Metabolic and mechanical control of the microcirculation

Abstract

Existing models of the microcirculatory control usually assume a single mechanical parameter which in an unspecified way relates to the oxygen levels or to the metabolic demand. This parameter changes the mechanical properties of the microvascular bed upstream of where the change is needed, and in most cases affect a very wide region of the myocardium, rather than a number of cells at a specific location. The model presented here suggests a control mechanism which relates to the metabolic demand of a single cell, or a small number of cells. The analysis shows that each specific structure has a potential for a different change, and that these changes can occur with a minimal change in the energy demand. The model shows that these specific changes can affect a 300-500% change in rate of flow. This range of change is consistent with experimental evidence which is hitherto unexplained by current existing models.