Féraille E, Marsy S, Cheval L, Barlet-Bas C, Khadouri C, Favre H, Doucet A
Laboratoire de Physiologie Cellulaire, Collège de France, Paris.
Am J Physiol. 1992 Jul;263(1 Pt 2):F175-9. doi: 10.1152/ajprenal.1992.263.1.F175.
This study was aimed at identifying the renal sites of the antinatriuretic action of insulin by evaluating whether this hormone may alter the function of Na-K-ATPase in specific nephron segments. For this purpose, possible actions of insulin on the rate of 86Rb uptake were evaluated in vitro on single segments of proximal convoluted tubule (PCT), thick ascending limb, and collecting tubule microdissected from collagenase-treated kidneys of normal rats. Results indicate that physiological concentrations of insulin inhibited by 44% the initial rate of ouabain-sensitive 86Rb uptake in the medullary and cortical thick ascending limb, whereas it increased it by 40% in proximal tubules and by 60% in both cortical and medullary collecting tubules. The kinetics and dose dependence of insulin actions were different in the thick ascending limb, the PCT, and the collecting tubule, with the latter less sensitive but displaying an earlier response to insulin than the PCT and the thick ascending limb.
本研究旨在通过评估胰岛素是否会改变特定肾单位节段中钠钾ATP酶的功能，来确定胰岛素利钠作用的肾脏部位。为此，在体外对从正常大鼠经胶原酶处理的肾脏中显微分离出的近端曲管（PCT）、髓袢升支粗段和集合管的单个节段，评估了胰岛素对86Rb摄取率的可能作用。结果表明，生理浓度的胰岛素使髓质和皮质髓袢升支粗段哇巴因敏感的86Rb摄取初始速率降低了44%，而在近端小管中使其增加了40%，在皮质和髓质集合管中均增加了60%。胰岛素作用的动力学和剂量依赖性在髓袢升支粗段、近端曲管和集合管中有所不同，集合管比近端曲管和髓袢升支粗段对胰岛素的敏感性更低，但反应更早。
