An oxygen transport model for human bone marrow microcirculation

Human bone marrow (BM) is the site for haematopoiesis, or blood cell formation, and a tissue of complex architectural organization, which promotes the micro-environmental niches that regulate haematopoietic stein cell renewal and differentiation. Oxygen tension distribution is an important modulator of stem and progenitor cell proliferation and differentiation. Currently, it is impossible to measure oxygen tension levels in situ and their spatial distribution within tissues and organs. Hence, conceptual models have been routinely utilized as an attractive alternative to simulate the oxygen tension distribution. However, detailed analyses of transport properties in the marrow have been deficient, despite its important function. In this report, we present the development of a mathematical model that simulates oxygen transport from the sinusoids (BM microcirculation) to the surrounding extravascular space using an extension to the Krogh-type genre. Based on the characteristics of the BM physiology, the sinus and tissue oxygen tension profiles are obtained for various cases including single- and multi-vessel systems. Furthermore, the effect of pre-sinusoidal vessels (arterioles) in the vicinity of the sinusoids on oxygen tension distribution is investigated. The parameter values are based on human BM and the results are correlated with known physiological BM phenomena.