银杏叶提取物对糖尿病大鼠心肌损伤的防护作用

目的:研究银杏叶提取物(EGb)对糖尿病大鼠心肌的防护作用.方法:用光镜和透射电镜观察EGb对糖尿病大鼠心肌的形态学改变,并测定心肌组织内超氧化物歧化酶(SOD)、一氧化氮合酶(NOS)、结构型一氧化氮合酶(cNOS)、诱导型一氧化氮合酶(iNOS)的活性及一氧化氮(NO)、丙二醛(MDA)的含量.结果:糖尿病大鼠心肌光镜下主要表现为心肌细胞空泡变性及心肌纤维局灶性溶解;电镜下主要表现为心肌线粒体肿胀,嵴变短,肌原纤维溶解;SOD活性下降,NOS、iNOS活性及MDA、NO含量增高.EGb治疗组病变明显减轻,EGb治疗组心肌组织内SOD活性明显高于糖尿病组,NOS、iNOS活性及MDA、NO含量低于糖尿病组.结论:EGb可能通过抗脂质过氧化作用和降低NO水平而对糖尿病心肌产生保护作用.

The beneficial effect of Gingko biloba extract on myocardial impairment in diabetic rats

Aim: To study the protective effect of Gingko biloba extract(EGb) against myocardial impairment in diabetic rats. Methods: Morphology of effect of EGb on myocardium in diabetic rats was observed under light microscopy(LM) and transmission electron microscopy(TEM). Activity of super oxide dismutase(SOD), nitric oxide synthase(NOS), constitutive nitric oxide synthase(cNOS),inductive nitric oxide synthase(iNOS) and content of malondiadehyde(MDA), nitric oxide(NO) were detected biochemically in myocardial homogenate. Results: It was manifestated as vacular degeneration and local lysis of myocardial fiber under LM and swelling of mitochondria, shorten of mitochondrial crest, lysis of myofibril under TEM, the activity of SOD decreased and the activity of NOS, iNOS, the centent of NO, MDA increased, but the morphological changes became slight in EGb treatment group. Activity of SOD increased while activity of NOS, iNOS and content of MDA, NO decreased in EGb treatment group compaired with diabetic group. Conclusion: EGb can protect diabetic myocardium and anti-lipid peroxidation and decrease of NO level may be involved in it.