Effect of electroacupuncture at Neiguan(PC6)at different time points on myocardial ischemia reperfusion arrhythmia in rats

OBJECTIVE:To observe the effects of electroacupuncture at Neiguan(PC6)at different time points on reperfusion arrhythmia(RA)after myocardial ischemia and reperfusion in rats,and to investigate the correlation of this protective effect with nerve growth factor(NGF),tyrosine kinase A(Trk A),tyrosine hydroxylase(TH),and norepinephrine(NE).METHODS:A total of 72 Sprague-Dawley male rats were randomly divided into six groups(n=12 rats/group):normal group(Norm),sham operation group(Sham),ischemia reperfusion group(I/R),pre-ischemic electroacupuncture group(EAI),pre-reperfusion electroacupuncture group(EAII),post-reperfusion electroacupuncture group(EAIII).The myocardial ischemia-reperfusion injury(MIRI)model was induced by occlusion of left anterior descending coronary artery for 20 min followed by reperfusion for 40 min in rats.With no intervention in the Norm group and only threading without ligation in the Sham group.Electroacupuncture pretreatment at 20 min/d for 7 d before ligation in the EAⅠgroup,20 min of electroacupuncture before reperfusion in the EAII group and 20 min of electroacupuncture after reperfusion in the EAIII group.The electrocardiogram(ECG)of each group was recorded throughout the whole process,and the success of the MIRI model was determined based on the changs of J-point and T-wave in the ECG.The arrhythmia score was used to record premature ventricular contractions,ventricular tachycardia and ventricular fibrillation during the reperfusion period to assess the reperfusion induced arrhythmias.The expression levels of NGF,Trk A,TH protein were measured by Western blot.Moreover,the expression levels of plasma and myocardial NE levels were detected by enzyme linked immunosorbent assay.RESULTS:The differences between Norm group and Sham group were not statistically significant in all indexes.Arrhythmia score,myocardial NGF,Trk A,TH,and NE expression were significantly higher in the I/R group compared with the Sham group.Arrhythmia score,myocardial NGF,Trk A,TH,and NE expression were significantly lower in each EA group compared with the I/R group.CONCLUSION:Electroacupuncture at Neiguan(PC6)at different time points can reduce the incidence and severity of reperfusion arrhythmias in rats.This protective effect is related to electroacupuncture regulating NGF,Trk A,TH,NE expression and reducing sympathetic hyperactivation.

Efficacy on rabbits with arrhythmia: needling acupoint of Neiguan(PC6) at shallow or deep depth, and retaining needles for 10, 20, or 30 min

OBJECTIVE:To compare the effects of Neiguan(PC6)acupuncture at different depths and retention time on arrhythmia duration,myocardial tissue morphology,mRNA expression level of L-type calcium channelα1C subunit and Ca^(2+)-Mg^(2+)-At Pase activity in tachirrhythmia model of rabbits.METHODS:The tachyarrhythmia model was made by intravenous injection of barium chloride into the ears of rabbits.A total of 56 healthy adult male New Zealand big-eared white rabbits,apply the random number table method,divided into normal control group(group A),model group(group B),shallow needling Neiguan(PC6)10 min group(group C),shallow needling Neiguan(PC6)20 min group(group D),shallow needling Neiguan(PC6)30 min group(group E),deep needling Neiguan(PC6)10 min group(group F),deep needling Neiguan(PC6)20 min group(group G),deep needling Neiguan(PC6)30 min group(group H),7 animals in each group.Electrocardiograms were used to collect the duration of arrhythmia;hematoxylin-eosin staining method was performed on myocardial tissue,RT-PCR tested the expression ofα1C subunit mRNA,and the activity of Ca^(2+)-Mg^(2+)-ATPase were quantified by phosphorus determination method.RESULTS:The duration of arrhythmia in each acupuncture treatment group was shortened to varying degrees.Compare to the model group,the tissue damage from barium chloride inducing was improved in the acupuncture group.Compared to the model group,except for group E,most treatment groups had varying degrees of improvement with significantly down-regulated L-type calcium channelα1C subunit mRNA expressions level and increased Ca^(2+)-Mg^(2+)-ATPase activity.CONCLUSIONS:The effect of acupuncture at Neiguan(PC6)with different depths and retention time can reduce the duration of arrhythmia induced by barium chloride relatively,improve the induced pathological changes,down regulate L-type calcium channelα1C subunit mRNA expressions level and increase Ca^(2+)-Mg^(2+)-ATPase activity.Both the shallow and deep tissues of Neiguan(PC6)may be involved in transmitting acupuncture information.There is an optimal induction period for shallow needling at Neiguan(PC6)to reach the best therapeutic effect.