Gandarias J M, Lacort M, Martinez M J, De Nicolas M A, Ochoa B
Biochem Med Metab Biol. 1986 Aug;36(1):14-24. doi: 10.1016/0885-4505(86)90102-7.
The regulation of the hydrolysis of cholesteryl oleate by female sex hormones was studied in the lysosomal fraction of rat liver. Cholesterol ester hydrolase activity was determined at pH 5.0 with an acetone-dissolved cholesteryl [1-14C]oleate substrate preparation. The administration of a single dose of progesterone decreased the enzyme activity during a 3- to 24-hr period following hormone injection. This effect was not correlated to changes in the lysosomal protein synthesis rate. The lysosomal hydrolysis of cholesteryl esters was also inhibited in a noncompetitive manner by the addition of progesterone at concentrations higher than 100 microM. The esterase failed to respond to the estradiol in vivo as well as in vitro. The findings of the present paper suggest that the lysosomal breakdown of cholesteryl esters in rat liver may be under selective hormonal regulation and that the inhibitory effect of progesterone on the enzyme activity might be, at least in part, responsible for the liver cholesterol ester accumulus produced by the administration of the hormone.
在大鼠肝脏的溶酶体部分研究了雌性激素对胆固醇油酸酯水解的调节作用。用丙酮溶解的胆固醇[1-¹⁴C]油酸酯底物制剂在pH 5.0条件下测定胆固醇酯水解酶活性。单次注射孕酮后，在3至24小时内酶活性降低。这种作用与溶酶体蛋白质合成速率的变化无关。当添加浓度高于100微摩尔的孕酮时，胆固醇酯的溶酶体水解也以非竞争性方式受到抑制。该酯酶在体内和体外均未对雌二醇产生反应。本文的研究结果表明，大鼠肝脏中胆固醇酯的溶酶体分解可能受到选择性激素调节，孕酮对酶活性的抑制作用可能至少部分地导致了该激素给药后肝脏胆固醇酯的积累。
