Pravastatin,an HMG-CoA Reductase Inhibitor,Is Transported by Rat Organic Anion Transporting Polypeptide,oatp2

Purpose. We previously demonstrated the HMG-CoA reductase inhibitor, pravastatin, is actively taken up into isolated rat hepatocytes through multispecific organic anion transporters. The present study examined whether a newly cloned organic anion transporting polypeptide (oatp2) transports pravastatin. Methods. We investigated functional expression of oatp2 in Xenopus laevis oocytes, to examine ¹⁴C] pravastatin uptake. Results. ¹⁴C] Pravastatin (30 M) uptake into oatp2 cRNA-injected oocytes was 40 times higher than that of water-injected control oocytes. The oatp2-mediated pravastatin uptake was Na⁺-independent and saturable. The Michaelis-Menten constant was 37.5 ± 9.9 M, a level comparable to that obtained in isolated rat hepatocytes in our previous study. As is the case with rat hepatocytes, the uptake of pravastatin (30 M) was inhibited by 300 M concentrations of taurocholate, cholate, bromosulfophthalein, estradiol-17-glucuronide, and simvastatin acid, but not by para-aminohippurate. On the other hand, ¹⁴C] simvastatin acid (30 M) uptake of oatp2 cRNA-injected oocytes was not significantly different from that of water-injected oocytes. Conclusions. The cloned oatp2 was identified as the transporter responsible for the active hepatocellular pravastatin uptake.