Objective: To observe the effect of Electroacupuncture (EA) of “Neiguan”(PC 6) on ATPase activity of capillaries in acute myocardial ischemia (AMI) rats. Methods: Sixty-six Wistar rats were randomized into normal (n=3)

sham-operation (n=3)

model and EA groups

and the last two groups were further divided into 2h

2d

1w

3w subgroups respectively

with 6 cases being in each subgroup. AMI model was established by occlusion of the descending anterior branch (DAB) of the left coronary artery. EA (40 Hz

4 V) was applied to “Neiguan”(PC 6) for 5 min

once daily till sampling (2h

2d

1w

3w). The reaction products of Mg 2+ -ATPase and Na+-K+-ATPase of the left cardiac ventricle and apical region tissues (cut into sections

10 μm in the thickness) were detected by using enzyme histochemical staining and enzyme cytochemical staining techniques and observed under electronic microscope

and the optic density (OD) or grey scale (GS) values of the reaction products of the tissue sections were detected with a multimedia image analysis system. Results: Comparison among different groups showed that the total area values of Mg 2+ -ATPase and Na+-K+-ATPase reaction products of the vascular endothelium in the myocardial tissue of model group from 2h to 3w were significantly lower than those of normal group (P<0.05～0.01)

those of EA group from 2h to 3w were significantly higher than those of model group (P<0.05～0.01). Regarding the average OD/GS values

compared with normal group

in model group

GS of Mg 2+ -ATPase reaction products increased significantly but OD of Na+-K+-ATPase reaction products lowered markedly (P<0.05～0.01); compared with model group

in EA group

GS of Mg 2+ -ATPase reaction products at different time courses decreased significantly further

while OD of Na+-K+-ATPase reaction products increased remarkably at all the time courses except 2w (P<0.05～ 0.01). In regard to the number of capillaries

those of model group from 2h to 3w were considerably fewer than that of normal group (P<0.01); compared with model group

those of EA group from 2 h to 2w were considerably more (P<0.05～0.01). No significant differences were found between normal and sham-operation groups in these indexes. Microscopic observation displayed that after AMI

the state of myocardial fiber fracture

edema

degeneration

necrosis

and the vague outline of micrangium in model group was severer

while that in EA group was lighter. Conclusion: EA of Neiguan (PC 6) has effects of improving ATPase activity in endothelial cells of the ischemic myocardial micrangium and protecting anoxic myocardial cells.