PT  - JOURNAL ARTICLE
AU  - Nakai, Daisuke
AU  - Nakagomi, Rie
AU  - Furuta, Yoshitake
AU  - Tokui, Taro
AU  - Abe, Takaaki
AU  - Ikeda, Toshihiko
AU  - Nishimura, Kenji
TI  - Human Liver-Specific Organic Anion Transporter, LST-1, Mediates Uptake of Pravastatin by Human Hepatocytes
DP  - 2001 Jun 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 861--867
VI  - 297
IP  - 3
4099  - http://jpet.aspetjournals.org/content/297/3/861.short
4100  - http://jpet.aspetjournals.org/content/297/3/861.full
SO  - J Pharmacol Exp Ther2001 Jun 01; 297
AB  - Involvement of LST-1 (a human liver-specific transporter, also called OATP2) as the major transporter in the uptake of pravastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, by human liver was demonstrated. The hepatic uptake of pravastatin evaluated using human hepatocytes was Na+-independent and reached saturation with a Michaelis constant (Km) of 11.5 ± 2.2 μM. The uptake of pravastatin was temperature-dependent and was inhibited by estradiol-17β-d-glucuronide, taurocholic acid, bromosulfophthalein, and simvastatin acid, but not byp-aminohippurate. Estradiol-17β-d-glucuronide competitively inhibited pravastatin uptake with an inhibition constant comparable to theKm value for estradiol-17β-d-glucuronide transport, indicating that a common transporter mediates the transport of pravastatin and estradiol-17β-d-glucuronide in human hepatocytes. The results obtained with human hepatocytes agreed with those obtained with LST-1 expressing Xenopus oocytes. Oocytes microinjected with human liver polyadenylated mRNA showed Na+-independent uptake of pravastatin and estradiol-17β-d-glucuronide. A simultaneous injection of LST-1 antisense oligonucleotides completely abolished this uptake. Expression of LST-1 was immunohistochemically demonstrated in the human hepatocytes, but not in Hep G2 cells, which showed very low uptake of pravastatin. Therefore, LST-1 was regarded as a key molecule for pravastatin in liver-specific inhibition of cholesterol synthesis, making pravastatin accessible to the target enzyme, which would otherwise not be inhibited by this hydrophilic drug. The American Society for Pharmacology and Experimental Therapeutics