Mitchell G F, Jeron A, Koren G
Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
Am J Physiol. 1998 Mar;274(3):H747-51. doi: 10.1152/ajpheart.1998.274.3.H747.
Transgenic mouse models provided a powerful tool to evaluate the physiological significance of altered quantities or characteristics of specific gene products, such as cardiac ion channels. We have developed a system to record and analyze changes in the electrocardiogram in the mouse using an implantable telemetry system. The R-R and Q-T intervals were measured on individual beats and on signal-averaged complexes derived from 1, 2, or 4 s of contiguous data each hour during a 24-h period in three male and three female FVB mice. Duration of averaging had minimal effect on the measured Q-T. The Q-T interval was shown to be related to the square root of the R-R interval, and an appropriate formula for a rate-corrected Q-T interval (Q-Tc) was derived. Ketamine anesthesia was shown to markedly increase duration and variability in R-R, Q-T, and Q-Tc intervals. In conscious animals, variability in Q-T was low across animals and over time, suggesting that this should be a sensitive model for detection of changes in the Q-T interval in transgenic mice with ion channel defects.
转基因小鼠模型为评估特定基因产物（如心脏离子通道）数量或特性改变的生理意义提供了一个强大的工具。我们开发了一种系统，使用植入式遥测系统记录和分析小鼠心电图的变化。在三只雄性和三只雌性FVB小鼠的24小时期间，每小时从连续1、2或4秒的数据中获取单个心跳和信号平均复合波，测量R-R和Q-T间期。平均持续时间对测量的Q-T影响最小。结果表明，Q-T间期与R-R间期的平方根相关，并推导出了心率校正Q-T间期（Q-Tc）的合适公式。结果显示，氯胺酮麻醉可显著增加R-R、Q-T和Q-Tc间期的持续时间和变异性。在清醒动物中，Q-T的变异性在不同动物和不同时间都很低，这表明这应该是检测有离子通道缺陷的转基因小鼠Q-T间期变化的一个敏感模型。
