Histophysiologic Changes in the Kidney and Adrenal Cortex in Rats on a Low-Sodium Diet1

Abstract

Rats given a low-sodium, highpotassium diet showed progressive kidney and adrenal changes over an 11-week period. The juxtaglomerular granulation index increased with time. After 2 weeks the size of the lumen in the proximal segment of the renal tubules decreased. By 4 weeks, glucose-6-phosphate dehydrogenase activity in the macula densa increased. Histologic and histochemical changes of the adrenal cortex indicated increasing steroid production by the zona glomerulosa throughout the experimental period, and decreasing steroid production by the inner 2 zones after 2 weeks. The latter change may indicate reduced ACTH production. When rats on the deficient diet for 4 weeks were then given adequate saline for 12 days, all the changes listed subsided and the parameters studied returned toward normal.