Rat adrenomedullin induces a selective arterial vasodilation via CGRP1 receptors in the double-perfused mesenteric bed of the rat.
The present work was undertaken to study the effect of rat adrenomedullin (rADM (1-50) and its C-terminal fragment (11-50)) in the endothelium-intact arterial and venous vasculatures of the rat perfused mesenteric bed. rADM (1-50) and the fragment rADM (11-50)(1-1000 pmol) induced a dose-dependent and endothelium-independent vasodilation on the arterial mesenteric vasculature. However, both peptides were inactive on the venous side of this vascular bed. The CGRP1 receptor antagonist, hCGRP8-37 (1 microM), markedly reduced the vasodilation caused by rADM (1-50) in the arterial mesenteric vasculature. Thus, our results show that rADM (1-50) in the arterial mesenteric vasculature. Thus, our results show that rADM (1-50) and its C-terminal fragment rADM(11-50) share properties similar to those of hCGRP. The blocking effect of hCGRP8-37 supports a role for CGRP1 receptor activation by adrenomedullin in this vascular preparation.
Berthiaume
N
N
Department of Pharmacology, Medical School, Université de Sherbrooke, QC, Canada.
Claing
A
A
Lippton
H
H
Cadieux
A
A
D'Orléans-Juste
P
P
D053607:Adrenomedullin; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D017538:Mesenteric Artery, Superior / Q000187:drug effects / Q000502:physiology; D008642:Mesenteric Veins / Q000187:drug effects / Q000502:physiology; D019331:NG-Nitroarginine Methyl Ester; D010446:Peptide Fragments / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D010477:Perfusion; D051381:Rats; D017208:Rats, Wistar; D018015:Receptors, Calcitonin Gene-Related Peptide / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects*
D000959:Antihypertensive Agents; D010446:Peptide Fragments; D010455:Peptides; D018015:Receptors, Calcitonin Gene-Related Peptide; D053607:Adrenomedullin; D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester