title: [Involvement of beta-adrenoceptors in cardioprotective effect of electroacupuncture intervention in mice with swimming fatigue-induced myocardial ischemia].
abstract: OBJECTIVE
  To observe the cardioprotective effect of electroacupuncture (EA) stimulation at "Neiguan" (PC 6) in mice with myocardial ischemia (MI) and to explore the involvement of cardiac beta-adrenergic receptors (beta-AR) in the cardioprotective effect of EA intervention.
  
  
  METHODS
  Adult male C 57 BL/6 mice of wild type and beta1/beta2-AR double-knockout (beta1/beta2-AR(-/-)) mice were randomly and respectively divided into control group and EA group, with 8 mice in each group. These mice were subject to procedures of basic control, fatigue swimming and fatigue swimming + EA. The model was established by fatigue swimming for inducing acute MI. EA (2 Hz, 0.5 mA) was applied to bilateral "Neiguan" (PC 6) for 30 min, once daily for 7 days in both EA groups. The ST-segment of electrocardiogram (ECG) of standard limb lead II, heart rate were recorded by using a biophysical amplifier and the arrhythmia score was assessed according to Curtis and Walker's methods (1988).
  
  
  RESULTS
  Self-comparison showed that, compared with the baseline, the amplitude of ECG-ST II segment was obviously increased in swimming fatigue C 57 BL/6 mice (P < 0.01) and further obviously increased in beta1/beta2-AR(-/-) mice (P < 0.01), suggesting an acute MI in C 57 BL/6 mice and a worsened MI in beta1/beta2-AR(-/-) mice. Simultaneously, the heart rate was markedly decreased (P < 0.05), and the score of arrhythmia obviously increased in both C 57 BL/6 and beta1/beta2-AR(-/-) mice (P < 0.05). Compared with the modeling procedures, ECG-ST II amplitude and arrhythmia score were significantly decreased in C 57 BL/6 mice of the EA group (P < 0.01, P < 0.05), rather than in the beta1/beta2-AR(-/-) mice of the EA group (P > 0.05). In addition, heart rate levels of both C 57 BL/6 mice and beta1/beta2-AR(-/-) mice had no significant differences between control and EA groups (P > 0.05).
  
  
  CONCLUSIONS
  EA at "Neiguan" (PC 6) can protect the heart from swimming fatigue-induced MI in C 57 BL/6 mice not in beta1/beta2-AR(-/-) mice, suggesting an involvement of beta1/beta2-AR in the protective effect of EA.
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.forename: Jun-Hong
authors.initials: JH
authors.lastname: Gao
authors.forename: Xiao-Chun
authors.initials: XC
authors.lastname: Yu
authors.forename: Yu-Xue
authors.initials: YX
authors.lastname: Zhao
authors.forename: Jing-Jun
authors.initials: JJ
authors.lastname: Zhao
authors.forename: Bing
authors.initials: B
authors.lastname: Zhu
authors.forename: Pei-Jing
authors.initials: PJ
authors.lastname: Rong
mesh_terms: D015669:Acupuncture Points; D000818:Animals; D015671:Electroacupuncture; D005221:Fatigue / Q000150:complications* / Q000235:genetics / Q000378:metabolism; D006339:Heart Rate; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D017202:Myocardial Ischemia / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D018342:Receptors, Adrenergic, beta-1 / Q000235:genetics / Q000378:metabolism*; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics / Q000378:metabolism; D013550:Swimming
chemical_list: D018342:Receptors, Adrenergic, beta-1; D018343:Receptors, Adrenergic, beta-2