Case C L, Ravin R R, Holani R, Gillette P C, Hewett K W
Medical University of South Carolina, South Carolina Children's Heart Center, Division of Pediatric Cardiology, Charleston 29425.
Eur J Pharmacol. 1992 Aug 6;218(2-3):213-8. doi: 10.1016/0014-2999(92)90171-y.
Using standard microelectrode techniques, the developmental cellular electrophysiologic effects of moricizine HCl on adult and neonatal canine Purkinje fibers were studied. Steady state and rate-related changes in the transmembrane action potentials produced by moricizine HCl in both age groups were characterized and compared. Also, the rate of barium-induced abnormal automaticity before and after drug was also investigated in neonatal and adult Purkinje fibers. The major findings of this study are as follows. (1) The steady state and rate-related depressant effects of moricizine HCl on Vmax were similar in both age groups. (2) Moricizine HCl shortened APD90 in the adult fibers to a greater extent than in the neonate. (3) The concentration of moricizine HCl required to significantly reduce the rate of abnormal automaticity was less in the neonate than in the adult. The effect of moricizine HCl on APD90 of individual Purkinje fibers is influenced both by their control APD90 value as well as by maturational factors. It is less clear whether developmental differences in the effects of moricizine HCl on abnormal automaticity are solely a result of differences in control rates of abnormal automaticity between the two age groups.
运用标准微电极技术，研究了盐酸莫雷西嗪对成年和新生犬浦肯野纤维发育过程中的细胞电生理效应。对两个年龄组中盐酸莫雷西嗪产生的跨膜动作电位的稳态和频率相关变化进行了表征和比较。此外，还研究了新生和成年浦肯野纤维在用药前后钡诱导的异常自律性频率。本研究的主要发现如下：（1）两个年龄组中盐酸莫雷西嗪对Vmax的稳态和频率相关抑制作用相似。（2）盐酸莫雷西嗪使成年纤维的APD90缩短的程度大于新生纤维。（3）显著降低异常自律性频率所需的盐酸莫雷西嗪浓度在新生犬中低于成年犬。盐酸莫雷西嗪对单个浦肯野纤维APD90的影响受其对照APD90值以及成熟因素的影响。盐酸莫雷西嗪对异常自律性影响的发育差异是否仅仅是两个年龄组异常自律性对照频率差异的结果尚不清楚。
