P-Glycoprotein (P-gp)-mediated multidrug resistance (MDR) in cancer cells may be modulated by competitive inhibitors of P-gp. In the liver, P-gp is localized on the canalicular membrane of hepatocytes. Quinidine and GF120918 inhibit the transport of P-gp substrates, including doxorubicin. Competitive inhibition of P-gp transport may alter biliary excretion of substrates. This study was designed...

The site of synthesis of Hageman factor (HF, Factor XII) has not been previously demonstrated with certainty. We have studied the production and release of HF in the isolated perfused rat liver and have compared rates of synthesis in this system with absolute rates of degradation measured in vivo. Rat livers, perfused for 5 h with a recycling fluid consisting of a perfluorochemical emulsion (Fl...

The combined effects of orchiectomy and estrogen administration on synthesis of selected hepatic secretory proteins--antithrombin (AT) III, plasminogen, fibrinogen, factor II (prothrombin), factor VII, fibronectin, and albumin--were studied using the isolated rat liver perfused in vitro for ten hours. Male rat liver donors underwent orchiectomy under ether anesthesia and then received 5.0 mg of...

The role of hepatic triacylglycerol lipase (H-TGL) in promoting the liver uptake of high density lipoprotein (HDL) free and esterified cholesterol was studied in a recirculating rat liver perfusion, a situation where the enzyme is physiologically expressed and is active at the vascular bed. For this purpose, reconstituted HDL of defined phospholipid composition were prepared, containing either ...