载脂蛋白A-Ⅰ在形成实验性高脂血症最初阶段时的作用

The role of apolipoprotein A I in the very early stage of experimental hyperlipidemia

目的探讨高胆固醇血症兔模型在血脂升高的最初阶段，血清中血脂水平的变化与合成新生ａｐｏＡⅠ主要部位的关系。方法两组实验，共用家兔３５只，在实验前和实验第１、２、４、７周末检测血清总胆固醇（ＴＣ），游离胆固醇（ＦＣ），高密度脂蛋白胆固醇（ＨＤＬＣ），主动脉内壁脂质沉积以及小肠和肝脏ａｐｏＡⅠｍＲＮＡ的变化。结果饲养１周后兔血清中ＴＣ和ＦＣ增高，卵磷脂胆固醇乙酰转移酶（ＬＣＡＴ）活性在２周后显著增高，ＨＤＬＣ在第１周内增高，至第７周末出现显著降低。小肠中ａｐｏＡⅠｍＲＮＡ第１周显著增高，肝中ａｐｏＡⅠｍＲＮＡ早期无明显变化。结论在家兔高脂血症最初阶段。

Objective To find out the change of serum total cholesterol, HDL cholesterol, LCAT activity, and the expression of apoA I mRNA in liver and intestine in the very early stage of experimental hyperlipidemia of rabbits. Methods Experimental hyperlipidemia models were established by cholesterol feeding in NZW rabbits. Animals of the experimental groups were sacrificed by the end of the 1st, 2nd, 4th and 7th week respectively. Serum total cholesterol (TC), free cholesterol (FC), LCAT activity, HDL were assayed. Slot blot were used to analyze the expression of apoA I mRNA in liver and intestine. Results TC and FC were noticed to be elevated at the end of the 1st week after cholesterol feeding. The increase of LCAT activity was proportional to the levels of serum lipid. Serum HDL C level did not drop down by the 7th week of cholesterol feeding. Analysis of lipid infiltration area in aorta of the experimental group rabbits showed apparent lipid disposition in intima since the 4th week of cholesterol feeding. Slot blot results showed that apoA I mRNA level increased at the end of the 1st week in the small intestine. The expression in liver was much weaker than in intestine. Conclusion In the very early stage of experimental hyperlipidemia, serum TC, FC, LCAT activity increase remarkably and apoA I, mainly produced in the small intestine, plays an important role in activating LCAT.