The Influence of Dietary Sodium Chloride on in Vitro Renin Release from Rat Kidney Slices 1

Summary

In vitro renin release from surviving rat kidney slices, expressed in Gold-blatt units/mg of protein or as percentage of the total renin content of the slice, was studied under anaerobic and aerobic conditions and in the presence of arsenite/arsenate blockade. Renin content and renin release from slices from donor rats kept on a sodium deficient diet were three times larger than for slices from rats on a normal diet. The release, expressed as a percentage of the total renin content, was the same. No release occurred under metabolic blockade, and release was much larger under aerobic than anaerobic conditions. Both the quantity and the percentage of the total renin content which was released as well as the Qo₂ decreased with decreasing sodium concentrations in the media. Under some conditions an apparent net synthesis of renin occurred. In vitro renin release is metabolically dependent, related to the quantity of renin stored in the slice, and in some manner influenced by the presence of sodium chloride. In vitro release appears to be much larger than in vivo release and is probably always maximal for a given metabolic state.