title: Stimulation and suppression of renin release from incubations of rat renal cortex by factors affecting calcium flux.
abstract: Inhibition of renin secretion from incubations of rat kidney cortex by angiotensin II (AII), ouabain and K+ depletion, depended on the presence of external Ca2+. AII inhibition of isoprenaline-stimulated renin secretion was only partially dependent on external Ca2+. Ouabain and K+ depletion inhibited isoprenaline-stimulated renin release but only in the presence of external Ca2+. Since, in Ca2+-free medium, isoprenaline stimulated renin release when the Na+/K+-ATPase was blocked, isoprenaline probably does not act through the Na+/K+-ATPase. Lanthanum blocked the stimulation of renin release by isoprenaline. Ethylenediamine tetra-acetic acid (EDTA) and ethyleneglycol-bis-(beta-amino-ethyl ether) N,N'-tetra-acetic acid (EGTA) increased renin secretion to a similar degree in Ca2+- and Mg2+-free buffer. When Mg2+ was present the effect of EGTA, but not EDTA, was considerably reduced. Verapamil reduced the fall in basal renin secretion in normal but not Ca2+-free buffer. Verapamil did not block the inhibitory effects of AII or ouabain and did not alter the stimulation of renin secretion by isoprenaline. Bay K 8644 inhibited renin secretion from cortex incubated in medium containing 15 mM K+ and this was dependent on extracellular Ca2+. In normal buffer (5.9 mM K+) Bay K 8644 increased renin secretion.
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D004558:Electric Stimulation; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D007672:Kidney Cortex / Q000378:metabolism / Q000502:physiology*; D007811:Lanthanum / Q000494:pharmacology; D008297:Male; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D012083:Renin / Q000378:metabolism*
chemical_list: D002121:Calcium Channel Blockers; D000804:Angiotensin II; D010042:Ouabain; D007811:Lanthanum; D012083:Renin; D007545:Isoproterenol; D011188:Potassium; D002118:Calcium