OXYGEN EXCHANGE AT THE CAPILLARY LEVEL

这项研究的主要目标是确定 载氧组分的离散性质在其中的作用 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的氧气交换。基本原理 对这些过程的理解一直基于 假设毛细血管血液是一种连续的血红蛋白 溶液中的氧气传输阻力 系统性毛细血管与血液中的毛细血管相比微不足道 组织。最近的证据反驳了这两种假设。这 研究将有助于更好地了解氧气交换 在毛细血管水平，肺摄取和全身摄取 发布，并将提供新的洞察力 活体组织中氧调节的机制。 毛细血管内氧转运的定量描述 将开发出直接解决两阶段性质的 毛细血管的血液。这样的描述很难用 现有的体内实验技术，因此一个模型将 用来弥合毛细血管内氧气之间的差距 运输量和可通过实验测量的量。氧 单个红细胞和红细胞的摄取和释放 单列悬浮液在毛细管尺寸中流动 将对渠道进行研究。这些研究将确定 红细胞内和毛细血管内的氧电导。 结果将与体外实验数据进行比较 单个红血球和红血球的氧摄取和释放 悬浮的细胞在微通道中流动。角色 红细胞形状、大小、间距和间距的异质性 毛细血管将被确定，功能也将被确定 供氧交换的毛细表面积。 毛细血管内描述和结果将与 氧在血管外运输的模型。这些 研究将确定组织运输的程度 无论有没有肌红蛋白，这些过程都能使离散的 毛细血管供氧。重点将主要放在 红细胞间距及其异质性的作用 在毛细血管中。体内氧气运输的阻力 将毛细血管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的下降。 预测结果将与已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.