Metabolism of irinotecan in vivo (IMAGE)

Xia & He Publishing Inc.

Metabolism of irinotecan in vivo

Caption

Irinotecan is metabolized by carboxylesterase (CES) into the active metabolite 7-ethyl-10-hydroxycamptothecin (SN-38). SN-38 can enter the liver via organic anion transporting polypeptide (OATP) 1B1 transporters and be transported out of the liver via ABC transporters. Within the liver, it is catalyzed by uridine diphosphate-glucuronosyltransferase (UGT) 1A1 and UGT1A9 into the inactive metabolite SN-38 glucuronide (SN-38G). Irinotecan and SN-38 are also excreted into the intestine via ABC transporter-mediated biliary secretion. In the intestine, irinotecan is metabolized by CES into SN-38, which is then glucuronidated by UGT1A1 and UGT1A7 to form SN-38G. SN-38G can also be converted back to SN-38 by β-glucuronidase.

Credit

Chengliang Zhang, Chengren Shu

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License

CC BY-NC

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