Jacobs R, Falconer J, Robinson J S, Webster M E
Aust J Biol Sci. 1986;39(1):79-83.
The development of secondary wool follicles in single fetal sheep subjected to hypobaric hypoxaemia was studied. One group of pregnant ewes were exposed to 57.1 kPa from 30 to 135 days gestation. Fetal weights (mean +/- s.d.) for the hypoxaemic group (3.35 +/- 0.53 kg; n = 4) were significantly lower than for the controls (4.19 +/- 0.31 kg; n = 3, P less than 0.05). At 110 days gestation, a second group had arterial and venous catheters surgically implanted into the ewe and fetus and skin samples were taken from the fetus. At 120 days gestation (10 days after surgery) these animals were subjected to hypoxia for 20 days, at a level to maintain fetal carotid pO2 between 1.47 and 1.87 kPa (mean carotid pO2 for the control fetuses was 2.84 +/- 0.28 kPa). Fetal weight at 140 days was not significantly different in the hypoxaemic and control groups. Morphometric analysis revealed that the secondary to primary follicle ratio (S:P) was less in both groups of hypoxaemic fetuses than in their respective controls. Although hypoxia for 20 days did not significantly alter fetal weight, it produced a low S:P ratio similar to the longer-term hypoxaemic animals. It is concluded that hypoxia has a marked effect in reducing the initiation of secondary follicles in the last third of gestation.
研究了处于低压低氧环境下单胎胎儿绵羊次级毛囊的发育情况。一组妊娠母羊在妊娠30至135天期间暴露于57.1千帕的环境中。低氧组胎儿体重（平均值±标准差）为（3.35±0.53千克；n = 4），显著低于对照组（4.19±0.31千克；n = 3，P<0.05）。在妊娠110天时，第二组母羊和胎儿通过手术植入动脉和静脉导管，并从胎儿身上采集皮肤样本。在妊娠120天（手术后10天），这些动物经历20天的缺氧处理，缺氧水平维持胎儿颈动脉血氧分压在1.47至1.87千帕之间（对照组胎儿的平均颈动脉血氧分压为2.84±0.28千帕）。低氧组和对照组在140天时胎儿体重无显著差异。形态学分析显示，两组低氧胎儿的次级与初级毛囊比例（S:P）均低于各自对照组。虽然20天缺氧未显著改变胎儿体重，但产生了与长期低氧动物相似的低S:P比例。研究得出结论，缺氧对妊娠最后三分之一阶段次级毛囊的起始有显著的抑制作用。
