Höchel J, Akiyama R, Masuko T, Pearson J T, Nichelmann M, Tazawa H
Humboldt-Universität zu Berlin, Institut für Biologie, AG Perinatale Anpassung, 10115 Berlin, Germany.
Am J Physiol. 1998 Aug;275(2):H527-33. doi: 10.1152/ajpheart.1998.275.2.H527.
Heart rate (HR) irregularities in chick embryos were defined as large fluctuations (>10 beats/min) comprising irregular, brief deceleration and/or acceleration of instantaneous HR (IHR). IHR was determined directly from the arterial blood pressure while adequate gas exchange was maintained through an eggshell and chorioallantoic membrane. Five embryos were examined on each day from day 11 to day 19 of incubation. Baseline HR was stable until day 12-13, and on around day 13-14 transient, rapid deceleration of HR (termed V pattern) began to appear, with a subsequent increase in its frequency and magnitude. The acceleration patterns (lambda, avian omega, and periodic patterns) appeared later, and the IHR became increasingly irregular, with additional, spontaneous deceleration and acceleration patterns toward hatching. Additional experiments with intravenous administration of autonomic drugs clearly showed that rapid deceleration of HR was mediated by parasympathetic nervous function but did not always show clear relations of sympathomimetic and sympathetic blocking agents to the acceleration patterns.
鸡胚心率（HR）异常被定义为大幅波动（>10次/分钟），包括瞬时心率（IHR）的不规则、短暂减速和/或加速。在通过蛋壳和尿囊绒膜维持充分气体交换的同时，直接从动脉血压测定IHR。在孵化的第11天至第19天，每天检查5个胚胎。基线心率在第12 - 13天之前保持稳定，在大约第13 - 14天开始出现短暂、快速的心率减速（称为V型），随后其频率和幅度增加。加速模式（λ、禽类ω和周期性模式）出现较晚，IHR变得越来越不规则，在接近孵化时出现额外的自发减速和加速模式。静脉注射自主神经药物的额外实验清楚地表明，心率的快速减速是由副交感神经功能介导的，但拟交感神经药和交感神经阻滞剂与加速模式并不总是表现出明确的关系。
