一氧化氮酶抑制剂对大鼠局灶性脑缺血的保护作用

目的 观察选择性和非选择性一氧化氮合酶抑制剂在大鼠局灶性脑缺血时的作用，为临床应用提供实验依据。方法 直接电凝大鼠大脑中动脉制成脑缺血模型，观察脑缺血后３０、６０、１２０、１８０ｍｉｎ各时点及使用两种一氧化氮合酶抑制剂（ＡＧ、Ｌ－ＮＡＭＥ）后亚硝酸盐含量、测定缺血脑组织坏死体积并用电镜观察损伤海马ＣＡＩ区。结果 脑梗塞体积测定及电镜显示，３０ｍｉｎ时ＡＧ、Ｌ－ＮＡＭＥ治疗组脑损伤程度重于缺陷组，而

Protective effect of nitric oxide synthase inhibitors on local cerebral ischemia

Objective To observe the effect of selective nitric oxide synthase inhibitor (AG) and non selective nitric oxide synthase inhibitor( L NAME) on infarct volume and ultrastructural changes of rat brain after focal cerebral ischemia for different time periods. Methods One hundred and sixty Wistar rats served as subjects. In ischemia groups the middle cerebral arteries (MCA) were blocked, and in control group pseudo operation was made. In AG group and L NAME group, AG or L NAME was given iv 15 min before blockage of MCA. The nitrites contents, infarct volume and ultrastructure of hippocampus CA1 region were examined 30, 60, 120 and 180 min after blockage of MCA. Results In ischemia group as well as AG and L NAME groups the nitrites contents showed tendency of lowering 30 min after blockage, and showed tendency of increasing from 60 min to 180 min after blockage. The pothological and ultrastructural changes 30 min after blockage of MCA in ischemia group were less serious than those in AG and L NAME groups, while these changes in ischemia group 60~ 180 min after blockage of MCA were more serious than those in AG and L NAME groups. Conc1usions It is suggested that nitric oxide synthase inhibitor is harmful in early stage of cerebral ischemia, but it has protective effect in the later stage. The selective nitric oxide synthase inhibitor is more effective than the non selective one.