Effect of acute hypernatremia, hyponatremia, and acidosis on bone sodium.

Acute experiments were carried out in cats and rabbits in which a sample of cortical bone was taken prior to and at the conclusion of the experimental procedure. Thus each animal served as its own control. Hyponatremia caused a decrease in bone Na and hypernatremia an increase. The observed changes could be accounted for entirely by that portion of bone Na which is associated with bone water in equilibrium with extracellular fluid. In these and additional experiments in the rat, acidosis unassociated with hyponatremia did not mobilize Na from bone.