Komai H, Rusy B F
Anesth Analg. 1984 Mar;63(3):313-8.
The negative inotropic effects of thiopental (10-30 mg/L) and halothane (0.5-1.5%) were compared in rabbit papillary muscles under various stimulation conditions to gain insight into the action of these anesthetics on the availability of Ca2+ for the activation of myocardial contractile activity. The negative inotropic effect of thiopental was more pronounced at short (0.5 sec) than at long (1 sec) beat-to-beat intervals under steady-state conditions, and thiopental's effect on potentiated state contractions was less than that on steady-state contractions. For all variables studied, the effect of halothane was opposite that of thiopental. These results suggest that thiopental reduces the influx of extracellular Ca2+ and the amount of Ca2+ in sarcolemmal sites and slows the transport of intracellular Ca2+ within the sarcoplasmic reticulum from sites of uptake to sites of release without markedly diminishing the amount of intracellular Ca2+. Halothane does not appreciably affect the transport but does diminish the amount of Ca2+ within the sarcoplasmic reticulum that is available for the activation of myocardial contractile activity.
在不同刺激条件下，比较了硫喷妥钠（10 - 30mg/L）和氟烷（0.5 - 1.5%）对兔乳头肌的负性肌力作用，以深入了解这些麻醉药对用于激活心肌收缩活动的Ca2+可用性的影响。在稳态条件下，硫喷妥钠在短的（0.5秒）逐搏间期比在长的（1秒）逐搏间期的负性肌力作用更明显，并且硫喷妥钠对增强状态收缩的作用小于对稳态收缩的作用。对于所有研究的变量，氟烷的作用与硫喷妥钠相反。这些结果表明，硫喷妥钠减少细胞外Ca2+的内流和肌膜部位的Ca2+量，并减缓肌浆网内细胞内Ca2+从摄取部位到释放部位的转运，而不会明显减少细胞内Ca2+的量。氟烷对转运没有明显影响，但会减少肌浆网内可用于激活心肌收缩活动的Ca2+量。
