation and analytical method of the unique pharmacokinetic behaviors of imidapril and imidaprilat in human, a new pharmacokinetic model was designed by introducing a saturable-reversible angiotensin I converting enzyme (ACE)-imidaprilat binding process and a linear imidapril-imidaprilat conversion process. According to the new model, six differential equations were given which considered the mass balance of both compounds in each component. Various pharmacokinetic parameters were estimated by the simultaneous curve fitting method using the plasma concentration data and the urinary excretion data of imidapril and imidaprilat in a multiple dosing study of healthy human volunteers. To validate the value of each parameter, this pharmacokinetic model was also applied to analyze the various plasma concentration data of both compounds in the single dosing studies with four different dosages, 2.5, 5, 10, and 20 mg. Excellent curve fitting was obtained in every case, suggesting that the proposed pharmacokinetic model is applicable for predicting the plasma concentrations of imidapril and imidaprilat under various dosage conditions of clinical use.
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  • Natsuo OHSHIMA, Hajime KOTAKI, Yasufumi SAWADA, Tatsuji IGA
    1995 Volume 18 Issue 1 Pages 70-74
    Published: January 15, 1995
    Released: April 10, 2008
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    The relationship between the plasma concentration of amitriptyline (AMI) and its pharmacological effect was investigated in rats. The plasma concentration of AMI was maintained constantly from 5 h to 7 d after intraperitoneal infusion by the implantation of an osmotic minipump with an adjusted release rate of 20 mg/kg/d of AMI. Neither the plasma or brain concentrations of AMI in a 24-h infusion group were significantly different as compared with those in the 7-d group. The pharmacological effect of AMI was measured by our improved forced-swimming test. When AMI (dose of 20 and 50 mg/kg/d) was infused, the pharmacological effect in both infusion groups of rats was increased significantly at each dose in comparison to that of the control rats (p<0.05). With 10 mg/kg/d infusion, the effect in the 7-d group increased significantly as compared with that of the control (p<0.05), although the effect in the 24-h group did not change. The effect was increased in both groups with an increase of dose. When the effect was plotted to the area under the plasma concentration-time curve (AUC), the effect approached a limiting value (12 μg/ml·h). Therefore, it was suggested that 12 μg/ml·h as the AUC for AMI was enough to obtain a maximum AMI pharmacological effect in rats. From these results, we concluded that the AUC for AMI may be a useful index to evaluate its pharmacological effect, rather than the plasma concentration.
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  • Taro OGISO, Masahiro IWAKI, Satoshi UNO
    1995 Volume 18 Issue 1 Pages 75-81
    Published: January 15, 1995
    Released: April 10, 2008
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    To further characterize the mode of drug interaction between theophylline (TP) and mexiletine (ME), in vitro kinetic studies were carried out using rat liver microsomes and 9000×g supernatant. The kinetic study revealed that the Km value and Vmax/Km ratio for the metabolic conversion of TP to 1, 3-dimethyluric acid (1, 3-DMU) were the second lowest and the highest, respectively, of four metabolic pathways. Thus, the rank of efficiency of the oxidative metabolism by microsomal cytochrome P-450 (P-450) isozymes was TP to 1, 3-DMU>TP to 1-methylxanthine (1-MX)>TP to 3-MX>1, 3-DMU to 1-methyluric acid, suggesting that the isozyme metabolizing TP would have a higher affinity for the oxidation at the 8-position in TP molecules than at the 1- and 3-positions. Lineweaver-Burk plots showed that the conversion of TP to 3-MX and to 1, 3-DMU was inhibited competitively by ME and its metabolites, and that the pathway of TP to 1-MX was inhibited noncompetitively. In consideration of the Ki values calculated, it seems probable that deamino-p-hydroxy ME (DApHME) might be the most potent inhibitor of the metabolic pathways of TP, and that the rank order of inhibition is approximately DApHME>p-hydroxy ME>deamino-hydroxymethyl ME>ME>hydroxymethyl ME, with some exceptions. The mechanism of the interaction between TP and ME is probably due to the metabolic antagonism in the liver, and TP, ME and their metabolites share some of the same metabolic pathways, mediated by P-450 isozymes.
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  • Naokazu MURAHASHI, Atsushi SASAKI, Kunio HIGASHI, Anri MORIKAWA, Harut ...
