Intramembranous solute and water fluxes during high intramembranous absorption rates in fetal sheep with and without lung liquid diversion
Intramembranous solute and water fluxes during high intramembranous absorption rates in fetal sheep with and without lung liquid diversion
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DOI：
10.1016/j.ajog.2009.02.018
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发表时间：
2009-07-01
影响因子：
9.8
通讯作者：
Brace, Robert A.
中科院分区：
文献类型：
--
作者：
Gesteland, Katherine M.;Anderson, Debra F.;Brace, Robert A.
目的：研究膜内溶质和水分吸收增加的机制。研究设计：测定胎羊在基础条件下和羊膜内输注乳酸林格氏液（4l /d）后3天的膜内溶质通量和水通量，有和没有肺液体分流。结果：膜内钠、钾、氯、钙、葡萄糖和乳酸通量增加2.5 ~ 7.9倍，与容积通量线性相关（r = 0.83 ~ 0.99），不受肺液影响。除乳酸外，所有清除率均增加至与输注时膜内体积吸收率相等。结论：在基础条件下，被动扩散对膜内溶质吸收的贡献较小，而体积流动对膜内溶质吸收的贡献较大。在高吸收率期间，溶质吸收率高于基础水平的增加似乎完全是由于体积流动，而不受肺液体的影响。大流量增加与囊性胞吞作用一致。
OBJECTIVE: To examine mechanisms that mediate increased intramembranous solute and water absorption.STUDY DESIGN: Intramembranous solute and water fluxes were measured in fetal sheep under basal conditions and after intraamniotic infusion of lactated Ringer's solution of 4 L/d for 3 days with and without lung liquid diversion.RESULTS: Intramembranous sodium, potassium, chloride, calcium, glucose, and lactate fluxes increased 2.5- to 7.9-fold, were linearly related to volume fluxes (r = 0.83-0.99), and were unaffected by lung liquid. All clearance rates, except that of lactate, increased to equal the intramembranous volume absorption rate during infusion.CONCLUSION: Under basal conditions, passive diffusion makes a minor and bulk flow a major contribution to intramembranous solute absorption. During high absorption rates, the increase in solute absorption above basal levels appears to be due entirely to bulk flow and is unaffected by lung liquid. The increased bulk flow is consistent with vesicular transcytosis.