Platou E S, Refsum H, Amlie J P, Landmark K
Cardiovasc Res. 1981 Mar;15(3):137-43. doi: 10.1093/cvr/15.3.137.
Melperone (0.5 to 12.5 mg.kg-1) reduced mean aortic blood pressure in pentobarbital anaesthetised dogs to a greater extent after beta1-adrenergic receptor blockade with atenolol than after cholinergic blockade with atropine. Electrophysiological studies demonstrated that increased heart rate and decreased atrioventricular nodal refractoriness after lower doses of melperone (0.5 to 2.5 mg.kg-1), could be prevented by pretreatment with atenolol. The melperone-induced decrease in atrioventricular nodal conduction time was, however, not affected by pretreatment with atenolol or atropine. Intra-atrial and His-Purkinje conduction times and QRS width were not affected by atenolol or atropine plus melperone. Melperone caused a dose-dependent and very pronounced increase in ventricular and, even more, atrial refractoriness after atenolol. The ventricular and atrial refractoriness increased less after pretreatment with atropine. Some of the cardiac electrophysiological effects of melperone thus depend on the degree of beta-adrenergic stimulation. The overall cardiac electrophysiological effects of melperone results from a combination of direct and indirect actions of the drug.
在戊巴比妥麻醉的犬中，与用阿托品进行胆碱能阻滞相比，美哌隆（0.5至12.5mg·kg⁻¹）在用阿替洛尔进行β1肾上腺素能受体阻滞后，能更大程度地降低平均主动脉血压。电生理研究表明，较低剂量美哌隆（0.5至2.5mg·kg⁻¹）后心率增加和房室结不应期缩短，可通过阿替洛尔预处理来预防。然而，美哌隆引起的房室结传导时间缩短不受阿替洛尔或阿托品预处理的影响。心房内和希氏-浦肯野纤维传导时间以及QRS波宽度不受阿替洛尔或阿托品加美哌隆的影响。美哌隆在阿替洛尔给药后引起剂量依赖性且非常明显的心室甚至心房不应期延长。用阿托品预处理后心室和心房不应期增加较少。因此，美哌隆的一些心脏电生理效应取决于β肾上腺素能刺激的程度。美哌隆的总体心脏电生理效应是该药物直接和间接作用共同作用的结果。
