OBJECTIVETo investigate the effect of exogenous carnitine on function of respiratory chain and antioxidant capacity in mitochondria of myocardium in rats.

METHODSForty male Wistar rats were randomized to 4 groups (n = 10): static control (C), supplementation of carnitine (LC), exercise-training (T) and training with supplementation of carnitine (TLC). LC and TLC animals were perfused carnitine by the dose of 300 mg/kg bw x d. T and TLC animals were forced to performed 6-week treadmill training. Heart were prepared immediately after exhaustive running. Myocardium mitochondria was extracted by differential centrifugation. Spectrophotometric analysis was used to evaluate activities of respiratory chain complex (C) I -IV and superoxide dismutase (SOD), malondialdehyde (MDA) level in myocardium mitochondria.

RESULTSTo compare with C group, C I and C IV activity in LC, T and TLC group were increased significantly (P < 0.05, P < 0.01), CII and C III activity in T and TLC group were increased significantly (P < 0.05, P < 0.01); to compare with LC group, C I - IV activity in TLC group were increased significantly (P < 0.05, P < 0.01); to compare with T group, CI and C IV activity in TLC group increased significantly (P < 0.05). To compare with C group, SOD activity increased remarkably, MDA was remarkably lower (P < 0.05, P < 0.01) in LC, T and TLC group; To compare with LC and T group, SOD activity increased remarkably, MDA was remarkably lower (P < 0.05) in TLC group.

CONCLUSIONCarnitine and training could improve function of respiratory chain and increased antioxidant capacity in myocardium mitochondria, there was better function of cooperation between carnitine and training.