Secretion control for active and inactive renin: interactions with calcium and sodium ions.
Excitation-secretion coupling for active and inactive renin was investigated by manipulating the ionic composition of media in which rabbit kidney cortex slices were incubated. Alterations in [Ca++] and [K+] produced qualitatively similar, but quantitatively distinct, changes in the release of the two forms of renin. Under control conditions, the slices secreted 15-20% of total renin in the inactive form and exposure to Ca++-free or low [K+] media increased this to 30-40%, a similar proportion to that stored within the kidney. Decreasing [Na+] stimulated release of active renin but reduced inactive renin. There appeared to be antagonism between the effects of Na+ and Ca++ ions in respect of active renin but synergism for release of the inactive form. It is suggested that the characteristics of a single renin release mechanism in the rat kidney resemble those for secretion of inactive, rather than active, renin in other species.
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D003080:Cold Temperature; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000378:metabolism; D066298:In Vitro Techniques; D007672:Kidney Cortex / Q000187:drug effects / Q000201:enzymology*; D007700:Kinetics; D011188:Potassium / Q000494:pharmacology; D011817:Rabbits; D012083:Renin / Q000378:metabolism*; D012964:Sodium / Q000494:pharmacology*
D004792:Enzyme Precursors; D012964:Sodium; D012083:Renin; D011188:Potassium; D002118:Calcium