[Effect of electroacupuncture of "Neiguan" (PC 6) on Na+-K+-ATPase activity and its gene expression in cardiocyte membrane in rats with myocardial ischemia-reperfusion injury].

Objective: To compare the effects of electroacupuncture (EA) of "Neiguan" and other acupoints on Na+ -K+ -ATPase activity and its gene expression in ischemic myocrardial cell membrane in rats.

Methods: A total of 50 Wistar rats were randomly divided into pseudo-operation (control), model, Neiguan (PC6), Shenmen (HT7) and Hegu (LI4) groups, with 10 rats in each group. Myocardial ischemia-reperfusion (I/R) model was duplicated by occlusion of the descending anterior branch of the left coronary artery and reperfusion. EA (30/100 Hz, 2-4 mA) was applied to the above-mentioned acupoints for 20 min respectively. Na+ -K+ -ATPase activity was determined by inorganic phosphorus colorimetry, and Na+ -K+ -ATPase gene expression was detected using reverse transcription polymerase chain reaction (RT-PCR) technique.

Results: Compared with control group, the activity of Na+ -K+ -ATPase in model, PC6, HT7 and LI4 groups decreased significantly after myocardial I/R (P<0.05, 0.01); while in comparison with model, the activity of Na+ -K+ -ATPase in PC6 group increased considerably (P<0.01). Regarding the expression of Na+ -K+ -ATPase mRNA, compared with control group, it was down-regulated significantly in model, HT7 and LI4 groups (P<0.01); while in PC6 group, Na+ -K+ -ATPase mRNA expression was up-regulated markedly compared with model group (P<0.05); The activity of Na+ -K+ -ATPase and the expression of Na+ -K+ -ATPase mRNA in HT7 and LI4 groups were significantly lower than those in PC6 group (P<0.01, 0.05). No significant differences were found between HT7 and LI4 groups in the activity of Na+ -K+ -ATPase and the expression of Na+ -K+ -ATPase mRNA (P>0.05).

Conclusion: EA of "Neiguan" (PC6) may potentiate the activity of Na+ -K+ -ATPase and up-regulate Na+ -K+ -ATPase mRNA expression, which may contribute to its protective effect on ischemic cardiocytes.