The Effect of Sodium on Renal Renin and on Glucose-6-Phosphate Dehydrogenase in the Kidneys, Salivary Glands and Adrenal Glands

Abstract

The effect of Na balance upon renal renin and renal, adrenal, and salivary gland G-6-PD activity was studied quantitatively and histochemically in the rat. The results indicate a negative Na balance (Na deficient diet) induces marked increases in renal renin and G-6-PD content of the kidney and salivary gland. Histochemically, the changes in activity appeared throughout cortical nephrons, markedly so in the macula densa, in the excretory ducts of the salivary glands, and in the adrenal cortex, particularly the zona glomerulosa. Under positive Na balance (high Na diet), a marked reduction of G-6-PD activity was observed throughout; renal renin content was similarly reduced. The parallelism between stainable enzyme activity in the macula densa, juxtaglomerular granularity, and total renal G-6-PD and renin content suggests a functional interplay of the structures of the juxtaglomerular apparatus in response to Na metabolism. Na balance also appears to affect enzyme activity of the adrenal cortex and salivary gland excretory ducts, either directly or through hormonal response.