丁丙诺啡对小鼠中脑导水管周围灰质Ca~(2)分布的影响:电镜及电子探针研究

用透射电镜及电子探针X-射线显微分析法研究了丁丙诺啡(Buprenorphine,BN)引起镇痛期间小鼠中脑导水管周围灰质区钙离子分布的改变.按照改进的Komnick方法,脑组织用含有2％焦锑酸钾的1％锇酸固定.实验结果表明,动物经腹腔注射BN(0.8mg/kg)30分钟后,在髓鞘、轴突、线粒体和细胞核中均可见到电子致密的沉淀颗粒,尤其在髓鞘的环状片层中形成大量的、密集的颗粒状沉淀.电子探针X-射线显微分析证实髓鞘中的沉淀颗粒含有元素钙,提示BN镇痛时髓鞘结合大量的钙离子,并且可能经过髓鞘的转运,钙离子进入轴突,贮存于线粒体中.本文讨论了在中枢神经系统中的钙离子转运的可能途径.

THE EFFECTS OF BUPRENORPHINT ON THE ULTRASTRUCTURAL DISTRIBUTION OF CALCIUM IONS IN THE PERIAQUEDUCTAL GRAY OF MICE: A STUDY WITH ELECTRON MICROSCOPY AND ELECTRON PROBE X-RAY MICROANALYSIS

The change of the distribution of calcium in periaqueductal gray of the mice was studied by the use of clccton microscopy and electron probe X-ray microanalysis during buprenorphinc induced analgesia. The brain tissue was fixed in the 1 % OsO_4 solution containing 2% potassium pyroantimonate according to the improved komnick's method. The experimental results indicated that large amount of dense precipitates occured consistently and reproducibly at the myelin sheaths, in the axons, mitochondria, and nuclei of neurons 30 minutes after intraperitoncal injection of BN (0.8mg/kg). Electron probe X-ray microanalysis showed the presence of Ca in the precipitates at the myelin sheaths, indicating that the precipitates may serve as measures of Ca localization and the myelin sheaths can combine calcium a lot of ions during the druginduced analgesia. The paper has discussed the possible transport pathway of calcium ions in CNS.