抗β_2-AR肾上腺素受体自身抗体功能的初步研究

Preliminary study on the biological activity of autoantibody against cardiac β_2-adrenoceptor in rats

目的研究抗β2-肾上腺素受体(β2-adrenoceptor,β2-AR)自身抗体对乳鼠心肌细胞跳动频率的影响。方法①手术结扎大鼠冠状动脉建立心梗模型;②在大鼠心力衰竭(心衰)的不同时期采用链霉亲和素-酶联免疫吸附法(SA-ELISA)检测大鼠血清中抗β2-AR自身抗体的滴度,同时检测大鼠的心功能;③将β2-AR激动剂硫酸特布他林、抗β2-AR自身抗体的阳性血清及抗β2-AR自身抗体+β2-AR组的血清加至培养的乳鼠心肌细胞中,观察该自身抗体对乳鼠心肌细胞跳动频率的影响。结果①将β2-AR激动剂硫酸特布他林(4.5μmol/L)加入培养的乳鼠心肌细胞中,加药前心肌细胞跳动频率(次/15 s)为20.0±6.20,加入后第5,15和30 min分别为16.92±4.89,13.17±3.21和11.85±2.84。②将大鼠抗β2-AR自身抗体的阳性血清加至培养的乳鼠心肌细胞中,加样前心肌细胞跳动频率(次/15 s)为26.43±3.63,加入后第5,15和30 min分别为9.42±3.03,10.00±1.76和9.25±2.56,心肌细胞跳动频率减慢,且在观察时间内不随时间递减,表现出类激动剂样生物效应。③大鼠抗β2-AR自身抗体+β2-AR组的血清加至培养的乳鼠心肌细胞中,加样前心肌细胞跳动频率(次/15 s)为21±3.4,加入后第5,15和30 min分别为18.9±2.72,17.6±2.48和16.1±2.9,心肌细胞的跳动频率无明显减慢。结论抗β2-AR自身抗体作用于培养的乳鼠心肌细胞,可使其跳动频率减慢,且在观察时间内不随时间递减,表现出类激动剂样生物学效应,加入相应抗原后基本可中和其效应。

Objective To observe the effects of autoantibody against ^-adrenoceptor on the beating rate of cultured neonatal rat eardiomyocytes. Methods （1）Rat myocardial infarction （MI） model was constructed by ligating the eoronary artery. （2）The titers of antibody against β2-adrenoceptor were ditermined by SA-ELISA during development of ischemic heart failure, and the cardiac function were measured concurrently. （3）Turbutaline Sulfate （a selective agonist of β2-adrenoceptor）, the positive sera for anti-β2-adrenoceptor autoantibodies and the sera of anti-β2-adrenoceptor autoantibodies ± β2-adrenoceptor group were added to the medium of cultured neonatal rat cardiomyocyte to observe the effects of antibody on the heart beating rate. Results （1）Terbutaline Sulfate decreased the beating rates from 20.2 ± 6.20 per 15 .seconds before treatment to 16.92 ± 4.89,13.17 ± 3.21,11.85 ± 2.84 at 5,15 and 30 minutes after treatment respectively. （2）The autoantibodies against β2 adrenoceptor decreased the beating rates from 26.43 ± 3.63 per 15 seconds before treatment to 9.42 ± 3.03,10.00 ± 1.76,9.25 ± 2.56 at 5,15 and 30 minutes after treatment respectively. Moreover, its effects were not decreased with time. The antoantibodies displayed analogous agonistic activity. （3）in anti-β2-adrenoceptor autoantibody ＋ β2-adrenoceptor group, the beating rates were 21 ± 3.4 per 15 seconds before treatment. At 5,15 and 30 minutes after treatment, they were 18.9 ± 2.72,17.6 ± 2.48和 16.1 ± 2.9 per 15 seconds respectively. There wasn＇ t a significant decrease. Condusicm The autoantibody against β2-adrenoceptors displayed an ＂agonistic-like activity＂ on the corresponding receptors as evidenced by its decreasing effects on the beating rate of cultured neonatal rat cardiomyocytes. The β2-adrenoceptors can essentially neutralize its effects.