中文摘要：

目的研究多肽P165对糖尿病模型小鼠学习记忆能力及海马神经元蛋白表达的影响。方法用链脲佐菌素诱发小鼠糖尿病模型，应用P165（0．07，0．17，0．3mg·kg^-1）灌胃治疗，5wk后进行Morris水迷宫试验；小鼠脑组织海马做Akt、P13K、P—CREB、Bcl-2、Bax、Cyto C免疫组织化学染色；另一部分鼠脑海马，做Bcl-2、Bax抗体蛋白免疫印记。结果①水迷宫试验：糖尿病模型小鼠到达站台游动时间比正常对照组延长（P〈0．01）；而P165（0．07，0．17，0．3mg·kg^-1）灌胃治疗组较DM组动物分别缩短（P〈0．01）。②神经免疫组织化学实验及Western blot结果：糖尿病给予P165小鼠与对照组小鼠海马组织内神经元表达细胞存活相关蛋白及抗凋亡相关蛋白P13K、Akt、P—CREB、Bcl-2阳性细胞数相似，明显高于糖尿病小鼠（P〈0．01）；糖尿病给予P165小鼠与对照组小鼠表达凋亡蛋白Bax、Cyto C阳性细胞数相似，明显少于糖尿病小鼠（P〈0．05）。Western blot结果相同。结论糖尿病小鼠海马神经元表达细胞存活相关蛋白下降，神经元表达细胞凋亡相关蛋白增加，导致其学习记忆能力下降。P165应用可以使上述蛋白恢复到接近正常，从而改善糖尿病小鼠学习记忆能力。

英文摘要：

Aim To study the effects of polypeptide P165 on the learning and memorization function and the protein expressions in hippocampal neuron of diabetic mice. Methods The mice diabetic model was induced by streptozotocin （STZ）. Polypeptide 165 （0.07, 0.17, 0.3 mg·kg^-1 ） was administered through a gastric tube every day, whereas the Control and Diabetes Millitus （DM） groups were given the same volume water. The cryostat sections of mice brain were then prepared and immunohistochemically stained using Akt, PI3K, P-CREB, Bcl-2, Bax, CytoC five weeks later subsequent to the water maze test. The hippocampus of mice was insolated to determine protein concentration using Western blot. The protein samples were immunoblotted with antibodies to Bcl-2 and Bax. Results （1） Morris water maze test： relative to mice in the control group, the swimming time to reach the platform was significantly longer in DM （ P 〈 0. 05 ）. The swimming time in the P 165 （0. 07,0. 17,0. 3 mg·kg^-1） groups, was apparently shorter compared to that of the DM group （P〈0.05）. （2） The DM mice with P165 were similar to the control mice in terms of the number of neurons with positive stain of PI3 K, Akt, P- CREB, Bcl-2 for survival related proteins. However, the number of neurons with positive stain was significantly higher in the DM with polypeptide 165 group than that in diabetic mice （P 〈0.01 ）. The number of neurons with positive stain using Bax and CytoC for ap- optosis related proteins was significantly lower in the DM with polypeptide 165 group than that in diabetic mice （P 〈 0. 05）. The results of Western blot were the same as the Immunohistochemical results. Conclusions Compared to control group, the expressions of survival related proteins in hippocampal neurons among DM mice decreased but that of apoptosis related proteins increased. They led to the deterioration of the learning and memory function of DM mice. P165 treatment for DM mice could help recover the expressions of protein in hippocamp