心房内分泌肌细胞的分泌方式及其与神经、毛细血管关系的超微结构研究

THE SECRETING MANNER OF THE ATRIAL MYOENDOCRINE CELLS AND THE RELATIONSHIP BETWEEN THE ATRIAL MYOENDOCRINE CELLS AND THE NERVES AND CAPILLARIES——AN ELECTRON MICROSCOPE STUDY

本研究用透射电镜观察心房内分泌肌细胞在心脏不同容量负荷时的超微结构变化,以及其周围的神经、毛细血管的分布及类型。禁水或不禁水大鼠,在经股静脉注入生理盐水(20ml/kg体重)30～120秒内取右心耳。用鞣酸、戊二醛、锇酸法和戊二醛、锇酸法固定,观察到肌细胞特殊颗粒界膜与肌膜融合、开口和释放的全过程。有不同种类的神经终末存在于肌细胞旁。毛细血管为连续内皮型,与肌细胞关系密切。本实验结果提示,心房内分泌肌细胞主要以胞吐方式分泌心房利尿因子,并为心房利尿因子的转运及与神经支配的生理、生物化学研究提供了形态学资料。

The ultrastructural changes of atrial myoendocrine cells (AMC) in various volume loading for heart, the type and the distribution of nerve endings and capillaries in the vicinity of AMC were observed with electron microscopy. The rats deprived or undeprived water received an injection of isotonic saline via the femoral vein (20 ml/mg), then the right auricle was removed and fixed with usual method for EM and partly with TAGO method. The process of atrial specific granules (ASG) secretion, i. e., the limiting membrane of ASG fused with the sarcolemma and opened at this place, and the ASG content was released through this opening into extracellular space, were observed. There were various types of nerve endings nearby AMC. The capillaries were continuous endothelium in type, and show close relation to AMC. The results of this study suggest that AMC secrete ANF by exocytosis mainly, and provide some morphologic data for the physiological and biochemical studies of ANF move and of reaction on each other between the ANF and nerves.