Biological and Pharmaceutical Bulletin
Online ISSN : 1347-5215
Print ISSN : 0918-6158
ISSN-L : 0918-6158
Volume 24 , Issue 11
Showing 1-25 articles out of 25 articles from the selected issue
Review
  • Katsutoshi GOTO
    2001 Volume 24 Issue 11 Pages 1219-1230
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    Three endothelin family peptides (endothelin-1, -2 and -3) exert an extremely potent and long-lasting vasoconstrictor action as well as other various actions through stimulating two subtypes of receptor (ETA and ETB). Vascular endothelial cells produce only endothelin-1. Although the pharmacological actions of exogenous endothelin-1 have been extensively analyzed, the physiological roles of endogenous endothelin-1 have long been obscure. Using potent and selective receptor antagonists, endothelin-1 has been demonstrated to contribute slightly to the maintenance of regional vascular tone. In gene-targeted mice, endothelin family peptides and their receptors have been shown to play an important role in the embryonic development of neural crest-derived tissues. In addition to its potent vasoconstrictor action, endothelin-1 has direct mitogenic actions on cardiovascular tissues, as well as co-mitogenic actions with a wide variety of growth factors and vasoactive substances. Endothelin-1 also promotes the synthesis and secretion of various substances including extracellular constituents. These effects of endogenous endothelin-1 would appear to be naturally concerned with the development and/or aggravation of chronic cardiovascular diseases, e.g. hypertension, pulmonary hypertension, vascular remodeling (restenosis, atherosclerosis), renal failure, and heart failure. A great many non-peptide and orally active endothelin receptor antagonists have been developed, and shown to exert excellent therapeutic effects in animal models as well as human patients with these diseases.
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Biochemistry/Molecular Biology
Regular Articles
  • Akihiro MICHIHARA, Kenji AKASAKI, Yukio YAMORI, Hiroshi TSUJI
    2001 Volume 24 Issue 11 Pages 1231-1234
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    The 45- and 35-kDa subunits of mevalonate pyrophosphate decarboxylase (MPD) have been purified from rat liver. In this study, we examined the relationship between 45- and 35-kDa MPD and the tissue distribution of a major MPD in rat liver. When the crude extract of rat liver fed on normal chow was subjected to immunoblot analysis using anti-rat 45-kDa MPD antibody, only the 45-kDa band was detected. In a pulse-chase experiment using anti-rat 45-kDa MPD antibody, there was no precursor-product relationship between the 45- and the 35-kDa MPD. In immunoprecipitation, more than 85% of MPD activity in the rat liver was depleted from the crude extract with an excess of the above antibody. When 45-kDa MPD contents in tissues were analyzed by immunoblotting, a single protein band with an apparent molecular weight of 45 kDa was detected in all tissues. The specific protein content of 45-kDa MPD in liver was markedly higher than in other tissues. The activity/amount ratio varied among brain, liver, and testis, being significantly highest in the liver. From these data, it is suggested that 45-kDa MPD serves as a major enzyme involved in cholesterol biosynthesis in rat liver and that a tissue-specific regulator or isozyme of 45-kDa MPD is present in rat liver.
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  • Akihiro MICHIHARA, Makoto SAWAMURA, Yukio YAMORI, Kenji AKASAKI, Hiros ...
    2001 Volume 24 Issue 11 Pages 1235-1240
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    Mevalonate pyrophosphate decarboxylase (MPD) is found in the 100000×g supernatant fraction of cells or tissues and is considered to be a cytosolic protein. Recently, other groups reported that MPD is mostly located in the peroxisomes. In this study, we used two different methods to determine whether MPD is predominantly located in the peroxisomes or the cytosol of rat hepatocytes. 1) In permeabilized rat hepatocytes or normal rat kidney cells treated with digitonin, which lack cytosolic enzyme, MPD was mainly present in the medium. 2) Double immunofluorescent labeling of cells with both anti-MPD antibody and anti-hexokinase antibody yielded an immunofluorescent pattern for both enzymes typical of the cytosolic protein. These results indicate that MPD is predominantly located in the cytosol of rat hepatocytes.
