Body weight loss in beef cows: II. Increased antioxidant messenger ribonucleic acid levels in skeletal muscle but not erythrocyte antioxidant activity

• Published in: Journal of animal science Vol. 87; no. 9; pp. 2867 - 2873
• Main Authors: Brennan, K.M, Terry, E.N, Michal, J.J, Kincaid, R.L, Johnson, K.A
• Format: Journal Article
• Language: English
• Published: Champaign, IL American Society of Animal Science 01.09.2009; Am Soc Animal Sci; Oxford University Press
• Subjects: adverse effects; Animal productions; Animals; antioxidant activity; Antioxidants; beef cows; Biological and medical sciences; biomarkers; body condition; Body fat; Body Weight - physiology; body weight changes; Cattle; Cattle - metabolism; erythrocytes; Erythrocytes - enzymology; Fatty Acids, Nonesterified - blood; Female; free fatty acids; Fundamental and applied biological sciences. Psychology; gene expression; gene expression regulation; Gene Expression Regulation, Enzymologic; glutathione peroxidase; Least-Squares Analysis; lipid metabolism; muscle physiology; Muscle, Skeletal - metabolism; Musculoskeletal system; oxidation; oxidative stress; Oxidoreductases - metabolism; protein synthesis; Random Allocation; RNA, Messenger - metabolism; skeletal muscle; superoxide dismutase; Terrestrial animal productions; Time Factors; Vertebrates; Weight; weight loss; Weight Loss - physiology; Glutathione peroxidase; Oxidative stress; Enzyme; Body weight; Weight loss; Superoxide dismutase; Antioxidant; Vertebrata; Mammalia; Peroxidases; Beef cattle; Muscle; Artiodactyla; Oxidoreductases; skeletal muscle; Ungulata
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/jas.2008-1301

Twenty-six Angus-cross cows were used to examine the effect of BW loss (WL) on skeletal muscle and erythrocyte markers of oxidative stress. Serum NEFA concentrations, erythrocyte superoxide dismutase, and glutathione peroxidase activities were measured during WL and BW maintenance. Real-time reverse-transcription-PCR was used to determine mRNA levels of antioxidant genes during both periods to assess skeletal muscle response to WL. Body weight loss resulted in elevated serum NEFA concentrations but no change in erythrocyte superoxide dismutase and glutathione peroxidase activities. During WL, mRNA levels of the antioxidant genes glutathione peroxidase 4, mitochondrial superoxide dismutase, thioredoxin reductase 1, and selenoprotein W increased. Abundance of mRNA of genes involved in antioxidant signaling, specifically, PPARγ coactivator-1 α, nuclear respiratory factor 1, estrogen-related receptor α, and tumor protein 53, was also increased. In summary, during WL cows had no change in peripheral antioxidant enzyme activity, but mRNA abundance of proteins involved in protecting the body from oxidative stress increased in skeletal muscle. During times when NEFA are used as a fuel source, signals such as mild reactive oxygen species production or increased concentration of lipid by-products activate the transcription of nuclear signaling molecules such as PPARγ gamma coactivator-1 α, nuclear respiratory factor 1, estrogen-related receptor α, and tumor protein 53. These genes work to activate antioxidant genes such as mitochondrial superoxide dismutase, glutathione peroxidase 4, and thioredoxin reductase 1 to aid in the detoxification of reactive oxygen species. These data suggest an important role for antioxidant genes to protect cattle that are mobilizing body fat.