The Effect of Bilateral Nephrectomy and Midcollicular Decerebration with Pinealectomy and Hypophysectomy on the Corticosteroid Secretion of Sodium-deficient Sheep *

Abstract

Eight sodium-replete and 19 sodium-depleted sheep were subjected to bilateral nephrectomy and midcollicular decerebration with pinealectomy and hypophysectomy. Adrenal venous blood collections were made after an initial left nephrectomy. The experiments in the sodium-deficient state were divided into 2 groups depending upon whether the condition of bilateral nephrectomy preceded the intracranial ablation by a period of 3 to 4 hours (NND), or followed it after an interval of 3 to 4 hrs. (NDN). In all instances the observations continued 2 to 7 hr. after completion of all ablations. The mean final aldosterone secretion rate of the sodium-replete group was 0.7 [plus or minus] 0.5 (SD) [m[mu]]g/hr., and for the sodium-depleted group the mean final outputs were NDN, 6.5 [plus or minus] 4.7 [m[mu]]g/hr., and NND 3.8 [plus or minus] 1.7 [m[mu]]g/hr. The results demonstrate that hypersecretion of aldosterone due to sodium depletion may continue for 2 to 7 hr. at 2-25 times the basal rate after removal of the pituitary, the pineal gland and both kidneys. The physiological significance of these experiments is discussed.