Influência da suplementa？？o aguda e cr？nica de creatina sobre marcadores enzimáticos de dano muscular de ratos sedentários e exercitados com nata？？o

the aim of this study was to investigate the effects of the short-term (5 g.kg-1 to 1 week) and long-term (1 g.kg-1 to 4-8 weeks) creatine supplementation (cr) on the creatine kinase (ck), lactate dehydrogenaze (ldh) and aspartate aminotransferase (ast) plasmatic concentrations of sedentary and exercised (swimming to 80% of the tolerated maximum load) rats. seventy two wistar males rats (250 ± 10 g) were equally divided in four groups: sedentary rats without supplementation (con; n = 18); exercised rats without supplementation (nat; n = 18); sedentary rats with supplementation (cre; n = 18); exercised rats with supplementation (cre+nat; n = 18). at the end of the first, fourth and eighth weeks six animals of each group were sacrificed. the results demonstrated: 1) improvement of ck, ldh and ast in nat-1 and cre+nat-1 groups vs. con-1 and cre-1 groups after the first experimental week; 2) higher values of ck and ldh only nat-4 group after four experimental weeks; and 3) only ast from cre-8 group differed from other groups at the end of the eighth experimental week. these findings suggest that the cr supplementation: 1) does not affect the muscle damage on swimming exercised rats after one week of high intensity training; 2) could be able to reduce the muscle damage after 4 weeks of training; and 3) after eight weeks of cr supplementation, the muscle damage seems to be attenuated by the exercise, nullifying the effects of cr.