Juxtaglomerular Cells

Abstract

Morphological and ultrastructural characteristics of JG cells are consistent with the concept of secretory or endocrine activity. At least in the chronic situation, evidence indicates that hypergranulation of JG cells--or elevated JGI--means hyperactivity. Factors that control cytological activity of JG cells are concerned with volume or pressure changes and with sodium. Despite the influence of potassium in the adrenal zona glomerulosa, potassium does not affect JG cells. The fluorescent antibody technique in the rabbit, dog, and domestic pig, demonstrates that renin is located in the JG cells, but not in the macula densa or other structures of the renal cortex. Inhibition of sodium retention by antirenin in sodium-deficient dogs provides further evidence that renin, secreted by JG cells, is concerned in the regulation of sodium excretion, whether by its influence on aldosterone or by an intrarenal mechanism.