高血压与高胆固醇血症对颅内动脉硬化形成的影响

目的:探讨高血压和高胆固醇血症单独或协同对颅内动脉退变的影响。方法:以雄性家兔为实验对象,分成4组:正常对照组(N组)、单纯高血压组(HT组)、单纯高胆固醇血症组(CH组)和高血压加高胆固醇血症组(HT CH组)。每日饲喂胆固醇造成高胆固醇血症,用双肾动脉狭窄法制成肾性高血压。实验结束后,兔脑标本全部HE染色,部分标本Masson、PTH和苏丹IV染色。另有部分标本进行电镜检查。结果:N组和CH组颅内脑实质内、外动脉未见明显异常。HT组光镜下可见脑实质内、外小动脉肌层增厚、血管收缩及透明变性。电镜下平滑肌细胞被激活,内皮细胞分泌物较多。在HT CH组,3只兔脑实质外较大动脉出现动脉粥样硬化病变。脑实质内、外小动脉病变与单纯高血压组所见相同。结论:单纯高血压可导致颅内小动脉发生动脉硬化;高血压和高胆固醇血症共同作用可导致脑实质外较大动脉发生动脉粥样硬化;而单纯高胆固醇血症不易造成颅内动脉退变。

Experimental Study on the Effects of Hypertension and Hypercholesterolemia on Cerebral Arteriosclerosis

Objective: To study the effects of hypertension and hypercholesterolemia,respectively or cooperatively,on disintegration of intracranial arteries. Methods: The domestic male rabbits were used as the experimental animals. They were divided into four groups including normal control group(N group,4 rabbits),hypertension group(HT group,4 rabbits),hypercholesterolemia group(CH group,10 rabbits)and hypertension plus hypercholesterolemia group(HT CH group,13 rabbits). Hypercholesterolemia was made by feeding 1 gram pure cholesterol every day. Hypertension was created by clipping the bilateral renal arteries. All samples of the brains were stained by HE. Some of them were stained by Masson,PTH and Sudan, and some were studied by electron microscope. Results: The evident abnormalities were not seen on the intra-and extra-parenchymal arteries in the cranium in the N group and the CH group. Thickening, contraction and hyaline degeneration could be seen on the small intra-and extra-parenchymal arteries in the HT group by microscope. The activated smooth muscle cells were found and there were more secretions by endothelium. Atherosclerotic lesions were found on a bit bigger arteries in the extra-parenchyma in 3 rabbits out of 13 rabbits in the HT CH group. The lesions of the small intra-and extra-parenchymal arteries were same as those seen in the HT group. Conclusion: Arteriosclerosis can be made by pure hypertension on the small arteries in the cranium. Atherosclerosis on a bit bigger arteries of the extra-parenchyma can be induced by both hypertension and hypercholesterolemia cooperatively. It is not easy for the disintegration of intracranial arteries to be induced by pure hypercholesterolemia .