Corticotropin-releasing hormone (CRH) is a 41 amino acid hypothalamic peptide whose chemical structure has recently been determined after more than two decades of intensive research. This peptide stimulates secretion of ACTH by the corticotroph cells of the pituitary gland. As with the previously discovered hypothalamic hormones, CRH has important diagnostic and therapeutic applications. This study seeks to explore these clinical applications by determining the dose-response relationship for single doses of ovine CRH (oCRH) in normal volunteers and in patients with disorders of the hypothalamic-pituitary-adrenal axis. CRH is administered intravenously at doses up to 10 pg/kg, given as a bolus or up to 1 ug/kg/b as a continuous infusion lasting up to 24 hours. Plasma levels of ACTH, cortisol and CRH are measured before, during and after CRH administration.