ABSTRACT
Objective:
To observe the effects of
electroacupuncture (EA) at Neiguan (PC6) on
arrhythmia during acute
myocardial ischemia-
reperfusion and the expression of
connexin 43 (
Cx43) in
rats.
Methods:
A total of 40 Sprague-Dawley
male rats were used. Ten
rats were randomly selected as the blank group, and the remaining 30
rats were randomly divided into a model group and an EA group, with 15
rats in each group. Before modeling,
rats in the EA group received one session of EA intervention at bilateral Neiguan (PC6) for 30 min; the other groups were treated with the same grasping and
anesthesia for 30 min without intervention. PowerLab physiological recorder was used to
record electrocardiograph within 30 min of
infarction. After the experiment, cardiac
tissue and
serum were collected from
rats.
Hematoxylin-
eosin (HE)
staining was used to observe the morphological changes of myocardial
tissue in the ventricular
infarction area of
rats in each group. The expression of
Cx43 protein in the
myocardium of each group was detected by
Western blotting (WB).
Enzyme-linked immunosorbent assay (
ELISA) was used to determine the activity of Na+-K+-
ATPase in myocardial
tissue and the
serum content of endogenous
digitalis-like factor (EDLF) in
rats.
Results:
There was no statistical difference in
arrhythmia score between the EA group and the model group, but the total duration and average duration of
arrhythmia in the EA group were decreased (P<0.01). HE
staining showed that compared with the blank group, myocardial
cells in the model group were disorganized and seriously damaged. The pathological changes in the EA group were
similar to those in the model group, but the damage was relatively
minor. The results of WB showed that compared with the blank group, the
Cx43 expression in myocardial
tissue of the model group was decreased (P<0.01); compared with the model group, the
Cx43 expression in the EA group was increased (P<0.01); compared with the blank group, the Na+-K+-
ATPase activity in myocardial
tissue of the model group was significantly decreased (P<0.01); compared with the model group, the Na+-K+-
ATPase activity in the EA group was increased (P<0.01).
ELISA results showed that compared with the blank group, the
serum EDLF content in the model group was significantly increased (P<0.01); compared with the model group, the EDLF content in the EA group was decreased (P<0.01).
Conclusion:
EA at Neiguan (PC6) can delay and reduce the onset of
arrhythmia during
myocardial infarction in the
rat model of
myocardial ischemia-
reperfusion. Its mechanism of action may be related to the
regulation of the
Cx43 expression in myocardial
tissue, improvement of the activity of Na+-K+-
ATPase in myocardial
tissue, and increase in the content of
serum EDLF.