Am J Physiol Renal Physiol
November 2003
In rat outer medullary collecting duct (OMCD), the mechanism(s) and regulation of H+ secretion are not understood fully. The effect of changes in acid-base balance and the renin-angiotensin system on net H+ secretion was explored. Rats received NaCl, NaHCO3, NH4Cl, or nothing in their drinking water for 7 days.
View Article and Find Full Text PDFIn rat kidney, the "secretory" isoform of the Na-K-Cl cotransporter, NKCC1 (BSC-2), localizes to the basolateral membrane of the alpha intercalated cell, the acid secreting cell of the outer medullary collecting duct (OMCD). This laboratory has reported that NKCC1 mediates Cl(-) uptake across the basolateral membrane in series with Cl(-) secretion across the apical membrane in rat OMCD. NKCC1 transports NH(4)(+), K(+), and Na(+) as well as Cl(-); therefore, a role for the cotransporter in the process of HCl, NH(4)Cl, KCl, and NaCl secretion has been suggested.
View Article and Find Full Text PDFAm J Physiol Renal Physiol
January 2002
In rat terminal inner medullary collecting duct (tIMCD), the Na,K-ATPase mediates NH uptake, which increases secretion of net H(+) equivalents. K(+) and NH compete for a common binding site on the Na,K-ATPase. Therefore, NH uptake should increase during hypokalemia because interstitial K(+) concentration is reduced.
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