Increased Renal Pressor Activity (Renin) in Sodium Deficient Rats and Correlation with Juxtaglomerular Cell Granulation.

Abstract

Various investigators have suggested that the renal juxtaglomerular (JG) cells are the source of the pressor substance, renin. However, granulation of JG cells and renin content of the kidney had rarely been studied in the same animals in a single experiment. The present experiment was undertaken to determine whether renin was increased in Na-deficient animals, as it should be if JG granules represented this substance, and to determine whether a correlation existed between these 2 variables in the same animals. Kidneys were removed from 14 Na-deficient and 14 control rats. One kidney from each rat was suitably fixed and stained for determination of indices of JG granulation and the other kidney was extracted with saline. The saline extracts were assayed for pressor activity. Both degree of granulation of JG cells and pressor activi ty (renin) of kidneys were much higher in Na-deficient than in control animals and the 2 variables correlated with each other in the same animals. This correlation strongly suggests that the granules of JG cells may consist of renin or a precursor,.