ADRENAL-FUNCTION IN YOUNG OF PROTEIN-DEPRIVED PREGNANT RATS

Corticosterone levels were determined in plasma and adrenal glands from 4-day- and 8-day-old young of rats fed diets containing 4% or 24% casein during pregnancy. Body and adrenal gland weights were determined in newborn 4-day- and 8-day-old young. Pups of protein-deprived dams had significantly smaller body and gland weights than did control young. Absolute adrenal weight in prenatally protein-deprived (PPD) young remained lower at all 3 ages. Differences in adrenal weight:body weight ratios disappeared after 4 postnatal days during which all young were suckled by stock diet-fed dams. Adrenal shrinkage was observed between birth and 4 days in control pups but not in PPD young. Unstressed pups of both groups had similar plasma and adrenal corticosterone levels. ACTH-injected PPD young at 4 days had increased adrenal corticosterone per mg tissue and at 8 days, decreased plasma corticosterone compared to ACTH-injected control young. Physiological stress by ether exposure resulted in similar plasma and adrenal corticosterone levels in both groups. Maternal protein deficiency did not affect the parameters of adrenal function studied in unstressed or ether-stressed rat pups. The capacity of adrenals of PPD young to respond to ACTH did decrease.