    1995 Volume 18 Issue 1 Pages 82-88
    Published: January 15, 1995
    Released: April 10, 2008
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    Liposomes which have been modified with (8-hexadecanoylamido-3, 6-dioxaoctyl)-β-D-galactose (Gal-t-pa), a straight chain palmitoyl derivative, and are composed of dipalmitoylphosphatidylcholine (DPPC), cholesterol (CH), and dicetyl phosphate (DCP) at a ratio of 10 : 10 : 1, showed the same accumulation in the liver as the control liposome. Also, liposomes which have been modified with {8-(2-hexadecyloctadecanoylamido)-3, 6-dioxaoctyl}-β-D-galactoside (Gal-t-psa) showed remarkable accumulation in the liver. The accumulation of liposomes modified with galactose derivatives in the rat liver differed markedly according to the anchor structure. To clarify the cause of this finding, we produced [3H] inulin entrapped [14C] Gal-t-pa modified double label liposomes and evaluated changes in their rat plasma concentration, distribution in the organs, and the in vitro interaction with rat plasma. [14C] Gal-t-pa on the liposome surface bound to serum albumin and was released, resulting in no accumulation in the liver. In addition, sialic acid palmitoyl derivatives and glucuronic acid palmitoyl derivatives behaved similarly. As with the galactose derivatives, they also bound to serum albumin, being released from liposomes. These results suggest that adequate attention should be paid to the anchor structure of the ligand, in order to incorporate a recognition element into liposomes for transport to cells.
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  • Naomi MOTOJI, Emiko HAYAMA, Akiyo SHIGEMATSU
    1995 Volume 18 Issue 1 Pages 89-93
    Published: January 15, 1995
    Released: April 10, 2008
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    Evidence is presented to elucidate whether or not quantitative analysis of autoradiographs can be obtained with a 14C-labelled compound by the use of a new type of radiosensor called Imaging plate (IP). Our results showed that a linear relationship between relative intensity of PSL-BG and radioactivity of a given area was obtained. The linearity was maintained in a relatively wide range from 101 to 105 dpm of radioactivity. About 100 times higher sensitivity of the IP than any commercially available X-ray film was demonstrated for not only 14C-radioactive standard sources but also experimentally obtained 14C-radioactive spots developed on a TLC plate. Results also showed a linear relationship between relative intensity and radioactivity of the specimens in a very wide range from 101 to 105 dpm/mg after exposure for 7 d. Furthermore, the relationship between PSL-BG and relative exposure (radioactivity×exposure time) was linear when PSL-BG was from 101 to 105. In addition to the above properties, a combination of IP and BAS2000, a computerized image display system, was able to completely erase the background prior to use.
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  • Naomi MOTOJI, Emiko HAYAMA, Akiyo SHIGEMATSU, Seiji TAZAKI, Nobufumi M ...
    1995 Volume 18 Issue 1 Pages 94-99
    Published: January 15, 1995
    Released: April 10, 2008
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    The process of obtaining 3H-autoradiographic (ARG) images has been expected for a long time. A few X-ray films with no protection layer are commercially available, however, they do not give a reliable image which can be quantitated and can give good contrast. We tried to fabricate a 3H-type sensor which has no protection layer on a highly sensitive sensor, and called it Imaging plate (IP). The IP is composed of one of the specially designed photo-stimulable phosphors containing of BaFX : Eu2+ (X=Cl, Br or I) crystals. Results indicated a good contrast and reliable whole-body ARG image of 3H-labelled glucose with trial IP, which has never been obtained with any X-ray films even if these were subjected to a long exposure time. The ARG image can be displayed by either black-and-white hard copy or a colored one with the digital display representing relative intensity of photostimulated luminescence (PSL) without back ground (BG) or relative intensity concentration ((PSL-BG)/S), where S was equivalent to 100 pixels (1 mm2). Similarly to the experimental results of 14C, the linear relationship relative intensity and radioactivity of the 3H standard sources was demonstrated with a very wide range of 102 to 105 dpm/mg upon the exposure for 7 d. Also the relationship between relative intensity and relative exposure (radioactivity×exposure time) was linear within the latitude of relative intensity 101 to 105 (PSL-BG). The trial IP was particularly effective for the quantitative autoradiography of TLC plates. After development, a good linearity was demonstrated between PSL intensity and radioactivity for each spot on the TLC plate, in a wide latitude of 1 to 104, which is similar to that obtained in the 14C experiments. These data strongly support the practical use of the IP and BAS2000 for processing a computerized image for quantitative analysis of macroautoradiographs obtained with not only 14C-labelled drugs but also 3H-labelled drugs.
