β_2-肾上腺素受体亚型激动对于血管平滑肌细胞增殖的影响

Effect of β_2-adrenergic receptor stimulation on vascular smooth muscle cell proliferation

目的研究β2-肾上腺素受体亚型(beta2-adrenergic receptor,β2-AR)激动对于血管平滑肌细胞(VSMC)增殖的调控效应。方法应用携带重组β2-AR片段的腺病毒感染VSMC制备受体过表达模型。分别应用Zinterol(ZIN)以及异丙基肾上腺素(ISO)刺激生理状态和β2-AR过表达的平滑肌细胞后,采用四甲基偶氮唑盐(MTT)比色法和细胞计数法检测吸光度(A,曾称光密度OD)值和细胞数目的改变。结果ZIN刺激1天时A值开始下降(P<0.05),3天时抑制作用达高峰,抑制率为(32.00±1.62)%。细胞计数法测得ZIN激动3天时细胞数为对照组的(69.29±9.26)%。应用CGP20712A阻断β1-AR激活后,非选择性-βAR激动剂ISO刺激细胞后得到结果相似。特异性β2-AR拮抗剂ICI 118,551可逆转此抑制效应。ISO刺激过表达的β2-AR 3天时MTT检测结果相似。结论β2-AR亚型激动可抑制VSMC的增殖。

Objective To investigate the specific regulatory effect of physiological and overexpressed β2-adrenergic receptor （β2-AR） stimulation on arterial smooth muscle cell proliferation.Method Overexpressed adrenergic receptor model was made by infection of vascular smooth muscle cell with adenoviris delivering recombinant β2-AR. Absorbance value and cell numbers were measured respectively by methyl thiazolyl tetrazolitrm （MTT） assay and cell counting after the physiological β2-AR as well as overexpressed β2-AR were stimulated by selective agonist. Results β2-AR stimulation by zinterol （ZIN） exhibited significant inhibitory effect on VSMC proliferation 1 day after stimulation（ P 〈 0.05） detected by MTT assay and peak inhibitory effect 3 days after stimulation with inhibitory rate of （32.00 ±1.62）%. The cell number after ZIN stimulation by cell counting was （69.29 ±9.26） % of that of control group. The similar result was obtained by the non-specific β3-AR agonist isoproterenol stimulation in case of β1-AR inactivated by CGP20712A. Stimulation of overexpressed β2-AR led to similar results. Conclusionβ2-AR stimulation might inhibit the proliferation of vascular smooth muscle cell.