Exercise Physiology and Pathophysiology of Lactate Acidosis and Clearance

lactate acid, skeletal muscle, mortality Lactic acid is a naturally occurring molecule with original detection falling into a category of lactic acid-producing bacterial organisms. However first detected in foods, its increased concentration in muscles of hunted animals was later linked with lactate acidosis origin. Physiologically, high rate of ATP hydrolysis, occurring during anaerobic glycolysis, contributes to the formation of lactate acidosis. Not only skeletal muscles, despite of their large mass, but also brain, liver, kidney and adipose tissue function as consumers of lactate. Elevated metabolic rate during physical work promotes lactate clearance via accelerated rate of its oxidation. Strong evidence about the effects of certain diseases on lactate metabolism exists. In pathophysiology, elevated concentration of lactate in blood may be caused by its increased production, decreased clearance, or a combination of both. Abnormally increased blood lactate levels occur during hypoperfusion/hypoxemia or dysfunction of cellular metabolism. The rising body of literature demonstrating that the initial level and/or the rate of blood lactate clearance predicts the mortality following trauma, severe sepsis or cardiac surgery has accumulated.