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  • Naomi MOTOJI, Yuko HAMAI, Yasuko NIIKURA, Akiyo SHIGEMATSU
    1995 Volume 18 Issue 1 Pages 100-107
    Published: January 15, 1995
    Released: April 10, 2008
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    A novel preparation technique, so called "Paste Mold, " was devised for organ and tissue distribution studies. This is the most powerful by joining with autoradioluminography (ARLG), which was established and validated recently in the working group of Forum '93 of Japanese Society for study of xenobiotics. A small piece (10-50 mg) of each organ or tissue was available for measuring its radioactive concentration and it was sampled from the remains of frozen carcass used for macroautoradiography (MARG). The solubilization of the frozen pieces was performed with mixing a suitable volume of gelatine and strong alkaline solution prior to mild heating kept at 40°C for a few hours. After that, the tissue paste was molded in template pattern to form the small plates. The molded plates were contacted with Imaging plate (IP) for recording their radioactive concentration. The recorded IP was processed by BAS2000. The molded plate was formed in thickness of 200 μm, so called infinit thickness against soft β rays, and therefore the resulting relative intensities, represented by (PSL-BG)/S values, indicated practically responsible ratio of the radioactive concentration in organs and tissues, without any calibulation for β-self absorption coefficiency. On the other hand, the left half body of the frozen carcass was used for making whole body autoradiography (WBA) before the Paste-Mold preparation. Comparison was performed for difference in (PSL-BG)/S values of organs and tissues between frozen and dried sections. A good concordance in relative intensities, (PSL-BG)/S by the Paste-Mold preparation was given with those by the frozen sections rather than dried sections. The combination of the Paste-Mold preparation prior to ARLG and WBA method must be the most powerful to give a quantitative and reliable data in the tissue distribution study.
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  • Naomi MOTOJI, Hiroyuki KUROIWA, Akiyo SHIGEMATSU
    1995 Volume 18 Issue 1 Pages 108-114
    Published: January 15, 1995
    Released: April 10, 2008
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    Phosphor Imaging plates (IPs) with high sensitivity to both low- and high-energy radiation have been on the market since 1988. The TLC-autoradioluminography (ARLG) method was developed utilizing such IPs. The conventional TLC method was suited for discrimination of microradioactive components ; however, the method could only present semi-quantitative values. Conversely, the TLC-ARLG method showed completely quantitative values. That is, the TLC-ARLG method could be used to measure the radioactivity ratio between 14C-radiolabeled spots A and B, which were spotted 1 mm apart on a TLC plate, after development with chromatogram, not only when the radioactivity ratio between spots A and B was 1 : 1, but even when it was 16 : 1, within the measurement error of ±10%. The ARLG method showed sensitivity, resolution, and quantitative reliability far superior to those of the scraping-liquid scintillation counter (LSC) method or radiochromatoscanner method. In the future, the ARLG method will be widely used as a quantitative microanalytical method for unknown radioactive metabolites existing as microcomponents in organisms, especially for quantitative analysis considering mass balance to dose in biological samples, which is considered to be an important point in pharmacokinetic research.
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  • Nobuhito SHIBATA, Tokuzo MINOUCHI, Akira YAMAJI, KyunIl PARK, Hitoshi ...
