ABSTRACT
Objective To study the effect of moxonidine (Mox) on the His bundle electrogram (HBE) of normal rabbits. Methods A total of 24 healthy rabbits were randomly divided into four groups: control group, small dose of Mox (0.1 mg?kg -1), medium dose of Mox (0.3 mg?kg -1) and large dose of Mox (0.9 mg?kg -1). The electrode catheter was inserted from the right carotid artery to record the HBE. The HBE and the synchronism surface ECG were recorded before and after intravenous injection. Results In normal rabbits, the R-R interphase, P-R interphase of the ECG and the H-V interphase of the HBE were prolonged in a dose-dependent manner after intravenous injection of Mox. Mox exerted no significant influence on the A-H interphase. Conclusion ① Mox decreases the heart rate of rabbits in a dose-dependent manner in vivo. ② Mox dose-dependently prolongs the P-R interphase of the surface ECG and the H-V interphase of HBE. This indicates that Mox mainly acts on the intraventricular conducting system.