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  • Hiroko TANINO, Toshihiro KUSUDA, Kazuki NAGASAWA, Shun SHIMOHAMA, Sada ...
    2001 Volume 24 Issue 11 Pages 1241-1245
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    The effect of hyperoxia on the level of three phospholipase C (PLC) isozymes (β1, γ1, δ1) was assessed in the rat cerebral cortex. When the rats were exposed to 100% oxygen for 60 h, there was a significant reduction in the catalytic activity of low molecular weight phosphotyrosine phosphatase, which was susceptible to activity loss under oxidative stress. The result suggests that oxidative stress is induced in the rat cerebral cortex through hyperoxia. The protein levels of PLC-β1 and -δ1 were significantly increased in the cerebral cortex where oxidative stress had been induced, although that of PLC-γ1 was not altered. There was no significant difference in the total PLC activity of the cerebral cortex between hyperoxia and control rats. Using gel filtration chromatography, it was revealed that the PLC-β1 activity in the cerebral cortex of the hyperoxia rats was higher than that in the control rats, but the PLC-δ1 activity in the former did not differ from that in the latter, despite an increase in the PLC-δ1 protein level. These findings suggest that the PLC-β1 and -δ1 protein levels of brain tissues are increased by oxidative stress, and that the increased PLC-δ1 molecule is less active.
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  • Noriko TAKEUCHI, Hiroka ITO, Keiko NAMIKI, Akira KAMEI
    2001 Volume 24 Issue 11 Pages 1246-1251
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    The crystallins in the lenses of ICR/f mutation rat, a known hereditary cataract model, were analyzed during cataractogenesis. Opacification of the mutant lenses was found to be accompanied by changes in crystallin structure and composition, including several deletions of the N-terminals of β-crystallins and low molecular weight α-crystallins. Because similar deletions were observed when the soluble fraction of normal lens protein was incubated with calpain, we considered that calpain could be related to the deletions in mutant lenses. Although measurement of the content of calpain protein by the ELISA method revealed no significant difference between mutant and normal lenses, it was found that the concentrations of Ca2+ and K+ were different between the two lenses and that calpain activity was dependent on both ion concentrations. Endogenous m-calpain in the soluble fraction from normal lenses was activated by addition of 1 mM calcium chloride in the presence of 50 mM KCl (the same concentration as in mutant lenses), and insoluble protein was found in the fraction 1 d after calpain activation. On the other hand, the presence of 120 mM KCl (the concentration in normal lenses) inhibited calpain activity and prevented this insolubilization. These results suggest that calpain in mutant lenses is involved in the proteolysis of crystallins and the progression of cataract formation.
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  • Tomaz VOVK, Marija BOGATAJ, Aleš MRHAR, Slavko PECAR, Milan SCH ...
    2001 Volume 24 Issue 11 Pages 1252-1257
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    The antioxidative properties of pig urinary bladder mucosa were compared with those of gastric and intestinal mucosa using nitroxide radicals. Electron paramagnetic resonance (EPR) method was used to monitor the metabolic processes of nitroxides in mucosae. The reduction of nitroxides was measured on intact luminal surfaces of gastric, intestinal, and urinary bladder mucosa, as well as in homogenates of mucosa surface layer. Furthermore, N-ethylmaleimide and ascorbate oxidase have been used to characterize the reducing agents in urinary bladder mucosa homogenates. The nitroxide concentration decrease on intact mucosa of the urinary bladder was significantly different from those of the gastric and the intestinal mucosa. The concentration decrease was the largest for intestinal mucosa and the smallest for bladder mucosa. On the other hand, homogenates exhibit the largest nitroxide reduction rates for the bladder mucosa and the smallest for the gastric mucosa. In the bladder surface layer homogenates ascorbate and thiol-containing reducing agents were found and their coupled action in the nitroxide reduction process was established. The mucosa of urinary bladder is protected against nitroxide free radicals by a relatively low permeability and very active endogenous reducing agents. The gastric and intestinal mucosa are more permeable and/or have greater antioxidant activity on their surface. The reduction of nitroxides in the urinary bladder mucosa occurs via the ascorbate-thiol coupled reducing system.
