摘要
研究糖尿病小鼠及用记忆增强肽（MEP）保护的糖尿病小鼠脑组织形态学的改变，并比较小鼠海马内脸碱乙酰转移酶（ChTA）神经元的表达。MEP是血管加压责（AVP）4～8的5肽衍生物，是一种促进神经元内源性神经生长因子（NGF）转录的多肽。方法用链脲佐菌素（STZ）制成小鼠糖尿病模型，并皮下注射MEP对糖尿病小鼠进行保护。4周后，小鼠灌注固定，取海马CA1区组织进行光镜和电镜观察，并行冰冻切片，做ChAT免疫组化染色。结果糖尿糖小鼠和用MEP保护的糖尿病小鼠都存在神经组织形态学的损害，但应用MEP保护的糖尿病小鼠脑神经元形态损害比糖尿病小鼠轻。正常小鼠海马内ChAT阳性神经元数目多，染色深，而糖尿病小鼠海马ChAT神经元数目明显减少，用MEP保护可使这种神经元的表达与正常小鼠接近。结论MEP虽只能略微改善糖尿病小鼠神经组织形态学的异常，但它能增加ChAT的表达，从而改善神经元的生化和机能。
Objective To study morphological changes, and compare the expression of choline acetyltransferase in the brain of diabetic mice with and without treatment with memory enhancing peptide. Memory enhancing peptide (MEP) is a 4～8 pentapeptide derivative of vasopressin, which can enhance transcription of endogenous nerve growth factor in neurons. Methods Mouse diabetic model was produced with streptozotocin. MEP as a protective was injected subcutaneouly into diabetic mice. Four weeks later, fixative was injected intravascularly into the brain: semi-thin and ultra-thin sections of tissues from hippocampal CA1 area were observed under light and electron microscopy, and cryostat sections were studied by immunohistochemical staining for choline acetyltransferase. Results Although morphological injury of brain tissue in the form of neuronal pyknosis, membrane depression and dissolution of nuclear chromatin was seen in diabetic mice whether protected or unprotected with MEP, the degree of injury was milder in the protected than in unprotected mice. In the hippocampus of normal mice, numerous neurons showed positive staining for choline acetyltransferase, the cytoplasm stained darkly, and 2～3 level dendritic branches were visible, while in diabetic ndce the positively stained neurons were markedly decreased in comparison with normal mice, and the staining was pale;the use of memory enhancing peptide was able to raise the expression to approach that of normal mice. Conclusion MEP may only slightly improve the neuronal morphological injury of diabetic mice, but was able to enhance the synthesis of choline acetyltransferase, thus upgrading the biochemical function of neurons.
出处
《中国糖尿病杂志》
CAS
CSCD
1999年第6期347-349,共3页
Chinese Journal of Diabetes
关键词
多肽
糖尿病
脑病
胆碱乙酰转移酶
Memory enhancing peptide
Diabetic encephalopathy
ChAT
