Chronic sodium chloride toxicity in the albino rat. II. Occurrence of hypertension and of a syndrome of edema and renal failure.

Sustained arterial hypertension developed in male, albino rats chronically fed diets rich in sodium chloride with demineralized drinking water available ad libitum. After 12 months of the experimental regimen a positive, linear correlation (r = 0.91) was found between the systolic blood pressure and the concentration of sodium chloride in the diet. A syndrome of edema and renal failure was observed in 18 per cent of the group fed at the level of 7.0 to 9.8 per cent of sodium chloride. Significant histologic changes occurred in the kidneys and certain other organs in rats consuming rations containing these levels of NaCl. The relative volume of the radiosodium space was increased in the rat by high dietary sodium chloride.