等渗溶液Ca2＋浓度改变对去神经主动脉平滑肌生物张力及兴奋性作用研究  

Denervated aortic smooth muscle tension and cellular membrane current in variations of calcium ion concentration in iso-osmotic solution

作　　者：丁文静[1] Annie Christel Bell 王晗[2] 陈志斌[1] 高凌峰[2] 王杨[2] 

机构地区：[1]海南医学院临床学院,海口571101 [2]海南医学院临床学院基础医学及生命科学院,海口571101

出　　处：《国际生物医学工程杂志》2017年第3期164-168,共5页International Journal of Biomedical Engineering

基　　金：国家大学生创新创业训练计划项目（201511810008）

摘　　要：目的研究等渗高Ca2＋环境对去神经主动脉平滑肌膜电流的影响，以及不同前负荷状态和Ca2＋通道阻滞剂干预下去神经主动脉平滑肌的肌源性自主舒缩变化。方法平滑肌标本取自昆明小鼠主动脉平滑肌层。标本在松弛状态下被两端固定并浸润于任氏液中，待稳定后于显微镜下将玻璃微电极吸附于平滑肌肌膜并高阻封接，观察生理渗透压环境下的膜电流状态。将任氏液中Ca2＋浓度由0．9mol／L提高至1．2mol／L，观察渗透压改变后的即刻膜电流变化。增加标本前负荷至1g，观察前负荷增加后标本在同等渗透压环境下膜电位的改变，并记录此时的标本自主舒缩曲线。结果平滑肌标本处于松弛状态时，在等渗环境下将Ca2＋浓度由0．9mol／L提高至1．2mol／L后，膜电流改变幅度由（10．25±1．34）pA增至（24．91±3．27）pA，差异具有统计学意义（P〈0．05）；前负荷增加后标本在等渗高ca“及低ca“环境下的膜电流改变幅度较松弛状态时均有所增加（低Ca2＋浓度时（15．33±4．33）pA比（10．25±1．34）pA，高Ca2＋浓度时（33．31±7．25）pA比（24．91±3．27）pA），差异均具有统计学意义（均P〈0．05）。低Ca2＋浓度为0．9mol／L时，若仅增加前负荷，标本肌源性自主舒缩幅度可增加175％；而Ca2＋浓度增至1．2mol／L时，标本自主舒缩幅度可进一步增长40％。经Ca2＋通道阻滞剂（质量浓度为0．5g／L尼群地平）预处理后，高Ca2＋环境下的膜电流及肌源性th主舒缩均明显减弱，结果表明膜电位及自主舒缩均由Ca2＋主导。结论细胞外Ca2＋浓度的增加既提高了主动脉平滑肌细胞膜的兴奋性，又使平滑肌产生较明显的自主性舒缩，可在前负荷改变时有效地改善平滑肌组织顺应性。Ca2＋百道阻滞剂抑制了Ca2＋主导的跨膜电流，降低了肌源性自主舒缩，增加了平滑肌的僵直度，这�Objective To study the influence of high calcium ion environment on the membrane current of denervated aortic smooth muscles in iso-osmotic condition, as well as study the myogenic spontaneous vasomotion of the aortic smooth muscles under different pre-load state and intervention of calcium-channel blockers. Methods Smooth muscle samples were taken from the aortic smooth muscle layer of Kunming mice. The samples were fixed at two-ends in relaxed state and infiltrated in Ringer＇s solution. After stabilization, a glass microelectrode was adsorbed on the smooth muscle membrane to form gigaohm-seal. The current state of the membrane was observed under the physiological osmotic pressure. Then, the calcium ions concentration in the Ringer＇s solution was increased from 0.9 mol/L to 1.2 mol/L, and the immediate change of membrane current was observed after changing of osmotic pressure. Finally, the membrane potential change in iso-osmotic condition was observed when the pre-load was increased to 1 g, and the spontaneous vasomotion curves of the samples were recorded. Results In the relaxation state, the membrane current of the smooth muscle was increased significantly, i.e. （10.25 ±1.34） pA vs. （24.91±3.27） pA （P〈0.05）, when the calcium ion concentration was increased from 0.9 mol/L to 1.2 mol/L in iso-osmotic condition. When the pre-load was increased, the variation amplitude of the membrane current was increased in iso-osmotic condition, i.e. （10.25±1.34） pA to （15.33±4.33） pA （P〈0.05） for the lower calcium ion concentration, and （24.91±3.27） pA to （33.31±7.25） pA （P〈0.05） for the higher calcium ion concentration. If only increasing the pre-load, the myogenic spontaneous vasomotion could be increased by 175% for the condition of lower calcium ion concentration （0.9 mol/L）. When the calcium ion concentration was increased to 1.2 mol/L, the spontaneous vasomotion frequency of the specimen was increased, and the range of the vasomotion could be further increased by 4

关 键 词：去神经平滑肌 快速牵拉 高负荷状态 自主性舒缩 膜电流 

分 类 号：R329.2[医药卫生—人体解剖和组织胚胎学]