目的:研究淫羊藿苷对糖尿病大鼠睾丸病变的改善,并初步讨论其可能的作用机制.方法:采用链脲佐菌素(40 mg·kg-1)尾静脉注射建立糖尿病大鼠模型.实验分为3组:正常组、模型组和淫羊藿苷组.淫羊藿苷组给予淫羊藿苷溶液80 mg·kg-1·d-1灌胃.12周末处死各组大鼠,测血清葡萄糖和睾酮含量,睾丸组织中特异性酶琥珀酸脱氢酶(SDH)、酸性磷酸酶(ACP)、γ-谷氨酰转肽酶(γ-GT)及乳酸脱氢酶(LDH)活性;HE染色,置光镜下观察睾丸组织病理变化;免疫组化法测定转化生长因子β1 (TGF-β1)和Ⅳ型胶原蛋白酶的表达.结果:与正常对照组比较,模型组血清葡萄糖水平上升和睾酮水平下降;睾丸组织特异性酶活性降低;病理学检测可见生精上皮层变薄,各级生精细胞减少;TGF-β1和Ⅳ型胶原蛋白酶表达增加.淫羊藿苷组明显改善上述指标(P<0.01).结论:淫羊藿苷对糖尿病所致的睾丸损伤有明显的保护作用,其机制可能与促进睾酮释放、抑制睾丸Ⅳ型胶原蛋白酶及TGF-β1表达有关.%AIM: To determine the beneficial effects of icariin on streptozotocin ( STZ ) - induced diabetic testopathy in rats.METHODS: The diabetic animal model was induced in male Sprague - Dawley rats by an injection of streptozotocin ( 40 mg/kg, iv ).The rats were randomly divided into 3 groups: control group, model group and icariin ( 80 mg/kg, ig) group.Twelve weeks after injected with streptozotocin, all rats were anaesthetized and killed to remove the testes from scrotum.Serum concentrations of glucose and testosterone, and the levels of succinate dehydrogenase ( SDH ), acid phosphatase ( ACP ), γ - glutamyl transpeptidase ( γ - GT ) and lactate dehydrogenase ( LDH ) in testes were measured.The morphology of the testicular tissues was observed under light microscope.Immunohistochemistry was employed to determine the protein levels of TGF - β1 and type Ⅳ collagen.RESULTS: Compared with control group, the content of serum glucose increased while the serum level of testosterone and the activitiy of SDH, ACP, γ - GT and LDH in testis decreased in model group ( P ＜ 0.01 ).The histopathological examination showed that the diameters of seminiferous tubules and various grades of spermatocytes in the testis were markedly decreased.Compared with control group, the expression of TGF - β, and collagen Ⅳ was significantly increased in model group.These alterations were significantly attenuated in icariin group ( P ＜0.01 ).CONCLUSION: Icariin evidently relieves testicular damage in rats with diabetic testopathy by improving the secretion of testosterone and reducing the expression of TGF - β1 and collagen Ⅳ at protein level.
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