Calcium in the control of renin secretion: Ca2+ influx as an inhibitory signal.
The mechanism for the inhibition of renin secretion in vitro from renal cortical slices by angiotensin II, antidiuretic hormone, ouabain, and high K+ concentration was studied. The inhibitory effect of these agents was blocked by a Ca antagonist, verapamil. In addition, epinephrine stimulated renin secretion and its stimulatory action was blocked by ouabain. These results support the hypothesis that Ca2+ influx into juxtaglomerular cells plays a role as an inhibitory signal whereas Ca2+ efflux is a stimulatory signal for renin secretion. Renin secretion was greatly stimulated by lowering incubation temperature, indicating that renin secretion is not energy dependent. The possibility is discussed that Ca2+ of juxtaglomerular cells might activate an enzyme(s) that then modulates some sequential steps of renin secretory processes, thereby controlling the rate of renin secretion.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004285:Dogs; D004837:Epinephrine / Q000494:pharmacology; D007672:Kidney Cortex / Q000187:drug effects; D010042:Ouabain / Q000494:pharmacology; D012083:Renin / Q000378:metabolism*; D013552:Swine; D013696:Temperature; D014700:Verapamil / Q000494:pharmacology
D010042:Ouabain; D014700:Verapamil; D012083:Renin; D002118:Calcium; D004837:Epinephrine