摘要
目的 :研究白介素 2 (IL 2 )对心肌跨膜电位和收缩作用的影响及其可能机制。方法 :在离体灌流大鼠右心室乳头肌标本上 ,采用常规细胞内玻璃微电极技术 ,观察IL 2 (0 .5～ 2 0 0u/ml)灌流 10min对心肌细胞跨膜电位的影响 ,并记录乳头肌收缩力变化。结果 :IL 2缩短心肌动作电位时程 (APD50 和APD80 ) ,但对静息电位、动作电位 0期去极化幅度及其速度无明显影响。IL 2呈剂量依赖性地抑制心肌收缩力 ,0 .5、2 .5、10、5 0和 2 0 0u/ml的IL 2分别使乳头肌收缩力下降至加药前的 94 .8%± 6 .8%、85 .8%± 6 .5 %、76 .3%± 7.8%、6 9.3%± 9.5 %和 5 2 .5 %±11.0 %。L NAME(10 -4mol/L)预处理 10min ,完全阻断较低浓度 (u/ml)IL 2 (0 .5、2 .5、10 )的心肌抑制作用 ,部分阻断高浓度IL 2 (5 0u/ml和 2 0 0u/ml)的作用。结论 :IL 2对离体右心室乳头肌的动作电位时程和收缩力有抑制作用 。
Aim:To investigate the effects of interleukin 2 (IL 2) on the transmembrane potential and contractile force in ventricular papillary muscle of rat and the underlying mechanism. Methods:The transmembrane potentials and contractile force were recorded by intracellular glass microelectrode and tension transducer in the isolated rat papillary muscles. Results:①IL 2 shortened the action potential duration (APD 50 and APD 80 ), while had no effects on resting potential, action potential amplitude and depolarization rate.②IL 2 depressed the contractile force of the muscle in dose dependent manner. IL 2 at concentrations of 0.5, 2.5, 10, 50 and 200 u/ml decreased the developed tension to 94.8% ( P <0.05), 85.8%, 76.3%, 69.3% and 52.5% ( P <0.01), respectively. ③Pretreatment with L NAME (10 -4 mol/L) attenuated the negative inotropic effect of IL 2, in which effect of IL 2 at concentrations from 0.5 to 10 u/ml was completely abolished, and the effect of IL 2 at high dose (50 and 200 u/ml) was partly attenuated by L NAME. Conclusion: IL 2 had inhibitory effects on action potential duration and contractile force of papillary muscle, and its negative inotropic effect was mediated by nitric oxide.
出处
《中国应用生理学杂志》
CAS
CSCD
北大核心
2002年第4期343-346,共4页
Chinese Journal of Applied Physiology
基金
浙江省自然科学基金青年人才专项资金资助项目(RC990 3 8)
