著者

渥美 亮 鈴木 亘 吉田 伸子 伯水 英夫

出版者

The Japanese Society for the Study of Xenobiotics

雑誌

薬物動態 (ISSN:09161139)

巻号頁・発行日

vol.5, no.2, pp.209-216, 1990 (Released:2007-03-29)

参考文献数

13

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To examine the drug interaction between LC9018 and tegafur, the tegafur was administered to LC9018 treated or control mice and plasma concentrations of tegafur and its active metabolite, 5-fluorouracil (5-FU) were monitored.1. In 300μg LC9018/animal (intravenous, i.v.) treated group, the maximum plasma level(Cmax) of 5-FU and the area under the curve (AUC)decreased to 43% and 64% of control values, respectively. On the other hand, no change was observed in tegafur level, suggesting that LC9018 inhibited the conversion of tegafur to 5-FU at this dose.2. In 300μg LC9018/animal (intrapleural, i. pl.) treated group, 5-FU level decreased to 55% of the control at 30min after administration. But the influence on the metabolism of tegafur was smaller compared to the intravenous treatment of LC9018.3. In 180μg/animal (i.v.), 150μg/animal (i.pl.) and 300μg LC9018/animal (subcutanous, s.c.) treated groups, both tegafur and 5-FU level did not alter compared to the control.4. From above results, influence of LC9018 on the metabolism of tegafur depends on the dose and the administration route (i.v.> i.pl.> s.c.). It is considered that LC9018 slightly affects the metabolism of tegafur at clinical dose (200μg/animal i.pl.).

著者

佐藤 哲男 細川 正清 渥美 亮 鈴木 亘 伯水 英夫 永井 栄一

出版者

The Pharmaceutical Society of Japan

雑誌

Biological and Pharmaceutical Bulletin (ISSN:09186158)

巻号頁・発行日

vol.17, no.5, pp.662-664, 1994-05-15 (Released:2008-04-10)

参考文献数

18

被引用文献数

79 131

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We measured the plasma concentrations of 7-ethyl-10-[4-(1-piperidino)-1-piperidine] carbonyloxycamptothecin (CPT-11) and the active metabolite 7-ethyl-10-hydroxycamptothecin (SN-38), after treatment with CPT-11 to rats pretreated with bis-p-nitrophenylphosphate (BNPP) which is a specific inhibitor of carboxylesterase, and non-pretreated rats. The plasma level of SN-38 was decreased in the BNPP-pretreated group compared with these of non-pretreated group, indicating that the esterase involved in CPT-11 metabolism is a carboxylesterase. We also characterized the molecular species of carboxylesterase involved in CPT-11 metabolism using enzyme preparations purified from liver microsomes. Thirteen carboxylesterase isozyme activities towards CPT-11 were compared and guinea pig GLP1 was found to have the highest activity, while human HU1 isozyme had relatively lower activity than those of animal species. In studies on the kinetic parameters of the hydrolysis of CPT-11 by the purified carboxylesterase isozymes the highest Vmax value of the isozymes was found in human HU1 and the smallest was seen in rat RL1. The Vmax/Km for RL1 showed the largest value of 21.7 nmol/mg protein/mM.