Blood lipid profile and myocardial superoxide dismutase in swim-trained young and middle-aged rats: comparison between left and right ventricular adaptations to oxidative stress

Abstract

Region-wise interactive effects of age, swim intensity, and duration on exercise performance in the myocardium and serum lipid profile in young (4 months) and middle-aged (12 months) rats were examined. Animals were allocated to the sedentary control (SE-C) or one of the nine trainee groups. Swim training was for 6 days/week and for 4 weeks at 3 durations (20, 40, and 60 min/day) and intensities (2%, low; 3%, medium; 5%, high). Swim velocity and external work showed an age-related decline with low-intensity of 20 min/day in the middle aged. Reduction in serum cholesterol, low-density lipoproteins (LDLs), and triglycerides were accompanied by elevated levels in high-density lipoprotein in the low-to-moderately trained ones for 20 and 40 min/day. Training at 2%, intensity for 20 min/day was sufficient to alter the blood lipid profile and improve swim performance, and endurance in terms of blood lactate. A concomitant increase in Mn-superoxide dismutase (Mn-SOD) activity and reduced malondialdehyde in the left ventricle (LV) and right ventricle (RV) were evident. Lipofuscin was higher in the LV compared to RV. Our results reflect the minimization of free radical generation through appropriate exercise protocols. Our findings on improved blood lipid profile could be related to lower free radicals, which would otherwise oxidize LDLs. Further, swim training when initiated in the young and middle age for as low as 20 min/day at 2% intensity improves the Mn-SOD in the LV and RV. However, the adaptive response of the LV was weaker when compared to the RV, more so in the middle aged.

Antioxidant enzyme activities and markers of oxidative stress in the life cycle of earthworm,Eudrilus eugeniae

“…A significant increase in the levels of MDA has been observed from juvenile to adult groups and which in part agrees with findings of Corriea et al (2003) and Ravi Kiran et al (2006) in invertebrates and vertebrates. A negative correlation has been observed, with increasing MDA levels and decreasing SOD activities, in all the earthworm age groups.…”

The effects of exhaustive swimming and probiotic administration in trained rats: Oxidative balance of selected organs, colon morphology, and contractility

“…Moreover, it reduces lipid peroxidation in the gastrocnemius muscle and in the heart (p < 0.01). Although acute exhaustive or chronic exercise increases oxidative stress (25), our findings support the idea that the chronic exercise has beneficial effects in improving metabolic adaptation and maintaining oxidant balance (37,42,44). The serum lactate levels were not examined in this study.…”

“…Because the exhausting swimming exercise does not cause oxidative stress, this protocol might not be considered as sufficiently exhausting. However, the moderate training protocol applied in this study (5% overload, 60 min/day-5 days/week) is considered as highly intensive according to Ravi Kiran et al (37). We also found that probiotic intake during exercise led to a reduction in lipid peroxidation of the liver, whereas it led to an increase in antioxidant enzymes such as SOD and/or CAT in the colon and in the heart.…”

Swimming Training Induces Liver Mitochondrial Adaptations to Oxidative Stress in Rats Submitted to Repeated Exhaustive Swimming Bouts

“…Other authors have also reported that swimming training stabilizes body weight in rats [52], [53]. According to Ravi Kiran et al [52], who investigated different training intensities and durations in 4 and 12 months-old rats, the training protocol intensity applied in our study can be considered as high intensity (5% overload, 60 min/day –5 days/week). A high intensity swimming protocol demands high energy matching capacities so as to overcome the task.…”