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  • Hiro-omi TAMURA, Kazunori TANIGUCHI, Eriko HAYASHI, Yasuko HIYOSHI, Fu ...
    2001 Volume 24 Issue 11 Pages 1258-1262
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    To explore the physiological roles of sulfotransferases (SULTs) in extra-hepatic tissues, we examined the expression of eight SULT genes by reverse transcription (RT)-PCR in human cell lines that were established from various tissues. Expression levels of SULTs were low in neural cell lines such as NB-1 and GI-1, and high in epithelial cell lines, such as Caco-2 and BeWo. SULT1C2 expression was abundant in all cell types, whereas that of SULT1E1, SULT1B1 or SULT2B1 was restricted to a specific cell type. SULT1C1, which can catalyze the sulfation of N-hydroxy-2-acetylaminofluorene, was expressed in Caco-2, BeWo and KB562. Induction of differentiation did not generally affect SULT expression, although that of SULT1C2 was reduced after differentiation of the neuroblastoma cell line, NB-1, was induced. The profile of SULT expression in the culture cells obtained here gives clues to understanding the physiological roles of SULT enzymes in extra-hepatic tissues or organs.
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Notes
  • Setsuko KOMATSU, Wengang LI, Hirosato KONISHI, Manabu YOSHIKAWA, Tomok ...
    2001 Volume 24 Issue 11 Pages 1316-1319
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    The Ca2+-dependent protein kinases (CDPKs) and abscisic acid (ABA) are known to be involved in low-temperature stress response. The focus of this study was to characterize the 45 kDa protein kinase identified in the crude extract of rice (Oryza sativa L.) seedling roots in response to cold (5°C) stress. The activity of the 45 kDa protein kinase decreased at low temperature as evident by an in-gel kinase assay using histone III-S as a substrate. Also, the Ca2+-dependent activity of this protein kinase was suppressed by cold in the membrane fractions of the root. A general protein kinase inhibitor and Ca2+ chelator inhibited the activity of the 45 kDa protein kinase, suggesting that it was a plant CDPK. The 45 kDa CDPK identified was found to be independent of photosynthetic tissues such as the leaf and leaf sheath of rice seedlings, supporting a direct sensing mechanism in the roots of rice seedlings to cold stress. The suppressed activity of the 45 kDa CDPK was reverted by supplementing with 5 μM ABA under cold stress. The 45 kDa CDPK activity was stronger in the cold-tolerant variety of the 4 types tested than it was in the cold-sensitive one. These results suggest the involvement of endogenous ABA in regulating the activity of the 45 kDa CDPK in response to cold stress.
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  • Tomoki IKUTA, Hiroyoshi ARIGA, Ken-ichi MATSUMOTO
    2001 Volume 24 Issue 11 Pages 1320-1323
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    Tenascin-X (TNX) is a large glycoprotein that appears in extracellular matrices. Previously, we demonstrated that TNX binds to vascular endothelial growth factors A and B (VEGF-A and -B) and that VEGF-B in combination with TNX induces DNA synthesis in endothelial cells via increased signals mediated by the VEGFR-1 receptor. In this study, we investigated the effect of TNX with VEGF-A on the cell proliferation in embryonic mouse heart explants from either wild-type (TNX+/+) or TNX-deficient (TNX−/−) mice. The addition of VEGF-A to the explants from TNX+/+ mice increased cell proliferation by 1.5 fold compared with that in TNX−/− mice, indicating that TNX with VEGF family member plays an important role in the control of endothelial cell proliferation in vivo.
