Effect of electroacupuncture preconditioning on the expressions of NF-κB p65, IκBα and IKKβ in myocardial tissue of the rats with acute myocardial ischemia-reperfusion injury

Abstract

To observe the effect of electroacupuncture (EA) preconditioning on the expressions of nuclear transcription factors-kappa B (NF-κB) p65, NF-κB inhibitor (IκB) α and IκB kinase (IKK) β in rats with acute myocardial ischemia-reperfusion injury (MIRI) and to explore the mechanism of EA on heart meridian in relieving MIRI. A total of 40 SD rats were randomized into a sham-operation group, a model group, an EA heart meridian group and an EA lung meridian group, 10 rats in each one. In the EA heart meridian group, acupuncture was applied to "Shenmen" (HT 7) and "Tongli" (HT 5). In the EA lung meridian group, acupuncture was applied to "Taiyuan" (LU 9) and "Lieque" (LU 7). In these two groups, EA was exerted for 20 min each time, 1 V in voltage and 2 Hz in frequency once a day. A total of 7-day EA stimulation was required before model duplication. In the model group, the EA heart meridian group and the EA lung meridian group, using ligating left anterior descending coronary artery to establish the acute MIRI models. In the sham-operation group, the chest was open, but no ligation was exerted, just the needle was penetrated through the corresponding sites for one time. The electrocardiogram (ECG) was detected and ST segment displacement was analyzed. Using Western blot method, the relative expressions of NF-κB p65, IκBα and IKKβ in myocardial tissue were determined in each group. Using ELISA method, the levels of serum IL-1β and IL-10 were determined in each group. Compared with the sham-operation group, ST segment displacement value was elevated 30 min after ligating and reperfusion for 120 min in the model group (P<0.05), and the value in the EA heart meridian group was lower than the model group and the EA lung meridian group (P<0.05). Compared with the sham-operation group, the expressions of NF-κB p65 and IKKβ in myocardial tissue were increased (P<0.05) and the expression of IκBα reduced in the rats of the model group (P<0.05). Compared with the model group, the expressions of NF-κB p65 and IKKβ in myocardial tissue were reduced (P<0.05) and the expressions of IκBα increased in the rats of the EA heart meridian group and the EA lung meridian group (P<0.05). Compared with the EA lung meridian group, the expressions of NF-κB p65 and IKKβ in myocardial tissue were reduced (P<0.05) and the expression of IκBα increased in the rats of the EA heart meridian group (P<0.05). Compared with the sham-operation group, the serum level of IL-1β was increased (P<0.05) and IL-10 reduced in the model group (P<0.05). Compared with the model group, the serum level of IL-1β was reduced (P<0.05) and IL-10 increased in the EA heart meridian group and the level of IL-1β was was reduced in the EA lung meridian group (P<0.05). Compared with the EA lung meridian group, the serum level of IL-1β was reduced (P<0.05) and IL-10 increased in the EA heart meridian group (P<0.05). Electroacupuncture preconditioning at heart meridian acupoints obviously alleviates acute MIRI. IKK/IκB/NF-κB signaling pathway possibly participates in the protective mechanism of electroacupuncture preconditioning on acute MIRI.