    1995 Volume 18 Issue 1 Pages 115-121
    Published: January 15, 1995
    Released: April 10, 2008
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    To establish an optimal method for determining a cyclosporin A (CyA) regimen based on physiological changes that occur during immunosuppressive therapy, the relationship between apparent CyA body clearance (CL/f) and the CyA erythrocyte-to-plasma distribution ratio (CyA-EP) was examined using clinical time courses obtained during routine monitoring. The CyA-EP, which was calculated by a multiple regression formula using routine data, was increased during renal dysfunction involving the normal recovery phase after transplantation, during nephrotoxicity, during acute tubular necrosis, and during acute renal rejection. CyA total body clearance (CLt), calculated by multiplying CL/f and converted bioavailability, fc (which is equal to 0.009×LD, where LD represents the CyA level in blood per dose ratio), showed hyperbolic decay with increasing CyA-EP (the mean CLt was defined as follows : CLt=0.937/CyA-EP), whereas fc showed exponential decay with increasing CyA-EP (the mean fc was defined as follows : fc=0.593×exp (-0.155×CyA-EP)). These findings suggest that total CyA body clearance and its bioavailability were suppressed during the renal dysfunction phase. Hence, the mean CL/f as a function of the CyA-EP was given by the following equation : CL/f=1.390×exp (0.204×CyA-EP)/CyA-EP. Since the CyA-EP reflects a patient's disease state and alterations in the CyA pharmacokinetic profile, these model formulae should provide an adequate method for determining a CyA dosage regimen for several disease states after renal transplantation.
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  • Ermin WANG, Masaoki TAKANO, Takayoshi OKAMOTO, Katsutoshi YAYAMA, Hiro ...
    1995 Volume 18 Issue 1 Pages 122-125
    Published: January 15, 1995
    Released: April 10, 2008
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    We determined the physiological importance of endogenous estrogen in the regulation of angiotensinogen synthesis in the liver. The plasma levels of angiotensinogen and hepatic levels of angiotensinogen mRNA were studied in the rat in comparison to those of T-kininogen, a plasma protein whose synthesis in the liver is primarily estrogen-dependent. Plasma levels of T-kininogen and hepatic levels of T-kininogen mRNA were 3- and 2-fold higher in adult females, respectively, than in adult males, whereas there were no sex differences in levels of either plasma angiotensinogen or hepatic angiotensinogen mRNA. Ovariectomy in female rats abolished the sex differences in the levels of plasma T-kininogen and hepatic T-kininogen mRNA, but it did not affect those of plasma angiotensinogen and hepatic angiotensinogen mRNA. These results suggest that, in contrast to T-kininogen, angiotensinogen synthesis in the liver is unlikely to be controlled by endogenous levels of estrogen.
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  • Naohito OHNO, Naoko ASADA, Yoshiyuki ADACHI, Toshiro YADOMAE
    1995 Volume 18 Issue 1 Pages 126-133
    Published: January 15, 1995
    Released: April 10, 2008
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    Effects of (1→3)-β-D-glucans on tumor necrosis factor-α (TNF-α) production in mice in vivo were investigated with or without triggering stimulation of lipopolysaccharide (LPS). Administration of grifolan (GRN) (100-250 μg/mouse) obtained from Grifola frondosa, did not elevate the TNF-α concentration in serum, but significantly elevated LPS (10 μg/mouse)-elicited TNF-α production in serum. The priming effect was observed as early as 2 h after administration and remained high for 3 weeks. The priming effect was dependent on the strain of mice, i. e. ICR, BALB/c, and MRL/lpr (15 weeks old) showed high response. In addition, GRN administration increased membrane-bound TNF-α assessed by Western blotting and flow cytometry. Comparing the activity using structurally related glucans obtained from other microorganisms, highly branched glucans, SSG isolated from Sclerotinia sclerotiorum IFO 9395 and OL-2 from Omphalia lapidescence significantly increased TNF-α production. Small molecular weight GRN derivatives prepared by heat degradation method showed weaker priming effect. These facts suggested that the glucans showed priming effect of TNF-α production in vivo and that this effect was related to the degree of branching and molecular weight.
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  • Hitoshi SEKIKAWA, Naomi YAGI, Emil T. LIN, Leslie Z. BENET
    1995 Volume 18 Issue 1 Pages 134-139
    Published: January 15, 1995
    Released: April 10, 2008
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    The stability of furosemide glucuronide (FG) was investigated in buffer solutions ranging from pH 1 through 10. This glucuronic acid conjugate was the major metabolite of furosemide (F) excreted in human urine. FG, obtained by extraction from human urine, was purified by ion-exchange chromatography. The concentration of FG, acyl migration isomers of FG (FG-iso), and F were determined simultaneously with an HPLC method that included fluorescence detection and gradient elution. FG was found to be unstable in highly acidic and in neutral to alkaline solutions. Hydrogen ion and hydroxy ion catalyzed the hydrolysis of FG below pH 2.8 and above pH 5.6, respectively. Above pH 3.7, FG instability led to the formation of eight FG-iso compounds. Though β-glucuronidase cleaved FG, the FG-iso compounds were resistant to the enzyme. The half-life of FG in a buffer solution at pH 7.4 and 37°C was 4.4 h. The maximum stability of FG (half-life about 62 d) occurred at approximately pH 3.2. Below pH 3.7, acyl migration products of FG were not detected. Instead, the hydrolysis of FG to F and glucuronic acid was followed by the formation of 4-chloro-5-sulfamoylanthranilic acid (CSA), a secondary product in acidic media.
