Electrolytes and blood pressure of rats drinking sodium chloride solutions

¹ Department of Internal Medicine, The University of Michigan, Ann Arbor, Michigan

Eighty per cent of rats surviving 8–12 weeks when given 1.75 or 2.0% sodium chloride solution in place of drinking water had at least 20 mm Hg elevation of systolic arterial blood pressure. Changes in tissue water and electrolytes were: a) a consistent increase in sodium, potassium, and chloride contents of aorta; b) an increase in sodium and extracellular water contents of muscle, more marked in skeletal than heart muscle; c) marked muscle potassium depletion in one series; and d) an increase in total body sodium and a tendency toward hypernatremia. At the time of sacrifice no consistent association was evident between blood pressure elevation and water and electrolyte changes.