Plasma Glucocorticoid Concentrations after Injections of Heroin, Corticotrophin, Saline, and Cortisol in Fetal and Neonatal Rabbits

Abstract

Concentrations of plasma glucocorticoids were measured in fetal and newborn rabbits at various stages of late gestation after injections of heroin, saline, ACTH, or glucocorticoid. No change in blood corticoid levels were found in response to injections of these substances in rabbit fetuses, nor were corticoid levels altered in full-term newborn rabbits by heroin injection. ACTH in premature newborn rabbits was associated with a minimal increase in corticoids, although survival of the premature newborn rabbits was insufficient to allow measurement of corticoids at a time when ACTH effect might be maximal.