Renal Juxtaglomerular Cell Granulation in Acute and Prolonged Increase in Renin Production Induced by Hydralazine in the Rat

Abstract

Acute renin release was induced in rats by bleeding combined with hydralazine administration. This effect was prevented by giving pentolinium. Differences in plasma renin activity between the various groups of rats were not associated with differences in the degree of juxtaglomerular cell granulation, the kidneys being removed 30 minutes after bleeding. A 10-day stimulus to renin production and release was induced in a second series of rats by a combination of renal artery clipping and hydralazine administration. This caused an increase in kidney renin content but no increase in the degree of juxtaglomerular cell granulation. It is concluded that stimuli to increased renin production (i) more easily elicit measurable increases in kidney renin content than perceptible increases in the degree of juxtaglomerular cell granulation, and (ii) may lead to increased plasma renin activity before any increase in juxtaglomerular cell granulation is evident.