Effect of electroacupuncture pretreatment on the protein expression of c-fos in fastigial nucleus and lateral hypothalamus area in rats with acute myocardial ischemia-reperfusion injury

Abstract

To observe the effect of electroacupuncture (EA) pretreatment on the protein expression of c-fos in fastigial nucleus (FN) and lateral hypothalamus area (LHA) in rats with acute myocardial ischemia-reperfusion injury (MIRI), and to explore the role and mechanism of FN and LHA in EA at the Heart Meridian fighting against acute MIRI reaction. Seventy Sprague-Dawley rats were randomly divided into a sham operation group, a model group, an EA-Heart Meridian group and an EA-Lung Meridian group, with 14 rats in each group; an LHA lesion plus EA-Heart Meridian group (LHA+EA-Heart Meridian group) and a FN lesion plus EA-Heart Meridian group (FN+EA-Heart Meridian group), with 7 rats in each group. Except the sham operation group, the left anterior descending branch of coronary artery was ligated to establish acute MIRI rat models in the other 5 groups. In the three groups with EA-Heart Meridian treatment, Shenmen (HT 7) and Tongli (HT 5) were selected; Taiyuan (LU 9) and Lieque (LU 7) were selected in the EA-Lung Meridian group. All the EA groups received EA stimulation prior to modeling, with 1 mA in current intensity and 2 Hz in frequency, 20 min each time, once a day for a total of 7 d. The sham operation group and the model group did not receive EA stimulation. The electrocardiogram was observed in the rats to analyze the ST-segment deviation and cardiac arrhythmia score. The expression of c-fos protein in FN and LHA was detected by immunohistochemistry method. Compared with the sham operation group, the ST-segment deviation, cardiac arrhythmia score and the expression of c-fos protein in the FN and LHA increased significantly in the model group (all P<0.05). Compared with the model group, the ST-segment deviation, cardiac arrhythmia score and the expression of c-fos protein in FN and LHA decreased significantly in the EA-Heart Meridian group (all P<0.05). Compared with the EA-Heart Meridian group, the ST-segment deviation and cardiac arrhythmia score increased significantly in the EA-Lung Meridian group, LHA+EA-Heart Meridian group and FN+EA-Heart Meridian group (all P<0.05); the expression of c-fos in FN increased significantly in the EA-Lung Meridian group and LHA+EA-Heart Meridian group (both P<0.05); the expression of c-fos in LHA increased significantly in the EA-Lung Meridian group and FN+EA-Heart Meridian group (both P<0.05). FN and LHA are involved in the mechanism of EA at Heart Meridian to improve the acute MIRI reactions, and the cerebellum may participate in the improvement of cardiac function by EA through the cerebellum-hypothalamus projection.