Contribution of the Na+-K+-2Cl- cotransporter NKCC1 to Cl- secretion in rat OMCD.

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Wall SM, Fischer MP, Mehta P, Hassell KA, Park SJ

Contribution of the Na+-K+-2Cl- cotransporter NKCC1 to Cl- secretion in rat OMCD.

Am J Physiol Renal Physiol. 2001 May;280(5):F913-21.

PubMed ID

11292635 [ View in PubMed

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Abstract

In rat kidney the "secretory" isoform of the Na+-K+-2Cl- cotransporter (NKCC1) localizes to the basolateral membrane of the alpha-intercalated cell. The purpose of this study was to determine whether rat outer medullary collecting duct (OMCD) secretes Cl- and whether transepithelial Cl- transport occurs, in part, through Cl- uptake across the basolateral membrane mediated by NKCC1 in series with Cl- efflux across the apical membrane. OMCD tubules from rats treated with deoxycorticosterone pivalate were perfused in vitro in symmetrical HCO/CO2-buffered solutions. Cl- secretion was observed in this segment, accompanied by a lumen positive transepithelial potential. Bumetanide (100 microM), when added to the bath, reduced Cl- secretion by 78%, although the lumen positive transepithelial potential and fluid flux were unchanged. Bumetanide-sensitive Cl- secretion was dependent on extracellular Na+ and either K+ or NH, consistent with the ion dependency of NKCC1-mediated Cl- transport. In conclusion, OMCD tubules from deoxycorticosterone pivalate-treated rats secrete Cl- into the luminal fluid through NKCC1-mediated Cl- uptake across the basolateral membrane in series with Cl- efflux across the apical membrane. The physiological role of NKCC1-mediated Cl- uptake remains to be determined. However, the role of NKCC1 in the process of fluid secretion could not be demonstrated.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Bumetanide	Solute carrier family 12 member 2	Protein	Humans	Yes	Inhibitor	Details