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  • Akira FUKUHARA, Teruko IMAI, Katsuhisa INOUE, Masaki OTAGIRI
    1995 Volume 18 Issue 1 Pages 140-147
    Published: January 15, 1995
    Released: April 10, 2008
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    Flurbiprofen (FP) was esterified with a histamine H2-antagonist, PPA (N-[3-{3-(1-piperidinylmethyl) phenoxy}-propyl]-2-(2-hydroxyethylthio) acetamide), to yield a chimera drug, FP-PPA, and its protective effect toward gastric lesions, other toxicities and the disposition kinetics were investigated, as compared to those of FP, in multiple oral administration to rats for 2 weeks. FP-PPA scarcely formed any disorder of the gastric mucosa following multiple oral administration. The body weight changes and hematological and serum biochemical parameters were found to be similar to those in the control group. Some drug metabolizing enzyme activities tested were the same as those of the control group. Further, the pharmacokinetic parameters were found to be the same after both single and multiple oral administration. On the other hand, in the FP treated group, the inhibition of body weight increase and changes in serum biochemical and hematological parameters were observed due to malabsorption. The absorption rate constant was increased significantly after multiple administration as compared to that of single administration. It is suggested that these changes in the absorption process of FP are due to variations in gastrointestinal permeability derived from gastrointestinal damage. The results obtained here indicate clearly that the chimera drug FP-PPA scarcely forms any disorder of the gastric mucosa, even after multiple oral administration, and is thus a potential candidate for oral use.
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  • Kazunori SEKINE, Jun OHTA, Masatoshi ONISHI, Taro TATSUKI, Yukiko SHIM ...
    1995 Volume 18 Issue 1 Pages 148-153
    Published: January 15, 1995
    Released: April 10, 2008
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    Intestinal Bifidobacterium species are thought to be beneficial in animal and human intestines. We studied the mechanisms of Bifidobacteria in antitumor activity using a cell wall preparation (WPG) of B. infantis (Cancer Res., 45, 1300, (1985)). WPG enhanced the in vitro antitumor activities of mouse peritoneal exudate cells elicited with proteose-peptone (P-PEC) and thioglycollate broth (TG-PEC), determined by cytostatic ([3H] thymidine uptake inhibition) and cytolytic ([3H] uridine release) assays. Tumor necrosis factor-α (TNF-α) and reactive nitrogen intermediates (RNI) play a role in such augmented cytotoxicity, because anti-TNF-α antibody almost completely blocked the increased cytolytic activity of P-PEC in the presence of WPG. Moreover, WPG induced RNI in the supernatant of TG-PEC in a dose-dependent manner. The mRNA expression of several cytokines (IL-1β, IL-6, IL-10, IFN-α and TNF-α) was induced in BALB/c mouse peritoneal cells 3 h after an intraperitoneal injection of WPG (3 h WPG-PEC). However, this expression disappeared from 24 h WPG-PEC, except for that of IFN-α. IFN-γ was not induced. Kinetic studies of the tumor neutralizing activities of the WPG-PECs by means of the in vivo Winn assay revealed that the activity emerged at 1.5 h, became maximal at 3 h and disappeared at 24 h. These results indicated that Bifidobacterial WPG is a Biological Response Modifier (BRM) with characteristics similar to those of other bacterial BRMs.
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  • Nobuo OKABE, Satoko YOSHIDA
    1995 Volume 18 Issue 1 Pages 154-155
    Published: January 15, 1995
    Released: April 10, 2008
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    Thyroid hormone, thyroxine (T4) binding to glycosylated human serum albumin (G-HSA), and native human serum albumin (HSA) were studied as a function of pH using the fluorescence method. T4 binding affinity for G-HSA was remarkably reduced in an alkaline pH as compared with the native HSA. The thermodynamic parameters for binding are estimated at pH 7.5 : (a) for G-HSA, ΔG=-8.50±0.04 kcal mol-1 (30°C), ΔH=-5.2 kcal mol-1, ΔS=+11 e. u. ; (b) for HSA, ΔG=-8.89±0.04 kcal mol-1 (30°C), ΔH=-3.5 kcal mol-1, ΔS=+18 e. u. These results suggest that the glycosylation of HSA causes a variation in the electrostatic interaction between T4 and HSA.
