CaSR 在大鼠血管收缩／舒张反应性调节中的作用

摘要

目的：研究钙敏感性受体（CaSR）激动剂对大鼠肠系膜动脉收缩和舒张反应性的影响、以及内皮在其中的作用。方法采用内皮完整和内皮去除的大鼠肠系膜动脉，观察 CaSR 特异性激动剂 cinacalcet 对血管基础张力和预收缩的血管张力的影响、以及不同剂量 cinacalcet 预处理对去甲肾上腺素（NE）诱导的血管收缩反应性和乙酰胆碱诱导的舒张反应性的影响。结果CaSR 激动剂 cinacalcet 对静息状态下内皮完整和内皮去除的血管基础张力均无明显影响。在内皮完整的血管环，cinacalcet 对预收缩血管有明显的舒张作用，并呈剂量依赖性；内皮去除取消了 cinacalcet 的舒张作用。Cinacalcet 预处理30 min，使内皮完整的血管的收缩反应性明显降低，而对舒张反应性无明显影响。对去除内皮的血管环，cinacalcet 预处理对血管收缩／舒张反应性均无明显影响。结论CaSR 在血管收缩反应性调节中有重要作用，并有明显的内皮依赖性。%Objective To investigate the effects of calcium sensing receptor (CaSR)on vasorelaxation/vasoconstriction of superior mes-enteric artery (SMA)in rats and its relationship to endothelium.Methods With endothelium-intact and endothelium-denuded SMA rings of rats,the effects of CaSR-specific allosteric modulator cinacalcet on the SMA rings pre-contracted with norepinephrine (NE),and vascular contractile response /relaxation reactivity were observed.Results Cinacalcet had no effects on resting tension of SMA rings with or without endothelium.Cinacalcet caused a significant relaxation in the endothelium-intact SMA rings pre-contraction with NE in a dose-dependent manner.Endothelium denudation abolished cinacalcet-induced vasorelaxation.Pretreatment with cinacalcet for 30 minutes decreased the con-tractile response of endothelium-intact SMA rings to NE,but had no significant influence on relaxation reactivity.In the endothelium-denuded SMA rings,cinacalcet did not affect both vasoconstriction and vasorelaxation.Conclusion CaSR plays an important role in the regulation of the vascular reactivity,and this effect is endothelium-dependent.