Transport of estrone 3-sulfate mediated by organic anion transporter OATP4C1: estrone 3-sulfate binds to the different recognition site for digoxin in OATP4C1.
Article Details
- CitationCopy to clipboard
Yamaguchi H, Sugie M, Okada M, Mikkaichi T, Toyohara T, Abe T, Goto J, Hishinuma T, Shimada M, Mano N
Transport of estrone 3-sulfate mediated by organic anion transporter OATP4C1: estrone 3-sulfate binds to the different recognition site for digoxin in OATP4C1.
Drug Metab Pharmacokinet. 2010;25(3):314-7.
- PubMed ID
- 20610891 [ View in PubMed]
- Abstract
Human organic anion transporter OATP4C1 is a member of the OATP family predominantly expressed in the kidney, and contributes to the renal secretion of digoxin. However, little is known about the characteristics of OATP4C1-madiated transport. We examined the transport of estrone 3-sulfate, which is known as a substrate for other OATPs, by OATP4C1-expressing cells. Estrone 3-sulfate was efficiently transported by OATP4C1. The Michaelis-Menten constant for estrone 3-sulfate uptake by OATP4C1 was 26.6+/-4.9 microM. Transport of estrone 3-sulfate was significantly inhibited by triiodothyronine, chenodeoxycholic acid, bromosulfophtalein, and cyclosporine, whereas known substrates of OATP4C1, digoxin and ouabain, did not change OATP4C1-mediated transport. We further examined the mutual inhibition study between estrone 3-sulfate and digoxin. Digoxin partially inhibited the estrone 3-sulfate transport, and estrone 3-sulfate did not significantly inhibit digoxin transport. The estimated IC(50) value of digoxin for OATP4C1-mediated estrone 3-sulfate transport was 119 microM. This value is not comparable with the Michaelis-Menten constant for digoxin uptake by OATP4C1 (7.8 microM) reported by Mikkaichi et al.(1)) In conclusion, we found that estrone 3-sulfate is a novel substrate for OATP4C1. Moreover, our results indicate that estrone 3-sulfate does not bind to the recognition site for digoxin in OATP4C1.
DrugBank Data that Cites this Article
- Drug Transporters
Drug Transporter Kind Organism Pharmacological Action Actions Digoxin Solute carrier organic anion transporter family member 4C1 Protein Humans UnknownSubstrateDetails