Effect Of TRP Channel On Micro - Injury Effect Of Acupuncture Intervention On Exercise Skeletal Muscle

1. Objective: Acute eccentric exercise can induce skeletal muscle ultrastructural damage, these micro-damage directly or indirectly induce the decline of muscle strength, symptoms of delayed onset muscle soreness and other symptoms, affect the training performance of athletes seriously. It is found that acupuncture can accelerate the recovery of skeletal muscle ultrastructure damage, but the mechanism is still not very clear. The latest research found that the TRP channel has relationship with the acupuncture effect. In this study, we used the eccentric exercise-induced skeletal muscle micro-damage animal model to investigate the mechanism of acupuncture on the recovery of skeletal muscle ultrastructure.2.Methods: Ninety-six male Wistar rats were randomly divided into 4 groups: control group(C), exercise groups(E), exercise and acupuncture groups(EA) and exercise, acupuncture and blocking agents groups(EAI). In addition to control group, the other groups rats performed a downhill running exercise on a treadmill at a-16° tilt and a constant speed for 90 min. No intervention was applied on E group after exercise, EA groups use a diameter of 0.25 mm needle sideways pierce both sides of the extensor digitorum longus,retaining needle 4 minutes. The rats of EAI were injected with Gd Cl3 solution in the tail vein after exercise immediately and acupuncture after 30 minutes. After the cessation of exercise, each group was divided into 2 h, 6 h, 24 h, 48 h, 120 h, the extensor digitorum longus was taken and detected for transmission electron microscopy, using Image J(NIH) software to analyze skeletal muscle ultrastructural changes(Z line destroyed,disrupted,wavy), mitochondria morphology(area, perimeter, roundness, Feret diameter, aspect ratio and form factor), distribution and volume changes, the number of caveolae and IMJs changes at different time points.3.Results: 3.1 The changes of skeletal muscle ultrastructural: the Z line complete degree of E, EA, EAI showed the trend of decreased first and then increased. The most serious injury time appeared at 24 h, but acupuncture. but the extent of damage is lightest in EA group. the TRP channel blocking agent is significantly weakened the effect of acupuncture.3.2 IMF mitochondria morphological changes: compared to EA and E, EAI, intermyofibrillar mitochondrial area, perimeter, Feret’s diameter, form factor shift right and roundness shift left, and the distribution has very significant difference(P<0.01), 6 h, 24 h mitochondrion form factor was highly significantly increased(P<0.001), 48 h and 120 h slightly downward.3.3 Subsarcolemmal(ss) mitochondria morphological changes: compared to EA and E, EAI, SS mitochondrial area, perimeter, Feret’s diameter, form factor shift right and roundness shift left, and the distribution has very significant difference(P<0.01). Compared EA with E, the form factor in 6 h was very significantly increased(P<0.01), at 24 h was highly significantly increased(P<0.001). EA compared with EAI, the shape factor at 6 h and 48 h was highly significantly increased(P<0.001).3.4 The changes of IMF mitochondrial volume: E, EA, EAI groups, the number of of IMF mitochondrial were decreased first and then increased, at least 24 h. After 24 h, the acupuncture intervention group increased rapidly, while the E group and the EA group were increased after 24 h, but the amplitude was not as significant as that of EA group.3.5 The changes of SS mitochondrial volume: E, EA, EAI groups showed the trend of first increased and then decreased, and the peak value occurred at 24 h, EA groups was most, compared to EA and E, 24 hours have increased very significantly(P<0.01) and 48 h was significantly increased(P<0.05); compared to EA and EAI, 2 h has increased very significantly(P<0.01), 24 h, 48 h has highly significantly increased(P<0.001).3.6 The number of IMJs changes: E, EA, EAI groups showed the trend of first increased and thendecreased, and the peak value occurred at 24 h, but the EA groups were more, the TRP channelblocking agent is significantly weakened the effect of acupuncture.3.7 The number of caveolae changes: E groups were higher than EA and EAI groups, and the peak value of E and EA groups occurred at 24 h, EAI groups showed little changes overall trend.4.Conclusion: 4.1An acute eccentric exercise can cause skeletal muscle ultrastructural damage, the number of caveolae, IMJs increased.4.2 Acupuncture can activate TRP channels, increase the number of caveolae and IMJs, promote mitochondrial fusion and promote the recovery of skeletal muscle ultrastructure.