ABSTRACT
Objective To observe the expression of tyrosine kinase 2(JAK2)and signal transducer and activator of transcription 3(STAT3)in myocardial tissue of rats with myocardial ischemia-reperfusion injury(MIRI)by electroacupuncture at"Neiguan"point,and explore the mechanism of electroacupuncture in up regulating JAK2/STAT3 signal pathway,promoting the expression of anti-inflammatory factors,and reducing MIRI injury.Methods Thirty male SD rats with normal echocardiography were randomly divided into sham operation group,model group and electroacupuncture group,with 10 rats in each group.MIRI models were prepared by ligation of left anterior descending coronary artery(LAD)in model group and electroacupuncture group,while in sham operation group,only threading was performed without ligation.In the electroacupuncture group,electroacupuncture(density wave,2 Hz/100 Hz,2 mA)at bilateral"Neiguan"points was performed on the 1st,3rd and 5th days after the modeling operation,once a day,20 minutes each time.The left ventricular ejection fraction(LVEF)of rats on the 1st,3rd and 5th day after operation was observed by echocardiography to evaluate cardiac function;HE staining was used to observe the pathological changes of rat myocardium;The myocardial fibrosis was observed by Masson staining;The expression of IL-4 and IL-6 in myocardium was detected by ELISA;The expressions of IL-1β and IL-10 in myocardial tissue were detected by immunohistochemistry;The expression of JAK2,p-JAK2,STAT3,p-STAT3 protein in myocardial infarction area was measured by Western blot.Results Compared with sham operation group,EF in model group decreased significantly(P<0.05),fibrosis area increased(P<0.05),IL-4,IL-6,IL-10,IL-1β The content of JAK2,p-JAK2,STAT3,p-STAT3 protein increased(P<0.05);Compared with the model group,the EF of rats in the electroacupuncture group increased(P<0.05),the fibrotic area of rats in the electroacupuncture group decreased(P<0.05),the content of IL-4 and IL-10 increased,and IL-6 and IL-1β The expression of JAK2,p-JAK2,STAT3,p-STAT3 protein increased(P<0.05).Conclusion Electroacupuncture at Neiguan point can significantly up regulate JAK2/STAT3 signal pathway,reduce the secretion of proinflammatory factors,increase the expression of anti-inflammatory factors,and alleviate myocardial ischemia reperfusion injury in rats.
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.