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  • Takahiro FUKUSHIMA, Tetsuo ADACHI, Kazuyuki HIRANO
    1995 Volume 18 Issue 1 Pages 156-158
    Published: January 15, 1995
    Released: April 10, 2008
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    The enzyme xanthine oxidase (XOD) has an affinity for heparin and can bind to cultured porcine aortic endothelial cells. We have reported that the exposure of human XOD (h-XOD) to the lysine-specific reagent trinitrobenzenesulfonic acid or the arginine-specific reagent phenylglyoxal caused it to lose its affinity for heparin-Sepharose. The heparin-binding sites in h-XOD are further studied in the present article. From a chymotryptic digest of cyanogen bromide fragmented h-XOD, two peptides with an affinity for heparin-HPLC, A-1 and A-2, were isolated. Amino acid sequence analysis showed that both peptides had lysine and/or arginine residues. The A-1 region may direct its charged side chains toward the solvent while burying its hydrophobic side chains against the hydrophobic inside, because the A-1 peptide forms a highly amphipathic structure. Peptide A-2 contains triple lysine residues and constitutes a hydrophilic region.
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  • Yasuyuki SADZUKA, Eiko MOCHIZUKI, Ayano IWAZAKI, Sadao HIROTA, Yoshio ...
    1995 Volume 18 Issue 1 Pages 159-161
    Published: January 15, 1995
    Released: April 10, 2008
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    We examined whether caffeine enhances the antitumor activity of adriamycin (ADR), in terms of prolonging survival in Ehrlich ascites carcinoma (ascites-type)-bearing mice. After administration of ADR at a dose of 0.5 mg/kg/d for 5 d together with caffeine (100 mg/kg/d×5 d), the survival period was increased by 39%. However, caffeine had little effect on this ADR induced-prolongation of survival following administration of ADR at 2.0 mg/kg/d for 4 d. Although a significant increase in ADR concentration in the ascites tumor was seen after administration of ADR at a dose of 0.5 mg/kg, caffeine failed to increase ADR concentration in the ascites tumor after administration of ADR at a dose of 2.0 mg/kg. The effect of caffeine thus appears to be due to its effect on the tumor distribution of ADR.
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  • Hitoshi MASAKI, Sachiko SAKAKI, Takamasa ATSUMI, Hiromu SAKURAI
    1995 Volume 18 Issue 1 Pages 162-166
    Published: January 15, 1995
    Released: April 10, 2008
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    To find antioxidative compounds present in plants, 65 types of plant extract were tested using the neotetrazolium method for evidence of superoxide anion-scavenging effects and 7 plant extracts were selected for further investigation. The activity of active-oxygen scavengers such as superoxide anion radicals, hydroxyl radicals, singlet oxygens and lipid peroxides in the 7 plant extracts (Aeseclus hippocastanum L., Hamamelis virginiana L. Polygonum cuspidatum SIEB., Quercus robur L., Rosemarinous officinalis L., Salvia officinalis L. and Sanguisorba officinalis L.) was examined in detail by both ESR spin-trapping and malondialdehyde generation. Furthermore, the active-oxygen scavenging activity of these plant extracts was evaluated using a murine dermal fibroblast culture system. Both Aeseclus hippocastanum L. and Hamamelis virginiana L. were found to have strong active-oxygen scavenging activity of and protective activity against cell damage induced by active oxygen. Both Aeseclus hippocastanum L. and Hamamelis virginiana L. are proposed as potent plant extracts with potential application as anti-aging or antiwrinkle material for the skin.
