Arginine vasopressin stimulates H+-ATPase in MDCK cells via V1 (cell Ca2+) and V2 (cAMP) receptors.
The effect of arginine vasopressin (AVP) and/or atrial natriuretic peptide (ANP) on the regulation of intracellular pH (pHi) via H+-ATPase and of cytosolic calcium ([Ca2+]i) was investigated in Madin-Darby canine kidney (MDCK) cells by the fluorescent probes BCECF-AM and fluo-4-AM, respectively. The pHi recovery rate was examined after intracellular acidification following an NH4Cl pulse, in the presence of zero Na+ plus Schering 28080 (a specific inhibitor of H+-K+-ATPase). AVP (10-12-10-6 M) increased the rate of pHi recovery and [Ca2+]i in a dose-dependent manner. V1- or V2-receptor antagonists impaired the effect of AVP on both processes, and DDAVP (10-12-10-6 M; a V2-selective agonist) caused a dose-dependent stimulation of them. [Ca2+]i or cAMP (as increased by 10-5 M thapsigargin or 8-BrcAMP, respectively) alone had no effect on H+-ATPase, but their synergic action was necessary to stimulate H+-ATPase. In agreement with these findings, ANP (10-6 M) or dimethyl-BAPTA-AM (5 x 10-5 M), impairing the increase of [Ca2+]i in response to AVP, blocks the stimulatory effect of AVP on H+-ATPase.
Oliveira-Souza
Maria
M
Department of Physiology and Biophysics, Instituto de Ciências Biomédicas, Univ. of São Paulo, SP 05508-900, Brazil.
Musa-Aziz
Raif
R
Malnic
Gerhard
G
De Mello Aires
Margarida
M
D000143:Acids / Q000378:metabolism; D000818:Animals; D065092:Antidiuretic Hormone Receptor Antagonists; D001127:Arginine Vasopressin / Q000494:pharmacology*; D009320:Atrial Natriuretic Factor / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D002614:Chelating Agents / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D003894:Deamino Arginine Vasopressin / Q000494:pharmacology; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007668:Kidney / Q000166:cytology / Q000201:enzymology*; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D011522:Protons; D017483:Receptors, Vasopressin / Q000819:agonists / Q000378:metabolism*; D012076:Renal Agents / Q000494:pharmacology*
D000143:Acids; D065092:Antidiuretic Hormone Receptor Antagonists; D002614:Chelating Agents; D011522:Protons; D017483:Receptors, Vasopressin; D012076:Renal Agents; D001127:Arginine Vasopressin; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D004533:Egtazic Acid; D009320:Atrial Natriuretic Factor; D000242:Cyclic AMP; D006180:Proton-Translocating ATPases; D003894:Deamino Arginine Vasopressin; D002118:Calcium