The Effect Of Exogenous L-Carnitine On Activities Of Respiratory Chain Complexes In Mitochondria And Free Radicals Metabolism From Rat's

Fatty acids are the Human and mammalian's major source of energy substances, in sufficient oxygen supply conditions, the fatty acids break down into CO2 and H2O and the release of substantial energy to the form of ATP for the body to use. It is clear that fatty acid oxidation can be seen to appear to be particularly important. Fatty acid oxidation must enter into the matrix of mitochondria, while the long-chain acyl-CoA can not through directly the mitochondrial, and it is necessary that carnitine transporter. Mitochondrial outer side exists carnitine acyltransferaseⅠ, it catalyzed long-chain acyl-CoA and carnitine acyl-carnitine synthesis, and then under the action of the carnitine acyl translocase which locates at the inner side of mitochondrial inner carnitine, it can enter into the mitochondrial matrix, into the mitochondria within the acyl-carnitine is located at the inner mitochondrial carnitine acyltransferaseⅡinto the role of acyl-CoA and release of carnitine, acyl-CoA in the mitochondria can matrix enzyme system under the role ofβ-oxidation, enhance mitochondrial oxidation rate. this experiment taken by exogenous L-carnitine supplement in combination with exercise training as a model to observe the rat skeletal muscle mitochondrial respiratory chain enzyme complex ofⅠ~Ⅳactivity to explore the sports training and supplementary L-carnitine of its impact, with a view to reasonable use of nutritional supplements to improve mitochondrial respiratory function, in order to improve exercise capacity study to provide information.Experimental Methods: Healthy male 50 two-month-old Wister rats, weight: 130±20g, after all the rats are feed suitability for one week, according to the requirements were randomly divided into quiet contraposition group (10), disposable exhaustive group (10), simple exercise group (10), simply add carnitine group (10), exercise + supplement carnitine group (10). The contraposition group and simply group have not do any exercise, simple exercise and exercise + supplement carnitine group incremental burthen intensity treadmill exercise, the training time for a total of six weeks. Supplementary carnitine group and training + supplementary carnitine group have been trained everyday at 19:00 pm -22:00 and have been gavaged to supply carnitine at 8:00 of the next day (300mg/kg body weight), the control group as well as the training group have been gavaged distilled water to their stomach at the same dose with the control group. The first seven weeks in all experimental rats Mondays (except the quiet control group) disposable to exhaustive treadmill exercise immediately after decapitation were killed, the rats were measured in skeletal muscle mitochondrial respiratory chain enzyme complexⅠ~Ⅳactivity and MDA content, SOD, GSH, CAT activity.The experimental results: (1) At the end of the experiment, the contraposition group compared with the simple exercise group, simply add exercise + L-carnitine group and added carnitine rats have significant differences in body weight, and its significant level, respectively (P <0.01, P <0.01, P <0.001), disposable exhaustive group no significant difference (P> 0.05); exercise + supplement group and simply added carnitine carnitine group (P <0.01), exercise + supplement L-carnitine group and simple exercise group, there is body weight also significantly different (P <0.001).(2) the contraposition group compared with the simple exercise group and supplementary carnitine in rats exercise treadmill time to exhaustion were significantly different (P <0.001). Purely supplementary carnitine in rats exercise treadmill time to exhaustion was no significant difference (P> 0.05). And simply added carnitine group, exercise + supplement carnitine Units rats running time to exhaustion was significantly longer (P <0.01).(3) the contraposition group compared with the simple exercise group CⅠ-CⅣactivity are increased but no significant difference; simply added skeletal muscle mitochondrial carnitine group CⅠ-CⅣincreased activity (P> 0.05), but no significant difference; Sports + supplementary carnitine group CⅠ~ CⅣwere significantly higher activity (P <0.001). Compared with the simple exercise, exercise + supplement carnitine group CⅠ, CⅢ, activity was significantly higher (P <0.01), CⅡ, CⅣactivity no significant changes (P> 0.05). And supplementary L-carnitine group alone compared to exercise + supplement carnitine group CⅠ~ CⅣactivity have no significant difference.(4) the contraposition group compared with the simple supplementary carnitine rats to treadmill exercise immediately after exhaustive activity in skeletal muscle mitochondrial SOD increased significantly (P <0.05), MDA content decreased slightly (P> 0.05), but CAT, GSH activity was no significant difference (P> 0.05). The control group compared with the quiet, simple exercise group, simply add in rat skeletal muscle mitochondrial carnitine group SOD, CAT, GSH increased activity, MDA content decreased, but the difference was not significant. + Supplementary exercise training in skeletal muscle mitochondrial carnitine group SOD, CAT, GSH increased activity, MDA content decreased.Experimental conclusions: (1) simply supplymentary carnitine on weight gain in rats has little effect on long-term exercise can add supplementary carnitine significantly delayed the growth rate of body weight in rats.(2) simply added carnitine on rat treadmill to exhaustive exercise did not significantly affect the time. Long-term exercise training can significantly extend the rats ran a one-time Units of time to exhaustion, long-term exercise can add supplementary carnitine in rats significantly improve treadmill to exhaustive disposable time, improve exercise capacity.(3) add a simple line-carnitine can improve skeletal muscle respiratory chain enzyme tablets CⅠ-CⅣactivity to accelerate the process of mitochondrial oxidative phosphorylation, in order to provide conditions of mitochondrial ATP synthesis, but added carnitine alone and should not be very effective to postpone the occurrence of exercise-induced fatigue.(4) simply added carnitine in rat skeletal muscle mitochondria can enhance SOD, CAT, GSH activity is not obvious, however, long-term exercise training can significantly add supplementary carnitine improve its activity and lower MDA content.