The metabolic systems: Anaerobic metabolism (glycolytic and phosphagen)

This chapter outlines the history of the study of anaerobic metabolism during exercise. The emphasis is on the early origins and progression of studies on phosphagen and glycolytic metabolism. Although the topic is "anaerobic" metabolism, the interrelationship between oxygen and lactic acid production is considered to be of prime importance. The prelactic acid era (1808-1907) is responsible for the discovery of lactic acid and its relationship with the physical activity and hypoxia. The era between 1926 and 1932 is considered as "the revolution in muscle physiology" because of the experiments performed on the "phosphagens" and the discovery of muscle adenylic acid. In 1962, D.F. Cain and R.E. Davies provided proof that ATP (Adenosine Triphosphate) is the immediate energy donor for muscle contraction. In 1980, Glenn Gaesser and George Brooks utilized 14C-tracers, indirect calorimetry, and two-dimensional chromatography to trace the paths of lactate and glucose disposal during recovery from exhausting exercise. The year 1984 is recognized for the observation of lactate production in canine muscle in situ when intramuscular PO2 is apparently above the critical value for mitochondrial oxidative phosphorylation. In 1994, monocarboxylate transport protein (MCT)encoding gene was sequenced and cloned. In 1998, magnetic resonance spectroscopy (MRS) was utilized to show lactate production and the net release from fully aerobic, working human skeletal muscle, followed by the cloning and sequencing of four new MCT isoforms and the description of tissue variability in MCT isoform expression