OBJECTIVETo observe change of expression level of Connexin 43 (Cx 43) in myocardial mitochondria of ischemia reperfusion injury after pretreatment of acupuncture and moxibustion at "Neiguan" (PC 6) in rabbits, Thirty-two New Zealand and compare the different effect between electroacupuncture and moxibustion.

METHODSbig-eared white rabbits were randomly divided into a model group, an electroacupuncture group, a moxibustion group and a sham-operation group, 8 cases in each one. The model of myocardial ischemia reperfusion injury was established in the first three groups. Before and after animal model was successfully made, the electroacupuncture and moxibustion were applied at "Neiguan" (PC 6) for 20 min respectively in the electroacupuncture group and moxibustion group. After the experiment, distribution of Cx 43 was observed under optical microscope while mean value of integral optical density (IOD) of Cx 43 in myocardial cell was tested.

RESULTSThe distribution of Cx 43 in the model group was obviously scattered and sparse, but more expression of Cx 43 could be seen in the other three groups that were shaped as strip, chain or irregular and was perpendicular to cell long axis or formed side-side connection that was parallel to long axis. Shape and distribution of Cx 43 expression in the moxibustion group were not obviously different from that in the electroacupuncture group. The mean value of IOD of Cx 43 expression in myocardial cell in the electroacupuncture group (735. 10 +/- 152. 01), moxibustion group (836. 15 +/- 247. 10) and sham-operation group (950.56+/-223.37) was higher than that in the model group (312. 68+/-1105. 20), and difference of the mean value in the electroacupuncture group was not statistically significant from that in the moxibustion group.

CONCLUSIONThe pretreatment of acupuncture and moxibustion at "Neiguan" (PC 6) in rabbit could increase expression of Cx 43 in myocardial cell and participate in electrical coupling and metabolic coupling to protect myocardial cell from ischemia reperfusion. However, differences of mean value of Cx 43 expression in myocardial cell were not statistically significant during electroacupuncture and moxibustion at "Neiguan" (PC 6).