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Pharmacology
Regular Articles
  • Takuo WASHIO, Hirohiko ARISAWA, Kazuhiro KOHSAKA, Hiroshi YASUDA
    2001 Volume 24 Issue 11 Pages 1263-1266
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    In vitro studies were conducted to identify human drug-metabolizing enzymes involved in the metabolism of SNI-2011 ((±)-cis-2-methylspiro [1,3-oxathiolane-5,3'-quinuclidine] monohydrochloride hemihydrate, cevimeline hydrochloride hydrate). When 14C-SNI-2011 was incubated with human liver microsomes, SNI-2011 trans-sulfoxide and cis-sulfoxide were detected as major metabolites. These oxidations required NADPH, and were markedly inhibited by SKF-525A, indicating that cytochrome P450 (CYP) was involved. In a chemical inhibition study, metabolism of SNI-2011 in liver microsomes was inhibited (35-65%) by CYP3A4 inhibitors (ketoconazole and troleandomycin) and CYP2D6 inhibitors (quinidine and chlorpromazine). Furthermore, using microsomes containing cDNA-expressed CYPs, it was found that high rates of sulfoxidation activities were observed with CYP2D6 and CYP3A4. On the other hand, when 14C-SNI-2011 was incubated with human kidney microsomes, SNI-2011 N-oxide was identified as a major metabolite. This N-oxidation required NADPH, and was completely inhibited by thiourea, indicating that flavin-containing monooxygenase (FMO) was involved. In addition, microsomes containing cDNA-expressed FMO1, a major isoform in human kidney, mainly catalyzed N-oxidation of SNI-2011, but microsomes containing FMO3, a major isoform in adult human liver, did not. These results suggest that SNI-2011 is mainly catalyzed to sulfoxides and N-oxide by CYP2D6/3A4 in liver and FMO1 in kidney, respectively.
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  • Mitsunobu YOSHIDA, Tomoki KIMURA, Kiyoyuki KITAICHI, Ryujiro SUZUKI, K ...
    2001 Volume 24 Issue 11 Pages 1267-1270
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    Human salivary histatins (Hsts), which belong to a salivary polypeptide family, have potent antifungal activity against Candida albicans and Cryptococcus neoformans, and are expected to be useful as therapeutic reagents against Candida species. However, little is known about the effect of Hsts on host immune systems. Thus we conducted a series of in vitro experiments with rat mast cells to determine whether histatin 5 (Hst 5) or histatin 8 (Hst 8) has a histamine-releasing effect on mast cells. Both Hst 5 and Hst 8 induced histamine release from rat peritoneal mast cells in a dose-dependent manner (10-9 to 10-5 M). Hst 5 had a stronger releasing effect than Hst 8. The histamine release induced by Hst 5 (10-6 M) was increased by the presence of 0.5 mM Ca2+, but decreased by 2 mM Ca2+. Alternatively, the histamine release induced by Hst 8 (10-6 M) was inhibited by the presence of Ca2+ (0.5 to 2 mM). These results suggest that Hsts have limited usefulness as therapeutic agents due to induction of histamine release from mast cells.
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  • George HSIAO, Yun-Ho LIN, Chien-Huang LIN, Duen-Suey CHOU, Wen-Chun LI ...
    2001 Volume 24 Issue 11 Pages 1271-1276
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    In this study, PMC (2,2,5,7,8-pentamethyl-6-hydroxychromane), a derivative of α-tocopherol, dose-dependently (1—10 mg/kg) ameliorated the increase in plasma aspartate aminotransferase (GOT) and alanine aminotransferase (GPT) levels caused by chronic repeated carbon tetrachloride (CCl4) intoxication in mice. Moreover, PMC significantly improved the CCl4-induced increase of hepatic glutathione peroxidase, reductase, and superoxide dismutase activities. PMC also restored the decrement in the glutathione content of hepatic tissues in CCl4-intoxicated mice. Furthermore, it also dose-dependently inhibited the formation of lipid peroxidative products during carbon tetrachloride treatment. Histopathological changes of hepatic lesions induced by carbon tetrachloride were significantly improved by treatment with PMC in a dose-dependent manner. These results suggest that PMC exerts effective protection in chronic chemical-induced hepatic injury in vivo.
