Control of Sodium and Potassium Transport in the Cortical Collecting Duct of the Rat
نویسنده
چکیده
Several factors interact to maintain precise control of electrolyte transport in the mammalian cortical collecting duct. We have studied the effects of deoxycorticosterone, arginine vasopressin, and bradykinin on net transepithelial sodium and potassium transport in isolated, perfused rat cortical collecting ducts. Chronic administration of deoxycorticosterone to rats increased both sodium absorption and potassium secretion above very low basal levels. Consequently, deoxycorticosterone-treated rats were used for all remaining studies. Arginine vasopressin (10-10 M in the bath) caused a sustained fourfold increase in net sodium absorption and a sustained threefold increase in net potassium secretion. Bradykinin (10-9 M in the bath) caused a reversible 40-50% inhibition of net sodium absorption without affecting net potassium transport or the transepithelial potential difference. In the perfusate, up to 10-6 M bradykinin had no effect. We conclude: (a) As in rabbits, chronic deoxycorticosterone administration to rats increases sodium absorption and potassium secretion in cortical collecting ducts perfused in vitro. (b) Arginine vasopressin causes a reversible increase in net potassium secretion and net sodium absorption. (c) Bradykinin in the peritubular bathing solution reversibly inhibits net sodium absorption, possibly by affecting an electroneutral sodium transport pathway.
منابع مشابه
Control of sodium and potassium transport in the cortical collecting duct of the rat. Effects of bradykinin, vasopressin, and deoxycorticosterone.
Several factors interact to maintain precise control of electrolyte transport in the mammalian cortical collecting duct. We have studied the effects of deoxycorticosterone, arginine vasopressin, and bradykinin on net transepithelial sodium and potassium transport in isolated, perfused rat cortical collecting ducts. Chronic administration of deoxycorticosterone to rats increased both sodium abso...
متن کاملEffects of vasopressin and bradykinin on anion transport by the rat cortical collecting duct. Evidence for an electroneutral sodium chloride transport pathway.
Our previous studies in cortical collecting ducts isolated from rat kidneys have shown that vasopressin increases both sodium absorption and potassium secretion, while bradykinin inhibits sodium absorption without affecting potassium transport. To determine which anions are affected by these agents, we perfused cortical collecting ducts from rats treated with deoxycorticosterone and measured ne...
متن کاملQuantitative estimation of transmembrane ion transport in rat renal collecting duct principal cells.
Kidney collecting duct principal cells play a key role in regulated tubular reabsorption of water and sodium and secretion of potassium. The importance of this function for the maintenance of the osmotic homeostasis of the whole organism motivates extensive study of the ion transport properties of collecting duct principal cells. We performed experimental measurements of cell volume and intrace...
متن کاملSome reflections on the mechanism of renal tubular potassium transport.
Analysis of the driving forces acting on the movement of potassium across individual membranes of tubule cells shows that both active and passive components play an important role in the regulation of potassium transport. Distal and cortical collecting tubule and papillary collecting duct elements are the key nephron sites participating in a complex fashion to translate a wide variety of metabo...
متن کاملAngiotensin I conversion to angiotensin II stimulates cortical collecting duct sodium transport.
Angiotensin (Ang) II directly stimulates epithelial sodium channel activity in the rabbit cortical collecting duct. Because Ang I and converting enzyme analogues might be present in the distal nephron, this raises the possibility of intraluminal generation of Ang II. Conversion of Ang I to Ang II was monitored by Ang II-dependent changes in intracellular sodium concentration as a reflection of ...
متن کامل