Swim exercise training and adaptations in the antioxidant defense system of myocardium of old rats: relationship to swim intensity and duration.
We examined a suitable swim program of different intensities and durations that could evoke changes in the myocardial antioxidant capacity in 22-month-old rats. Male rats (Rattus norvegicus) were assigned to either a sedentary control (SE-C) group or one of six trainee groups. Animals were swim-exercised for 4 weeks with either 20 min or 40 min/day, and three intensities, low, moderate and high. Low-intensity at 20 min/day elicited maximum swim velocity (Sv) and endurance capacity (P<0.05). While serum total cholesterol, triglyceride and low-density lipoprotein (LDL-C) levels were significantly reduced, high-density lipoprotein (HDL-C) showed an increase (P<0.05) in low-intensity trained rats (20 min/day) over SE-C. Notable reduction in blood lactate was also evident. Exercise training significantly increased superoxide dismutase (Mn-SOD), decreased lipid peroxidation products, malondialdehyde and lipofuscin in the left and right ventricles. Increased Mn-SOD with concomitant decrease in lipofuscin in left ventricle was significantly greater than in right ventricle. Moderate- to high-intensity exercise was not effective in either reducing lipid peroxidation products or elevating Mn-SOD activity. These data suggest that swim training at low-intensity of 20 min/day is beneficial as a major protective adaptation against oxidative stress in old myocardium.
Laboratory of Gerontology, Department of Zoology, Bangalore University, Bangalore 560 056, India.
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T
Ravi Kiran
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Subramanyam
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Asha Devi
D000222:Adaptation, Physiological / Q000502:physiology*; D000367:Age Factors; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D019344:Lactic Acid / Q000097:blood; D015227:Lipid Peroxidation / Q000502:physiology; D008062:Lipofuscin / Q000378:metabolism; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D018384:Oxidative Stress / Q000502:physiology; D010805:Physical Conditioning, Animal; D010807:Physical Endurance / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D014280:Triglycerides / Q000097:blood
D000975:Antioxidants; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D008062:Lipofuscin; D014280:Triglycerides; D019344:Lactic Acid; D008315:Malondialdehyde; D002784:Cholesterol; D013482:Superoxide Dismutase