Vasodilating actions of calcitonin gene-related peptide in normal man: comparison with atrial natriuretic peptide.
To compare the vasodilator effect of calcitonin gene-related peptide (CGRP) with that of atrial natriuretic peptide (ANP), forearm blood flow (FBF) was measured by strain-gauge plethysmography during the continuous infusion of different doses of the peptides dissolved in 5% dextrose into the brachial artery in healthy subjects. Either CGRP or ANP increased FBF in a dose-dependent fashion. Although 100 ng/ml CGRP increased FBF from 3.27 +/- 0.41 to 10.70 +/- 1.77 ml/100 ml/min, the same dose of ANP increased FBF from 2.40 +/- 0.38 to 5.39 +/- 0.22 ml/100 ml/min, which was significantly lower than the increase in CGRP (p less than 0.01): Plasma concentration of peptides (on a molar basis) was positively correlated with FBF in CGRP (r = 0.820, p less than 0.01) or ANP (r = 0.722, p less than 0.01). However, the slope of the regression line between plasma level and FBF was significantly higher (p less than 0.01) in CGRP (12.88 +/- 0.99) than in ANP (2.10 +/- 0.27). Thus the vasodilator effect of CGRP was more potent than that of ANP. The present findings are compatible with functional involvement of CGRP in the regulation of forearm circulation.
Ando
K
K
Fourth Department of Internal Medicine, University of Tokyo School of Medicine, Japan.
Ito
Y
Y
Ogata
E
E
Fujita
T
T
D000328:Adult; D009320:Atrial Natriuretic Factor / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D015740:Calcitonin Gene-Related Peptide / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005542:Forearm / Q000098:blood supply*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007269:Injections, Intra-Arterial; D008297:Male; D010991:Plethysmography; D012039:Regional Blood Flow / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*
D009320:Atrial Natriuretic Factor; D015740:Calcitonin Gene-Related Peptide