雷尼替丁对体外培养乳鼠心肌细胞自发性搏动及动作电位的影响

Effects of ranitidine on spontaneous beating and action potential of cultured mycardial cells of neonatal rats

本实验以培养大白鼠乳鼠心肌细胞为模型,观察了雷尼替丁对培养心肌细胞自发性搏动频率及动作电位的影响.结果表明:雷尼替丁1～100μmol·L^(-1)对正常心肌细胞搏动频率影响不大,但100μmol·L^(-1)可以阻止组胺10μmol·L^(-1)引起的心肌细胞搏动频率的增快,而对异丙肾上腺素2μmol·L^(-1)引起的心肌细胞搏动频率无明显抑制作用.组胺10μmol·L^(-1)可以使心肌细胞动作电位的APA,V_(max)及OS明显增高,APD_(50)和APD_(90)明显延长,SCL明显缩短.雷尼替丁100μmol·L^(-1)可以抑制此反应.以上结果,说明雷尼替丁对组胺增高所致的心律失常可能有防治作用.

The effects of ranitidine (Ran) on cultured myocardial cells of neonatal rats were observed. Ran 100 μmol·L-1 took no effect on spontaneous beating rates of cultured myocardial cells, but it decreased the beating rates increased by histamine 10 μmol·L-1 and did not inhibit the beating rates increased by isoprenaline 2μmol·L-1. Histamine 10μmol·L-1 increased the amplitude, maximal rate of rise and pro-longed action potential duration at 50% (APD50) and 90% (APD90) repolarization. The effect was abolished by Ran 100μmol·L-1. The results suggested that Ran may possess antiarrhythmic action induced by histamine's increase.