Quantifying the impact of tissue metabolism on solute transport in feto-placental microvascular networks
Quantifying the impact of tissue metabolism on solute transport in feto-placental microvascular networks
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DOI：
10.1098/rsfs.2019.0021
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发表时间：
2019-10-06
期刊：
影响因子：
4.4
通讯作者：
Chernyavsky, Igor L.
中科院分区：
文献类型：
--
作者：
Erlich, Alexander;Nye, Gareth A.;Chernyavsky, Igor L.
人类胎盘中的主要交换单位是终末绒毛，其中胎儿毛细血管网络被一层薄薄的绒毛组织包围，将胎儿血液与母体血液分开。为了了解绒毛的复杂空间结构如何影响其功能，我们使用基于图像的理论模型来研究组织代谢对溶质从母体血液运输到胎儿循环中的影响。对于溶质是采取了一阶动力学，我们表明，流量限制和扩散限制运输之间的过渡取决于两个新的无量纲参数定义的关键几何量，与强溶质吸收促进流量限制运输条件。我们提出了一个简单的代数近似的溶质吸收率作为流动条件，代谢率和绒毛几何形状的函数。对于氧气，占非线性动力学使用生理参数值，我们的模型预测，绒毛代谢并不显着影响氧气转移到胎儿血液，虽然绒毛组织和毛细血管网络之间的流量的分区强烈依赖于流动制度。
The primary exchange units in the human placenta are terminal villi, in which fetal capillary networks are surrounded by a thin layer of villous tissue, separating fetal from maternal blood. To understand how the complex spatial structure of villi influences their function, we use an image-based theoretical model to study the effect of tissue metabolism on the transport of solutes from maternal blood into the fetal circulation. For solute that is taken up under first-order kinetics, we show that the transition between flow-limited and diffusion-limited transport depends on two new dimensionless parameters defined in terms of key geometric quantities, with strong solute uptake promoting flow-limited transport conditions. We present a simple algebraic approximation for solute uptake rate as a function of flow conditions, metabolic rate and villous geometry. For oxygen, accounting for nonlinear kinetics using physiological parameter values, our model predicts that villous metabolism does not significantly impact oxygen transfer to fetal blood, although the partitioning of fluxes between the villous tissue and the capillary network depends strongly on the flow regime.