EFFECTS OF BUPIVACAINE ON CONTRACTION AND MEMBRANE-POTENTIAL IN ISOLATED CANINE PAPILLARY-MUSCLES
EFFECTS OF BUPIVACAINE ON CONTRACTION AND MEMBRANE-POTENTIAL IN ISOLATED CANINE PAPILLARY-MUSCLES
复制标题
DOI：
10.1159/000139093
复制
发表时间：
1993-09-01
期刊：
影响因子：
3.1
通讯作者：
ITO, Y
中科院分区：
文献类型：
--
作者：
SHIBUYA, N;MOMOSE, Y;ITO, Y
本文观察了布比卡因对犬右室乳头肌收缩和膜电位的影响。布比卡因(10(-6)~10(-4)m ol/l)对犬右室乳头肌的收缩反应具有剂量依赖性和可逆性抑制作用。布比卡因对收缩的抑制作用在高频(2和3赫兹)比低频(1赫兹)更明显。静息膜电位不受布比卡因影响。10(-6)m ol/L布比卡因可使动作电位最大上升速度降低(为对照组的74+/-28%)，且呈剂量依赖关系。在10-4mol/L时，布比卡因可阻断正常台氏液中的快动作电位。此外，布比卡因(10(-4)和10(-3)m ol/L)可缩短高K+(26 mm o l/l)台氏液中的慢动作电位时程和相关收缩。我们的结果提示，低浓度布比卡因抑制收缩主要是通过阻断安娜+通道，而在较高浓度时，这种局部麻醉剂可能阻断钙通道。
The effects of bupivacaine on myocardial contraction and membrane potential were examined in isolated canine right ventricular papillary muscles. Bupivacaine (10(-6) to 10(-4) mol/1) produced a dose-dependent and reversible decrease in the electrically induced contractile response of canine right ventricular papillary muscles. The inhibitory effects of bupivacaine on contraction were more pronounced at high stimulation frequencies (2 and 3 Hz) than at low frequency (< 1 Hz). The resting membrane potential was not affected by bupivacaine. The maximal upstroke velocity of the action potential was reduced by 10(-6) mol/l bupivacaine (74 +/- 28% of control), and these effects were also dose dependent. At 10-4 mol/l, bupivacaine blocked fast action potentials in normal Tyrode's solution. Furthermore, bupivacaine (10(-4) and 10(-3) mol/l) decreased both slow action potential duration and associated contractions in high-K+ (26 mmol/1) Tyrode's solution in the presence of isoproterenol. Our results suggest that low concentrations of bupivacaine depress contraction mainly due to an Na+ channel block, whereas at higher concentration, this local anesthetic may block Ca2+ channels.