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Notes
  • Kazumi SANO, Yoji IKEGAMI, Takashi UESUGI
    2001 Volume 24 Issue 11 Pages 1324-1328
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    The disposition of S-benzyl-glutathione (BSG) in male Wistar rats was evaluated by the HPLC method to examine whether the kidney and liver contributed independently to the biosynthesis of S-benzyl-N-acetylcysteine (BNAc), a mercapturic acid (Chart 1). After intravenous injection, BSG was rapidly transported in both the kidney and the liver at a ratio of about 7:3. Simultaneously, a large amount of BNAc was found in both the kidney and the liver. In the kidney, S-benzyl-cysteine (BCys) reached a maximum concentration (Cmax) at 2 min after BSG injection, whereas BNAc reached Cmax within 3 to 5 min. The generation of BNAc was also observed in the liver. While renal BNAc reached Cmax within 3 to 5 min, hepatic BNAc reached Cmax around 5 min after BSG injection. Moreover, the elimination half-life of the BNAc after intravenous injection of the BSG was equivalent to that observed after intravenous injection of the BNAc itself. These results demonstrate that the kidney contributes to the initial intraorgan generation of BNAc and that this mercapturic acid is also synthesized in the liver and preferentially excreted into urine.
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  • Kazuya OOI, Toshiki OHKUBO, Masamune HIGASHIGAWA, Hajime KAWASAKI, Hid ...
    2001 Volume 24 Issue 11 Pages 1329-1331
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    Several 5-fluorouracil (5-FU) derivatives, 1-hexylcarbamoyl-5-fluorouracil (HCFU), 5'-deoxy-5-fluorouridine (5'-DFUR) and UFT (mixed compound of tegafur and uracil), have been developed and clinically widely used. However, comparative pharmacokinetic studies of the parent compound and other fluorinated drivatives have not been precisely reported. The dosage of the oral clinical use for human cancer of 5-FU, HCFU, 5'-DFUR and UFT as tegafur (FT) is 200—300 mg/d, 600 mg/d, 800—1200 mg/d and 300—600 mg/d respectively. These amounts of the drugs are almost equimolar. Previously, we reported the effect of oral equimolar administration of each four drugs on thymidilate synthase activity, deoxyribonucleotide metabolism and cell cycle progression in L1210 ascites tumor. In this study, we examined the antitumor effect and 5-FU concentration in the plasma, intestine and tumor after oral equimolar administrations of each drug using BDF1 mice bearing L1210 ascites tumor. In our study, UFT showed the best life prolongation among these four drugs. The intestine 5-FU level was highest by treatment with 5-FU during the initial 4h. The plasma 5-FU level was highest by treatment with HCFU for 4 h. But the tumor 5-FU level was highest by treatment with UFT over the 24 h. In spite of the high plasma 5-FU concentration after the treatment with HCFU, the 5-FU concentration in the tumor was below the detectable level until 24 h. These findings suggested that the highest specific accumulation of 5-FU in tumor cells may explain the best therapeutic results of UFT.
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  • Fumitake TSUKADA, Yukie OHUCHI, Takahiro TERUNUMA, Mika SUGAWARA, Hiro ...
    2001 Volume 24 Issue 11 Pages 1332-1334
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    We previously reported that small intestinal motility was significantly inhibited by restraint stress, but not by footshock stress. In the present study, we found that plasma β-endorphin levels were more significantly elevated by footshock stress than restraint stress, and that preloading of footshock stimulus canceled the inhibition of small intestinal motility by restraint stress. Pretreatment with the μ-opioid receptor antagonist naltrexone significantly attenuated this canceling effect of footshock stimulus. These results suggest that footshock stimulus may cancel the inhibition of small intestinal motility by restraint stress via activation of μ-opioid receptors.
