EFFECT OF SODIUM DEFICIENCY ON SECRETION OF HORMONES BY THE RAT ADRENAL CORTEX1

Previous studies have shown that when adrenals of sodium deficient rats are incubated in vitro there is increased production of aldosterone but reduced secretion of other Δ4,3-ketosteroid hormones including corticosterone. Other investigators have demonstrated increased aldosterone secretion after sodium restriction but reduced production of other hormones has not been described. For this reason, the effect of salt depletion on adrenocortical hormone secretion of the rat was reinvestigated by inducing sodium deficiency in animals and measuring hormone content of adrenal vein plasma. The results demonstrate that in salt-depleted rats the plasma level of corticosterone and the rate of secretion of this hormone are decreased. There is also a reduction in plasma concentration of Δ4,3-ketosteroids which is probably a result of the marked decline in corticosterone production. The fact that corticosterone secretion of sodium depleted rats is diminished whereas similar changes have not been observed in other animals indicates that the response of the rat adrenal to sodium restriction is different from that of most other species.