牛磺酸和硫酸镁对缺血/再灌心肌~(45)Ca内流及cAMP含量的影响

本实验采用同位素示踪法以及竞争性蛋白结合法,对大鼠心肌缺血10min,再灌30s~(46)Ca内流和cAMP含量变化与再灌心律失常关系,以及牛磺酸(Taur),硫酸镁(MgSO_4)抗再灌心律失常与影响心肌~(45)Ca内流和cAMP含量关系进行了研究.结果表明,心肌缺血10_(min)再灌30s~(45)Ca内流明显高于正常和缺血心肌.Taur,MgSO_4单用及合用均能降低再灌心律失常发生率和抑制再灌心肌~(45)Ca,内流,两药合用更为明显。心肌缺血10min再灌30s cAMP含量未见变化,Taur,MgSO_4亦对其未见影响。证实两药抗再灌心律失常机制与抑制Ca~(2+)内流,防止“钙超负荷”相关。

Effect of taurine alone and in combination with magnesium sulfate on 45Ca influx and content of cAMP in ischemia/reperfusion myocardium

The relationship detween ischemia/reperfusion-inducedarr-hythmias and change of 45Ca infux or myocardial content of cAMP was, studied in anesthetized rats.The effect of taur ine (Taur ) alone and in Com- bination with magnesium sulfate ( MgSO4 ) on ischemia/reperfusion 45Ca influx and Cortent of cAMp in myocardium were also investigated.The results showed that in control group after reperfusion the 45Ca influx in myocardium was increased significantly.This effect was inhibited by pretreatment with Taur ( 50mg.kg-1 ) , MgSO4( 25mg.kg-1 ) and co-mbination of both agents. This study showed also that reperfusion did not increas myocardial content of cAMP. Taur or MgSO4 did not influence the myocardial content of cAMP in ischemia/reperfusion arrhythmic rats.These finding indicated that development of ischemia/reperfusion arrhythmia was related with the intraccllular Ca2+ over load. Taur, MgSO4 were more effect on reperfusion arrhythmia. The mechanism of antiarrhy-thmic effect of Taur and MgSO4 may be involved in the inhibition of