Format

Send to

Choose Destination
Can J Vet Res. 2015 Oct;79(4):329-38.

Relationship of oxidative stress in skeletal muscle with obesity and obesity-associated hyperinsulinemia in horses.

Author information

1
Department of Physiological Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, Oklahoma 74078, USA (Banse, McFarlane); Department of Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts 01536, USA (Frank); Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta T2N 4Z6 (Kwong).

Abstract

in English, French

In horses, hyperinsulinemia and insulin resistance (insulin dysregulation) are associated with the development of laminitis. Although obesity is associated with insulin dysregulation, the mechanism of obesity-associated insulin dysregulation remains to be established. We hypothesized that oxidative stress in skeletal muscle is associated with obesity-associated hyperinsulinemia in horses. Thirty-five light breed horses with body condition scores (BCS) of 3/9 to 9/9 were studied, including 7 obese, normoinsulinemic (BCS ≥ 7, resting serum insulin < 30 μIU/mL) and 6 obese, hyperinsulinemic (resting serum insulin ≥ 30 μIU/mL) horses. Markers of oxidative stress (oxidative damage, mitochondrial function, and antioxidant capacity) were evaluated in skeletal muscle biopsies. A Spearman's rank correlation coefficient was used to determine relationships between markers of oxidative stress and BCS. Furthermore, to assess the role of oxidative stress in obesity-related hyperinsulinemia, markers of antioxidant capacity and oxidative damage were compared among lean, normoinsulinemic (L-NI); obese, normoinsulinemic (O-NI); and obese, hyperinsulinemic (O-HI) horses. Increasing BCS was associated with an increase in gene expression of a mitochondrial protein responsible for mitochondrial biogenesis (estrogen-related receptor alpha, ERRα) and with increased antioxidant enzyme total superoxide dismutase (TotSOD) activity. When groups (L-NI, O-NI, and O-HI) were compared, TotSOD activity was increased and protein carbonyls, a marker of oxidative damage, decreased in the O-HI compared to the L-NI horses. These findings suggest that a protective antioxidant response occurred in the muscle of obese animals and that obesity-associated oxidative damage in skeletal muscle is not central to the pathogenesis of equine hyperinsulinemia.

PMID:
26424915
PMCID:
PMC4581679
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for PubMed Central
Loading ...
Support Center