ABSTRACT
Objective:To explore the central neurobiological mechanisms of pleasure effect on rats with neuralgia treated by tuina manipulations of An-pressing and Rou-kneading Huantiao (GB 30).Methods:A total of 64 male Sprague-Dawley (SD) rats were used in this study.Eighteen rats were randomly selected as a normal group,and the other 46 rats were used to duplicate the chronic constriction injury (CCI) model.Ten rats failed in modeling and 36 rats succeeded.These 36 rats were then randomly divided into a model group and a tuina group,with 18 rats in each group.The rats in the normal group and the model group did not receive any interventions,while those in the tuina group received An-pressing and Rou-kneading Huantiao (GB 30),1 min for each time,once a day,3 weeks in total.Heating tests were evaluated to observe the change of pain-sensitivity score before intervention,1 week after intervention,2 weeks after intervention,and 3 weeks after intervention.After 1 week of intervention,2 weeks of intervention,and 3 weeks of intervention,6 rats were randomly selected from each group respectively for brain extraction.The change of Nissl's body and β-endorphin in the accumbens nucleus as well as amygdaloid nucleus of pleasure circuits,and pro-opiomelanocortin (POMC) in the arcuate nucleus were analyzed by methods of histochemistry and molecular biology.Results:After modeling,the pain-sensitivity scores of the tuina group and the model group were statistically different from the score of the normal group (both P＜0.05).After An-pressing and Rou-kneading Huantiao (GB 30) for one week,the pain-sensitivity score of the tuina group had statistical difference compared with that of the model group (P＜0.05).At each different time point:the amounts of Nissl's body in accumbens nucleus and amygdaloid nucleus of the tuina group were significantly more than those of the model group (all P＜0.01).Besides,the numbers of β-endorphin immunoreactive cells in the accumbens nucleus and amygdaloid nucleus of the rats in the tuina group were significantly higher than those in the model group (all P＜0.01),and so was the expression of POMC in arcuate nucleus (all P＜0.01).Conclusion:An-pressing and Rou-kneading Huantiao (GB 30),where the sciatic nerve is ligated,can reduce pain-sensitivity score and increase pain tolerance value of rats with chronic neuralgia.It can increase the activity of neurons in accumbens nucleus and amygdaloid nucleus of pleasure circuits,which indicates that the analgesia effect of tuina therapy may correlate with pleasure effect,and also reveals a part of neurobiological mechanisms of neuralgia.