Species difference in intestinal absorption mechanism of etoposide and digoxin between cynomolgus monkey and rat

フォーマット:

論文

責任表示:

Nishimura, T. ; Kato, Yukio ; Amano, N. ; Ono, M. ; Kubo, Yoshiyuki ; Kimura, Y. ; Fujita, H. ; Tsuji, Akira

言語:

英語

出版情報:

Springer Science+Business Media B.V., 2008-11-01

著者名:

Nishimura, T.

Kato, Yukio

Amano, N.

Ono, M.

Kubo, Yoshiyuki

Kimura, Y.

Fujita, H.

Tsuji, Akira

続きを見る

掲載情報:

Pharmaceutical Research

ISSN:

0724-8741      

巻:

25

通号:

11

開始ページ:

2467

終了ページ:

2476

バージョン:

author

概要:

金沢大学医薬保健研究域薬学系 金沢大学医薬保健研究域医学系<br />Purpose. The oral bioavailability of some therapeutic agents is markedly lower in cynomolgus monkeys than in humans. We investigated small-intestinal absorption of the P-glycoprotein (P-gp) substrate … s etoposide and digoxin in monkeys to clarify the influence of efflux transport on their intestinal permeability. Methods. The pharmacokinetics of etoposide and digoxin was examined in monkeys and rats after oral and intravenous administration. Intestinal permeability and segmental differences in permeability were investigated with an Ussing-type chamber. Results. The bioavailability of etoposide was 12.9 and 13.9% in monkeys and rats, respectively. Total body clearance of etoposide in monkeys was much less than hepatic blood flow, suggesting that the bioavailability would be limited at intestinal absorption. Marked vectorial transport of etoposide in the secretory direction was observed in rats, especially in the lower small intestine, and segmental differences were consistent with the distribution of P-gp expression. Vectorial transport was minimal in monkey small intestine. Our kinetic analysis indicated that P-gp contributes little to the intestinal permeability of etoposide and digoxin in monkeys, and apical uptake is rate-limiting. Conclusion. Low bioavailability of etoposide in monkeys is due to poor intestinal uptake resulting from low influx from the apical side, rather than secretion via P-gp. © 2008 Springer Science+Business Media, LLC. 続きを見る

URL:

http://hdl.handle.net/2297/12346