Atriopeptin stimulation of rectal gland function in Squalus acanthias.
Atriopeptin stimulation of rectal gland function in Squalus acanthias.
复制标题
心房肽刺激角鲨直肠腺功能。
DOI：
10.1152/ajpregu.1985.249.3.r348
复制
发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Epstein,FH
中科院分区：
文献类型：
--
作者：
Solomon,R;Taylor,M;Dorsey,D;Silva,P;Epstein,FH
鲨鱼的直肠腺在细胞外容量的稳态中起着重要的作用。直肠腺功能的调节受激素控制，但体液介质的确切身份尚不清楚。心房肽素在体内刺激直肠腺氯化物分泌。这种上皮转运的刺激伴随着全身和局部血液动力学效应。心房肽素还刺激体外灌注直肠腺的氯化物分泌，这种作用不伴有血液动力学变化。鲨鱼心脏的提取物，而不是肌肉、脑、肾或肠，含有一种热稳定的胰蛋白酶敏感物质，能够在体外刺激直肠腺氯化物分泌。电子显微镜分析显示，心房心肌细胞中有多种神经分泌物样颗粒，而心室心肌细胞中很少见到。通过使用体外灌注的腺体作为生物测定，细胞外体积扩增后获得的血清揭示了扩增前血清中不存在的直肠腺刺激因子的存在。这些结果与心房肽素存在于鲨鱼心肌细胞中并在体积扩张过程中释放的假设一致。心房肽刺激直肠腺氯化物分泌，为细胞外容量的调节提供负反馈机制。
The rectal gland of the shark plays a significant role in the homeostasis of extracellular volume. Regulation of rectal gland function is under hormonal control, but the precise identity of the humoral mediator is unknown. Atriopeptin stimulates rectal gland chloride secretion in vivo. This stimulation of epithelial transport is accompanied by systemic and local hemodynamic effects. Atriopeptin also stimulates chloride secretion by the in vitro perfused rectal gland, an effect that is not accompanied by hemodynamic changes. Extracts of shark heart, but not muscle, brain, kidney, or intestine, contain a heat-stable trypsin-sensitive substance capable of in vitro stimulation of rectal gland chloride secretion. Electron micrographic analysis reveals multiple neurosecretory-like granules in atrial cardiocytes that are only rarely seen in ventricular cardiocytes. By using the in vitro perfused gland as a biologic assay, serum obtained after extracellular volume expansion reveals the presence of a rectal gland stimulatory factor that is not present in serum before expansion. These results are consistent with the hypothesis that atriopeptin is present in shark cardiocytes and is released during volume expansion. The atriopeptin stimulates rectal gland chloride secretion, providing a negative feedback mechanism for the regulation of extracellular volume.