Gas exchange across avian eggshells oscillates in phase with heartbeat.
Gas exchange across avian eggshells oscillates in phase with heartbeat.
复制标题
鸟类蛋壳之间的气体交换与心跳同相振荡。
DOI：
10.1152/jappl.1990.69.4.1549
复制
发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Banzett,RB
中科院分区：
文献类型：
--
作者：
Wang,N;Butler,JP;Banzett,RB
拉恩等人。 (J. Appl. Physiol. 69: 1546-1548, 1990)表明，含有完整蛋的体积描记器中的气压与心电图 (ECG) 同相振荡，并且这种压力变化可以用作确定禽类胚胎心率的非侵入性方法。解释压力振荡的一种可能机制是胚胎心脏的机械运动，这导致体积描记器内气体的体积变化。另一种可能是，气压随心跳的振荡是脉动血流引起的脉动气体交换。如果气体交换暂时停止，则依赖于气体交换的压力信号应该消失，而依赖于心血管运动的压力信号应该持续存在。我们使用一些晚期鸡蛋（孵化第 15-20 天），通过突然改变鸡蛋周围的气体成分并测量压力振荡的影响来测试这些假设。我们发现 1) 将 5% CO2-95% N2 冲入体积描记器后（大概停止气体交换），压力振荡几乎为零，心电图信号仍然存在；空气被冲回体积描记器后，压力信号恢复到控制水平； 2）将20%CO2-20%O2-60%N2冲入体积描记器后（推测增加了净气体交换），压力信号与空气中相比增加了2.5倍； 3）将1％CO2-99％N2冲入体积描记器后（推测是反向气体交换），振荡压力降至空气中的四分之一，并且相对于ECG的压力相位与空气中的相位相反。（摘要截断为250字）
Rahn et al. (J. Appl. Physiol. 69: 1546-1548, 1990) showed that the gas pressure in a plethysmograph containing an intact egg oscillates in phase with electrocardiogram (ECG) and that this pressure variation could be used as a noninvasive way to determine the heart rate of an avian embryo. One possible mechanism to account for the pressure oscillation is the mechanical movement of the embryonic heart, which leads to volume shifts of gas within the plethysmograph. Another possibility is that the oscillation of gas pressure with heartbeat is pulsatile gas exchange resulting from pulsatile blood flow. If gas exchange were transiently stopped, a pressure signal dependent on gas exchange should disappear, while a pressure signal dependent on cardiovascular motion should persist. Using a number of late-age hen eggs (at days 15-20 of incubation), we tested these hypotheses by suddenly changing the gas composition surrounding an egg and measuring the effect of the pressure oscillation. We found that 1) after 5% CO2-95% N2 was flushed into the plethysmograph (presumably halting gas exchange), pressure oscillations went almost to zero and the ECG signal remained; after air was flushed back to the plethysmograph, the pressure signal returned to control level; 2) after 20% CO2-20% O2-60% N2 was flushed into the plethysmograph (presumably increasing net gas exchange), the pressure signal increased 2.5-fold compared with that in air; and 3) after 1% CO2-99% N2 was flushed into the plethysmograph (presumably reversing gas exchange), the oscillation pressure decreased to one-fourth of that in air and the phase of pressure relative to ECG reversed compared with the phase in air.(ABSTRACT TRUNCATED AT 250 WORDS)