Biological and Pharmaceutical Bulletin
Online ISSN : 1347-5215
Print ISSN : 0918-6158
ISSN-L : 0918-6158
21 巻 , 7 号
選択された号の論文の28件中1~28を表示しています
  • Jiro HIROSE, Toshiko OZAWA, Toshihisa MIURA, Mitsuko ISAJI, Yuji NAGAO ...
    1998 年 21 巻 7 号 p. 651-656
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    Urinary trypsin inhibitor (UTI) is a physiological protease inhibitor and inter-α-trypsin inhibitor (ITI) is regarded as a precursor of UTI. The purpose of this study is to determine the mechanism of the UTI release from ITI. To examine this, ITI was digested by human neutrophil elastase at various concentrations, and UIT-related proteins which were of the same size as UTI were obtained. The amino acid sequence of the 15 amino acid residues at the N-terminal of UTI-related proteins, corresponded to that of UTI. The amino acid sequences of the small amount of peptides detected corresponded to those of peptides from the heavy chain1 (H1) and the heavy chain2 (H2) of ITI, suggesting that most UTI-related proteins do not combine with peptides from the H1 and H2 of ITI. It was also revealed that UTI-related proteins have several physiological activities similar to those of UTI, i.e., human trypsin inhibitory activity, human neutrophil elastase inhibitory activity, inhibition o tumor necrosis factor-α (TNF-α) production from rat macrophages and of superoxide from rabbit leukocytes.These results demonstrated that ITI is a precursor of UTI which is digested by human neutrophil elastase to release UTI, and that its elastase inhibitory activity is derived from UTI.
  • Emi SUZUKI, Taemi KONDO, Masaki MAKISE, Shinji MIMA, Kenji SAKAMOTO, T ...
    1998 年 21 巻 7 号 p. 657-661
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    We previously reported that mutations in the dnaA gene which encodes the initiator of chromosomal DNA replication in Escherichia coli caused an alteration in the levels of unsaturated fatty acids of phospholipids in membranes. In this study, we examined fatty acid compositions in other mutants which are defective in DNA replication. As in the case of temperature-sensitive dnaA mutants, temperature-sensitive dnaC and dnaE mutants, which have defects in initiation and elongation, respectively, of DNA replication showed a lower level of unsaturation of fatty acids (ratio of unsaturated to saturated fatty acids) compared with the wild-type strain, especially at high temperatures. On the other hand, temperature-sensitive mutants defective in cellular processes other than DNA replication, such as RNA synthesis and cell division, did not show a lower level of unsaturation of fatty acids compared with the wild-type strain. These results suggest that the inhibition of DNA replication causes a lower level of unsaturation of fatty acids in Escherichia coli cells.
  • Yosimaru KUMANO, Tetsuo SAKAMOTO, Mariko EGAWA, Muneo TANAKA, Itaru YA ...
    1998 年 21 巻 7 号 p. 662-666
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    The objective of the present study was to compare 2-O-α-D-gludopyranosyl-L-ascorbic acid (AA-2G) with ascorbic acid (AA) and ascorbic acid 2-phosphate (AA-2P) concerning the promotion of collagen production in human skin fibroblasts.Though AA-2G was still observed to be promoting collagen synthesis at the same level on the 8th day of the culture, collagen synthesis was seen to decrease on the fifth day of culturing with AA and AA-2P. This sustained collagen synthesis-promoting action is considered to be a major feature of the novel vitamin C derivative, AA-2G by conducting an experiment in which an α-glucosidase inhibitor was present, it was shown that AA-2G exerts its collagen synthesis-promoting action after being decomposed to AA by α-glucosidase. Further, we observed that for AA-2G, even on the 8th day of the culture, the amount of AA in the fibroblasts was virtually unchanged from the beginning of the experiment, whereas, in the case of adding AA and AA-2P, virtually no AA was detectable in the culture medium on the fifth day.These findings suggests that AA-2G in decomposed to AA by α-glucosidase in the cells. This AA promotes collagen synthesis, which is prolonged through AA-2G's sustained decomposition.
  • Kenzo FUNATSUKI, Reiji TANAKA, Shuichiro INAGAKI, Haruyoshi KONNO, Ken ...
    1998 年 21 巻 7 号 p. 667-672
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    DNA gyrases were constructed to posses the quinolone-resistant (D87N in GyrA or K447E in GyrB) and acrB (S759R-R760C in GyrB) mutations and their sensitivities to acriflavine and oxolinic acid were examined. Both quinolone-resistant mutations in GyrA and GyrB increased acriflavine sensitivities in the supercoiling assay irrespective of the co-presence of the acrB mutation. In the DNA binding assay, however, the hypersensitivity caused by the GyrB (K447E) mutation was observed only in the co-presence of the acrB mutation; the presence of the acrB mutation, which not affecting acriflavine sensitivity, reduces the extent of DNA binding, as reported previously. Thus, the quinolone-resistant mutation site in GyrB is likely to be involved in DNA binding which is not detectable in acrB+ gyrase. Furthermore, oxolinic acid was found to enhance DNA binding of the gyrase having GyrB (acrB-K447E), supporting a recent proposal that quinolone binding to the DNA-gyrase complex does not require DNA breakage.