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  • Atsushi KATO, Toshihiro MIURA, Tomoji FUKUNAGA
    1995 Volume 18 Issue 1 Pages 167-168
    Published: January 15, 1995
    Released: April 10, 2008
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    Two steroidal glycosides, PO-1 and PO-2, were tested as a new hypoglycemic drug. PO-2 showed remarkable hypoglycemic activity on i. p. injection into normal mice. PO-1 slightly lowered the blood glucose in normal mice. Furthermore, PO-1 and PO-2 exhibited significant hypoglycemic effects in streptozotocin-induced diabetic mice. However, a steroid, diosgenin, did not affect the blood glucose level in either normal or streptozocin-induced diabetic mice, indicating that the branching glucose units are essential for the biological activity.
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  • Hitoshi SASAKI, Choyu TEI, Koyo NISHIDA, Junzo NAKAMURA
    1995 Volume 18 Issue 1 Pages 169-171
    Published: January 15, 1995
    Released: April 10, 2008
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    We previously compared hypoglycemic responses after the instillation of insulin formulations. A hypoglycemic response was actually observed after an instillation of insulin with ophthalmic preservatives. In the present study, in order to evaluate the usefulness of insulin formulation containing ophthalmic preservatives, a serum concentration of insulin and an irritation to the eye were investigated after instillation of the insulin formulation in albino rabbits. The ophthalmic preservatives used were benzalkonium chloride, paraben, 2-phenylethanol, benzyl alcohol and sorbic acid. As a result, ophthalmic preservatives, especially benzalkonium chloride and paraben, increased the serum concentration of insulin. The insulin concentration showed a significant correlation with the hypoglycemic response reported previously. This result indicates that ophthalmic preservatives increase the absorption of ocularly applied insulin, and the absorbed insulin decreases serum glucose concentration. The insulin formulation with preservatives showed little irritation on rabbit eyes according to blinking measurements. These results indicate that ophthalmic preservatives are useful for the systemic delivery of ocularly applied insulin.
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  • Akinobu HAMADA, Shoji FUKUSHIMA, Mineo SANEYOSHI, Takeo KAWAGUCHI, Mas ...
    1995 Volume 18 Issue 1 Pages 172-175
    Published: January 15, 1995
    Released: April 10, 2008
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    This study examined the inhibitory effect of acyclopyrimidinenucleosides on 5'-deoxy-5-fluorouridine (5'-DFUR) phosphorolysis in intestinal tissue derived from rabbit, rat, mouse, and human. 5-Bromoacyclouridine, 5-fluoroacyclouridine, acyclouridine, and 5-nitroacyclouridine showed little or only moderate effect, but acyclothymidine [5-methyl-1-(2'-hydroxyethoxymethyl) uracil] showed strong inhibitory effect on 5'-DFUR phosphorolysis in intestinal tissue homogenates derived from human. In the absence of inhibitor (acyclothymidine), the Vmax of 5'-DFUR phosphorolysis was 2.66 μmol/min and the Km was 0.57 mM in human intestinal homogenates. The Vmax was unaltered by increased inhibitor concentration. The maximal inhibitory effect of acyclothymidine on 5'-DFUR phosphorolysis in rat homogenates was over 90%. The Ki/Km was 0.63 in human, 2.14 in rabbit, 1.09×10-2 in rat, and 1.71×10-2 in mouse. These data show that acyclothymidine is a competitive inhibitor of 5'-DFUR phosphorolysis, and that it can inhibit not only uridine phosphorylase but also thymidine phosphorylase.
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  • CheonKoo LEE, Kazuhisa KITAGAWA, Takahiro UCHIDA, NakSeo KIM, Shigeru ...
    1995 Volume 18 Issue 1 Pages 176-180
    Published: January 15, 1995
    Released: April 10, 2008
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    A novel ethylcellulose gel preparation using an ethanol/panasate 800 (tricaprylin) (40/60) binary lipophilic vehicle was developed and applied to the transdermal delivery of theophylline. The in vitro skin permeability of theophylline across excised hairless mouse skin was improved by the use of this ethanol/panasate 800 (40/60) binary vehicle compared with either ethanol or panasate 800 as a single vehicle, and the addition of lauric acid as a permeation enhancer to the binary vehicle shortened the lag time and increased the permeated amount of theophylline up to 6 h (initial permeation amount). The in vitro permeability of theophylline from the ethanol/panasate 800 (40/60)-ethylcellulose gels decreased with an increase in the content of ethylcellulose in the gels. In the in vivo evaluation using abdominal rat skin, the ethanol/panasate 800 (40/60)-7% (w/w) ethylcellulose gel produced a good feature as a sustained-release preparation, with a relatively high bioavailability (BA) of theophylline, and dose dependency was observed.
