香菇多糖对糖尿病大鼠心肌损伤影响的实验研究

Effect of lentinan on myocardial impairment in diabetic rats

目的 :研究香菇多糖 (LNT)对糖尿病大鼠心肌的保护作用。方法 :用光镜和透射电镜观察LNT对链脲佐菌素诱导的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)的活性及一氧化氮 (NO)、丙二醛 (MDA)的含量。结果 :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 ,心肌间质纤维增生 ;电镜下主要表现为心肌线粒体扩张 ,嵴变短 ,肌原纤维溶解 ,间质胶原纤维增生 ,SOD活性下降 ,NOS活性及MDA、NO含量增高。LNT治疗组心肌纤维损伤及间质纤维增生明显减轻 ,心肌组织内SOD活性LNT治疗组明显高于糖尿病组 ,NOS活性及MDA、NO含量LNT治疗组低于糖尿病组。结论 :LNT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。

AIM: To study the protective effect of lentinan against myocardial impairment in diabetic rats. METHODS: Morphology of myocardium from streptozocin induced diabetic rats treated with lentinan was observed under light microscopy(LM) and transmission electron microscopy(TEM). Activity of superoxide dismutase(SOD), nitric oxide synthase (NOS) and contents of malondialdehyde (MDA) and nitric oxide (NO) were detected biochemically in myocardial homogenate. RESULTS: Vacuolar degeneration, local lysis of myocardium and interstitial proliferation under LM and expansion of mitochondria, shortening of mitochondrial crest, lysis of myofibril and proliferation of interstitial collogenous fiber under TEM were observed. The activity of SOD decreased and the activity of NOS, the contents of NO, MDA increased, but the morphological change became slight in LNT-treatment group. Activity of SOD increased while activity of NOS and contents of MDA, NO decreased in LNT-treated rats compared with diabetic rats. CONCLUSION: LNT protectes diabetic myocardium, and the anti-lipid peroxidation and decreasing of NO level may be involved in it.