【摘要】 目的： 观察自然衰老大鼠不同脑区Ｍ 胆碱受体包括Ｍ１ 亚型受体的变化。方法： 采用放射自显影技术显示大鼠脑Ｍ 受体，并用图像分析仪进行灰度分析，以反映Ｍ 受体在不同脑区的相对定量分布。结果： 所得脑切片自显影灰度层次清晰，主要分布在大脑皮质，海马，纹状体等部位，非特异结合灰度很低，图像分析仪分别给出不同脑区的平均灰度值，老年鼠皮质，海马，纹状体部位的灰度显著低于青年鼠，Ｍ 受体分别降低２４８７ ％ ，１４１２ ％ ，１２７６ ％ （ Ｐ＜ ００５） ，Ｍ１ 亚型受体分别降低１５７８ ％ ，８６９ ％ ，１２３６ ％ （ Ｐ＜ ００１） 。结论： 以上３ 个重要脑区Ｍ 胆碱受体密度的改变可能是脑衰老的一个重要机制更多还原

【Abstract】 Objective: To study the change of muscarinic cholinergic receptors and M 1 subtype in brain regions of aged rats.Methods: An autoradiographic technique with 3H-QNB (quinuclidinyl benzilate) and 3H-PZ (pirenzipine) as radioactive probes was used to study the change of M receptor and M 1 subtype receptor density in brain slices.Results: It was found that the specific binding was mainly localized in cerebral cortex,hippocampus and striatum.The mean grey of the specific binding of the above three brain areas of aged rats,with the non specific binding subtracted by using a computerized image analysis system,were significantly lower than that of young rats.The decrease of M receptor density was about 24.87%, 14.12% and 12 76% ( P <0 05) respectively.The decrease of M 1 subtype receptor density was about 15.87%,8.69%, 12.36% ( P <0 05).Conclusion: The density of M receptor and M 1 subtype in cerebral cortex,hippocampus and striatum decreases significantly in aged rats,and this may be an important mechanism in brain aging.更多还原