Changes in prolactin secretion in the short- and long-term after adrenalectomy

objective: to evaluate the modulation of the hypothalamus-pituitary-adrenal axis (hpa) on prolactin secretion in rats after adrenalectomy (adx). materials and methods: plasma corticosterone, acth, and prolactin concentrations were measured by radioimmunoassay in rats after bilateral adx in the short- (3 hours and 1day) and long-term (3, 7, and 14 days). results: animals that underwent adx showed undetectable corticosterone levels and a triphasic acth response with a transient increase (3h), a decrease (1d), and further increase in the long-term after adx. sham animals showed a marked increase in corticosterone and acth levels three hours after surgery, with a decrease to basal levels thereafter. plasma prolactin levels were not changed after adx. conclusion: there are different points of equilibrium in the hpa axis after the glucocorticoid negative feedback is removed. prolactin plasma secretion is not altered in the short or long- term after adx, suggesting that the peptidergic neurons essential for prolactin release are not activated after adx.