四氧嘧啶性糖尿病大鼠体内高密度脂蛋白和胆固醇的代谢

四氧嘧啶性糖尿病大鼠,血清总胆固醇(TC)、胆固醇酯(CE)、高密度脂蛋白-胆固醇(HDL-C)和低密度脂蛋白-胆固醇(LDL-C)较对照均显著上升,但极低密度脂蛋白-胆固醇(VLDL-C)和HDL-C/LDL-C则没有差别。影响血清高密度脂蛋白(HDL)水平的几个因素测定结果为脂蛋白脂酶(LPL)和肝内皮细胞脂酶(HEL)及肝细胞对~(125)I-HDL的吸收和分解能力显著低于对照;卵磷脂胆固醇酰基转移酶(LCAT)活性和肝灌流液中HDL-C水平显著上升。 可见糖尿病大鼠由于体内胰岛素绝对缺乏可通过以下几个方面影响HDL和胆固醇代谢:降低肝细胞对HDL的吸收和分解;促进肝脏分泌HDL;抑制HEL和LPL的活性;升高LCAT活性;升高血清TC、CE、HDL-C和LDL-C水平,而对VLDL-C及HDD-C/LDL-C没有影响。

METABOLISM OF HIGH DENSITY LIPOPROTEIN AND CHOLESTEROL IN ALLOXAN DIABETIC RATS

Serum levels of total cholesterol (TC), cholesterol ester (CE), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LPL-C) were all significantly higher in allozan diabetic rats than in the controls (p<0.05, p<0.05, p<0.02, p<0.05 respectively). Very low density lipoprotein cholesterol (VLDL-0) and the ratio of HDL-O/LDL-C were similar in the 2 groups. Factors which influence the serum level of HDL in alloxan diabetic rats were studied in the following parameters:Lipoprotein lipase (LPL) and hepatic endothelial lipase (HEL) activities, both were lower than the controls (in both p<0.001) Ability of liver cells to uptake and degradet 135I-HDL, were both lower than that of controls (p<0.02, p<0.05 respectively) .Serum lecithin-cholesterol acyltransferase (LCAT) activity and the HDL-C level in liver perfusate were significantly increased over the controls (p<0.02, p <0.02 respectively).