体外循环期间外周血淋巴细胞β肾上腺素能受体的变化

The Changes of β-adrenergic receptor function in lymphocytes during cardiopulmonary bypass

目的:研究体外循环期间β肾上腺素能受体(β受体)功能的变化。方法:16例择期心脏直视手术病人,于麻醉前、CPB前、CPB15分、CPB60分和CPB结束时取血,用放射配基结合法和放免分析法测定淋巴细胞β受体数目和异丙肾上腺素刺激的淋巴细胞cAMP产量,血浆儿茶酚胺的测定用高效液相色谱电化学法。结果:血浆儿茶酚胺在CPB期间显著升高,淋巴细胞β受体数目在CPB60分和CPB结束时显著降低,异丙肾上腺素刺激的cAMP产量在CPB15分明显下降,CPB60分和CPB结束时维持在较低水平。结论:CPB可降低淋巴细胞β受体功能。CPB早期表现为受体脱耦联,晚期主要表现为受体向下调节。

Objective: To investgate the changes of β-adrenergic receptor function in lymphocytes during cardiopulmonary bypass(CPB). Method; Density of β-adrenergic receptor(Bmax)and isoproterenol-stimulated cAPM product in lymphocytes at the different time point duing CPB were measured with radioligand binding assay and radioimmunoassay in sixteen patients undergoing cardiac surgery. Plasma catecholamine level was assaied wtih high performance liquid chromatography. Result: Plasma catecholamine concentration increased significantly during CPB. The Bmax and affinity of β-receptor decreased significantly at CPB 60th min and CPB end. The isoproterenol-stimulated cAMP content in lymphocytes reduced significantly at CPB 15th min and was maintained at low level till CPB ended. Conclusion:CPB can decrease function of β-adrenergic receptor, the receptor uncopling or down-regulation is demonstrated at early or late stage.