出版社：American Society for Biochemistry and Molecular Biology
摘要：The primary determinants of hepatic uptake of long chain fatty acids have been considered to be the plasma concentrations of fatty acid and albumin, with little or no intrinsic control by the hepatocyte itself. However, recent studies of liver cell suspensions have shown that in immature, adult, castrated, and hormone-treated rats, sex steroids exert striking effects on [(14)C]oleate uptake and utilization (which were significantly increased by estradiol and diminished by testosterone). To determine whether these observed sex differences in fatty acid uptake also were present in the intact liver, single-pass [(14)C]oleate uptake was measured in isolated perfused livers. Livers from sexually mature female and male rats were perfused single-pass with albumin-bound [(14)C]oleate in Krebs-Ringer bicarbonate buffer. Net uptake, calculated as the product of the transhepatic difference in (14)C-labeled fatty acid concentration and perfusate flow rate, reached a steady-state within 1 min and remained constant throughout the 10-min perfusion period. At 0.17 mM [(14)C]oleate and 0.15 mM albumin, extraction fraction and net uptake of [(14)C]oleate per gram liver were more than twice as great in females as in male livers (0.33 +/- 0.03 versus 0.15 +/- 0.02, P
