目的观察银杏内酯注射液、银杏内酯ABC以及银杏叶提取物注射液(EGb761)对家兔血小板聚集功能、超微结构及PF-4和β-TG含量的影响比较。方法将日本大耳兔分为对照(生理盐水)组、EGb761(1.02 m L/kg)组、银杏内酯ABC(5.13 mg/kg)组、银杏...目的观察银杏内酯注射液、银杏内酯ABC以及银杏叶提取物注射液(EGb761)对家兔血小板聚集功能、超微结构及PF-4和β-TG含量的影响比较。方法将日本大耳兔分为对照(生理盐水)组、EGb761(1.02 m L/kg)组、银杏内酯ABC(5.13 mg/kg)组、银杏内酯注射液(1.02 m L/kg,以萜内酯计5.1 mg/kg)组、白果内酯(5.13 mg/kg)组,分别iv相应药物1周。给药结束后,家兔心脏取血,观察PAF诱导下血小板聚集率;电镜观察血小板超微结构;试剂盒法观察PAF诱导下血清中血小板因子-4(PF-4)和β-血小板球蛋白(β-TG)含量。结果与对照组比较,EGb761组、银杏内酯ABC组、银杏内酯注射液组的血小板聚集率均显著降低(P<0.05、0.01),白果内酯组无显著变化;血小板聚集抑制率:银杏内酯注射液(43.76%)>银杏内酯ABC(35.3%)>EGb761(26.52%)>白果内酯(5.48%)。与对照组比较,EGb761、银杏内酯ABC、银杏内酯注射液均能减少聚集型血小板数量,使树突型血小板突起变少变短。与对照组比较,银杏内酯注射液和银杏内酯ABC均使PF-4和β-TG表达显著降低(P<0.01),EGb761仅显著降低β-TG表达(P<0.05)。结论银杏内酯注射液通过PAF途径发挥抗血小板聚集作用,其作用强于银杏内酯ABC,可能是白果内酯发挥了协同增效作用。展开更多
Objective The mechanism through which platelet activating factor （PAF） induces cardiac electrical activity and arrhythmia is not well understood and previous studies have suggested a potential involvement of ion cha...Objective The mechanism through which platelet activating factor （PAF） induces cardiac electrical activity and arrhythmia is not well understood and previous studies have suggested a potential involvement of ion channels in its action. The present study was aimed to clarify the role of PAF in fatal arrhythmias following acute myocardia infarction （AMI） and the underlying mechanism. Methods （1） Blood PAF levels were measured among 72 AMI patients at the time of diagnosis with AMI and 48 h later, and their electrocardiogram （ECG） was recorded continuously. （2） Ischemia simulation and surface electrocardiogram were conducted in 20 pigs and their PAF levels were measured. （3） PAF perfusion and standard microelectrode recording were performed on guinea pig papillarymuscles. Results In both humans and pigs, elevated PAF levels were detected in AMI and simulated ischemia, respectively, and even higher PAF levels were found when fatal arrhythmias occurred. In guinea pig myocardium, PAF induced a shortening of action potential duration at 90% level of repolarization （APD 90 ）under non-ischemic conditions and a more pronounced shortening under early simulated ischemic conditions. Conclusion AMI and ischemia are associated with increased PAF levels in humans and pigs, which are further raised when fatal arrhythmia follows. The effects of PAF on the myocardium may be mediated by multiple ion channels.展开更多
文摘目的观察银杏内酯注射液、银杏内酯ABC以及银杏叶提取物注射液(EGb761)对家兔血小板聚集功能、超微结构及PF-4和β-TG含量的影响比较。方法将日本大耳兔分为对照(生理盐水)组、EGb761(1.02 m L/kg)组、银杏内酯ABC(5.13 mg/kg)组、银杏内酯注射液(1.02 m L/kg,以萜内酯计5.1 mg/kg)组、白果内酯(5.13 mg/kg)组,分别iv相应药物1周。给药结束后,家兔心脏取血,观察PAF诱导下血小板聚集率;电镜观察血小板超微结构;试剂盒法观察PAF诱导下血清中血小板因子-4(PF-4)和β-血小板球蛋白(β-TG)含量。结果与对照组比较,EGb761组、银杏内酯ABC组、银杏内酯注射液组的血小板聚集率均显著降低(P<0.05、0.01),白果内酯组无显著变化;血小板聚集抑制率:银杏内酯注射液(43.76%)>银杏内酯ABC(35.3%)>EGb761(26.52%)>白果内酯(5.48%)。与对照组比较,EGb761、银杏内酯ABC、银杏内酯注射液均能减少聚集型血小板数量,使树突型血小板突起变少变短。与对照组比较,银杏内酯注射液和银杏内酯ABC均使PF-4和β-TG表达显著降低(P<0.01),EGb761仅显著降低β-TG表达(P<0.05)。结论银杏内酯注射液通过PAF途径发挥抗血小板聚集作用,其作用强于银杏内酯ABC,可能是白果内酯发挥了协同增效作用。
文摘Objective The mechanism through which platelet activating factor （PAF） induces cardiac electrical activity and arrhythmia is not well understood and previous studies have suggested a potential involvement of ion channels in its action. The present study was aimed to clarify the role of PAF in fatal arrhythmias following acute myocardia infarction （AMI） and the underlying mechanism. Methods （1） Blood PAF levels were measured among 72 AMI patients at the time of diagnosis with AMI and 48 h later, and their electrocardiogram （ECG） was recorded continuously. （2） Ischemia simulation and surface electrocardiogram were conducted in 20 pigs and their PAF levels were measured. （3） PAF perfusion and standard microelectrode recording were performed on guinea pig papillarymuscles. Results In both humans and pigs, elevated PAF levels were detected in AMI and simulated ischemia, respectively, and even higher PAF levels were found when fatal arrhythmias occurred. In guinea pig myocardium, PAF induced a shortening of action potential duration at 90% level of repolarization （APD 90 ）under non-ischemic conditions and a more pronounced shortening under early simulated ischemic conditions. Conclusion AMI and ischemia are associated with increased PAF levels in humans and pigs, which are further raised when fatal arrhythmia follows. The effects of PAF on the myocardium may be mediated by multiple ion channels.
