镍对豚鼠心室肌收缩活动及慢反应电位的影响  

Effects of Ni^(2+) on contractions and slow action potentials in guinea pig ventricular myocardium

作　　者：刘北英[1] 钮伟真[1] 曹敬清[1] 韩大英[1] 

机构地区：[1]首都医科大学心血管研究室,北京100054

出　　处：《中国药理学与毒理学杂志》2001年第1期31-34,共4页Chinese Journal of Pharmacology and Toxicology

摘　　要：应用微张力换能及微电极方法观察了镍离子(Ni2 +)对豚鼠心室肌收缩活动及慢反应电位的影响 .结果显示 :①NiCl2 0 .0 5mmol·L- 1有增加收缩活动的倾向 ,而在大于 0 .50mmol·L- 1时 ,收缩活动呈剂量依赖性下降 .②Ni2 +能明显抑制正阶梯现象及静息后增强效应 ,但未使正阶梯现象翻转 .③Ni2 +使慢反应电位的幅度及 0期最大上升速率 ( Vmax)降低 .④高浓度Ni2 +对收缩活动的抑制作用强而持久 ,且对活动心肌的影响更加明显 .上述结果表明 :Ni2 +通过多种途径拮抗Ca2 +而影响心肌的收缩活动 ,它是一种非特异性的Ca2 +拮抗剂 .而低浓度Ni2 +增加收缩活动的现象 ,则提示Ni2The effects of Ni 2+ on contractions and slow action potentials were studied by using micro force transducer and microelectrode methods in vitro in guinea pig ventricular myocardium. The results showed:① 0.05 mmol·L -1 NiCl 2 produced a positive chronotropic effect,but in the high concentrations (0.1-1.0 mmol·L -1 ),Ni 2+ produced a dose dependent negative chronotropic effect. ②NiCl 2 0.5 mmol·L -1 inhibited post rest potentiation and positive staircase phenomena(PSP), but didn′t reverse PSP. ③NiCl 2 0.1-1.0 mmol·L -1 reduced max and amplitude of slow action potentials. ④In high concentrations (>0.5 mmol·L -1 ),the effects of Ni 2+ were strong and lasted long,and were more significant in active preparations.These results suggest that Ni 2+ inhibit myocardial contraction by many ways as Ca 2+ antagonist, and from the event that low concentration of Ni 2+ potentiated myocardial contraction, there be different mechanisms of its effects on myocardial contraction.

关 键 词：镍 心肌收缩 动作电位 慢反应电位 豚鼠 

分 类 号：R331.31[医药卫生—人体生理学]