丝胶干预2型糖尿病大鼠海马及大脑皮质血红素加氧酶1的表达

目的：探讨丝胶对2型大鼠海马及大脑皮质血红素加氧酶1（HO-1）表达的影响。方法：30只雄性SD大鼠随机分为3组，正常对照组、糖尿病模型组和丝胶治疗组，每组10只。糖尿病模型组和丝胶治疗组大鼠均采用链脲佐菌素连续腹腔注射建立2型糖尿病大鼠模型，以血糖≥16.7mmol/L作为成模标准。待模型成功建立后，模型组大鼠不再作任何处理，丝胶治疗组大鼠给予丝胶（2.4g/kg/d）灌胃35天。HE染色观察海马和大脑皮质的形态变化；分别采用Western Blotting和RT-PCR法检测海马和大脑皮质HO-1蛋白及mRNA的表达。结果：糖尿病模型组大鼠海马及大脑皮质的神经细胞均出现明显的病理变化，HO-1蛋白及mRNA的表达明显高于正常对照组大鼠（P＜0.01）。丝胶治疗组大鼠海马、大脑皮质神经细胞的病理变化明显减轻，HO-1蛋白及mRNA的表达明显低于模型组大鼠（P＜0.01，P＜0.05）。结论：丝胶可通过下调海马及大脑皮质HO-1的表达，减轻糖尿病时HO-1高表达对海马及大脑皮质神经细胞的毒性损害，发挥对糖尿病神经系统损伤的保护作用。

Effects of sericin on heme oxygenase-1 expression in the hippocampus and cerebral cortex of type 2 diabetes mellitus rats

Previous studies have demonstrated that sericin effectively reduces blood glucose, and protects islet cells, as well as the gonads and kidneys. However, whether sericin improves diabetes mellitus-induced structural and functional problems in the central nervous system remains poorly understood. Rat models of type 2 diabetes mellitus were established by intraperitoneal injection of streptozotocin. The present study observed histological changes in the hippocampus and cerebral cortex, as well as heme oxygenase-1 expression, and explored sericin effects on the central nervous system in diabetic rats. Pathological damage to neural cells in the rat hippocampus and cerebral cortex was relieved following intragastric administration of sericin at a dose of 2.4 g/kg for 35 consecutive days. Heme oxygenase-1 protein and mRNA expressions were decreased in the hippocampus and cerebral cortex of diabetes mellitus rats after sericin treatment. The results suggest that sericin plays a protective effect on the nervous system by decreasing the high expression of heme oxygenase-1 following diabetes mellitus.