Exercise-induced oxidative stress and muscle stress protein responses in trotters

Abstract

Acute exercise induces oxidative stress and heat shock protein (HSP) expression. Information on the protection of stress proteins against oxidant insult and muscle damage during moderate exercise is scanty. We aimed to show how a single bout of moderate exercise affects the markers of oxidative stress and heat shock factor-1 (HSF1; the transcriptional regulator of HSP synthesis), and HSP70, HSP90 and glucose-regulated protein (GRP75) expression in horses. Eight clinically normal and regularly trained standardbred trotters were treadmill-exercised for 45 min at moderate intensity. Blood samples were collected prior to and immediately after exercise and at 4 and 24 h of recovery. Muscle biopsy samples from the middle gluteal muscle were taken before exercise and after 4 h of recovery. Acute exercise did not activate HSF1 or induce expression of HSP70, HSP90 or GRP75 in skeletal muscle. One bout of acute exercise increased protein oxidation, which was measured by protein carbonyls in plasma and muscle, but it did not effect 4-hydroxynonenal protein adducts, which are markers of lipid peroxidation. Furthermore, mild muscle damage was observed 4 h after exercise. Our results showed that horses are susceptible to oxidative stress. One bout of exercise at moderate intensity and duration did not induce HSP responses despite the increased protein oxidation and tissue inflammation in equine muscle.

The Effect of Exercise in Cool, Control and Hot Environments on Cardioprotective HSP70 Induction

“…In a situation such as an aerobic exercise bout of moderate intensity and duration, additional signals besides an elevation in core temperature are present that could potentially activate HSP expression, including acidosis, energy depletion, reductions in blood flow to visceral organs and an associated tissue hypoxia, and generation of ROS (Davies et al, 1982;Hall et al, 1999;Hall et al, 1994;Kinnunen et al, 2004;Kregel andMoseley, 1996, Kregel, 2002;Srivastava, 1993). Furthermore, in addition to HSPs, cells will express other important stress proteins such as antioxidant enzymes, providing an organism with multiple cytoprotective options.…”

Effects of muscular dystrophy, exercise and blocking activin receptor IIB ligands on the unfolded protein response and oxidative stress

“…After SDS-PAGE, proteins were transferred to a nitrocellulose membrane (Millipore, Bedford, Mass., USA) as previously described [28]. The membranes were blocked and after that treated with antibodies overnight at 4°C.…”

Effect of Dietary Supplementation with Vitamin E and Selenium in Thoroughbred Horses on the Concentration of F2-isoprostanes in the Blood Plasma as a Marker of Lipid Peroxidation

“…Intensive exercise generates free radicals, and without an adequate rest period this may cause accumulation of these dangerous substances (Chiaradia et al 1998). Strenuous training on a daily basis may increase the rate of lipid peroxidation and protein oxidation, leading to an inflammatory reaction and muscle disease (Kinnunen et al 2005;Sacheck and Blumberg 2001). The protective role of antioxidant supplementation against excessive oxidative damage of trained horses was confirmed (Avellini et al 1999;White et al 2001;de Morffarts et al 2005).…”

“…The organism is protected against overproduction of ROS by an effective antioxidant defence system (Sen 1995;Sacheck and Blumberg 2001;Deaton et al 2004;Kinnunen et al 2005). Vitamin E and selenium are considered to be the key antioxidant components in the feed ratio.…”