  • Tetsuji NODA, Fumio AMANO
    1998 年 21 巻 7 号 p. 673-677
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    Nitric oxide (·NO)-generating activity was examined in a lipopolysaccharide (LPS)-resistant mutant of a murine macrophage-like cell line, J774.1, treated with LPS or LPS and interferon-γ(IFN-γ). This mutant, an LPS1916 cell line, showed no NO2- accumulation in the culture medium, and no expression of NOS activity in the cell extract, ·NO synthase (NOS(II)) protein or NOS(II) mRNA on treatment with up to 104 ng/ml LPS, although the parental cell line, JA-4, showed significant·NO production. The addition of 10 U/ml IFN-γ, together with more than 1 ng/ml LPS to JA-4 cells, increased·NO production remarkably, while IFN-γ did not reverse the defect of·NO production in LPS1916 cells when they were treated with less than 10 ng/ml LPS; however, it induced·NO production by the mutant cells with more than 100 ng/ml LPS. Analysis of NOS activity, NOS(II) protein and NOS(II) mRNA revealed that LPS1916 cells are not devoid of the NOS(II) gene, but are rather defective in transcription of the gene in response to LPS, and this defect is partly reversed by IFN-γ with higher LPS doses at more than 100 ng/ml. In addition, the delay of NOS(II) mRNA induction in LPS1916 cells, compared to that in JA-4 cells, treated with LPS+IFN-γ seems to suggest some additional inducer(s) of NOS(II) transcription, followed by LPS signaling.
  • Takahiro HIRATA, Rumi WAKATABE, Joergen NIELSEN, Tomoko SATOH, Shin-ic ...
    1998 年 21 巻 7 号 p. 678-681
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    Clinically-isolated methicillin-resistant Staphylococcus aureus (MRSA) strain 743 exhibited resistance to tetracycline as judged from the active efflux of the drug. The efflux of tetracycline was inhibited by an uncoupler, carbonyl cyanide m-chlorophenylhydrazone (CCCP), and minocycline. Inhibitors of the efflux pump were examined in this strain to determine the cellular accumulation of tetracycline. Out of seven compounds examined, three caused a significant increase in the cellular concentration of tetracycline by inhibiting the efflux pump. Two of them seem to be energy inhibitors. Ro 07-3149 inhibited the efflux pump without affecting the energy state, and exhibited very low antibacterial activity but showed weak synergy with tetracycline.
  • Megumi NAGAOKA, Mayu SAITOH, Takayuki SHIRAISHI, Hiroaki NAGAOKA, Naok ...
    1998 年 21 巻 7 号 p. 682-687
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    Sialidase [E.C.3.2.1.18] has previously been purified from porcine liver by procedures including extraction, ammonium sulfate precipitation, concanavalin A-Sepharose adsorption, activation, CM-Sepharose ion exchange chromatography, and HPLC on a Shim pack Diol 300 column. Two sialidase preparations, sialidase I and II, were obtained by CM-Sepharose column chromatography and were eluted with pH 4.5 and 5.0 buffers, respectively. The two enzyme preparations showed the same optimum pH, pH stability, and specificities for natural substrates. The two final preparations contained β-galactosidase activity and showed three protein components of 64, 30, and 21 kDa with sodium dodecyl sulfate-polyacrylamide gel electrophoresis, which are derived from the β-galactosidase multimer. The anti-β-galactosidase multimer antiserum was able to precipitate sialidase activity. It is likely that porcine liver sialidase exists as a multienzyme complex with β-galactosidase and carboxypeptidase (protective protein).
  • George HSIAO, Feng-Nien KO, Ting-Ting JONG, Che-Ming TENG
    1998 年 21 巻 7 号 p. 688-692
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    3', 4'-Diisovalerylkhellactone diester (PJ-1) is a coumarin derivative purified from the medicinal herb Peucedanum japonicum Thunb. We examined its in vitro effects on various aspects of platelet reactivity. PJ-1 inhibited the aggregation and ATP release of rabbit platelets induced by PAF (platelet-activating factor) and collagen. The IC50 values of PJ-1 and BN52021 on PAF (2 ng/ml)-induced platelet aggregation were about 56.3 and 22.0 μM, respectively. And, the IC50 value of PJ-1 toward collagen (10 μg/ml)-induced platelet aggregation was 89.4 μM. Although the platelet aggregation caused by arachidonic acid and thrombin were barely inhibited by PJ-1, the release reactions were partially suppressed. PJ-1 also inhibited the thromboxane B2 formation caused by collagen, while formations of thromboxane B2 and prostaglandin D2 caused by arachidonic acid were not affected. The phosphoinositide breakdown caused by PAF was inhibited by PJ-1, but those by other inducers were not affected significantly. PJ-1 inhibited the intracellular Ca2+ increase caused by PAF in fura-2-loaded platelets. PJ-1 also concentration-dependently inhibited [3H]PAF (3.03 ng/ml) binding to washed platelets with an IC50 value of 3.9 μM. It is concluded that the main antiplatelet effect of PJ-1 may be due to dual activities on the blockade of PAF receptor-induced activation and also the inhibition of phospholipase A2 in rabbit platelets.
