香菇多糖对糖尿病大鼠脑组织损伤的影响

目的研究香菇多糖(LNT)对糖尿病大鼠脑组织的保护作用。方法SD大鼠分3组：正常对照组、糖尿病组、LNT治疗组。用光镜和透射电镜观察LNT治疗前后糖尿病大鼠脑组织的形态学改变，并测定脑组织内超氧化物歧化酶(SOD)、一氧化氮合酶(NOS)的活性及丙二醛(MDA)、一氧化氮(NO)的含量。结果镜下可见脑水肿、脑软化、白质脱髓鞘；透射电镜下见到神经元及神经胶质细胞内线粒体肿胀、嵴变短、神经纤维脱髓鞘，血脑屏障受损；脑组织内SOD活性下降，NOS活性及MDA、NO含量增高。LNT治疗后病变明显减轻，脑组织内SOD活性明显升高，NOS活性及NO、MDA含量明显下降。结论LNT能清除自由基和降低一氧化氮水平，从而对糖尿病大鼠脑组织起到保护作用。

Effects of Lentinan on Brain Tissues Impairment in Diabetic Rats

Objective To investigate the effects of lentinan (LNT) on lipid peroxidation and NO level in brain tissues of diabetic rats. Methods Twenty nine male Sprague Dawley rats were randomly divided into three groups: normal control group(n=10), diabetic group(n=10) and LNT treatment group(n=9). The morphological changes of brain tissues were examined by light and electron microscopy. The activity of superoxide dismutase(SOD), nitric oxide synthase(NOS) and content of malondialdehyde (MDA), nitric oxide (NO) in the brain tissues were assayed by spectophotometer, respectivly. Results Cerebral edema, encephalomalacia,demyelination in the white matter were observed by histopathology. Swelling and criste loss of mitochondria in neurons and neuroglial cells, demyelination of nerve fibers and vascular endothelial cell damages were seen by electron microscopy. The activities of SOD in diabetic brain tissues was decreased; but the activities of NOS and content of NO increased in comparison with those of control group. After treatment with LNT, the activities of SOD were increased and NOS activity, content of NO and MDA were decreased in comparison with those in diabetic rats. Conclusion LNT possesses effects on prevention of brain tissue damages in diabetic rats by enhancement of anti oxidation activities and reduction of NO level.