Adrenocorticotropic hormone (ACTH) (7-38) is a peptide fragment of ACTH and an antagonist of melanocortin receptor 2 (MC2R), also known as the ACTH receptor.1 It inhibits ACTH-induced corticosterone production in isolated rat adrenal cells when used at concentrations of 0.455 or 4.55 ?M. ACTH (7-38) also inhibits angiotensin-converting enzyme 1 (ACE1; IC50 = 750 nM for the dog enzyme).2 It inhibits basal cAMP secretion by isolated rat inner adrenocortical cells when used at a concentration of 1 ?M.3 ACTH (7-38) induces hypotension in normotensive dogs (ED50 = 0.109 nmol/kg).4
References:
[1]. Li, C.H., Chung, D., Yamashiro, D., et al.Isolation, characterization, and synthesis of a corticotropin-inhibiting peptide from human pituitary glandsProc. Natl. Acad. Sci. U.S.A.75(9)4306-4309(1978).
[2]. Verma, P.S., Miller, R.L., Taylor, R.E., et al.Inhibition of canine lung angiotensin converting enzyme by ACTH and structurally related peptidesBiochem. Biophys. Res. Commun.104(4)1484-1488(1982).
[3]. Mazzocchi, G., Rebuffat, P., Gottardo, L., et al.Vasoactive intestinal peptide stimulates rat adrenal glucocorticoid secretion, through an ACTH receptor-dependent activation of the adenylate cyclase signaling pathwayHorm. Metab. Res.30(5)241-243(1998).
[4]. Tenner, T.E., Jr., Yang, C.M., Chang, J.K., et al.Pharmacological comparison of bPTH-(1-34) and other hypotensive peptides in the dogPeptides1(4)285-288(1980).