title: Possible mechanism of the inhibitory effect of ouabain on renin secretion from rat renal cortical slices.
abstract: 1. The effects of ouabain on renin secretion by rat renal cortical slices were studied. 2. Renin secretion was inhibited by 10(-3) M-ouabain in the presence of free Ca (10(-4) to 2.6 x 10(-3) M). Inhibition was blocked at Ca less than 10(-8) M. 3. The effect of free Ca on ouabain-inhibition was shown to be independent of the presence of EGTA, completely reversible, and unrelated to passive leakage of renin from non-viable cells, as assessed by simultaneous release of lactate dehydrogenase activity (LDH). 4. It is proposed that, as a result of inhibition of Na, K-ATPase by ouabain, (a) intracellular Na increases in the renin-secreting juxtaglomerular cells, (b) intracellular Ca increases, via an Na-Ca exchange mechanism, and (c) that Ca accumulation, in some unknown manner, inhibits renin secretion.
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D066298:In Vitro Techniques; D007672:Kidney Cortex / Q000187:drug effects / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D010042:Ouabain / Q000494:pharmacology*; D051381:Rats; D012083:Renin / Q000378:metabolism*; D012636:Secretory Rate / Q000187:drug effects
chemical_list: D004533:Egtazic Acid; D010042:Ouabain; D007770:L-Lactate Dehydrogenase; D012083:Renin; D002118:Calcium