Central nervous system regulation of adrenocorticotropin secretion: role of somatostatins.

Somatostatin-28 (SS-28) and desAA1,2,4,5,12,13[D-Trp8]somatostatin (ODT8-SS), but not somatostatin-14, given intracerebroventricularly, but not when given iv, inhibit stress-induced pituitary ACTH and adrenomedullary epinephrine secretion in rats. The elevation of ACTH after tail-suspension stress is totally prevented by iv administration of antisera raised against corticotropin-releasing factor (CRF). SS-28 and ODT8-SS do not inhibit CRF-induced ACTH secretion in vivo or in vitro. These results are consistent with the hypothesis that SS-28 and ODT8-SS prevent stress-induced ACTH secretion by inhibition of CRF release.