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Aging attenuates adenosine triphosphate‐induced, but not muscarinic and nicotinic, cutaneous vasodilation in men
Author(s) -
Fujii Naoto,
Nishiyasu Takeshi,
Sigal Ronald J.,
Boulay Pierre,
McGarr Gregory W.,
Kenny Glen P.
Publication year - 2018
Publication title -
microcirculation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.793
H-Index - 83
eISSN - 1549-8719
pISSN - 1073-9688
DOI - 10.1111/micc.12462
Subject(s) - methacholine , agonist , muscarinic acetylcholine receptor , medicine , endocrinology , nicotinic agonist , nicotine , chemistry , vasodilation , muscarinic agonist , receptor , respiratory disease , lung
Objective We evaluated the hypothesis that aging attenuates muscarinic, nicotinic, and ATP ‐related cutaneous vasodilation. Methods In 11 young (24 ± 4 years) and 11 older males (61 ± 8 years), CVC was assessed at 3 forearm skin sites that were infused with either: (i) methacholine (muscarinic receptor agonist, 5 doses: 0.0125, 0.25, 5, 100, 2000 mmol/L), (ii) nicotine (nicotinic receptor agonist, 5 doses: 1.2, 3.6, 11, 33, 100 mmol/L), or (iii) ATP (purinergic receptor agonist, 5 doses: 0.03, 0.3, 3, 30, 300 mmol/L). Each agonist was administered for 25 minutes per dose. Results We showed that CVC at all doses of methacholine did not differ between groups. Similarly, no between‐group differences in CVC were observed during nicotine administration at all doses administered. By contrast, while no differences in CVC were measured during the administration of ATP at low (0.03 and 0.3 mmol/L) or high (300 mmol/L) concentrations, CVC was reduced in the older relative to the young males at moderate concentrations of ATP (3 mmol/L: 23 ± 6 vs 40 ± 13%max, 30 mmol/L: 62 ± 11 vs 83 ± 8%max, both P ≤ .05). Conclusions We show that aging attenuates ATP ‐induced, but not muscarinic or nicotinic, cutaneous vasodilation in men.