Advertisement

Effect of dietary supplements containing antioxidants on attenuation of muscle damage in exercising sled dogs

View More View Less
  • 1 Department of Clinical Veterinary Sciences, College of Veterinary Medicine ,The Ohio State University, Columbus, OH 43210.
  • | 2 Department of Clinical Veterinary Sciences, College of Veterinary Medicine ,The Ohio State University, Columbus, OH 43210.
  • | 3 Department of Human Nutrition and Food Management, College of Human Ecology , The Ohio State University, Columbus, OH 43210.
  • | 4 Department of Research and Development, The Iams Company,P O Box 189, Lewisburg, OH 45338.
  • | 5 Department of Clinical Veterinary Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210.
  • | 6 Department of Research and Development, The Iams Company,P O Box 189, Lewisburg, OH 45338.
  • | 7 Department of Research and Development, The Iams Company,P O Box 189, Lewisburg, OH 45338.
  • | 8 Lightning Bolt Express Kennels, 7075 Pawprint Trail, Two Rivers, AK 99716.

Abstract

Objective—To determine whether dietary antioxidants would attenuate exercise-induced increases in plasma creatine kinase (CK) activity in sled dogs.

Animals—41 trained adult sled dogs.

Procedure—Dogs, randomly assigned to 2 groups, received the same base diet throughout the study. After 8 weeks on that diet, 1 group (21 dogs) received a daily supplement containing vitamins E (457 U) and C (706 mg) and β-carotene (5.1 mg), and a control group (20 dogs) received a supplement containing minimal amounts of antioxidants. After 3 weeks, both groups performed identical endurance exercise on each of 3 days. Blood samples were collected before and 3 weeks after addition of supplements and after each day of exercise. Plasma was analyzed for vitamins E and C, retinol, uric acid, triglyceride, and cholesterol concentrations, total antioxidant status (TAS), and CK activity.

Results—Feeding supplements containing antioxidants caused a significant increase in vitamin E concentration but did not change retinol or vitamin C concentrations or TAS. Exercise caused significantly higher CK activity, but did not cause a significant difference in CK activity between groups. Exercise was associated with significantly lower vitamin E, retinol, and cholesterol concentrations and TAS but significantly higher vitamin C, triglyceride, and uric acid concentrations in both groups.

Conclusions and Clinical Relevance—Use of supplements containing the doses of antioxidants used here failed to attenuate exercise-induced increases in CK activity. Muscle damage in sled dogs, as measured by plasma CK activity, may be caused by a mechanism other than oxidant stress. (Am J Vet Res 2000;61:1438–1445)

Abstract

Objective—To determine whether dietary antioxidants would attenuate exercise-induced increases in plasma creatine kinase (CK) activity in sled dogs.

Animals—41 trained adult sled dogs.

Procedure—Dogs, randomly assigned to 2 groups, received the same base diet throughout the study. After 8 weeks on that diet, 1 group (21 dogs) received a daily supplement containing vitamins E (457 U) and C (706 mg) and β-carotene (5.1 mg), and a control group (20 dogs) received a supplement containing minimal amounts of antioxidants. After 3 weeks, both groups performed identical endurance exercise on each of 3 days. Blood samples were collected before and 3 weeks after addition of supplements and after each day of exercise. Plasma was analyzed for vitamins E and C, retinol, uric acid, triglyceride, and cholesterol concentrations, total antioxidant status (TAS), and CK activity.

Results—Feeding supplements containing antioxidants caused a significant increase in vitamin E concentration but did not change retinol or vitamin C concentrations or TAS. Exercise caused significantly higher CK activity, but did not cause a significant difference in CK activity between groups. Exercise was associated with significantly lower vitamin E, retinol, and cholesterol concentrations and TAS but significantly higher vitamin C, triglyceride, and uric acid concentrations in both groups.

Conclusions and Clinical Relevance—Use of supplements containing the doses of antioxidants used here failed to attenuate exercise-induced increases in CK activity. Muscle damage in sled dogs, as measured by plasma CK activity, may be caused by a mechanism other than oxidant stress. (Am J Vet Res 2000;61:1438–1445)