昆布寡糖对2型糖尿病大鼠睾丸的保护作用

Protective Effect of Thallus Laminariae Oligosaccharide on Testis in Rats with Type 2 Diabetes Mellitus

目的探讨昆布寡糖溶液对2型糖尿病大鼠睾丸的保护作用。方法 SD大鼠60只以高脂饲料联合STZ法进行造模,造模成功大鼠随机分组,试验组大鼠分别灌胃给予昆布寡糖溶液1 000,500,250 mg.kg-1,每天一次,连续8周。采集血液标本检测昆布寡糖溶液对血糖、胰岛素及睾酮含量的影响;睾丸组织匀浆检测昆布寡糖溶液对氧化性损伤指标MDA、SOD和CAT水平的影响;对睾丸病理切片进行HE染色检测昆布寡糖溶液对睾丸组织损伤的修复,免疫组织化学法检测睾丸组织血管内皮生长因子(vascular endothelial growth factor,VEGF)的表达。结果昆布寡糖能够降低2型糖尿病大鼠的血糖,升高胰岛素及睾酮含量;试验组大鼠睾丸MDA含量明显降低(P<0.05),SOD及CAT活力明显上升(P<0.05);HE染色结果显示,昆布寡糖对糖尿病睾丸组织的损伤有一定的修复作用;免疫组织化学结果显示,各试验组VEGF的表达有不同程度的降低。结论昆布寡糖溶液对糖尿病睾丸的损伤起到一定修复作用,能够提高糖尿病睾丸分泌睾酮的能力,其机制可能与抗氧化损伤及VEGF表达的降低有关。

Objective To study the effect of Thallus Laminariae oligosaccharide solution on testis in rats with type-2 diabetes mellitus.Methods Type 2 diabetes mellitus models were induced by feeding with high-fat diet and intraperitoneal injection of streptozotocin in sixty male Sprague-Dawley rats.Rats were divided into groups and treated with Thallus Laminariae oligosaccharide at the concentrations of 1 000,500,250 mg·kg-1 by intragastric administration once a day for continuous 8 weeks.Blood was collected for the examination of blood glucose,serum insulin and testosterone levels.MDA,SOD and CAT levels were detected to evaluate the effect of Thallus Laminariae oligosaccharide solution on oxidative damage of testis tissue.Testis histological sections were stained with hematoxylin and eosin（HE） to examine the reparation of Thallus Laminariae oligosaccharide solution on testis tissue.The expression of vascular endothelial growth factor（VEGF） in testis tissue was detected by immunohistochemical method.Results Significant decrease in blood glucose and significant increase in serum insulin and testosterone were shown in oligosaccharide-treated rats.Significant decrease in MDA and significant increase in SOD and CAT activity were presented in the testis of diabetic rats.The results of HE staining of testis histological sections showed that Thallus Laminariae oligosaccharide solution repaired the damage of testis to some extent.The results of immunohistochemical assay demonstrated that the expression of VEGF in Thallus Laminariae oligosaccharide groups decreased to different degrees compared with that in the negative control group.Conclusion Thallus Laminariae oligosaccharide shows certain reparation of testis tissue and enhances the testosterone secretion in the diabetic rats.The mechanism may be associated with anti-oxidative damage and with the decrease of VEGF expression.