美西律对犬窦房结的作用  

Effects of mexiletine on direct perfusion of sinus node and electrophysi-ological parameter in canine heart

作　　者：严桦[1] 黄伟民[1] 金洁美[1] 顾洪安[1] 

机构地区：[1]上海市徐汇区中心医院心血管研究室

出　　处：《中国药学杂志》1994年第12期722-725,共4页Chinese Pharmaceutical Journal

摘　　要：犬２０只，１２～１８ｋｇ，静脉注射戊巴比妥钠麻醉，监测心电图、希氏束电图、动脉压力及一系列电生理指标，并用ＨＰＬＣ监测美西律的血药浓度变化。窦房结直接给美西律剂量大于１０μｇ时，心率明显降低，与对照组比较１ｍｉｎ心率变化百分率与浓度成负相关。美西律剂量加大到５００μｇ时，心房激动被抑制，心房激动抑制率也有剂量依赖性。静脉注射美西律５ｍｇ·ｋｇ￣（－１）＋３０μｇ·ｋｇ￣（－１）·ｍｉｎ￣（－１），血药浓度维持在２．０μｇ·ｍｌ￣（－１）水平，此时窦房结恢复时间校正值明显延长，其它心脏电生理参数变化无一致性。本实验结果提示大剂量美西律有抑制窦房结的作用。Twenty dogs weighing 12～18kg were anaesthetized with sodium pentobarbital. Electrocardiograph,His-bundle electrogram,aortic blood pressure and electrophysiological param-eters were recorded.The concentration of mexitetine in plasma was determined by HPLC. Directperfusion of the sinus node:after the treatment of mexiletine(10～5000μg· ml￣(-1)),the heart ratewas obviously depressed.Compared with control group, the inhibitory effect of mexiletine wasdose-dependent.When the dose of mexiletine was 500μg, His-bundle electrogram showed that a-trial excitement was inhibited and the percentage inhibition of atrial excitement was also dose de-pendent.After intravenous mexiletine 5mg· kg￣(-1)within 3 minutes and following continuous infu-sion of 30μg,kg￣(-1) per minute, plasma concentrations of mexiletine maintain at 2. 0μg·ml￣(-1) orso. Sino-atrial recovery time correction was significantly prolonged and other electrophysiologicalparameters were changed differently.This study showed that large dose of mexiletine inhibited si-nus node.

关 键 词：美西律 窦房结 直接给药 心率 血药浓度 

分 类 号：R965.1[医药卫生—药理学]