On Rat Skeletal Muscle Satellite Cells And Related Cytokines In Exhaustive Exercise And Blunt Trauma

Objective:The purpose of this paper was to investigated how exhaustive exercise and contusion affected skeletal muscle satellite cells, platelet growth factor (PDGF) and transforming growth factor-beta (TGF-beta) in rat.Methods:24wistar male rats were randomly divided into four groups (n=6) and control group (C) did not exercise. The exercise groups were given disposable treadmill exhaustive exercise and slaughtered after exhaustion instantly and24hours and48hours (E0, E24, E48). Then the left gastrocnemius muscle was removed, and the gastrocnemius was split in two. One was used to a cell culture experiments immediately, and the other kept in storage to liquid nitrogen to be detected platelet-derived growth factor (PDGF) and transforming growth factor-beta(TGF-beta) changes.Contusion group:3wistar male rats were given contusion experiments, and anesthetized after contusion instantly and24hours and48hours. The left gastrocnemius was removed and used to a cell culture experiments immediatly. On the other hand, take another newborn rat and remove the left gastrocnemius muscle to do a cell culture experiments,too.Result(1) Through the muscle satellite cell culture results it can be observed that at the incipient stage of muscle statellite cell culture satellite cells were proliferated slowly untile on the fifth day satellite cells were proliferated significantly. On the eighth day of muscle statellite cell culture satellite cells had been covered with most Petri dish, then the growth slow down. Each group can be seen by comparison, the content of muscle satellite cells proliferation in the quiet control was the least, and they grow slowest; On the other hand, the content in the newborn rat group was the highest, and they grow fastest which could be seen a small amount of spindle cell only the next day after culture. The results of exhaustive exercise group and contusion group were similar, and showed no significant difference between the two groups.(2) The results of ELISA detection of PDGF showed that there was a significant change in PDGF content in skeletal muscle after an exhaustive exercise. Compared with the control group, Exhaustive exercise groups E0, E24, E48increased significantly and the difference was very significant (P<0.01). But there were no significant change among these exercise groups.(3) ELISA detection of TGF-beta results show:once after exhaustive exercise, there are obvious changes in skeletal muscle content of TGF-beta, exhaustive exercise group E0, E24, E48and quiet control group significantly reduced, all of exhaustive exercise group (EO, E24,E48) has particularly significant difference (P<0.01), There are significant changes in myocardial TGF-beta in content, were decreased have special significant difference (P<0.01).Conclusion:(1) According to the results of cell culture in vitro,it showed that exhaustive exercise and contusion can activated obviously the resting period of skeletal muscle satellite cell, which bred faster and more than the control group, But there was no significant difference about the quantity of muscle satellite cells between exhaustion exercise group and contusion group.It indicated that both of exhaustive exercise and contusion had the similar way to repaired of damage. On the other hand, the newborn mice muscle under no stimulated condition had more satellite cells and the stronger proliferation ability, which indicated that muscle satellite cells of newborn mice were not in a resting state in the body.(2) By compared with control group, the PDGF levels of skeletal muscle was more higher during exhaustion exercise and recovery than in control group, and there was no significant change among groups in terms of exhaustion (E0, E24, E48).It indicated that PDGF may played an important role to promote the restoration of skeletal muscle.(3) The TGF-beta levels of skeletal muscle during exhaustion exercise and recovery were significantly lower than the control group, but there was no significant change among the exhaustive groups (E0, E24, E48). On one hand it may be due to the inhibitory effect of other positive regulatory factor to TGF-beta, on the other hand due to the permeability change of cell membrane induced from injury made it leak out. The action mechanism of TGF-beta remained to be further researched.