  • Kazuhiko TSUTSUMI, Takeshi IWAMOTO, Akifumi HAGI, Hideaki KOHRI
    1998 年 21 巻 7 号 p. 693-697
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    Hypertriglyceridemia with low high-density lipoprotein (HDL) cholesterol is a risk factor of cardiovascular disease. We attempted to create an animal model of hypertriglyceridemia with low HDL cholesterol by intravenously injecting 30 mg/kg body weight streptozotocin (STZ) to cynomolgus monkeys. This induced hypoinsulinemia and resulted in a decrease in postheparin plasma lipoprotein lipase (LPL) activity and LPL enzyme mass, reduction of plasma HDL cholesterol and elevation of triglycerides. Low HDL cholesterol subsequently caused a reduction of HDL2b cholesterol, while hypertriglyceridemia caused an elevation of very low-density lipoprotein (VLDL) triglyceridemia. Apolipoprotein CII, a co-factor of LPL, was not affected by STZ administration. These results show that hypertriglyceridemia with low HDL cholesterol results from a reduction of LPL activity without affecting apolipoprotein CII after STZ administration. The STZ-induced diabetic cynomolgus monkey is a model of hypertriglyceridemia with low HDL cholesterol, and may be potentially beneficial for studying atherosclerosis caused by hypertriglyceridemia with low HDL cholesterol.
  • Tsunemasa SUZUKI, Kiyotaka HIROOKA, Kazumi KANDA, Hiroko HIROOKA, Keni ...
    1998 年 21 巻 7 号 p. 698-703
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    We examined the effects of N-[2-(1-azabicyclo[3, 3, 0] octan-5-yl)ethyl]2-nitroaniline fumarate (SK-946) on cognition in various rodent models. SK-946 slightly suppressed spontaneous motor activity, but had no effect on scopolamine-induced motor facilitation. SK-946 ameliorated scopolamine-, pirenzepine-, cycloheximide- and electric shock-induced passive avoidance deficits in rodents when administered before acquiring the training. In an active avoidance test, SK-946 accelerated avoidance acquisition in the later half of training without a marked increase in lever-pressing. In more reliable models of cognitive disorders, i.e. an AF64A intracerebroventricular infusion model using the step-through passive avoidance test, an aged rat model using the step-down passive avoidance test and methylazoxymethanol (MAM)-induced microencephalic rat model using the Morris water maze test, SK-946 ameliorated impaired learning and memory. These results suggest an ability of SK-946 to enhance cognitive functions.
  • Tsunemasa SUZUKI, Kiyotaka HIROOKA, Kazumi KANDA, Hiroshi UESAKA, Hiro ...
    1998 年 21 巻 7 号 p. 704-709
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    The neurochemical effects of SK-946, N-[2-(1-azabicyclo[3, 3, 0]octan-5-yl)ethyl]2-nitroaniline fumarate, were investigated in an attempt to elucidate cognition activating properties. In rat brain cortical membranes and in cloned human receptors expressed in Sf9 cells, SK-946 had submicromolar affinities for muscarinic receptors with a moderate selectivity for M1 (m1) sites. Althouth no increase in the antagonist (N-methylscopolamine)/agonist (oxotremorine-M) binding ratio was observed, SK-946 exhibited a partial agonistic effect on receptor-stimulated phosphoinositide hydrolysis in primary cultured rat fetal hippocampal cells. Heterogeneous, reversible and concentration-dependent excitations of the hippocampal neuronal cells treated with SK-946 (10-5-10-3 M) were confirmed as increases in cytosolic Ca2+ concentrations measured in Fura-PE3 preloaded cells. Furthermore, SK-946 (>10-5 M) increased [3H]myo-inositol uptake into the hippocampal cells. On the other hand, SK-946 had no effect on adenylate cyclase activities in primary cultured rat heart cells, and showed a weak antagonistic effect on carbachol-induced adenylate cyclase inhibition, suggesting that it is an M2 antagonist. Using in vivo microdialysis, it was found that relatively low concentrations (>10-7 M) of SK-946 increased acetylcholine release and decreased choline content in that hippocampal area in rats. These results suggest that SK-946 accelerates muscarinic neuronal transmission in the central nervous system.
