Objective To observe the effect of captopril and losartan on free radical and nitric oxide (NO) and nitric oxide synthase NOS) change after cerebral ischemia in rats and analyze the mechanisms of captopril and losartan anti-cerebral ischemia action. Methods SD rats were randomly divided into sham-operated, untreated, captopril-treated and losartan-treated groups. The animal models were produced by permanent occlusion in two times operation at 3 days interval of bilateral common carotid arteries of rats. Captopril and losartan were fed to the captopril-treated and losartan-treated groups rats for 4 weeks. Ability of learning and memory of the rats were tested by Morris water maze. Changes of the activity of superoxide dismutase (SOD) and NOS, the content of malondialdehyde (MDA) and NO in cortex and hippocampus were observed by means of spectro-photometry. Results Captopril and losartan could enhanced SOD activities, reduced the MDA content, captopril and losartan reduced the contents of NO and the activities of NOS. Conclusions Captopril and losartan can improve the ability of learning and memory of the rats with vascular dementia, which may be mediated by its anti-free radical and reducing the contents of NO and the activities of NOS.%目的 观察卡托普利和氯沙坦对血管性痴呆(VD)模型大鼠超氧化物歧化酶(SOD),丙二醛(MDA),一氧化氮(NO)及一氧化氮合酶(NOS)的影响,分析卡托普利和氯沙坦抗脑缺血损伤的作用机制.方法 采用不同时间点分别结扎左、右颈总动脉建立大鼠血管性痴呆模型,用卡托普利和氯沙坦灌胃给药4 w观察学习记忆能力后,测定脑组织SOD活性、MDA、NO含量及NOS活力的变化.结果 卡托普利组和氯沙坦组均可拮抗脑缺血引起的脑组织SOD活性的下降及MDA含量的升高,能明显抑制脑组织NOS活性及NO的含量.结论 卡托普利及氯沙坦均可通过增加氧自由基的清除,影响NOS的活性及NO的含量改善VD模型大鼠学习记忆能力.
展开▼
