Proadrenomedullin N-terminal 20 peptide (PAMP) is a novel hypotensive peptide found in the precursor to adrenomedullin. The purpose of the present study is to investigate responses to synthetic human PAMP and the carboxy terminal 12-20 amino acid fragment of PAMP in the mesenteric vascular bed of the cat under constant flow conditions. Intraarterial injections of PAMP in doses of 3-100 nmol and PAMP (12-20) in doses of 3-100 nmol caused dose-related decreases in mesenteric perfusion pressure. When compared on a nmol basis, PAMP was approximately 3-fold more potent than PAMP (12-20). The two peptides were approximately 100fold less potent than adrenomedullin (ADM) and approximately 1000-fold less potent than acetylcholine. The dose of PAMP required to reduce mesenteric perfusion pressure 20 mmHg (ED20 mmHg) was significantly lower than the ED20 mmHg for adrenomedullin and calcitonin gene-related peptide (CORP). The half-time of the vasodilator response to PAMP and PAMP (12-20) was significantly greater than the half-time of vasodilator responses to ADM, CORP. acetylcholine, and bradykinin. The present data demonstrate that PAMP and PAMP (12-20) have potent and relatively longlasting vasodilator activity in the mesenteric vascular bed of the cat. These data further suggest that amino acid residues 1-11 of PAMP are important for the expression of full efficacy of the vasodilator response of PAMP in the mesenteric vascular bed of the cat.
|Original language||English (US)|
|State||Published - Dec 1 1996|
ASJC Scopus subject areas
- Molecular Biology