  • Jon-Son KUO, Jen-Pey WU, Pi-Ju TSAI, Chung-Shi YANG
    1998 年 21 巻 7 号 p. 710-712
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    This investigation was to examine the effect of ferrous ion (a prooxidant) on the antiarrhythmic effect of naloxone (an endogenous opioid receptor antagonist) in isolated rat hearts. Isolated Sprague-Dawley rat hearts were perfused in the Langendorff mode and myocardial ischemia was performed by ligating the left descending coronary artery. Cardiac rhythm was recorded. Heart α-tocopherol concentrations were analyzed. Naloxone (1, 2 μmol/heart) was effective in reducing the severity of arrhythmia (arrhythmia score; mean±S.E.M : 2.82±0.69 for naloxone vs. 5.18±0.38 for control, p<0.01). Fe2+ (100nmol/heart) alone did not significantly affect the arrhythmia score (5.63±0.32) when compared with the control, however, Fe2+ administration did cause significant early onset of ventricular premature contraction and ventricular tachycardia. Additionally, Fe2+ administration diminished the naloxone's antiarrhythmic effect (arrhythmia score 4.12±0.40). α-Tocopherol, a major free radical scavenger that exerts protective functions on heart tissues during myocardial ischemia/reperfusion, was significantly higher in the naloxone-treated group (59.05±3.00 nmol/g wet wt) than in the control group (43.84±4.17 nmol/g wet wt, p<0.05). These results suggest that endogenous opioid peptides and reactive oxygen species might be related to ischemia-induced arrhythmia.
  • Tohru ISHIKAWA, Yu FUKASE, Taeko YAMAMOTO, Fumiko SEKIGUCHI, Hideo ISH ...
    1998 年 21 巻 7 号 p. 713-717
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    Capecitabine (N4-pentyloxycarbonyl-5'-fluorocytidine) is a novel fluoropyrimidine carbamate that was synthesized for the purpose of finding antitumor drugs with improved safety and efficacy profiles compared with those of 5-fluorouracil (5-FUra) and doxifluridine (5'-deoxy-5-fluorouridine, 5'-dFUrd). The present study compared the antitumor activities of the compound with those of other fluoropyrimidines in 12 human cancer xenograft models and their antimetastatic activities in murine tumor models. The antitumor efficacy of capecitabine was greater than those of 5'-dFUrd, UFT (a mixture of tegafur and uracil) and 5FUra. Capecitabine was also much safer, particularly much less toxic to the intestinal tract, than the other compounds, indicating higher therapeutic indices. The therapeutic indices. The therapeutic indices of capecitabine, 5'-dFUrd and 5-FUra were >40, >20 and 2.0 against the human CXF280 colon cancer xenograft, the most sensitive line to the fluoropyrimidines so far tested, and 5.1, 1.5, and <1.5 against the human HCT116 colon cancer xenograft with ordinary sensitivity, respectively. In addition, capecitabine, as well as 5'-dFUrd, selectively suppressed the spontaneous metastasis of mouse Lewis lung carcinoma in mice at extremely low doses, 32-64 fold lower than their minimum effective dose (MED) against the primary tumor growth. Capecitabine was even more antimetastatic than 5'-dFUrd. These results indicate that dapecitabine has high therapeutic potential.
  • Mitsutoshi SATOH, Mikiko TAKADA, Noriko OHSHIMA, Issei TAKAYANAGI, Kat ...
    1998 年 21 巻 7 号 p. 718-722
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    We observed encothelin (ET)-induced contractile responses on prostatic and epididymal segments, as well as the facilitation of an electrically stimulated tone on prostatic segments of isolated rat vas deferens. In both segments, the selective ETB-receptor agonists, IRL 1620 and safafotoxin S6c, produced only a small contraction or no contraction at a concentration of 1 μM. The rank order of contraction potencies (pD2 value) was ET-1=ET-2>ET-3<Gt>sarafotoxin S6c=IRL 1620. The maximum responses of ET-induced contractions in the prostatic segments were larger than those in the epididymal segments. The contractile response to ET-3 was antagonized by pretreatment for 30 min with BQ-123 (10 nM), a selective ETA receptor antagonist, and BQ-788 (1 μM), a selective ETB receptor antagonist. The contractile responses to ET-1 were antagonized by pretreatment with BQ-123 (10 μM), but not with BQ-788 (1 μM). The ET-3-induced facilitation on the twitch response to electrical stimulation in the prostatic segment of the vas deferens was antagonized by BQ-123 (0.1 μM) and BQ-788 (1 μM). The ET-1-induced facilitation was antagonized by pretreatment with BQ-123 (3 μM), but not with BQ-788 (10 μM). These results suggest that in rat vas deferens the ETA receptors are divided into BQ-123-sensitive ETA1 and BQ-123-insensitive ETA2 subtypes, and the production of a contractile response of smooth muscle as well as the facilitation of neurotransmission are accomplished through mediation by ETA1-and ETA2-subtypes.
  • Hideki MIYATAKA, Mayumi NISHIKI, Hitoshi MATSUMOTO, Takunori FUJIMOTO, ...
