不同浓度β_(1)肾上腺素能受体自身抗体对大鼠心电指标和心肌病理的早期影响

Early effects of different concentrations ofβ_(1)adrenergic receptor autoantibodies on ECG indexes and pathology in rats

目的探讨不同浓度β_(1)肾上腺素能受体自身抗体(β_(1)-adrenergic receptor autoantibodies,β_(1)AAbs)对大鼠心电指标及心肌细胞病理的早期影响。方法24只雄性SD大鼠随机分为对照组,免疫组(低浓度组、中浓度组、高浓度组),免疫组经尾静脉注射β_(1)AAbs建立被动免疫β_(1)AAbs升高模型,通过酶联免疫吸附试验测定大鼠心肌组织中环磷酸腺苷(cAMP)含量,验证造模是否成功。各组大鼠均佩戴穿戴式心电传感器在自然状态下连续监测5 d,分析心率,昼夜节律;使用LEAD-7000心电生理仪记录大鼠基线、免疫第一天、第三天、第五天的6导心电图,免疫5 d后行大鼠心肌细胞HE染色。结果(1)各组大鼠夜间心率均高于白天,各免疫组5 d内平均心率较对照组增快(P<0.05);(2)免疫低浓度组在免疫第四天达到心率高峰;中浓度组在免疫5 d内心率持续增快;高浓度组在免疫第二天达到心率高峰,第三天开始下降(P<0.05);(3)各免疫组P波时限延长,免疫中、高浓度组P波振幅增高,免疫低浓度组QTc间期延长,免疫低、中浓度组QRS波振幅增高(P<0.05);(4)免疫低、中浓度组心肌细胞完整性降低,免疫高浓度组心肌细胞明显碎裂,细胞核空泡状。结论β_(1)AAbs增高早期可增加大鼠心率,延长P波时限;低浓度β_(1)AAbs延长QTc间期;低、中浓度β_(1)AAbs可使心肌细胞完整性降低,高浓度使心肌细胞碎裂。

Objective To investigate the early effects of elevated expression of different concentrationsβ_(1)-adrenergic receptor autoantibodies(β_(1)AAbs)on ECG indexes and cardiomyocyte pathology in rats.Methods 24 male SD rats were randomly divided into control group,immune group(low concentration group,medium concentration group,high concentration group),and the immune group was injectedβ_(1)AAbs through the tail vein to establish a passive immuneβ_(1)AAbs elevation model,and the content of cyclic adenosine monophosphate(cAMP)in rat myocardial tissue was determined by enzyme-linked immunosorbent assay to verify the success of the modeling.All groups of the rats wore wearable ECG sensors to continuously monitor for 5 days in the natural state to analyze heart rate and circadian rhythm.The rat baseline,6-lead ECG on the first day,day 3,and day 5 of immunization was recorded with using the LEAD-7000 electrophysiology instrument,and the rat cardiomyocytes HE staining was performed after 5 days of immunization.Results(1)The nighttime heart rate of the rats in all groups were higher than that during the day,and the average heart rate of each immune group within 5 days was increased faster than that of the control group(P<0.05).(2)The heart rate of the rats in each immunization group was compared before and after,and the low concentration group reached the peak heart rate on the fourth day of immunization;the heart rate of the concentration group in the immunization group continued to increase within 5 days of immunization;the group with high concentration reached a peak heart rate on the second day of immunization and began to decrease on the third day(P<0.05).(3)The P wave duration in each immune group was extended,the amplitude of P wave in the group with medium and high concentration was increased,the QTc interval in the group with low concentration was extended,and the amplitude of QRS complex amplitude in the group with low and medium concentration was increased(P<0.05).(4)The integrity of cardiomyocytes in the low and medium concentration groups were reduced,and the cardiomyocytes in the high concentration group were significantly fragmented,and the nucleus was vacuole-like.Conclusion Early increase ofβ_(1)AAbs can increase the heart rate of the rats and prolong P wave duration.Low concentrationβ_(1)AAbs prolongs the QTc interval.Low and moderate concentrations ofβ_(1)AAbs can reduce the integrity of cardiomyocytes,and high concentrations can fragment cardiomyocytes.