Dietary vitamin E and physical exercise: II. Antioxidant status and lipofuscin-like substances in aging rat heart

Abstract

The heart faces a high risk of free radical injury owing to a slow generation of antioxidant (AO) enzymes by its cells. A general decline in this system may be another reason for the development of age-related diseases. Although the correlation between aging and exercise has been studied extensively, these studies have produced conflicting data on the effects of vitamin E on the aging heart, when it is introduced as an intervening factor. To investigate these effects, we determined the activities of antioxidant enzymes (AOEs) such as superoxide dismutase (SOD) and catalase (CAT), lipid peroxidation (LP), lipofuscin (LF)-like autofluorescent substances and vitamin E content in the left and right ventricles (LV and RV) of the heart in male Wistar albino rats of 4-(young adults), 8-(old adults), 12-(middle-age) and 22-mos(old) of age. Animals were orally supplemented with vitamin E and allowed to swim for 30 min/day, 5 days/week and for a total period of 60 days. Exercise training in all the age groups except the old was effective in upregulating the SOD activity. Old trainees showed an increase in SOD activity when supplemented with vitamin E. In the 22-mo-olds, a remarkable decrease in CAT activity was seen. Exercise by itself upregulated the CAT as well as SOD activity in all age groups except the old wherein vitamin E was effective in increasing the activities of AOEs. Supplementation significantly reduced LP as evidenced by lowered malondialdehyde (MDA) and LF-like autofluorescent substances in the trained as well as sedentary rats. Tissue vitamin E content was low in the swim trainees that were not supplemented. This change, well emphasized in the trainee groups of 22-mo-old suggests the probable utilization of vitamin E in keeping free radicals at bay. Our results suggest that vitamin E can stand out as a significant tool in ameliorating the declining AO defense in the old rats. q

Age and sex-related changes in superoxide dismutase activity in bovine tissues

“…Asha Devi et al (2003) observed the decrease in SOD activity with age in the heart of rats, similarly as in the present study. Rinaldi et al (2006) examined the effect of exercise in rats and found no changes in the activity of Mn-SOD and CuZn-SOD in the heart with regard to age.…”

Age-related changes in the brain antioxidant status: modulation by dietary supplementation of Decalepis hamiltonii and physical exercise

“…We chose swimming as physical exercise as these animals are inborn swimmers and are less stressed when compared to treadmill exercise [30], and also there is no requirement of electric shock to promote this exercise protocol. In the present study, the body weight is decreased in swim-trained and supplemented groups, which indicates the beneficial effects of exercise training and supplementation of root extract.…”

Cardiovascular Effects of Exercise Training

“…In animal models of aging, increased malondialdehyde levels were observed in sedentary old rats. Although the expression of antioxidative enzymes such as superoxide dismutase (SOD) was unchanged, 6,7 its enzymatic activity was reduced, 8 resulting in a net decline of antioxidative protection. Regular physical exercise seems to delay the accumulation of ROSmediated cell damage by improving the antioxidative protection in the myocardium.…”