Renal nerves and sodium conservation in conscious rats of different strains kept on various diets.

Earlier contradictory results as to whether renal nerves are necessary for adaptation to a low dietary sodium intake in the rat were ascribed to strain differences or to sympathetic stimulation caused by carbohydrates when changing from a low-sucrose normal-sodium diet to a high-sucrose sodium-deficient diet. In the present work, daily sodium excretion was studied for 4 days before and after bilateral renal denervation or sham operation in three strains of rats (CFY, Wistar, and Long Evans). After ingesting a normal sodium diet containing no sucrose, CFY and Wistar rats were fed a sodium-deficient diet containing 67% sucrose. Long Evans rats were sodium-depleted by feeding them boiled rice. Daily and cumulative sodium excretion and sodium balance were similar in all three groups during 4-day sodium-depletion periods before and after bilateral renal denervation or sham operation. The results suggest that in sodium-depleted rats denervation natriuresis can be ascribed neither to strain differences nor to the high sucrose content of the low-sodium diet.