    1998 年 21 巻 7 号 p. 723-729
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    To establish a biological method for evaluating propolis and to reveal their anti-allergic action, the effects of the ethanol and water extracts (EA-ET and WA-WT, respectively) from Brazilian, Chinese and Japanese propolis on the histamine release induced by compound 48/80 and concanavalin A (Con A) were investigated. The relation between the inhibitory activities of these extracts on the histamine release and their E1%1cm values were also examined. As a result, the following was found : 1) 0.003-0.01% ethanol and 0.03-0.1% water extracts inhibited the histamine release induced by compound 48/80 and Con A, and the inhibitory potencies of the former extracts were more than 10 times stronger than those of the latter extracts, making it clear that both the ethanol and water extracts possesse an anti-allergic action; 2) most of the ethanol and water extracts responded to the histamine release induced by both the histamine releasers in a concentration-dependent manner; 3) the inhibitory activities of 0.003% EM from Hebei Province, EP from Sichuan Province, EQ from Zhejiang Province and ER from Anhui Province in China were weaker than those of 0.01% corresponding extracts, whereas 0.001% ED-EH from Brazilian propolis, EM, EN from Henan Province in China and EP-ER promoted the Con A-induced histamine release of more than 10%, suggesting that such extracts must be carefully given to humans; 4) the inhibitory potencies of only 0.03-0.1% water extracts from Chimese propolis on the Con A-induced histamine release related excellently with their E1%1cm values; 5) from the results of the relation between the inhibitory potencies of the propolis extracts and their E1%1cm values, it was suggested that an unknown compound, being a poorly water-soluble compound which is a non-flavonoid, with an anti-allergic action is contained in propolis; 6) to precisely evaluate the anti-allergic action of the propolis, the biological method, which measures the inhibitory activities of the propolis extracts on histamine release, was markedly superior to the physicochemical method.
  • Tomomi HOSHINO, Toshimitsu HAYASHI, Kyoko HAYASHI, Jin HAMADA, Jung-Bu ...
    1998 年 21 巻 7 号 p. 730-734
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    A sulfated polysaccharide was isolated from the hot water extract of a brown alga, Sargassum horneri (TURNER) C.AGARDH. Fucose was detected as the main component sugar of this polysaccharide. This compound showed potent antiviral activity against herpes simplex virus type 1, human cytomegalovirus and human immunodeficiency virus type 1. Time-of-addition experiments suggested that it inhibited not only the initial stages of viral infection, such as attachment to and penetration into host cells, but also later replication stages after virus penetration.
  • Junko NISHIGAKI, Yuka SUZUKI, Akiyo SHIGEMATSU
    1998 年 21 巻 7 号 p. 735-740
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    A method to analyze in vivo metabolites in blood obtained from the hepatic vein after the intraportal injection of a drug was established. This method includes cannulation into the portal vein, hepatic vein and bile duct, followed by TLC-autoradioluminography of a non-extracted sample.Either [14C]diazepam, L-3, 4-dihydroxyphenyl[3-14C]alanine or [14C]inulin was administered on the day following the surgical operation to avoid the influence of anesthesia. Radioactive concentrations of [14C]DOPA decreased rapidly in the first 1 min, then decreased gradually. The concentrations of [14C]diazepam increased within the first 1 min and then decreased gradually. The concentration of [14C]inulin was approximately 10 times higher than that of [14C]DOPA, and both decreased gradually. These results show that the uptake levels of the drugs to the liver varied depending on the drugs. The metabolites of [14C]diazepam and [14C]DOPA were detected as early as 5s after administration. These results suggest that the in vivo hepatic first pass effect of drugs in the early period of injection (5s) can be studied using these techniques.
  • Kazuyuki SHIMIZU, Xian-Rong QI, Yoshie MAITANI, Mayumi YOSHII, Kumi KA ...
    1998 年 21 巻 7 号 p. 741-746
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    The blood clearance, tissue uptake and antitumor efficacy against liver metastasis of M5076 reticulosarcoma in mice and against primary liver cancer in rats of doxorubicin (DOX) encapsulated in two types of liposomes, with and without a soybean-derived sterylglucoside mixture (SG), were examined. Liposomes entrapping DOX were composed of dipalmitoylphosphatidylcholine (DPPC), SG and cholesterol (Ch) at a molar ratio of 6 : 1 : 3, (SG-liposomes) and 6 : 0 : 4 (non-SG-liposomes). Pharmacokinetic analysis of drug disposition was based on the area under the curve (AUC) for liposomes up to 24h following i.v. injection. SG-liposomes showed lower DOX concentrations in blood and higher concentrations in liver compared with non-SG-liposomes. The highest AUC of SG-liposomes in tissue was in liver, 2.4 times higher than that of the free drug. The antitumor efficacy of SG-liposomes was compared with that of free DOX and non-SG-liposomes at a dose of 5 mg DOX/kg. SG-liposomes displayed stronger antitumor activity than the free drug and non-SG-liposomes in murine reticulosarcoma M5076 tumor models and primary liver cancer models reflecting accumulation in hepatocytes. The antitumor activity of SG-liposomes in rats with primary liver cancer was significantly higher compared with free DOX and non-SG-liposomes (ILS : 92.7%).
