Study Of Relationship Between Delayed Rectified Potassium Current And Drug-induced Arrythmia

Objevtive:To investigate the effects of different concentration of haloperidol on delayed rectified potassium current(IK) in guinea pigs ventricular myocytes. Methods: Ventricular myocytes were isolated by acute enzymatic dissociation from hearts of guinea pigs. Whole-cell patch-clamp was used to observe the effects of haloperidol on delayed rectified potassium current. Results:In single ventricular myocytes of guinea pig, different concentration of haloperidol decreased IK in dose-dependent manner. Haloperidol at concentration of 0.3,1.0,3.0μmol·L-1 respectively decreased IK from (16.6604±1.5717) pA/pF to (5.0255±1.9372), (9.8572±3.9002) and (7.1794±1.816) pA/pF (n=7,P<0.01) at +70mV, and a significant decrease was observed at 0.3μmol·L-1. Conclusion: Haloperidol decreased IK in dose-dependent manner. The induced arrythmic effects of haloperidol may be related to its inhibitory effects on delayed rectified potassium current.