Haemodynamic responses to dehydration in the resting and exercising human leg

verfasst von

James Pearson, Kameljit K. Kalsi, Eric J. Stöhr, David A. Low, Horace Barker, Leena Ali, José González-Alonso

Abstract

Dehydration and hyperthermia reduces leg blood flow (LBF), cardiac output (Q̇) and arterial pressure during whole-body exercise. It is unknown whether the reductions in blood flow are associated with dehydration-induced alterations in arterial blood oxygen content (C_aO₂) and O₂-dependent signalling. This study investigated the impact of dehydration and concomitant alterations in C_aO₂ upon LBF and Q̇. Haemodynamics, arterial and femoral venous blood parameters and plasma [ATP] were measured at rest and during one-legged knee-extensor exercise in 7 males in four conditions: (1) control, (2) mild dehydration, (3) moderate dehydration, and (4) rehydration. Relative to control, C_aO ₂ and LBF increased with dehydration at rest and during exercise (C_aO₂: from 199 ± 1 to 208 ± 2, and 202 ± 2 to 210 ± 2 ml L^-1 and LBF: from 0.38 ± 0.04 to 0.77 ± 0.09, and 1.64 ± 0.09 to 1.88 ± 0.1 L min ^-1, respectively). Similarly, Q̇ was unchanged or increased with dehydration at rest and during exercise, whereas arterial and leg perfusion pressures declined. Following rehydration, C_aO₂ declined (to 193 ± 2 mL L^-1) but LBF remained elevated. Alterations in LBF were unrelated to C_aO₂ (r ² = 0.13-0.27, P = 0.48-0.64) and plasma [ATP]. These findings suggest dehydration and concomitant alterations in C_aO₂ do not compromise LBF despite reductions in plasma [ATP]. While an additive or synergistic effect cannot be excluded, reductions in LBF during exercise with dehydration may not necessarily be associated with alterations in C_aO₂ and/or intravascular [ATP].

Externe Organisation(en)

Brunel University
Cardiff Metropolitan University
Imperial College London
Ealing Hospital

Typ

Artikel

Journal

European Journal of Applied Physiology

Band

113

Seiten

1499-1509

Anzahl der Seiten

11

ISSN

1439-6319

Publikationsdatum

06.2013

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Orthopädie und Sportmedizin, Öffentliche Gesundheit, Umwelt- und Arbeitsmedizin, Physiologie (medizinische)

Ziele für nachhaltige Entwicklung

SDG 3 – Gute Gesundheit und Wohlergehen

Elektronische Version(en)

https://doi.org/10.1007/s00421-012-2579-2 (Zugang: Geschlossen)
https://doi.org/10.1007/s00421-013-2679-7 (Zugang: Offen)