Lactate dynamics during circulatory hypoxia. Mathematical model and analysis

摘要

The mechanistic basis of the relationship between O/sub 2/ and lactate (LA) concentration in muscle are not fully understood. Increases in LA are frequently observed under hypoxic conditions and during high intensity exercise. However, there are other instances in which lactate can accumulate for reasons other than O/sub 2/ limitation. Our aim is to investigate, using a mathematical model and computer simulations, potential regulatory mechanisms affecting the dynamics of LA in various tissues during hypoxic conditions. Simulations of circulatory hypoxia closely predicted the pattern of change in substrates observed experimentally. Model analysis suggests that the rate of lactate production is regulated with high sensitivity through changes in ADP/ATP and NADH/NAD which are induced indirectly by a small drop in the rate of oxygen consumption due to a decrease in muscle O/sub 2/ concentration.