Hyporesponsiveness of the pituitary to CRH during slow wave sleep is not mimicked by systemic GHRH.

During slow wave sleep (SWS) pituitary responsiveness to CRH is reduced. Since GHRH is involved in the promotion of SWS in humans and rats, it was examined whether the blunted CRH-induced ACTH and cortisol release during SWS could be mimicked by systemic GHRH. Young healthy men (n = 7) participated in 4 sleep-endocrine protocols: (A) lights off at 23.