  • Kenjiro KOGA, Masahiro MURAKAMI, Susumu KAWASHIMA
    1998 年 21 巻 7 号 p. 747-751
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    The effects of fatty acid sucrose esters on membrane lipid dynamics and ceftibuten transport by rat intestinal brush-border membrane vesicles (BBMV) were examined to clarify the differences in the action of mono- and poly-acyl sucrose esters on the drug transport. Fatty acid sucrose mono-acyl ester (SS) inhibited ceftibuten transport by BBMV similar to the action of polyoxyethylene sorbitans (Tweens), while fatty acid sucrose polyacyl ester mixtures (F-160 and F-140) did not affect the drug transport by BBMV. SS but not F-160 and F-140 caused an increase in the anisotropy of 1, 6-diphenyl-1, 3, 5-hexatriene (DPH)- and 1-(4-trimethylammonium-phenyl)-6-phenyl-1, 3, 5-hexatriene iodide (TMA-DPH)-labeled BBMV in a concentration-dependent manner. Thus, the uptake of ceftibuten by BBMV was strongly correlated with the lipid fluidity of BBMV, in the outer layer and in the inner hydrophobic regions; however, there was no strong correlation between the membrane lipid fluidity and the drug uptake by BBMV. The micelle size and the size distribution of F-160 and F-140 were larger and more widely dispersed, respectively, compared to those of SS and Tweens. These results suggest that the effects of fatty acid sucrose esters on ceftibuten transport by BBMV are related to the dispersion parameter of these pharmaceutical adjuvants.
  • Kenji MATSUDA, Hiroaki YUASA, Jun WATANABE
    1998 年 21 巻 7 号 p. 752-755
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    We evaluated the fractional absorption of L-carnitine, a γ-amino acid essential cofactor for the transfer of long-chain fatty acids, in rats in vivo after oral administration to determine its absorption behavior. At both low (0.05 μmol/rat) and high (100 μmol/rat) doses, L-carnitine was recovered only from the region of the cecum and below at 10 h after administration. During a major shift in distribution from cecum at 10 h to feces at 24 h, there was no significant change in the total recovery at each dose, suggesting that L-carnitine absorption is negligible in the cecum and the large intestine (colon and rectum). However, the recovery of L-carnitine was incomplete and the fraction recovered was larger at the high dose than at the low dose. The fractions absorbed were estimated to be 96.7 and 33.0% for the low and high doses, respectively, as these were the fractions that disappeared from the gastrointestinal tract. These values were comparable with 100 and 42%, respectively, of bioavailability values by the pharmacokinetic analysis of plasma concentration data in our preceding study [Matsuda et al., Biopharmaceutics & Drug Disposition, in press]. These results suggest that L-carnitine is significantly absorbed only in the small intestine, without undergoing first-pass degradation, and in a dose-dependent manner presumably due to the involvement of saturable transport by L-carnitine carriers. Consistent with the suggestions in vivo, L-carnitine absorption in the closed intestinal loop in situ was concentration-dependent in the small intestine but not in the large intestine, and the apparent membrane permeability in the large intestine was smaller by an order of magnitude than that of passive transport in the small intestine. These findings support our preceding kinetic modeling strategy assuming the small intestine to be the sole absorption site, and should be of help in guiding studies on development of more efficient oral L-carnitine delivery strategies.
  • Taiyo SUGANUMA, Toyofumi SUZUKI, Masakazu OSHIMI, Manabu HANANO
    1998 年 21 巻 7 号 p. 756-760
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    This study aimed to investigate the behavior of an endogenous β-endorphin (β-EP) in the brain after subcutaneous (s.c.) injection of carrageenin or intravenous (i.v.) injection of indomethacin (IDM). The carrageenin was injected into rat hind paw subcutaneously in order to evoke only a local nociceptive stimulus. The β-EP concentration in the brain region was determined by radioimmunoassay at designated sampling times after the injection. It was observed that the β-EP concentration in the midbrain declined from 2.8±0.3 at 1 h to 1.3±0.02 ng/mg protein at 9h. After the s.c. injecction of carrageenin, the β-EP concentrations in the midbrain were found to be closely related to the nociceptive sensitivity which was determined by the Randall-Selitto test. On the other hand, a significant elevation of the β-EP concentration was observed in the hypothalamus from 3 h until 5 h compared with that of control. IDM was injected into rats at doses of 2.9, 5.8 and 8.6 mg/kg via the femoral vein. After i.v. administration of IDM, the β-EP increased in the hypothalamus, medulla oblongata, and midbrain, depending on the doses used. The value of hypothalamic β-EP concentration was two times higher than that of carrageenin. We found that nociceptive stimuli and IDM brought a change in the β-EP concentration in the brain of rats.
  • Yasuharu ONISHI, Takeshi YAMAURA, Katsunori TAUCHI, Takashi SAKAMOTO, ...
