炔诺酮和甲地孕酮对大鼠血浆脂蛋白代谢的影响

The Effects and Mechanism of Norethisterone and Megestrol on Lipoprotein Metabolism in Rats

炔诺酮可明显降低大鼠血浆胆固醇水平,而甲地孕酮则呈现相反结果,可能的机制是:1)炔诺酮明显抑制灌流肝合成分泌HDL及VLDL,虽然它也抑制^(125)Ⅰ-LDL降解,但前者作用大于后者,综合表现为血胆固醇水平的降低;2)甲地孕酮明显促进肝合成分泌HDL及VLDL,抑制HDL降解,致使血胆固醇水平升高。

We studied the rats lipoprotein metabolism treated by norsthistrone on megestrol(2mg/rat/day for 15 days).The results were as follows: Female SD rats treated with norethisrone had lower plasma TC,LDL-C and HDL-C.Rats treated with megestrel showed opposite results.To explain these results,we measuredthe concentration of HDL-C and yLDL-C turnocer by injecting ^(125)I-labeled human-LDLinto rats. The results showed that megestrol could increase the synthesis and or secretion ofHDL-C and VLDL-C from rat liver and decrease the binding and degradation of rat ^(125)I-HDL in rat hepatocytes,while the uptake and degradation of human ^(125)I-LDL was unchan-ged.Norethistrone could inhibit the synthesis and secretion of HDL-C and VLDL-C fromrat liver;it could also inhibit the upake and degradation of LDL,but the former inhilbi-tion was dominant.If Norethistrone and Megestrol were not used continuously,the ch-anged metabolism would teturn to normal.