Martinez M J, Lacort M, Gandarias J M, Ochoa B
Department of Physiology, University of The Basque Country Medical School, Bilbao/Spain.
Exp Clin Endocrinol. 1990 Apr;95(2):181-91. doi: 10.1055/s-0029-1210950.
The regulation of the enzymatic synthesis and hydrolysis of cholesteryl esters by female sex hormones has been investigated in rat liver. When the effects of estradiol and progesterone were studied in "in vitro" incubations of hepatic microsomes, a dual effect was observed. Progesterone inhibited both microsomal cholesterol ester hydrolase and acyl-CoA: cholesterol acyltransferase activities in a concentration-dependent manner; however, the presence of estradiol stimulated cholesterol ester hydrolysis while it inhibited cholesterol ester formation. The administration of pharmacological doses of estradiol for three consecutive days resulted in decreased cytosolic and microsomal cholesterol esterase activities followed by an increased microsomal cholesteryl esters content whereas acyl-CoA: cholesterol acyltransferase and other microsomal parameters remained unchanged. Examination of the effects of the short-term treatment with pharmacological doses of progesterone showed that treatment was less effective in changing the hepatic pattern of the cholesteryl esters cycle, since only cytosolic cholesterol ester hydrolase activity diminished slightly. Neither cytosolic nor microsomal cholesterol esterase or acyl-CoA: cholesterol acyltransferase were consistently affected by the administration of therapeutical doses of estradiol or progesterone for 21 days, although both the free cholesterol-phospholipid and the total cholesterol-phospholipid molar ratios decreased moderately. The effect of the hormonal vehicle, propylene glycol, on some microsomal lipid parameters is finally discussed.
在大鼠肝脏中研究了雌性激素对胆固醇酯酶促合成及水解的调节作用。当在肝微粒体的“体外”孵育中研究雌二醇和孕酮的作用时，观察到了双重效应。孕酮以浓度依赖的方式抑制微粒体胆固醇酯水解酶和酰基辅酶A：胆固醇酰基转移酶的活性；然而，雌二醇的存在刺激了胆固醇酯的水解，同时抑制了胆固醇酯的形成。连续三天给予药理剂量的雌二醇导致胞质和微粒体胆固醇酯酶活性降低，随后微粒体胆固醇酯含量增加，而酰基辅酶A：胆固醇酰基转移酶和其他微粒体参数保持不变。对药理剂量的孕酮进行短期治疗的效果检查表明，该治疗对改变胆固醇酯循环的肝脏模式效果较差，因为只有胞质胆固醇酯水解酶活性略有降低。连续21天给予治疗剂量的雌二醇或孕酮，胞质和微粒体胆固醇酯酶或酰基辅酶A：胆固醇酰基转移酶均未受到持续影响，尽管游离胆固醇-磷脂和总胆固醇-磷脂摩尔比均适度降低。最后讨论了激素载体丙二醇对一些微粒体脂质参数的影响。
