摘要
本实验采用放射自显影技术与细胞电生理学方法发现：大鼠脊髓腰膨大部含有较高密度能与（１２５）Ⅰ－胰高血糖素发生特异性结合的受体，其在脊髓内的分布以脊髓背角尤其是背角边缘区和胶质区的受体含量最为丰富；背髓背角内直接注射胰高血糖素（５～１５μｇ）可明显兴奋脊髓内伤害性反应神经元的细胞放电（１２／２２），而对少数伤害性反应神经元（４／２２）和伤害性抑制性反应神经元的放电活动则产生或加深其抑制作用；而这些对胰高血糖素产生兴奋或抑制反应的神经元亦主要位于脊髓背角，并以背角边缘区和胶质区的细胞数量为多。提示大鼠脊髓内不仅含有胰高血糖素的受体，而且还可能参与了脊髓内多种功能尤其是感觉功能的调节。
In this study,we investigated the autoradiographic distri-bution of glucagon receptors in the lumbar spinal cord and the effects of glucagon on the firing rates of the spinal neurons in the rats. The results showed that the specific ￣(125)Ⅰ-glucagon receptor binding sites were wide -ly distributed in the spinal cord , especially in the superficial layers(Rexed's Laminae Ⅰ-Ⅲ)of the dorsal horn; considerably lower densities of the binding sites were present in the remaining area of the spinal cord; Glucagon(5～15μg),applied into the dorsal surface of the lumbar spinal cord significantly faciliated the firings of the neurons recorded (12/22)which were responses to noxious stimuli to their peripheral recepting field or their sciatic nerves.The histological examination showed that these neurons responsive to glucagon were also mainly located in the dorsal horn, especially in the superficial laminae(Ⅰ-Ⅲ)which were closely consistent with the distribution of glucagon receptors identified by autoradiography.These findings demonstrated that there are specific glucagon receptors in the rat spinal cord,and functionally they may play a role in modulating the sensory function in the spinal cord.
关键词
胰高血糖素
受体
脊髓
放射自显影
细胞放电
glucagon
glucagon receptors
autoradiography
neuron disch arge
spinal cord
