OXYGEN EXCHANGE AT THE CAPILLARY LEVEL

本研究的主要目的是确定 氧载体成分的离散性的作用 血液（悬浮在血浆中的颗粒红细胞） 毛细血管内和毛细血管周围氧交换。 基本 对这些过程的理解是基于 假设毛细血管血是连续的血红蛋白 溶液中的氧传输阻力 全身毛细血管相对于 组织. 最近的证据反驳了这两种假设。 这 研究将使人们更好地了解氧气交换 在毛细血管水平，肺吸收和全身吸收 释放，并将提供新的见解解开 活组织中的氧调节机制。 毛细血管内氧转运的定量描述 将开发直接解决两阶段性质的 毛细血管的血液。 这样的描述很难与 现有的体内实验技术和模型将 用于桥接毛细血管内氧气之间的差距 传输和实验可测量的量。 氧 单个红细胞和红细胞的摄取和释放 在单列悬浮液中流动， 渠道将被研究。 这些研究将决定 红细胞内和毛细血管内氧传导。 将结果与以下的体外实验数据进行比较： 单个红细胞和红细胞的氧摄取和释放 细胞悬浮在微通道中流动。 的角色 红细胞的形状、大小、间距和间距异质性， 毛细血管将被确定，因为将是功能性的 用于氧交换的毛细管表面积。 毛细管内检查和结果将与 血管外氧气运输的模型。 这些 研究将确定组织运输的程度 过程，有和没有肌红蛋白，平滑离散 毛细血管供氧。 重点将主要放在 红细胞间距和间距异质性的作用 在毛细血管中。 内部氧气运输的阻力 毛细血管将与周围组织中的毛细血管进行比较， 检测从红细胞到组织的氧分压下降。 预测结果将与现有的实验结果进行比较 数据

The principal objectives of this research are to ascertain the role of the discrete nature of the oxygen carrying component of blood (particulate red cells suspended in plasma) on intracapillary and pericapillary oxygen exchange. Fundamental understanding of these processes has been based on the assumptions that capillary blood is a continuum hemoglobin solution and that the oxygen transport resistance within systemic capillaries is negligible relative to that in the tissue. Recent evidence argues against both assumptions. This research will permit a better understanding of oxygen exchange at the capillary level, both pulmonary uptake and systemic release, and will provide new insight for unravelling the mechanisms of oxygen rgulation in living tissues. A quantitative description of intracapillary oxygen transport will be developed that directly addresses the two-phase nature of capillary blood. Such a description is difficult with existing in-vivo experimental techniques and thus a model will be used to bridge the gap between intracapillary oxygen transport and experimentally measurable quantities. Oxygen uptake and release from single red cells and from red cells flowing in single-file suspension through capillary-size channels will be studied. These studies will determine intra-erthrocyte and intracapillary oxygen conductances. Results will be compared against in-vitro experimental data of oxygen uptake and release from single red cells and from red cells flowing in suspension through microchannels. The roles of red cell shape, size, spacing, and spacing heterogeneity in capillaries will be ascertained, as will be the functional capillary surface area for oxygen exchange. The intracapillary descriptio and results will be combined with models for the extravascular transport of oxygen. These studies will ascertain the extent to which tissue transport processes, with and without myoglobin, smooth-out the discrete oxygen supply from capillaries. The focus will be primarily on the role of the spacing and spacing heterogeneity of red cells in capillaries. The resistance to oxygen transport within capillaries will be compared to that in surrounding tissue by examining the drop in oxygen tension from red cells to tissue. The predicted result will be compared to available experimental data.