高脂血症、脂质过氧化、抗氧化酶活性与动脉粥样硬化的关系

The relation of hyperlipidemia, lipid peroxidation, anti-oxidative enzyme activity to atherosclerosis

用大剂量胆固醇(1.5g/日)喂家兔60天后停胆固醇30天塑造动脉粥样硬化(AS)模型。观察血胆固醇、过氧化脂(LPO)含量和抗氧化酶活性与AS病变发生发展的关系。发现:血清胆固醇水平随喂胆固醇时间延长而升高,至60天时达高峰,停饲胆固醇,血清胆固醇水平迅速下降,而同样升高的LPO水平不但未降,反而继续升高,明显高于对照的水平。抗氧化酶SOD和GSH-Px活性在LPO升高的早期显示代偿性增高,以后即降低并保持在低于对照的水平。主动脉、肺动脉和冠状动脉均发生程度不等的AS病变,即使在停饲胆固醇一个月后亦可见进行性病变,如大量平滑肌细胞增生和炎细胞浸润,且其病变较前更重。以上结果提示,血中过量的LPO抑制了抗氧化酶活性,可能在AS的发生发展中起重要作用。

Atherosclerotic model of rabbit was established by feeding heavy dosage of cholesterol for 60 days and then withdrew it for 30 days. The relation between cholesterol content, lipld peroxide (LPO), activity of antioxidative enzyme and the evolution of ath- erosclerotic lesions was observed. It was found that the serum cholesterol level increased with the increased duration of cholesterol feeding and reached a peak at the 60th day, then decreased rapidly after feeding was stopped. However the LPO level didn't fall, in- stead it was increased continuously to a much higher level than that of the control. The anti-oxidative enzymes SOD and GSH-Px showed compensatory increase at the early stage of high LPO level. There after, it was decreased and was kept in lower level than that of the control. There were developed atherosclerotic lesions of various degree in aorta, pulmonary and coronary arteries. Even one month after the stop of cholesterol feeding, progressive changes, such as large amount of smooth muscle cell proliferation and inflam- matory cell infiltration were observed, and the lesions became much more severe than before. These results suggested that the exess of LPO in the serum resulted in inhibition of anti-oxidative enzyine activity Which might play an important role in the initiating and developing of atherosclerosis.