Lindheimer M D, Barron W M, Dürr J, Davison J M
Am J Kidney Dis. 1987 Apr;9(4):270-5. doi: 10.1016/s0272-6386(87)80121-x.
Body tonicity decreases during both human and rodent gestation, manifested by a decrease in Posm of approximately 10 mosm/kg. In humans, the decrease in the osmotic threshold for thirst may precede decrements in the arginine vasopressin (AVP) secretory threshold by several weeks, whereas the metabolic clearance rate of AVP appears markedly increased in the third trimester. The cause of these osmoregulatory changes are unclear, since through 1986 we have been unable to implicate placental extracts, estrogens, progesterone, prolactin, angiotensin II, and certain endorphins in the decreased Posm observed during rat pregnancy. Changes also occur in volume-AVP secretory relationships in pregnancy. For instance, the volume-sensing AVP release mechanisms are altered during gestation in Sprague-Dawley rats in such a way that the increased intravascular volume is recognized as normal.
在人类和啮齿动物的妊娠期，身体张力都会降低，表现为血浆渗透压（Posm）下降约10毫渗摩尔/千克。在人类中，口渴的渗透阈值下降可能比精氨酸加压素（AVP）分泌阈值的下降提前几周，而在妊娠晚期，AVP的代谢清除率明显增加。这些渗透调节变化的原因尚不清楚，因为直到1986年，我们还无法将胎盘提取物、雌激素、孕酮、催乳素、血管紧张素II和某些内啡肽与大鼠妊娠期间观察到的Posm下降联系起来。妊娠期间容量与AVP分泌的关系也会发生变化。例如，在斯普拉格-道利大鼠的妊娠期，容量感应性AVP释放机制发生改变，使得血管内容量增加被视为正常。
