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Experimental Physiology - 2022 - Peden - Ischaemic preconditioning blunts exercise‐induced mitochondrial dysfunction .pdf (736.57 kB)

Ischaemic preconditioning blunts exercise-induced mitochondrial dysfunction, speeds oxygen uptake kinetics but does not alter severe-intensity exercise capacity

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posted on 2022-11-11, 16:26 authored by Donald Peden, Emma Mitchell, Stephen BaileyStephen Bailey, Richard FergusonRichard Ferguson

We examined the effect of ischaemic preconditioning (IPC) on severe-intensity exercise performance, pulmonary oxygen uptake (̇VO2) kinetics, skeletal muscle oxygenation (muscle tissue O2 saturation index) and mitochondrial respiration. Eight men underwent contralateral IPC (4 × 5 min at 220 mmHg) or sham-control (SHAM; 20 mmHg) before performing a cycling time-to-exhaustion test (92% maximum aerobic power). Muscle (vastus lateralis) biopsies were obtained before IPC or SHAM and ∼1.5 min postexercise. The time to exhaustion did not differ between SHAM and IPC (249 ± 37 vs. 240 ± 32 s; P = 0.62). Pre- and postexercise ADP-stimulated (P) and maximal (E) mitochondrial respiration through protein complexes (C) I, II and IV did not differ (P > 0.05). Complex I leak respiration was greater postexercise compared with baseline in SHAM, but not in IPC, when normalized to wet mass (P = 0.01 vs. P = 0.19), mitochondrial content (citrate synthase activity, P = 0.003 vs. P = 0.16; CI+IIP, P = 0.03 vs. P = 0.23) and expressed relative to P (P = 0.006 vs. P = 0.30) and E (P = 0.004 vs. P = 0.26). The (̇VO2) mean response time was faster (51.3 ± 15.5 vs. 63.7 ± 14.5 s; P = 0.003), with a smaller slow component (270 ± 105 vs. 377 ± 188 ml min−1; P = 0.03), in IPC compared with SHAM. The muscle tissue O2 saturation index did not differ between trials (P > 0.05). Ischaemic preconditioning expedited (̇VO2) kinetics and appeared to prevent an increase in leak respiration through CI, when expressed proportional to E and P evoked by severe-intensity exercise, but did not improve exercise performance.

Funding

NIHR Leicester Biomedical Research Centre

History

School

  • Sport, Exercise and Health Sciences

Published in

Experimental Physiology

Volume

107

Issue

11

Pages

1241-1254

Publisher

Wiley

Version

  • VoR (Version of Record)

Rights holder

© The Authors

Publisher statement

This is an Open Access Article. It is published by Wiley under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence (CC BY-NC-ND). Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Acceptance date

2022-08-12

Publication date

2022-09-13

Copyright date

2022

ISSN

0958-0670

eISSN

1469-445X

Language

  • en

Depositor

Dr Richard Ferguson. Deposit date: 27 September 2022

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