Abstract:
Red blood cells (RBCs) are vital for transporting oxygen from the lungs to the body\'s tissues through the intricate circulatory system. They achieve this by binding and releasing oxygen molecules to the abundant hemoglobin within their cytosol. The volume of RBCs affects the amount of oxygen they can carry, yet whether this volume is optimal for transporting oxygen through the circulatory system remains an open question. This study explores, through high-fidelity numerical simulations, the impact of RBC volume on advective oxygen transport efficiency through arterioles, which form the area of greatest flow resistance in the circulatory system. The results show that, strikingly, RBCs with volumes similar to those found in vivo are most efficient to transport oxygen through arterioles. The flow resistance is related to the cell-free layer thickness, which is influenced by the shape and the motion of the RBCs: at low volumes, RBCs deform and fold, while at high volumes, RBCs collide and follow more diffuse trajectories. In contrast, RBCs with a healthy volume maximize the cell-free layer thickness, resulting in a more efficient advective transport of oxygen.
摘要:
红细胞(RBC)对于通过复杂的循环系统将氧气从肺部输送到人体组织至关重要。它们通过将氧分子结合并释放到其胞质溶胶内的丰富血红蛋白来实现这一点。红细胞的体积影响它们可以携带的氧气量,然而,这个体积是否最适合通过循环系统输送氧气仍然是一个悬而未决的问题。本研究探讨,通过高保真数值模拟,红细胞体积对通过构成循环系统中最大流动阻力区域的小动脉的优先氧转运效率的影响。结果表明,惊人的,具有与体内发现的那些相似的体积的RBC最有效地通过小动脉运输氧。流动阻力与无细胞层厚度有关,受RBC的形状和运动的影响:在低体积下,RBC变形并折叠,而在高体积下,RBC碰撞并遵循更多的扩散轨迹。相比之下,具有健康体积的红细胞最大化无细胞层厚度,导致氧气的更有效的预先运输。