Rurak D W, Gruber N C
J Appl Physiol Respir Environ Exerc Physiol. 1983 Mar;54(3):701-7. doi: 10.1152/jappl.1983.54.3.701.
To examine the relationship between fetal O2 consumption and fetal breathing movements, we measured O2 consumption, umbilical blood flow, and cardiovascular and blood gas data before, during, and after fetal breathing movements in conscious chronically catheterized fetal lambs. During fetal breathing movements, O2 consumption increased by 30% from a control value of 7.7 +/- 0.7 (SE) ml X min-1 X kg-1. Umbilical blood flow was 210 +/- 21 ml X min-1 X kg-1 before fetal breathing movements; in 9 of 16 samples it increased by 52 +/- 12 ml X min-1 X kg-1, while in the other 7 it decreased by 23 +/- 9 ml X min-1 X kg-1. Umbilical arterial and venous O2 partial pressures and pH fell during fetal breathing movements, and the fall was greater when umbilical blood flow was decreased. Partial CO2 pressure rose in both vessels, and again the increase was greatest when umbilical blood flow fell during fetal breathing movements. Also associated with a fall in umbilical blood flow was the transition from low-amplitude irregular to large-amplitude regular fetal breathing movements. It is concluded that fetal breathing movements increase fetal O2 demands and are associated with a transient deterioration in fetal blood gas status, which is most severe during large-amplitude breathing movements.
为了研究胎儿氧消耗与胎儿呼吸运动之间的关系，我们在清醒且长期插管的胎羊中，测量了胎儿呼吸运动前、期间和之后的氧消耗、脐血流量以及心血管和血气数据。在胎儿呼吸运动期间，氧消耗从7.7±0.7（SE）ml·min⁻¹·kg⁻¹的对照值增加了30%。胎儿呼吸运动前脐血流量为210±21 ml·min⁻¹·kg⁻¹；在16个样本中有9个样本中，脐血流量增加了52±12 ml·min⁻¹·kg⁻¹，而在另外7个样本中则减少了23±9 ml·min⁻¹·kg⁻¹。胎儿呼吸运动期间，脐动脉和静脉的氧分压及pH值下降，当脐血流量减少时下降幅度更大。两个血管中的二氧化碳分压均升高，同样，当胎儿呼吸运动期间脐血流量下降时升高幅度最大。从低振幅不规则胎儿呼吸运动向高振幅规则胎儿呼吸运动的转变也与脐血流量下降有关。得出的结论是，胎儿呼吸运动增加了胎儿的氧需求，并与胎儿血气状态的短暂恶化有关，在高振幅呼吸运动期间这种恶化最为严重。