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Medicinal chemistry
Regular Articles
  • Hiroyuki HIRANO, Eriko OSAWA, Yumiko YAMAOKA, Toshio YOKOI
    2001 Volume 24 Issue 11 Pages 1277-1281
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    Coptisine and 8-oxocoptisine were isolated as principles of the gastric-mucous membrane protection from Coptidis rhizoma. The two compounds showed stronger activity than cimetidine and sucralfate. We prepared several derivatives having a partial structure of coptisine from commercially available starting materials. The compounds obtained were tested for gastric-mucous membrane protective activity and a correlation between activity and structure was studied. Our results suggest that the partial charge of the catechol skeleton is related to activity.
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Notes
  • Masami KAWASE, Katsuyoshi SUNAGA, Satoru TANI, Masayuki NIWA, Toshihik ...
    2001 Volume 24 Issue 11 Pages 1335-1337
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    A variety of aromatic trifluoromethyl ketone derivatives has been studied as inhibitors of apoptosis in cerebellar granule neurons (CGNs). Among them, α-trifluoromethyl diketone (2) and benzyl trifluoromethyl ketone (11) were found to be apoptosis inhibitors which can prevent a neurodegenerative disease. Compounds 2 and 11 showed neuroprotection effect on low K+-induced apoptosis in CGNs. Furthermore, these compounds effectively suppressed DNA fragmentation accompanied with apoptosis. The neuroprotection mode of 2 and 11 was not related to inhibition of caspase-3.
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Pharmacognosy
Regular Articles
  • Akira INADA, Hoyoku NISHINO, Masashi KUCHIDE, Junko TAKAYASU, Teruo MU ...
    2001 Volume 24 Issue 11 Pages 1282-1285
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    In the course of our continuing search for novel cancer chemo-preventive agents from natural sources, we have carried out a primary screening in vitro assay of the compounds isolated from Aglaia odorata. Consequently, aminopyrrolidine-diamides, odorine and odorinol, were obtained as active constituents. These compounds exhibited potent anti-carcinogenic effects in a two-stage carcinogenesis test of mouse skin induced by 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and 12-O-tetradecanoylphorbol-13-acetate (TPA) as a promoter. Further, both compounds showed remarkable inhibitory effects in two-stage mouse skin carcinogenesis models induced by nitric oxide (NO) donors such as (±)-(E)-methyl-2-[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexenamide (NOR-1) or peroxynitrite as an initiator and TPA as a promoter. From these results, it was concluded that odorine and odorinol inhibited both the initiation and promotion stages of two-stage skin carcinogenesis.
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  • Yoshihiro MIMAKI, Akihito YOKOSUKA, Minpei KURODA, Yutaka SASHIDA
    2001 Volume 24 Issue 11 Pages 1286-1289
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    We have systematically examined the cytotoxic activities of the steroidal saponins mainly isolated from the Liliaceae plants against HL-60 human promyelocytic leukemia cells and found several structure-activity relationships. Some steroidal saponins evaluated in the assay system showed considerable cytotoxic activities, which were almost as potent as that of etoposide used as a positive control. The activities were found to be sensitive to the monosaccharides constituting the sugar moieties and their sequences, as well as to the structures of the aglycons.
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Notes
  • Tsuneatsu NAGAO, Fumiko ABE, Hikaru OKABE
    2001 Volume 24 Issue 11 Pages 1338-1341
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    The constituents of the leaves of Clerodendron bungei STEUD. (Verbenaceae) and leaves and bark of C. trichotomum THUNB. were investigated guided by the antiproliferative activity against three tumor cell lines (MK-1: human gastric adenocarcinoma, HeLa: human uterus carcinoma, and B16F10: murine melanoma). Two phenylethanoid glycoside caffeic acid esters, acteoside and isoacteoside, were isolated as the constituents which selectively inhibit the growth of B16F10 cells.
