Akagi K, Challis J R
Lawson Research Institute, St. Joseph's Health Centre, Department of Obstetrics and Gynecology, University of Western Ontario, London, Canada.
Can J Physiol Pharmacol. 1990 Dec;68(12):1527-32. doi: 10.1139/y90-232.
We examined whether there was a minimal change in fetal arterial Po2 necessary to elicit alterations in plasma adrenocorticotropic hormone, arginine vasopressin, or cortisol or to affect the incidence of breathing movements or eye movements in fetal sheep at 106-117 days of gestation. Fetal sheep were exposed to two levels of hypoxemia, mild (4.1 mmHg Po2 drop) (1 mmHg = 133.32 Pa) and moderate (8.4 mmHg Po2 drop), for 1 h without acidemia. Hypoxemia was induced by altering the inspired percent oxygen of the mother. No significant hormonal and biophysical changes were observed in mild hypoxemia. In moderate hypoxemia, there were significant increases of fetal adrenocorticotropic hormone and arginine vasopressin and decreased incidence of fetal breathing movements. However, there were no significant changes in cortisol or eye movements. We conclude that a fetal arterial Po2 drop of between 4.1 and 8.4 mmHg is necessary to elicit responses to hypoxemia in fetal sheep at 106-117 days of gestation in adrenocorticotropic hormone, arginine vasopressin, and fetal breathing movements, but this degree of hypoxemia does not cause changes in cortisol or fetal eye movements.
我们研究了在妊娠106 - 117天的胎羊中，引起血浆促肾上腺皮质激素、精氨酸加压素或皮质醇变化，或影响呼吸运动或眼球运动发生率所需的胎儿动脉血氧分压的最小变化。将胎羊暴露于两种低氧水平，轻度（动脉血氧分压下降4.1 mmHg）（1 mmHg = 133.32 Pa）和中度（动脉血氧分压下降8.4 mmHg），持续1小时且无酸血症。通过改变母体吸入氧百分比诱导低氧血症。在轻度低氧血症中未观察到显著的激素和生物物理变化。在中度低氧血症中，胎儿促肾上腺皮质激素和精氨酸加压素显著增加，胎儿呼吸运动发生率降低。然而，皮质醇或眼球运动无显著变化。我们得出结论，在妊娠106 - 117天的胎羊中，动脉血氧分压下降4.1至8.4 mmHg对于促肾上腺皮质激素、精氨酸加压素和胎儿呼吸运动引起对低氧血症的反应是必要的，但这种程度的低氧血症不会导致皮质醇或胎儿眼球运动的变化。
