Moderate Effects of Hypoxic Training at Low and Supramaximal Intensities on Skeletal Muscle Metabolic Gene Expression in Mice

Svitlana Drozdovska; Nadège Zanou; Jessica Lavier; Lucia Mazzolai; Grégoire P Millet; Maxime Pellegrin

doi:10.3390/metabo13101103

Moderate Effects of Hypoxic Training at Low and Supramaximal Intensities on Skeletal Muscle Metabolic Gene Expression in Mice

Metabolites. 2023 Oct 21;13(10):1103. doi: 10.3390/metabo13101103.

Authors

Svitlana Drozdovska^{1

2}, Nadège Zanou^{1

3}, Jessica Lavier^{1

4}, Lucia Mazzolai⁴, Grégoire P Millet¹, Maxime Pellegrin^{1

4}

Affiliations

¹ Institute of Sport Sciences, University of Lausanne, 1015 Lausanne, Switzerland.
² Biomedical Disciplines Department, Health, Physical Education and Tourism Faculty, National University of Ukraine on Physical Education and Sport, 03150 Kyiv, Ukraine.
³ Department of Biomedical Sciences, University of Lausanne, 1005 Lausanne, Switzerland.
⁴ Angiology Division, Heart and Vessel Department, Lausanne University Hospital (CHUV), 1011 Lausanne, Switzerland.

Abstract

The muscle molecular adaptations to different exercise intensities in combination with hypoxia are not well understood. This study investigated the effect of low- and supramaximal-intensity hypoxic training on muscle metabolic gene expression in mice. C57BL/6 mice were divided into two groups: sedentary and training. Training consisted of 4 weeks at low or supramaximal intensity, either in normoxia or hypoxia (FiO₂ = 0.13). The expression levels of genes involved in the hypoxia signaling pathway (Hif1a and Vegfa), the metabolism of glucose (Gys1, Glut4, Hk2, Pfk, and Pkm1), lactate (Ldha, Mct1, Mct4, Pdh, and Pdk4) and lipid (Cd36, Fabp3, Ucp2, Hsl, and Mcad), and mitochondrial energy metabolism and biogenesis (mtNd1, mtNd6, CytC, CytB, Pgc1a, Pgc1β, Nrf1, Tfam, and Cs) were determined in the gastrocnemius muscle. No physical performance improvement was observed between groups. In normoxia, supramaximal intensity training caused upregulation of major genes involved in the transport of glucose and lactate, fatty acid oxidation, and mitochondrial biogenesis, while low intensity training had a minor effect. The exposure to hypoxia changed the expression of some genes in the sedentary mice but had a moderate effect in trained mice compared to respective normoxic mice. In hypoxic groups, low-intensity training increased the mRNA levels of Mcad and Cs, while supramaximal intensity training decreased the mRNA levels of Mct1 and Mct4. The results indicate that hypoxic training, regardless of exercise intensity, has a moderate effect on muscle metabolic gene expression in healthy mice.

Keywords: exercise intensity; gene expression; metabolic pathways; mice; normobaric hypoxia; skeletal muscle.

Grants and funding

This research received no external funding.