Effect Of Acupuncture Point Embedding On Skeletal Muscle Of Rats With Exercise Fatigue Model And Study Of CaN/NFAT Signaling Pathway

In this study,exercise-induced fatigue model rats were used as experimental subjects to explore the prevention and mechanism of acupoint catgut embedding therapy on exercise-induced fatigue.Forty Wistar male rats were randomly divided into blank group,running group,acupoint catgut embedding running group I and acupoint catgut embedding running group II,and the acupoint catgut embedding running group was subjected to the corresponding buried threads at the acupoints.Heart blood was collected to determine blood gas and biochemical indexes,and the soleus and gastrocnemius muscles of the hind limbs of the rats were dissected and analyzed for morphological changes of skeletal muscle by HE staining and immunofluorescence double-label staining,and the MHC isoforms were determined and analyzed by PCR nucleic acid electrophoresis,RT-q PCR and SDS-PAGE gel electrophoresis,and the CaN/NFAT signaling pathway was used to explore the effect of CaN/NFAT signaling pathway on skeletal muscle by RT-q PCR and WB methods.The mechanism of CaN/NFAT signaling pathway on the transformation of skeletal muscle fiber types was investigated by RT-q PCR and WB.The results showed that the exhaustion time of rats in acupoint catgut embedding running groupⅠand acupoint catgut embedding running groupⅡwas significantly higher than that of the running group（P<0.05）.Compared with the running group,the blood gas TCO₂,HCO₃^-,and serum Hct were significantly higher in the acupoint catgut embedding running group I rats（P<0.05）,and the blood gas PCO₂,TCO₂,and HCO₃^-were significantly lower in the acupoint catgut embedding running group II rats（P<0.05）,and the serum Glu,NOS,SOD,and CAT were significantly higher in the acupoint catgut embedding running group I and acupoint catgut embedding running group II rats（P<0.05）,and BUN,TNF-α,ROS,and CAT were significantly higher in the acupoint catgut embedding running group II rats（P<0.05）,TNF-α,ROS,MDA,Lac were significantly decreased（P<0.05）.Compared with the blank group,the specific gravity of soleus and gastrocnemius muscles was significantly higher in the running group,acupoint catgut embedding running group I and acupoint catgut embedding running group II（P<0.05）.HE staining showed that compared with the blank group,the muscle bundles of soleus muscles were tighter and the number of muscle fibers was higher in the exercising groups,and the muscle fiber structure was damaged in the running group;compared with the blank group,the muscle fibers of gastrocnemius muscles were tighter in the exercising groups,and the muscle bundle interval was The muscle bundle interval was larger in the running group.The results of immunofluorescence double-label staining showed that the MHCI type muscle fibers were significantly higher（P<0.05）and the MHCII type muscle fibers were significantly lower（P<0.05）in both acupoint catgut embedding running group I and acupoint catgut embedding running group II rats compared with the running group.The MHCI type muscle fibers were significantly higher（P<0.05）and the MHCII type muscle fibers were reduced（P<0.05）in the gastrocnemius muscle of both acupoint catgut embedding running group I and acupoint catgut embedding running group II rats.The MHCI type muscle fibers were significantly decreased（P<0.05）and MHCII type muscle fibers were significantly increased（P<0.05）in the gastrocnemius muscle of rats in the acupoint catgut embedding running group I than in the acupoint catgut embedding running group II.The results of the mechanism study showed that the rats in the running group had elevated Ca M and CaN and decreased NFAT in the soleus muscle,which did not show the advantage of shifting to type I muscle fibers;the rats in the acupoint catgut embedding running group I and acupoint catgut embedding running group II had decreased Ca M and CaN and significantly increased NFAT in the soleus muscle,which obviously showed the trend of shifting from MHC IIa,MHC IIx and MHC IIb to MHCI.The Ca M,CaN,and NFAT of gastrocnemius muscle of rats in the runner group decreased,and the m RNA and protein of MHCⅡa,MHCⅡx,MHCⅡb,and MHCI showed a trend of decrease;the Ca M,CaN,and NFAT of gastrocnemius muscle of rats in the buried runner groupⅠand buried runner groupⅡincreased,showing a trend of decrease of MHCI and increase of MHCⅡa,MHCⅡx,and MHCⅡb.Conclusions:（1）Acupoint catgut embedding can improve blood gas and biochemical indicators in exercise induced fatigue rats,promoting the recovery of the body.（2）Acupoint embedding can increase the wet mass/body mass and muscle fibers of soleus and gastrocnemius muscles,prolong exercise time and improve exercise endurance in rats.（3）Acupoint embedding can increase the advantage of type II muscle fibers to type I muscle fibers in rat soleus muscle by activating CaN/NFAT signaling pathway;reduce the tendency of type I muscle fibers to type II muscle fibers in rat gastrocnemius muscle.