    The antiproliferative activities against B16F10 cells of acteoside (GI50: 8 μM), isoacteoside (8 μM) and their methanolysis products, methyl caffeate (26 μM), 3,4-dihydroxyphenethyl alcohol (8 μM), 3,4-dihydroxyphenethyl glucoside (10 μM), desrhamnosyl acteoside (6 μM), and desrhamnosyl isoacteoside (6μM) suggested that the 3,4-dihydroxyphenethyl alcohol group might be more responsible for the activities of acteoside and isoacteoside than the caffeoyl group. The activities of chlorogenic acid, 3,4-dihydroxyphenylacetic acid, 3-(3,4-dihydroxyphenyl) alanine, 3,4-dihydroxy-phenethylamine hydrochloride, ferulic acid, sinapic acid, and five dihydroxybenzoic acids were also determined and compared with those of the above compounds.
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Biopharmacy
Regular Articles
  • Yoshiyuki OHNO, Yasuhiko YAMADA, Takashi USUI, Koichiro TAKAHASHI, Fum ...
    2001 Volume 24 Issue 11 Pages 1290-1293
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    Incadronate concentrates into the bone as a target organ after intravenous administration of incadronate disodium. Mature osteoclasts has take up incadronate from the bone surface and convert it from an active to an inactive form. As a result, incadronate decreases the plasma calcium concentration by suppressing bone resorption. In this study, the pharmacokinetic and pharmacodynamic (PK/PD) analysis model for ascertaining the antihypercalcemic effects of incadronate disodium was developed in rats. Data on both the concentration of incadronate in bone and that of free calcium in blood after intravenous administration from our previous study were used for analysis. To estimate the concentrations in the surface layer of bone, data on the concentration of incadronate in bone after single intravenous administration were analyzed based on the PK model considering three-compartments. The estimated concentrations in the surface layer in bone were applied to the PD model as an input function. The PD model was developed to analyze the changes in the plasma calcium concentration after a single intravenous administration considering an irreversible inhibition of osteoclast activity. The obtained fitted curves were in good agreement with the observed data. The model could explain the long duration of the antihypercalcemic effect of incadronate disodium and should be useful for planning rational dose regimens for effective antihypercalcemic therapy.
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  • Ehab AHMED HOSNY, Hasan Ibrahim AL-SHORA, Mohamad MOHEY ALDIN ELMAZAR
    2001 Volume 24 Issue 11 Pages 1294-1297
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    The effect of insulin suppositories containing different amounts and concentrations of sodium salicylate (50, 100 mg) and polyoxyethylene-9-lauryl ether (POELE 1, 3, 4%), respectively, on the plasma glucose concentration of diabetic beagle dogs was investigated after rectal administration. Comparison of the effects of these formulations was made with that produced after subcutaneous insulin injections. Insulin suppositories containing sodium salicylate (50 mg) produced a maximum reduction of plasma glucose concentration (Cmax) of 55±11%, an area under the curve (AUC) of 252±59% reduction h; and a relative hypoglycemia (RH) of 49±12% relative to subcutaneous injection of insulin (4 U/kg). Increasing sodium salicylate to 100 mg/suppository did not improve the hypoglycemic effect of insulin suppositories further. Investigation of the influence of insulin suppositories containing different concentrations of the nonionic surfactant POELE (1, 3, 4%) showed that; the suppositories containing the lowest concentration (1%) produced the highest hypoglycemic effect with a Cmax of 68%, AUC of 332±67% reduction h, and RH of 55±11%. Incorporation of sodium salicylate 50 mg in insulin suppositories containing 1% POELE did not improve further the effects found with these suppositories.
    In conclusion, a relative hypoglycemic effect of about 50—55% can be achieved using insulin suppositories containing Witepsol W35 as a base, insulin (5 U/kg), and sodium salicylate (50 mg) or POELE (1%) as rectal absorption enhancers.
