Efficacy of rotigaptide on prevention of negative chronotropic effect caused by dexmedetomidine lengthening myocardial repolarization duration / 临床麻醉学杂志

ABSTRACT

Objective To evaluate efficacy of rotigaptide ZP123 on prevention of negative chronotropic effect caused by dexmedetomidine lengthening repolarization duration of the isolated rat hearts.Methods Eighteen healthy adult SD rats of either gender,weighing (300±30) g,were prepared isolated heart perfusion model by Langendorff.After 15 min perfusion and balance of K-H fluid,the isolated hearts were randomly divided into 3 groups (n=6 each) The hearts were continuously pefused for 30 min with 37℃ K-H solution in control group (group C),with dexmedetomidine 50 ng/ml in dexmedetomidine group (group D),or with rotigaptide 80 nmol/L combined with dexmedetomidine 50 ng/ml in rotigaptide combined with dexmedetomidine group (group ZD).In the whole Langendorff-perfused hearts,at the end of balanced infusion for 15 min (T0) and at 15(T1),30(T2) min of continued perfusion with K-H solution,the monophasic action potential (MAP) and heart rate (HR) were recorded from left anterior free wall,MAP duration at 50% repolarization (MAPD50) and at 90% repolarization (MAPD90),monophasic action potential amplitude (MAPA) and maximal velocity (Vmax) were calculated.Results Compared with T0,HR in group D was significantly declined at T1,T2;MAPD90 and MAPD50 in group D were significantly increased at T1,T2 (P<0.05).Compared with groups C and ZD,HR in group D was significantly declined at T1,T2;MAPD90 and MAPD50 in group D were significantly increased at T1,T2 (P<0.05).There was no significant difference in MAPA and Vmax between the three groups.Conclusion Rotigaptide antagonizes negative chronotropic effect induced by dexmedetomidine through shortening monophasic action potential duration in the myocardium of left ventricle of the isolated rat hearts.