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Mineralocorticoids stimulate the activity and expression of renal H,K‐ATPases
Author(s) -
Greenlee Megan Michelle,
Lynch I. Jeanette,
Gumz Michelle L.,
Cain Brian D.,
Wingo Charles S.
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.1002.3
Subject(s) - reabsorption , endocrinology , medicine , secretion , chemistry , hypokalemia , atpase , kidney , intracellular , renal sodium reabsorption , metabolic alkalosis , mineralocorticoid , aldosterone , enzyme , biology , biochemistry
Mineralocorticoids such as deoxycorticosterone activate Na + reabsorption and H + secretion in the renal collecting duct. In this study, the effect of deoxycorticosterone pivalate (DOCP) on renal H + ,K + ‐ATPase activity and expression was investigated. Eight days after female wild type (WT) mice received DOCP, collecting ducts were perfused in vitro to measure H + ,K + ‐ATPase‐dependent H + secretion after an acute intracellular acid load. DOCP stimulated H + ,K + ‐ATPase mediated H + secretion in A type intercalated cells of inner cortical collecting ducts by 70% whereas no effect of DOCP was observed in B type intercalated cells compared to control. DOCP dramatically increased HKα 2 mRNA expression in outer and inner medulla (246% and 1040%, respectively) and did not affect HKα 1 mRNA expression. DOCP treatment caused significant body weight gain in WT mice and had little effect on body weight in mice lacking both α subunits (HKα 1,2 −/− ). DOCP caused a similar degree of hypokalemia in WT and HKα 1,2 −/− mice. Importantly, WT developed metabolic alkalosis whereas HKα 1,2 −/− mice did not. In summary, these data clearly demonstrate a physiological role for renal H + ,K + ‐ATPases in mineralocorticoid stimulated H + secretion and suggest a role for these enzymes in Na + reabsorption. Studies were funded by NIH RO1‐DK‐049750 to C.S.W and 5T32DK007518‐22 to M.M.G.