    1998 年 21 巻 7 号 p. 761-765
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    We investigated the inhibitory effect of oral administration of Juzen-taiho-to, a Kampo Japanese herbal medicine, and its related formulations on the experimental liver and lung metastasis of tumor cells in vivo. Oral administration of Juzen-taiho-to for 7 d before tumor inoculation significantly reduced the number of liver metastatic colonies of colon 26-L5 carcinoma cells and attenuated the increase of liver weight in a dose-dependent manner ranging from 4 to 40 mg/d. Its oral administration for this same period before tumor inoculation also significantly inhibited lung metastasis of B16-BL6 melanoma cells. Juzen-taiho-to originally consisted of 8 crude drugs derived from Shimotsu-to and Shikunshi-to prescriptions together with two crude drugs (Cinnamomi Cortex and Astragali Radix). Oral administration of Shimotsu-to as well as Juzen-taiho-to for 7 d before tumor inoculation resulted in a significant reduction in the number of metastatic colonies and the liver weight as compared with the control, whereas Shikuhshi-to did not exhibit such an inhibitory effect. Unsei-in containing four Shimotsu-to constituents was also active in inhibiting liver metastasis. Toki-shakuyaku-san and Ninjin-yoei-to, which include all Shimotsu-to constituents except Rehmanniae Radix and Cnidii Rhizoma, respectively, did not show a significant anti-metastatic effect. Rikkunshi-to and Ninjin-yoei-to, which contain Shikunshi-to constituents, did not affect the inhibition of liver metastasis. Hochu-ekki-to treatment before tumor inoculation also led to a significant inhibition of liver metastasis, probably through an inhibitory mechanism different from Juzen-taiho-to. These results suggest that the anti-metastatic effect of Juzen-taiho-to is partly associated with its Shimotsu-to-derived constituents.
  • Tomohiro ASAI, Kohta KUROHANE, Satoshi SHUTO, Hirokazu AWANO, Akira MA ...
    1998 年 21 巻 7 号 p. 766-771
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    We previously synthesized the 5'-O-diacylphosphatidyl derivative of 2'-C-cyano-2'-deoxy-1-β-D-arabino-pentofuranosylcytosine (CNDAC), a novel antitumor nucleoside, and observed it to have a high antitumor activity. Since this compound is readily incorporated into liposomal membranes, we liposomalized the compound using a formulation for conventional and long-circulating liposomes, and investigated the antitumor activity of liposomal 5'-O-dipalmitoylphosphatidyl CNDAC (DPP-CNDAC). Long-circulating liposomes composed of DPP-CNDAC, dipalmitoylphosphatidylcholine, cholesterol and palmityl-D-glucuronide (PGlcUA) (2 : 2 : 2 : 1 as a molar ratio), as well as liposomes containing dipalmitoylphosphatidylglycerol (DPPG) instead of palmityl-D-glu-curonide and those composed of only DPP-CNDAC, were injected intravenously into Meth A sarcoma-bearing mice, DPP-CNDAC showed suppression of tumor grouwth, whereas CNDAC did not at the same concentration, suggesting that 5'-phosphatidylation is useful to enhance therapeutic efficacy. Furthermore, liposomal DPP-CNDAC reduced the acute toxicity, and liposomes containing PGlcUA showed more enhanced activities of reducing tumor growth and increasing the lifetime of the mice than liposomes containing DPPG. To obtain a higher therapeutic efficacy, we injected long-circulating liposomal DPP-CNDAC 5 times. The tumor growth was suppressed to 13.2% (86.8% inhibition), and the survival time of the tumor-bearing mice increased to 128.5% with one completely cured mouse out of five. Next, the effect of DPP-CNDAC incorporation on the in vivo behavior of PGlcUA and DPPG liposomes was examined by a non-invasive method using positron emission tomography (PET). Liposomes were labeled with [2-18F]-2-fluoro-2-deoxy-D-glucose, and administered to tumor-bearing mice. PET images and time-activity curves indicated that DPP-CNDAC/PGlcUA-liposomes tended to accumulate in tumor tissues a little bit more than DPP-CNDAC/DPPG-liposomes, although the difference between the two kinds of liposomal distribution was not as marked as between PGlcUA and DPPG liposomes, suggesting that DPP-CNDAC incorporation partly affected the liposomal behavior in vivo but that the long-circulating character of PGlcUA-liposomes might not be fully abolished. Thus, the enhanced therapeutic efficacy of long circulating liposomalized DPP-CNDAC observed here may be due to passive targeting of DPP-CNDAC to the tumor tissue, making this formulation of DPP-CNDAC useful for cancer chemotherapy.
