Coupled oxygen–carbon dioxide transport model for the human bone marrow

Oxygen is an important modulator of stem and progenitor cell proliferation and differentiation in the human bone marrow (BM). The complexity and physical inaccessibility of BM have hindered the elucidation of the spatial oxygen tension distribution. The aim of this study is the utilisation of mathematical modelling to simulate the oxygen tension distribution in the BM microcirculatory region. The model aims to capture the necessary blood chemistries that are coupled to the gas transport process; in particular, the model incorporates the simultaneous oxygen and carbon dioxide transport combined with pH regulation. Additional studies were also carried to illustrate the importance of capturing the true physiology of the oxygen transport process and its possible effects on the functionality of the BM. In particular, the results demonstrate that: (1) the Haldane effect is more critical to the oxygen transport process than the Bohr effect, (2) the sinusoidal pH is within the range for which certain haematopoietic cell lineages can proliferate and differentiate optimally, and (3) the oxygen tension in the extravascular space (3–5%) corresponds to the concentration required for the cellular growth.