Vasopressor activities of N-terminal fragments of adrenomedullin in anesthetized rat.
Adrenomedullin (AM) is a vasorelaxant peptide that was recently isolated from human pheochromocytoma. In contrast to human (h) AM, which has vasodepressor activity, a synthetic N-terminal fragment of hAM, hAM-(1-25)-NH2 showed vasopressor activity in the anesthetized rat. The N-terminal peptides hAM-1-31)-NH2, hAM-(1-25)-OH, hAM-(1-21)-NH2, acetyl-hAM-(16-21)-NH2, and acetyl-hAM-(16-36)-OH all showed vasopressor activities. The potency of hAM-(1-21)-NH2, acetyl-hAM-(16-21)-NH2 was greater than that of hAM-(1-25)-NH2. Pretreatment with phenoxybenzamine, guanethidine, or reserpine attenuated vasopressor activities of these peptides. These data suggested that vasopressor activity of N-terminal fragment of hAM is due to a stimulation of endogenous catecholamine release.
Watanabe
T X
TX
Peptide Institute, Inc., Protein Research Foundation, Osaka, Japan.
Itahara
Y
Y
Inui
T
T
Yoshizawa-Kumagaye
K
K
Nakajima
K
K
Sakakibara
S
S
D000310:Adrenal Gland Neoplasms / Q000737:chemistry; D053607:Adrenomedullin; D000768:Anesthesia, General; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D003243:Consciousness; D006145:Guanethidine / Q000494:pharmacology; D006801:Humans; D008297:Male; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000494:pharmacology*; D010455:Peptides / Q000302:isolation & purification / Q000494:pharmacology*; D010643:Phenoxybenzamine / Q000494:pharmacology; D010673:Pheochromocytoma / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D012110:Reserpine / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014665:Vasodilator Agents / Q000494:pharmacology*
D010446:Peptide Fragments; D010455:Peptides; D014665:Vasodilator Agents; D010643:Phenoxybenzamine; D053607:Adrenomedullin; D012110:Reserpine; D006145:Guanethidine