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  • Shinya UEDA, Kiyoshi YAMAOKA, Yoneichi SAWAI, Terumichi NAKAGAWA
    2001 Volume 24 Issue 11 Pages 1298-1304
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    Recirculatory analysis was introduced into the portal and systemic concentration difference method with double dosing (PS-DD method), which is an evaluation system for the local intestinal and hepatic first-pass effect. 5-Fluorouracil (5-FU) and cephalexin (CEX) were selected as model drugs. A new recirculatory system was constructed to predict the time courses of a drug concentration in the systemic and portal bloods. Bioavailability (F), local absorption ratio (Fa), hepatic recovery ratio (FH), and local mean absorption time (¯ta) estimated by recirculatory analysis were close to those calculated by moment analysis with numerical integration. Using recirculatory analysis, the sampling period was considerably shortened and the sampling number was also reduced, which demonstrates that recirculatory analysis is useful in PS-DD method.
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  • Noriko MATSUNAGA, Taeko NISHIJIMA, Kenji HATTORI, Hisashi IIZASA, Keik ...
    2001 Volume 24 Issue 11 Pages 1305-1310
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    Previous reports have shown that the determination of drug metabolism capacity can be made by the pharmacokinetic estimation of the quantity of cytochrome P450 (CYP) in vivo (PKCYP-test), in which an apparent liver-to-blood free concentration gradient in vivo (qg) is introduced, which is useful for evaluating fluctuations of CYP1A2 in rats. The aim of the present study was to examine the application of the PKCYP-test to evaluate the quantity of in vivo CYP2C11 by using tolbutamide as a probe, to confirm its validity using a physiologically-based pharmacokinetic rat model.
    Rats treated with carbon tetrachloride (CCl4-treated rats) were used as a model for low levels of CYP2C11 in the liver. In CCl4-treated rats, the total body clearance (CLtot) of tolbutamide and the amount of CYP2C11 fell to about a quarter and a third of that in control rats, respectively. The time-course of tolbutamide concentrations in serum in control rats could be simulated by a physiologically-based pharmacokinetic model. In CCl4-treated rats, take into consideration the qg value of control rats, the level of CYP2C11 was accurately predicted by the PKCYP-test, and the time-course of tolbutamide concentrations in serum could be predicted by the same physiologically-based pharmacokinetic model.
    In conclusion, we have shown that the PKCYP-test can be used to predict levels of CYP2C11. It was also demonstrated that the qg and amount of CYP are useful parameters in the PKCYP-test by constructing a physiologically-based pharmacokinetic model which was applied to the PKCYP-test.
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Miscellaneous
Regular Articles
  • Abhay P. SAGARE, Chao-Lin KUO, Fu-Shin CHUEH, Hsin-Sheng TSAY
    2001 Volume 24 Issue 11 Pages 1311-1315
    Published: 2001
    Released: June 28, 2002
    JOURNALS FREE ACCESS
    A protocol for de novo regeneration and rapid micropropagation of Scrophularia yoshimurae (Scrophulariaceae) has been developed. Multiple shoot development was achieved by culturing the shoot-tip, leaf-base, stem-node and stem-internode explants on Murashige and Skoog (MS) medium supplemented with 4.44 μM N6-benzyladenine (BA) and 1.07 μM α-naphthaleneacetic acid (NAA). Stem-node and shoot-tip explants showed the highest response (100%) followed by stem-internode (74.4%) and leaf-base (7.7%) explants. The shoots were multiplied by subculturing on the same medium used for shoot induction. Shoots were rooted on growth regulator-free MS basal medium and the plantlets were transplanted to soil and acclimatized in the growth chamber. The content of harpagoside, a quantitatively predominant iridoid glycoside, in different plant material was determined by high performance liquid chromatography (HPLC). The analysis revealed that the content of harpagoside in the aerial and underground parts of S. yoshimurae was significantly higher than the marketed crude drug (underground parts of Scrophularia ningpoensis).
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