Adrenomedullin(16–31) Has Pressor Activity in the Rat But Not the Cat

• Published in: Peptides (New York, N.Y. : 1980) N.Y. : 1980), 1997, Vol.18 (1), p.133-136
• Main Authors: Champion, H.C, Friedman, D.E, Lambert, D.G, Murphy, W.A, Coy, D.H, Kadowitz, P.J
• Format: Article
• Language: English
• Subjects: Adrenergic alpha-Agonists - pharmacology; Adrenergic alpha-Antagonists - pharmacology; Adrenergic Uptake Inhibitors - pharmacology; Adrenomedullin; Animals; Blood Pressure - drug effects; Cats; Dose-Response Relationship, Drug; Female; hADM(16–31); Male; Norepinephrine - pharmacology; Peptide Fragments - chemistry; Peptide Fragments - pharmacology; Peptides - pharmacology; Phentolamine - pharmacology; Rats; Receptors, Adrenergic, alpha - physiology; Reserpine - pharmacology; Species differences; Tyramine - pharmacology; Vasoconstrictor Agents - pharmacology; Vasopressor; α-Receptor activation
• ISSN: 0196-9781; 1873-5169
• DOI: 10.1016/S0196-9781(96)00251-3

Champion, H. C., D. E. Friedman, D. G. Lambert, W. A. Murphy, D. H. Coy and P. J. Kadowitz. Adrenomedullin(16–31) has pressor activity in the rat but not the cat. Peptides 18(1) 133–136, 1997.—Responses to a newly synthesized human adrenomedullin (hADM) analog, hADM(16–31), were investigated in the rat and cat. Unlike the full-sequence peptide, which has potent hypotensive activity, hADM(16–31) had pressor activity in the rat but not in the cat. Injection of hADM(16–31) in doses of 10–300 nmol/kg IV induced dose-dependent increases in systemic arterial pressure in the rat, and the peptide was approximately 10-fold less potent than norepinephrine when doses are compared on a nanomole basis. In contrast, injection of hADM(16–31) in doses up to 1000 nmol/kg IV had no significant effect on systemic arterial pressure in the cat. Increases in systemic arterial pressure in response to hADM(16–31) in the rat were significantly reduced after administration of phentolamine or reserpine. These data suggest that increases in systemic arterial pressure in response to hADM(16–31) are mediated by release of catecholamines and activation of α-adrenergic receptors in the rat. These data show that hADM(16–31) has significant pressor activity and that there are marked species differences in the response to hADM(16–31).