Contribution of the Na+-K+-2Cl- cotransporter NKCC1 to Cl- secretion in rat OMCD
| Autor: | Stanley J. Park, Pramod Mehta, Susan M. Wall, Kathryn A. Hassell, Michael P. Fischer |
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| Rok vydání: | 2001 |
| Předmět: |
Gene isoform
Male medicine.medical_specialty Physiology Sodium Cell chemistry.chemical_element 4 4'-Diisothiocyanostilbene-2 2'-Disulfonic Acid Rats Sprague-Dawley Chlorides Internal medicine medicine Renal medulla Animals Kidney Tubules Collecting Diuretics Bumetanide Cells Cultured Epithelial polarity Kidney Kidney Medulla Hydrogen-Ion Concentration Molecular biology Rats medicine.anatomical_structure Endocrinology chemistry Cotransporter Algorithms medicine.drug |
| Zdroj: | American journal of physiology. Renal physiology. 280(5) |
| ISSN: | 1931-857X |
| Popis: | In rat kidney the “secretory” isoform of the Na+-K+-2Cl−cotransporter (NKCC1) localizes to the basolateral membrane of the α-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[Formula: see text]/CO2-buffered solutions. Cl−secretion was observed in this segment, accompanied by a lumen positive transepithelial potential. Bumetanide (100 μM), 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[Formula: see text], 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. |
| Databáze: | OpenAIRE |
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