Diffusion Mechanisms Across Human Placental Tissue
- 1 January 1973
- journal article
- Published by S. Karger AG in Gynecologic and Obstetric Investigation
- Vol. 4 (1) , 31-37
- https://doi.org/10.1159/000301706
Abstract
The temperature dependence of tritiated water (THO), p-amino hippurate, salicylate and antipyrine diffusion across human placental tissue in vitro was measured. From this data the following activation energies for diffusion of THO were obtained: 4.2 kcal/mol for chorioamnion; 3.6 kcal/mol for chorion leave; 4.7 kcal/mol for amnion. Values of 4.6 kcal/mol for salicylate and 4.3 kcal/mol for p-amino hippurate diffusion across chorion leave were measured. These relatively low activation energies suggest that these solutes cross this tissue principally through large water-filled extracellular channels. An activation energy for antipyrine diffusion of 14.6 kcal/mol between 25 and 38 °C indicates that the increased permeability of chorion leave to this molecule results from a combination of transcellular and extracellular diffusion.Keywords
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