Experimental Studies of the Mechanisms Producing Hypocalcemia in Hypernatremic States1

Abstract

Thirsting rats were injected with solutions of hypertonic Na salts producing hypernatremia, increased body Na, reduced body K, and hypocalcemia, which did not occur in control animals. Extracellular fluid dilution, hyperphosphatemia and serum protein changes were not responsible for the hypocalcemia. Experiments further showed that the reduction of body K per se was not accompanied by hypocalcemia. Finally it was shown that when K was added to the Na loading solution to adjust the total carcass Na/K ratio to that of controls, the hypocalcemia did not occur despite hypernatremia and increased body Na. The possible relationship of these findings to the hypocalcemia encountered in infants with hypernatremic dehydration is discussed.