心力衰竭患者抗β1肾上腺素能受体自身抗体阳性血清对心肌细胞L-型钙通道的影响

目的探讨心力衰竭患者抗β1肾上腺素能受体自身抗体(Abs)阳性血清对豚鼠心室肌细胞膜上L型钙电流(IGa-L)的影响.方法应用全细胞钳制技术,定量观察并比较β1肾上腺素能受体激动剂异丙肾上腺素(Iso)和心力衰竭患者Abs阳性血清对豚鼠单个心室肌细胞的ICa-L电流强度的影响.结果β1肾上腺素能受体激动剂Iso可使基础ICa-L峰值电流强度和标准电流密度从(997.09±227.5)pA和(8.20±0.86)pA/pF增大到(2 241.01±348.5)pA和(18.98±1.18)pA/pF(P＜0.01),而β1肾上腺素能受体阻滞剂艾司洛尔(Esm)可以阻断这一作用.同样,心力衰竭患者Abs阳性血清可使基础ICa-L峰值电流强度从(963.57±207.56)pA增大到(1 382.41±241.36)pA,标准电流密度从(8.14±0.72)pA/pF增大到(11.70±1.03)pA/pF(P＜0.01),Esm也可阻断此作用.结论人类心脏Abs阳性血清对心肌细胞受体有异丙肾上腺素样激动剂效应,可能参与了心力衰竭时心肌细胞的病理生理过程.

Effect of the positive sera of autoantibodies against the human beta1-adrenoceptor from patients with congestive heart failure on activity of L-type Ca2+ channel in guinea pig cardiac myocytes

OBJECTIVE: To investigate the effect of the positive sera of autoantibodies against the human beta1-adrenoceptor from patients with congestive heart failure on activity of L-Type Ca2+ channel in guinea pig cardiac myocytes. METHOD: Using whole cell patch-clamp technique, we quantitatively researched the ionic intensity and density of L-type Ca2+ channel (ICa-L). RESULTS: The beta-adrenocepter agonist isoprenaline increased the ICa-L peak intensity and density from (997.09 +/- 227.5) pA and (8.20 +/- 0.86) pA/pF to (2241.01 +/- 348.5) pA and (18.98 +/- 1.18) pA/pF, respectively (P < 0.01). The positive sera of autoantibodies against the beta1-adrenoceptor could also increase ICa-L peak intensity and density from (963.57 +/- 207.56) pA and (8.14 +/- 0.72) pA/pF to (1382.41 +/- 241.36) pA and (11.70 +/- 1.03) pA/pF (P < 0.01). Esmolol, a beta1-adrenoceptor antagonist blocked these effects of isoprenaline and autoantibodies. CONCLUSIONS: Human cardiac positive sera of autoantibodies against the beta1-adrenoceptor has an isoproterenol-like effect on cardiac myocytes receptor. It may participate in the pathophysiologic process of cardiac myocytes.