  • Katsutoshi YAYAMA, Hiroki SHIBATA, Masaoki TAKANO, Hiroshi OKAMOTO
    1998 年 21 巻 7 号 p. 772-774
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    To determine the existence of the kallikrein-kinin system in vascular wall, the expression of low-molecuar-weith (LMW) kininogen, a precursor protein of kinins, was studied in mouse aortic smooth muscle in vivo or in cultured vascular smooth muscle cells (VSMC) derived from mouse aorta in vitro. Although LMW-kininogen mRNA was undetectable in aortic smooth muscle of untreated mice using either Northern blotting or reverse transcription-polymerase chain reactions (RT-PCR) followed by Southern blotting, administration of lipopolysaccharide (LPS; 1 mg/kg, i.v.) induced the expression of LMW-kininogen mRNA at levels detectable by RT-PCR within 12 h. Cultured VSMC not only expressed LMW-kininogen mRNA at levels easily detectable by RT-PCR, but also secreted LMW-kininogen-like protein that was immunoreactive to anti-mouse LMW-kininogen antibody. These results demonstrate that VSMC are a source of LMW-kininogen in the mouse, and suggest the presence of a local kallikrein-kinin system in vascular tissue. LPS-induced up-regulatin of LMW-kininogen expression suggests a role for vascular LMW-kininogen in tissue trauma or inflammation.
  • Takeshi KOBAYASHI, Toru OSAKABE, Yoshiyuki SEYAMA
    1998 年 21 巻 7 号 p. 775-777
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    In order to clarify the degradation of elastin under abnormal conditions, we examined the aortic elastolytic activity in rat experimental diabetes mellitus induced by treatment with streptozotocin and in rat experimental aneurysm induced by treatment with an inhibitor of lysyloxidase (β-aminopropionitrile : BAPN). Measurement of the aortic elastolytic activity used 14C-labeled elastin as the substrate, and the determined value was compared with the aortic lysosomal enzyme (acid phosphatase) activity. In the case of experimental diabetes, the aortic elastolytic activity was not changed, but the aortic acid phosphatase activity was significantly increased compared with the control. In the case of the experimental aneurysm, the aortic elastolytic activity measured after 2 and 3 weeks was increased compared with each control. These was a negative correlation (r=-0.435, n=36) between the elastolytic activity and the cross-linking (desmosine) content in the aorta. The ratio of elastolytic activity to desmosine content was significantly increased compared with the control. Therefore, the degradation of aortic elastin in the experimental aneurysm was caused by elastase, not by lysosomal enzymes. We concluded that an elastase-like enzyme mainly contributed to the degradation of elastin in the experimental aneurysm since the inhibitory pattern of the elastolytic activity in the experimental aneurysm was similar to that of pancreatic elastase.
  • Hideyuki YAMADA, Sachiko IKEDA-WADA, Kazuta OGURI
    1998 年 21 巻 7 号 p. 778-781
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    A new screening method for ampheramines was developed. It consists of derivatization with dansyl chloride, extraction of the derivative using a Sep-Pak C18 or a Bond Elut C18, solid phase extraction columns, and visualization of the fluorescence of the cartridge. A control test using drug-free urine showed no fluorescence. Amphetamine, methamphetamine and the methylenedioxy derivatives exhibited strong fluorescence, while related compounds, such as N-ethylamphetamine and fenetylline, were negative or weakly positive. The disadvantage of the present method is that it is a multi-step procedure and 20-30 min is required for screening. However, since it has a different specificity from the widely used immunochemical technique, it is suggested to be a useful screen for amphetamines.
  • Hiroaki HAYASHI, Noriko HOSONO, Mieko KONDO, Noboru HIRAOKA, Yasumasa ...
    1998 年 21 巻 7 号 p. 782-783
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    The nucleotide sequences of the ribulose-1, 5-bisphosphate carboxylase/oxygenase large subunit gene (rbcL) of Glycyrrhiza glabra, G. uralensis, G. inflata, G. echinata, and G. pallidiflora have been determined to construct the phylogenetic tree. In the phylogenetic tree based on the rbcL sequences, the five Glycyrrhiza species were divided into two groups : the three glycyrrhizin-producing species G. glabra, G. uralensis, and G. inflata; and the two glycyrrhizin-nonproducing species G. echinata and G. pallidiflora. Among the three glycyrrhizin-producing species, only two nucleotide substitutions were observed between the rbcL sequence of G. glabra and G. uralensis, and the sequence of G. uralensis was identical to that of G. inflata, indicating that the three glycyrrhizin-producing species are closely related.
  • Jae Yoon LEEN, Ho Yong PARK, Hidesuke FUKAZAWA, Yoshimasa UEHARA, Shun ...
    1998 年 21 巻 7 号 p. 784-785
    発行日: 1998/07/15
    公開日: 2008/04/10
    ジャーナル フリー
    We examined the inhibitory effects of N-β-alanyl-5-S-glutathionyl-3, 4-dihydroxyphenylalanine (5-S-GAD), a novel antibacterial substance from the immunized adult Sarcophaga peregrina (flesh fly), on protein phosphorylation using immune complexes of protein tyrosine kinases (PTKs) with anti-PTKs monoclonal antibody. We found that 5-S-GAD directly inhibited not only tyrosine phosphorylation of PTK p60v-src, but also tyrosine phosphorylation of PTK p210BCR-ABL. The inhibitory potency of 5-S-GAD was comparable to that of radicicol and herbimycin A of PTK inhibitor.
feedback
Top