异丙酚和硫喷妥钠对心肌内游离Ca2+浓度的影响

目的　观察异丙酚和硫喷妥钠对心肌细胞内游离Ｃａ２＋ 浓度的影响，以探讨静脉麻醉药对心肌细胞内游离Ｃａ２＋ 的作用及其机制。方法　心肌细胞分离培养７～９ 天，以Ｆｕｒａ２／ＡＭ 荧光指示剂负载后，实验组Ａ 加入实验用药孵育１０ 分钟进行Ｃａ２＋ 测定；实验组Ｂ：加入实验用药１０ 分钟后，加ＫＣｌ４０ｍ ｍ ｏｌ／Ｌ，１ 分钟后进行Ｃａ２＋ 测定。结果　临床剂量的异丙酚和硫喷妥钠对静息心肌细胞内Ｃａ２＋ 浓度无明显影响，超临床剂量的异丙酚和硫喷妥钠使静息细胞内Ｃａ２＋ 明显降低。４０ｍ ｍ ｏｌ／Ｌ的ＫＣｌ可使心肌细胞内Ｃａ２＋ 浓度明显升高，异丙酚和硫喷妥钠对高浓度ＫＣｌ所激发Ｃａ２＋ 内流均有明显的抑制，并呈剂量依赖性。结论　异丙酚和硫喷妥钠降低心肌细胞内钙离子浓度。他们在完整心肌的负性肌力作用可能与其部分抑制兴奋收缩耦联过程中钙离子内流和抑制静息状态下的钙溢流有关

Effects of propofol and thiopental sodium on cultured primary myocardial intracellular free calcium concentration in rarts

Objective The aim of this study was to investigate the effects of propofol and thiopental sodium on the regulation of intracellular free Ca 2 in cultured rat myocardial cells Methods The Ca 2 content in rat myocardial cells loaded with Fura 2 was recorded from a fluorescence microscope Propofol and thiopental sodium were applied to resting cells for 10 min,then stimulation was given by membrane depolarization (by high K concentration stimulation) Results The propofol and thiopental sodium did not alter baseline of Ca 2 at clinical concentration,but decreased intracellular free Ca 2 level at more than clinical relevant concentrations After administration of calcium channel agonist KCl,the free Ca 2 intracellular level obviously elevated,but administration of propofol and thiopental sodium previously,followed by KCl,the free Ca 2 level significantly decreased,compared with that of normal control group,furthermore,the effects of propofol and thiopental sodium were dose depenednt Conclusion Propofol and thiopental sodium appear to possess inhibitory effects on myocardial cells voltage dependent Ca 2 channels