Osmotic flow through the placental barrier of chronically prepared sheep.
Osmotic flow through the placental barrier of chronically prepared sheep.
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通过长期准备的绵羊胎盘屏障的渗透流。
DOI：
10.1152/ajpheart.1977.233.4.h466
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发表时间：
1977
期刊：
影响因子：
--
通讯作者：
J. Faber
中科院分区：
文献类型：
--
作者：
T. Armentrout;S. Katz;K. Thornburg;J. Faber
将电磁流量传感器放置在子宫内绵羊胎儿的远端主动脉上，并将导管放置在股动脉和脐总静脉中。导管也被放置在怀孕母羊的颈动脉和子宫静脉。术后3天，所有方法测定的母体血浆相对于胎儿血浆均为高渗：蒸气压渗透压法测定的SE为+5.8 +/- 1.4，冰点下降渗透压法测定的SE为+2.2 +/- 0.7，校正碳酸氢盐损失;血浆成分化学测定的SE为+3.26 mosmol/L。通过输注甘露醇、蔗糖或NaCl的浓缩溶液，使母体或胎儿血浆在体内高渗。通过胎盘血流量和血液含水量的动静脉差异计算经胎盘水通量。胎盘的表观渗透传导率为61 ml ~ 2-mosmol ~（-1）-kg ~（-1），但该值应除以未知的反射系数以获得真实的渗透传导率。分别测量了5只长期准备的羊胎的Na+和Cl-胎盘扩散渗透性：PSNa+ =0.20 +/- 0.04，PSCl- = 0.27 +/- 0.04 ml/（min-kg胎）。胎盘总通透性与胎儿体重呈显著正相关。
An electromagnetic flow sensor was placed on the distal aorta of sheep fetuses in utero, and catheters were placed in a femoral artery and the common umbilical vein. Catheters were also placed in a carotid artery and a uterine vein of the pregnant ewe. Three days postoperatively maternal plasma was hyperosmotic with respect to fetal plasma by all methods: +5.8 +/- 1.4 SE by vapor-pressure osmometry, +2.2 +/- 0.7 SE by freezing-point depression osmometry corrected for bicarbonate loss; and +3.26 mosmol/liter by chemical measurement of plasma constituents. Maternal or fetal plasma was made hypertonic in vivo by infusion of concentrated solutions of mannitol, sucrose, or NaCl. Transplacental water flux was calculated from placental blood flows and arteriovenous differences in water content of the blood. The apparent osmotic conductivity of the placenta was 61 ml2-mosmol-1-kg-1, but this value should be divided by an unknown reflection coefficient to yield the true osmotic conductivity. Separate measurements were made of the placental diffusional permeability of Na+ and Cl- in five chronically prepared sheep fetuses: PSNa+ =0.20 +/- 0.04, PSCl- = 0.27 +/- 0.04 ml/(min-kg fetus). There was a highly significant positive regression between (total) placental permeability and fetal weight.