Experiments were carried out on the adult male rabbits. The animals were divided in three experimental groups and one control group. The animals of all experimental groups were given NaCl, through different ways. The degree of granularity of juxtaglomerular cells was evaluated by counting the JGI (juxtaglomerular index) according to HARTROFT. In all experimental groups, the JGI was lowered. The lowest was found in the first experimental group, that was given NaCl drinking fluid. The width of the zona glomerulosa was measured microscopically on the adrenal gland tissue colored by HE. It was smaller in all experimental groups. The smallest was in the first experimental group of animals. The diminution of the zona glomerulosa corresponds with the decrease of granularity of juxtaglomerular cells.