The Participation of Bone in the Sodium and Potassium Metabolism of the Rat. III The effect of adrenalectomy, cortisone, desoxycorticosterone and 2‐methyl‐9‐α‐fluorohydrocortisone

Experiments were performed on the effect of sodium loading and sodium depletion in adrenalectomized rats. These treatments were combined with injections of cortisone, desoxycorticosterone acetate and 2‐methyl‐9‐α‐fluorohydrocortisone in unoperated as well as adrenalectomized animals. In the moribund stage after adrenalectomy, when total body exchangeable sodium was reduced by more than 25 per cent, only 6 per cent of the Iost sodium was derived from bone. The effect of the cortical compounds was found to be entirely dependent on, and varying with, the particular state of the test animal, its electrolyte intake, the length of time on the diet regime, and whether it was adrenalectomized or not. Only slight contributions from the bone to the total body pool of sodium and potassium were noted in these experiments with the cortical compounds. Profound changes were, however, produced in the relationship between the exchangeable and inexchangeable fraction of the bone sodium by these compounds in combination with sodium loading of the animals. The observations are discussed in relation to present day concepts of the mechanism of sodium binding in bone, and a possible connection to the pathology of collagen disease is pointed out.