Vasodilator effect of adrenomedullin and calcitonin gene-related peptide receptors in rat mesenteric vascular beds.
The effect of adrenomedullin, a novel peptide of 52 amino acids, on vascular tone was investigated in the perfused rat mesenteric vascular bed. In the vasculature contracted with methoxamine, perfusion of adrenomedullin (10(-11)-10(-7) M) caused a concentration-dependent decrease in perfusion pressure due to vasodilation. Additionally, a bolus infusion of adrenomedullin (300 and 500 pmol) produced a long-lasting vasodilator response, which was not affected in the presence of atropine (10(-7) M) and propranolol (10(-7) M). However, this response was inhibited in the presence of CGRP [8-37] (10(-6) M), an antagonist for CGRP receptor. These results suggest that adrenomedullin induces nonadrenergic and noncholinergic vasodilation in which CGRP receptors may be involved.
Nuki
C
C
Department of Pharmacology, Miyazaki Medical College, Japan.
Kawasaki
H
H
Kitamura
K
K
Takenaga
M
M
Kangawa
K
K
Eto
T
T
Wada
A
A
D053607:Adrenomedullin; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D008297:Male; D008643:Mesentery / Q000098:blood supply*; D010446:Peptide Fragments / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D010477:Perfusion; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018015:Receptors, Calcitonin Gene-Related Peptide / Q000378:metabolism*; D014655:Vascular Resistance; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*
D010446:Peptide Fragments; D010455:Peptides; D018015:Receptors, Calcitonin Gene-Related Peptide; C058636:calcitonin gene-related peptide (8-37); D053607:Adrenomedullin; D001285:Atropine; D011433:Propranolol; D015740:Calcitonin Gene-Related Peptide