The Effect Of Qixian Tongluo Recipe On The Axon Regeneration In The Remotely Damaged Part Of MCAO Rats And Its Mechanism

Objective: To observe the location of distant injury in MCAO rats after cerebral infarction;To explore the effect and mechanism of Qixian Tongluo Decoction on axon regeneration in the remote damaged area of MCAO rats,so as to provide scientific basis for the clinical application of Qixian Tongluo Decoction in the treatment of cerebral infarction.Methods: The MCAO rat model was made by the modified thread bolt method.100 rats were selected and divided into 5 groups according to the random number table:high dose group,middle dose group,low dose group,citicoline group and model group,20 rats in each group,and 20 rats in the sham operation group as the control.On the 3th,7th and 14 th day after MCAO,8 rats in each group were randomly selected for Berdson neurological score.On the 14 th day,four rats were randomly selected from the sham operation group and the model group to be stained with glycine and silver,and the axonal degeneration was observed to determine the location of the distant injury;Then,5 rats were selected from each group to detect the expression level of GAP-43 protein in the distant lesion site and observe the axon regeneration;At last,Western blot was used to detect the expression of c AMP,PKA,Nogo-A and Nogo R protein in the ipsilateral brain tissue of each group.Results:(1)Compared with the sham operated group,the neural function score of the model group was significantly higher(P<0.01);the brain tissue of the rats was stained by glycine silver immersion,and under 5 times of microscope,the main blood supply area and the left thalamus and substantia nigra area of the left middle cerebral artery were found to be blocked,and the brain tissue was obviously necrotic,indicating that the model was successful and the thalamus and substantia nigra had remote damage.However,there was no morphological difference between the two groups under 20 times of microscope,suggesting that there was no distant lesion in the cervical spinal cord after cerebral infarction.(2)Nerve function score: compared with the model group,the nerve function scores of citicoline group and Qixian Tongluo Decoction high,middle and low dose groups were significantly reduced on the 3rd,7th and 14 th day(P<0.05);compared with citicoline group,the nerve function scores of each dose group of Qixian Tongluo Decoction were improved on the 7th and 14 th day(P<0.05).On the 7th and 14 th day,the recovery of nerve function in middle dose group was the best(P<0.05),It is suggested that the effect of Chinese and Western medicine is clear in improving the score of nerve function.The dose of Qixian Tongluo Decoction is better than that of citicoline group,and the effect of Qixian Tongluo Decoction is the most obvious.(3)GAP-43 protein expression: compared with the model group,the expression of GAP-43 protein in the axon regeneration marker of the remote damage site in the citicoline group and the high,middle and low dose groups of Qixian Tongluo Decoction was significantly increased(P<0.01);compared with the citicoline group,the expression of GAP-43 protein in the high,middle and low dose groups of Qixian Tongluo Decoction was increased(P<0.05).The expression of GAP-43 protein in middle dose group was the most significant(P<0.05).It is suggested that both Chinese and Western medicine can promote axon regeneration in the distant lesion after cerebral infarction,and the dose of Qixian Tongluo Decoction is better than that of citicoline group,and the most obvious promoting effect is Qixian Tongluo Decoction.(4)c AMP,PKA,Nogo-A,Nogo R protein expression: compared with the model group,cytosine group and Qixian Tongluo Decoction high,middle and low dose groups can significantly increase the expression level of c AMP and PKA protein(P<0.05),and down regulate the expression of Nogo-A and Nogo R protein(P<0.05);Compared with the citicoline group,the expression of c AMP and PKA protein increased(P<0.05),Nogo-A and Nogo R protein decreased(P<0.05)in the high,middle and low dose groups of Qixian Tongluo Decoction;compared with the different dose groups of Qixian Tongluo Decoction,the expression of c AMP and PKA protein increased most significantly(P<0.05),Nogo-A and Nogo R protein decreased most significantly(P<0.05)in the middle dose group.It is suggested that both Chinese and Western medicine can promote axon regeneration in the remote injury site after cerebral infarction by up regulating the expression of c AMP and PKA,down regulating the expression of Nogo-A and Nogo R protein.Qixian Tongluo Decoction is superior to citicoline in each dose group,and Qixian Tongluo Decoction has the most obvious effect in promoting axon regeneration.Conclusion:(1)In MCAO rats,the axons of thalamus and substantia nigra on the same side of infarct had distant damage,but the axons of cervical spinal cord had no change.(2)Qixian Tongluo Decoction can promote axonal regeneration of thalamus and substantia nigra in the remote damaged area of MCAO rats after cerebral infarction.(3)One of the mechanisms of Qixian Tongluo Decoction in promoting the recovery of neurological function after cerebral infarction in MCAO rats may be through activating c AMP/PKA signal pathway and inhibiting Nogo-A/Nogo R signal pathway,so as to jointly promote the axonal regeneration of thalamus and substantia nigra at the remote damage site.