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Heat shock protein 90 does not contribute to cutaneous vasodilatation in older adults during heat stress
Author(s) -
Fujii Naoto,
McGarr Gregory W.,
Hatam Kion,
Chandran Nithila,
Muia Caroline M.,
Nishiyasu Takeshi,
Boulay Pierre,
Ghassa Reem,
Kenny Glen P.
Publication year - 2019
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.12541
Subject(s) - geldanamycin , nitric oxide synthase , heat shock protein , medicine , vasodilation , shock (circulatory) , nitric oxide , hsp70 , endocrinology , forearm , thermoregulation , chemistry , hsp90 , surgery , biochemistry , gene
Objectives Heat shock protein 90 ( HSP 90) contributes to cutaneous vasodilatation during exercise in the heat through nitric oxide (NO) synthase ( NOS )–dependent mechanisms in young adults. We hypothesized that similar responses would be observed in older middle‐aged adults. Methods In nineteen habitually active older middle‐aged (56 ± 5 years) men (n = 9) and women (n = 10), cutaneous vascular conductance ( CVC ) was measured at four forearm skin sites continuously treated with (a) lactated Ringers solution (Control), (b) 10 mmol/L L‐ NAME ( NOS inhibitor), (c) 178 μmol/L geldanamycin ( HSP 90 inhibitor), or (d) 10 mmol/L L‐ NAME and 178 μmol/L geldanamycin combined. Participants rested in an upright semi‐recumbent position in the heat (35°C) for 70 minutes, followed by a 50‐minute bout of moderate‐intensity cycling (~55% peak oxygen uptake) and a 30‐minute recovery period in the heat. Results In both men and women, we observed no significant effects of HSP 90 inhibition on CVC throughout rest, exercise, and recovery in the heat (all P > 0.27). Conversely, NOS inhibition and dual NOS and HSP 90 inhibition attenuated CVC relative to Control throughout the protocol (all P ≤ 0.05). Conclusions While NOS mediates cutaneous vasodilatation during rest, exercise, and recovery in the heat, HSP 90 does not measurably influence this response in habitually active older middle‐aged men or women under these conditions.