Sites of hormone action in the mammalian nephron.
Sites of hormone action in the mammalian nephron.
复制标题
哺乳动物肾单位中激素作用的部位。
作者：
F. Morel
结合胶原酶处理的兔肾脏的显微解剖和单管酶微量测定法，分别测定了不同肾单位部分激素依赖性腺苷环化酶的活性。给出并讨论了加压素、甲状旁腺激素、降钙素和异丙肾上腺素在兔体内的实验结果。每种激素都以高度特异和可重复性的方式刺激几个定位良好的小管段的腺苷环化酶活性。反应性和非反应性肾单位之间的急剧转变通常被注意到。在大鼠肾脏中，远端曲管的功能分段不像在兔肾脏中那样清晰。观察到大鼠肾脏的不同肾单位段含有对胰高血糖素敏感的腺苷环化酶活性。当在兔、大鼠、小鼠和人类肾脏中比较后叶加压素的结果时，在Henle‘s环的粗大升支的髓质部分对精氨酸后叶加压素的反应性存在物种差异。因此，生化方法可以用来研究非常接近细胞水平的肾脏生理学问题。
Hormone-dependent adenylate cyclase activity was measured separately in the different nephron portions by combining the microdissection of collagenase-treated rabbit kidneys and the use of a single tubule enzyme microassay. The results obtained in the rabbit for vasopressin, parathyroid hormone, calcitonin, and isoproterenol are given and discussed. Each hormone stimulated adenylate cyclase activity in several well-localized segments of tubule according to a highly specific and reproducible pattern. Sharp transitions were generally noted between responsive and unresponsive nephron portions. In the rat kidney, the functional segmentation of the distal convoluted tubule was not as clearly delineated as in the rabbit kidney. Various nephron segments of the rat kidney were observed to contain glucagon-sensitive adenylate cyclase activity. When the results obtained for vasopressin are compared in rabbit, rat, mouse, and human kidneys, species differences are noted with respect to the responsiveness to arginine vasopressin in the medullary portion of thick ascending limbs of Henle's loops. It is concluded that biochemical approaches can be used as a means of investigating problems dealing with kidney physiology very near the cell level.