RELATION BETWEEN TOTAL ANTIOXIDANT CAPACITY AND LIPID PEROXIDATION PRODUCTS IN SERUM AFTER PROLONGED EXERCISE 1673

Abstract

The purpose of this study was to investigate the change in lipid peroxidation products and total antioxidant capacity in serum, and to determine the relation between the two after prolonged exercise. Fourteen male triathletes (39.2±9.7 yr.) who participated in the '95 Ironman Japan in Lake Biwa (3.8km swim, 180.2km bike, 42.2km run, average duration time: 10hr. 49min.) were examined. Blood samples were taken four times (before, immediately after, one day after and one week after the race) to determine the serum thiobarbituric acid reactive substances (TBARS), which were used as an index of lipid peroxidation products. The lag time for the initiation of conjugated diene formation in serum exposed to 50μM CuSO4in vitro was used as an index of total antioxidant capacity of serum. Serum vitamin C (V.C) levels were also measured. Serum TBARS decreased significantly immediately after the race (-13.3%), however, they showed a significant increase one week after the race (30.2%). The lag time was prolonged significantly immediately after the race (27.6%), however, it tended to be shortened one week after the race (-8.2%). There was a significant increase of serum V.C immediately after the race (49.8%), however, it showed a significant decrease one week after the race (-10.2%). A negative correlation between serum TBARS and the lag time was observed one week after the race (r=0.600, p<0.05). Further, serum V.C tended to correlate with the lag time one week after the race. Table These results suggest that subjects who had an obvious shortened lag time, showed higher serum TBARS one week after the race. Decreased serum V.C may be one of the possible causes of shortened lag time one week after the race. From these results, we conclude that decreased serum V.C and other antioxidants lead to a decline in total antioxidant capacity, and that lipid peroxidation products increase at some interval after prolonged exercise.