| Mitochondria are energy metabolism and energy supply of the cell organelles core for human body.It ensures energy supply within the cells through oxidative phosphorylation of the body. Mitochondrial structure and function of small changes can directly or indirectly affect skeletal muscle function, even the health of the body. Mitofusin-2 participate in the mitochondrial outer membrane fusion. In addition it also is involved in a variety of cell biology process,such as affecting cell energy metabolism and the signal transduction of apoptosis.Mitofusin-2 leads to cell proliferation and apoptosis occur. Aging can lead to mitochondrial structure and function change. Resistance exercise can serve as a more effective means, and regulate the expression of protein Mitofusin-2, which accelerating the formation of the integration and networking of mitochondrial mitochondria. The indicators which Include mitochondrial membrane potential, reactive oxygen species(ROS) and free calcium can reflect the change of mitochondrial function in a timely manner.In this way, it can resistance movement regulation of mitochondrial structure and function.This, in turn, can provide the basis for anti-aging.Method:The research object is the male SD rats,which were randomly divided into four groups: the adult quiet control group(group C), the adult resistance exercise group(group R), the aging quiet control group(group O), the aging resistance exercise group(group Y). Each group has 10 rats.The quiet control group: rats did not participate in any sport, free diet, drinking water. The SD rats of group R and Y trained for 8 weeks on treadmill, slope of 35 degrees, speed of 15m/min. To determine each Mitofusin-2 protein in rats using Western blott method.To test the mitochondrial membrane potential, reactive oxygen species and free calcium using flow cytometry instrument.Results:1.Expression of Mitofusin-2 proteinThe quadriceps Mfn2 protein expression in rats of group R has a slight increase compared to the group C,but there is no significant difference.The quadriceps Mfn2 protein expression in rats of group O has dropped significantly compared to group C, which has a very significant difference(P<0.01). The quadriceps Mfn2 protein expression in rats of group Y has risen compared to the group O,which has a significant difference(P<0.05).2.Changes of mitochondrial Ca2+The cytosolic free calcium of rats in group C is in a higher level. The Ca2+ in cytoplasm of group R rats compared with group C has dropped significantly.After 8 weeks of resistance training, it has a very significant difference(P<0.01). The Ca2+ in cytoplasm of group O has increased significantly compared to group C, which has a very significant difference(P<0.01). The Ca2+ in cytoplasm of group Y is still at a higher level,after 8 weeks of resistance training.It has a significant reduction compared to the group O,which has a very significant difference(P<0.01).3.The change of mitochondrial reactive oxygenThe mitochondrial reactive oxygen of group C is in a low level.After 8 weeks of resistance training,the mitochondrial reactive oxygen of group R has a slight increase,but there is no significant difference between group R and group C.The mitochondrial reactive oxygen of group O increased significantly compared to group C,which has a very significant difference(P<0.01).The mitochondrial reactive oxygen of group Y is still at a higher level,after 8 weeks of resistance training.It has a significant reduction compared to the group O,which has a very significant difference(P<0.01).4.The change of mitochondrial membrane potentialThe mitochondrial membrane potential of group C and group R did not change significantly.There was no significant difference between the two groups.The mitochondrial membrane potential of group O has a significant reduction compared to the group C,which has a very significant difference(P<0.01).The mitochondria of group Y rats returned to normal levels,after 8 weeks of resistance training.There was no significant difference between group Y and group C. A marked increase in the mitochondrial membrane potential in group Y rats,compared to the group O,which has a very significant difference(P<0.01). Conclusion:1.Resistance exercise can make adult rats weight has a certain degree of growth.It keeps weight in aged rats with stable or slightly decreased. It can be used to speculate on aging rats thin weight gain and reduce body fat.2.Resistance movement has little effect on Mfn2 in adult rats.Mfn2 protein expression in aged rats showed a significant decline.From which we can infer the aging rats appeared mitochondrial function decline phenomenon.Mfn2 protein in aged rats was significantly upregulated after resistance exercise.So we can infer that resistance exercise promotes mitochondrial fusion mediated by Mfn2.Resistance exercise also improves mitochondrial function and inhibited the cell apoptosis.3.Cytoplasmic calcium in aged rats increased significantly.So we can infer that the accumulation of calcium ions was already having an impact on the function of mitochondria in aged rats.And so there is a skeletal muscle function decline, exercise ability drops phenomenon,and so on. Cytosolic calcium in the adult and aged rats were significantly decreased compared with the control group,after resistance exercise.From which it can be speculated that resistance exercise can improve the ability of calcium uptake by mitochondria.Resistance exercise also can maintain the proton gradient internal and external.It also can reduce cytoplasm calcium accumulation damage to cells and improve the exercise capacity in adult and aged rats.4.The smaller the influence of content of resistance exercise on mitochondrial reactive oxygen species in adult rats.Mitochondrial reactive oxygen species in aged rats showed significant increase.So it can be assumed that excess ROS have produced oxidative stress in aging rats.The body appear oxidative damage in rats.Mitochondrial ROS in aged rats decreased significantly.Thus speculated that resistance exercise can improve the cell and the capacity of antioxidant.It can also accelerate the removal of aged rats of excess ROS.5.The mitochondrial membrane potential in aged rats showed a significant decrease.So we can infer that mitochondrial membrane permeability of aged rats changed. Cells of aged rats showed early apoptosis.Mitochondrial membrane potential in aged rats rise significantly,after resistance exercise.So we can infer that Resistance exercise can improve the mitochondrial membrane potential in aged rats,in order to fight against early apoptosis phenomenon caused by aging.6.After resistance exercise,Mfn2 protein expression in aged rats increased Significant compared with the control group of rats.Cytosolic free calcium in aged rats compared with the control group of rats decreased significantly.Mitochondrial ROS in aged rats decreased significantly compared with the control group of rats.The mitochondrial membrane potential in aged rats increased significantly compared with the control group of rats..So we can infer that resistance exercise can improve mitochondrial function by regulating the expression of Mfn2 protein.Thus it can be against the cell apoptosis phenomenon, caused by the aging of skeletal muscle function decline, decreased exercise capacity,and so on. |
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