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  • Naoto OKU, Shinji YAMASHITA, Naoko SAKURAGI, Kanako DOI, Shoji OKADA, ...
    1995 Volume 18 Issue 1 Pages 181-184
    Published: January 15, 1995
    Released: April 10, 2008
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    To establish a novel drug delivery system for 5-fluorouracil (5FU), we have developed a system in which the low-molecular-weight prodrugs of 5FU bound to endogenous serum proteins, thus circulating like those proteins. Subsequently, the prodrugs were slowly hydrolyzed to generate active 5FU in the bloodstream. To examine the therapeutic effect of these prodrugs, we injected them into BALB/c mice previously implanted subcutaneously with Meth A sarcoma. Among the prodrugs, 1-(N-4-chlorophenyl-N-methylcarbamoyl)-5-fluorouracil (5FU-1pCPMC) was effective in reducing tumors and prolonging survival time. The non-hydrolyzable compound, 1-(4-chlorobenzyl)-5-fluorouracil, did not show any therapeutic effect, suggesting that the therapeutic efficacy of 5FU-1pCPMC is due to the sustained release of 5FU from the serum protein-prodrug complex. The data shown here may create a new field in drug delivery system technology.
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  • Noriko N. MIURA, Naohito OHNO, Yoshiyuki ADACHI, Jun AKETAGAWA, Hirosh ...
    1995 Volume 18 Issue 1 Pages 185-189
    Published: January 15, 1995
    Released: April 10, 2008
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    (1→3)-β-D-Glucans exhibit a variety of biological and immunopharmacological activities, and the degree of these activities depends on the nature of the individual glucans e. q. molecular weight, degree of branching and conformation. Based on the generally accepted evidence that the conformation of Sonifilan (SPG) used clinically is a triple helix, we prepared alkali-denatured SPG (SPG-OH) as a single helix conformer. In this report, we measured the concentration of β-glucan administered to mice by using a β-glucan-specific reagent prepared from limulus amebocyte lysate (Gluspecy [G test], Seikagaku Corporation, Tokyo) and discuss the blood clearance of SPG and SPG-OH following intraperitoneal (i. p.) or intravenous (i. v.) administration. Comparing the clearance of SPG-OH from the blood with that of SPG, SPG-OH was removed faster than SPG following both i. p. and i. v. administration. This strongly suggests that the clearance of β-glucans is dependent on their conformation.
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  • Kazuo OKUSHIO, Natsuki MATSUMOTO, Masayuki SUZUKI, Fumio NANJO, Yukihi ...
    1995 Volume 18 Issue 1 Pages 190-191
    Published: January 15, 1995
    Released: April 10, 2008
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    Following oral administration of (-)-epigallocatechin gallate to rats, the presence of (-)-epigallocatechin gallate was examined in the portal blood. A compound present in the blood was identified as (-)-epigallocatechin gallate by HPLC and mass spectrometry analysis. The results clearly demonstrate that (-)-epigallocatechin gallate is absorbed, at least in part, into rat portal blood.
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  • Toshimitsu OHKI, Tokuji SUZUKI, Sigeru GOTO
    1995 Volume 18 Issue 1 Pages 192-194
    Published: January 15, 1995
    Released: April 10, 2008
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    A simplified procedure of interval hypothesis testing was investigated and established for bioequivalence studies. The characteristics of this procedure were compared with those of other statistical procedures.
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  • Masayuki KUSANO, Masaaki SHIBUYA, Ushio SANKAWA, Yutaka EBIZUKA
    1995 Volume 18 Issue 1 Pages 195-197
    Published: January 15, 1995
    Released: April 10, 2008
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    A cDNA encoding rat 2, 3-oxidosqualene : lanosterol cyclase, the enzyme responsible for the complex cyclization/rearrangement step in sterol biosynthesis, was cloned by extensive application of PCRs. Oligonucleotide primers were designed in sense and anti-sense directions corresponding to internal peptide sequences of purified enzyme. Successive PCRs with all possible combinations of these primers yielded a 178-bp fragment, and based on its sequence full nucleotide sequence of cDNA was obtained by a "rapid amplification of cDNA ends"(RACE) method.
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