Effect of fasting on body composition and proteolysis gene expression in skeletal muscles and liver of BEH+/+ and BEL mice

Growth Factors. 2020 Dec;38(5-6):259-268. doi: 10.1080/08977194.2021.1960831. Epub 2021 Aug 6.

Abstract

Fasting improves health, but can cause muscle weakness. We assessed body composition in 21-week old males of Berlin high (BEH+/+) and Berlin low (BEL) strains after two bouts of 48-h or 40-h of fasting with 5-day refeeding in between, respectively. BEH+/+ mice tended to loose less weight than BEL in bout 1 and 2 (16.0 ± 2.7 versus 23.5 ± 2.9%, p < 0.001 and 17.1 ± 3.4 versus 20.4 ± 3.4%, p = 0.17, respectively). In spite of greater serum IGF-1 and body fat levels, BEH+/+ mice showed more severe muscle atrophy, but less marked liver wasting and fat depletion than BEL mice. BEH+/+ mice also showed smaller increases in expression of p62, Atrogin-1, and Mstn genes in skeletal muscles. In summary, BEL mice show resistance to fasting-induced muscle wasting in spite of low serum IGF-1 levels and high expression of genes associated with muscle atrophy.

Keywords: Fasting; autophagy; brown adipose tissue; muscle atrophy.

MeSH terms

  • Animals
  • Body Composition
  • Fasting*
  • Gene Expression
  • Liver
  • Male
  • Mice
  • Muscle, Skeletal* / metabolism
  • Proteolysis