硝苯地平对溴氰菊酯中毒豚鼠心血管毒性的拮抗作用

The antagonistic effect of nifedipine on cardiovascular toxicity induced by deltamethrin in guinea pigs

目的 探讨钙离子通道阻滞剂———硝苯地平对溴氰菊酯 (DM)心血管毒性的拮抗作用。方法 应用生理多导记录仪观察DM染毒及硝苯地平给药后豚鼠 2h内心血管功能的变化。结果 豚鼠一次性腹腔注射DM 2 5mg/kg,其收缩压、舒张压和心肌最大收缩速率 (dp/dt+max)值分别在15、90和 3 0min后明显升高 ,与染毒前即刻 ( 0min)相比差异有显著性 (P <0 .0 5 ) ;中毒豚鼠心电图表现为 :( 1)心率减慢 ,3 0min后降至平台期 ;( 2 )在观察时间内QRS间期持续性延长 ;( 3 )QT比值 (QTr)增大 ,15min后增至平台期 ;( 4 )心律失常发生率为 5 0 %,主要表现为房室传导阻滞和室性早搏。以硝苯地平治疗后 ,中毒豚鼠的上述心血管功能指标与染毒前即刻相比未见明显改变。结论 硝苯地平对DM中毒豚鼠的心血管毒性具有拮抗作用。

Objective Toexploretheantagonisticeffectofcalciumchannelblocker,nifedipine ,oncardio vasculartoxicityinducedbydeltamethrin .Methods Thecardiovascularfunctionsofguineapigsintoxicatedby deltamethrinandtreatedwithnifedipinewereobservedbyphysiologicalpolygraphintwohours.Results Thesig nificantincreaseofsystolicanddiastolicbloodpressureandthemaximumvelocityofmyocardialcontraction (dp/dt+max)werefoundinguineapigintoxicatedbyasingledoseof 2 5mg/kgdeltamethrin(i.p)after 15 ,90and 3 0minutes,respectively,ascomparedwiththoseinaninstantbeforeintoxication( 0min ,P <0 .0 5 ) .Afteranalyzing therecordsofelectrocardiogram ,thefollowingresultswerefoundintheintoxicatedguineapigs :( 1)Heartratede creasedwithastablestageafter 3 0min .( 2 )QRSintervalwascontinuallyprolongedin 2h .( 3 )QTratio(QTr)in creasedwithastablestageafter 15min .( 4 )Theincidenceofarrhythmiaincludingablockoftransmissionbetween atriumandventricleandearlyventricularbeatingwas 5 0 %.Theseindicatorsofcardiovascularfunctionwerenot significantlychangedaftertreatmentwithnifedipineduringtheobservation ,ascomparedwiththosebeforeintoxica tion(P >0 .0 5 ) .Conclusion Nifedipinehadtheantagonisticeffectonthecardiovasculartoxicityinducedby deltamethrininguineapig.