[Carbohydrate and lipid metabolites and blood serum enzymes in humans during graded exercise test in long-term anti-orthostatic hypokinesia].

Abstract

Exercise tests were carried out before as well as on days 128 and 248 of a 370-day head-down tilt study. The test subjects, who took part in the study, were divided into two groups that used different regimens of countermeasures (drugs and exercise). During exercise tests the following serum parameters were measured: lactate, pyruvate, glucose, triglycerides, nonesterified fatty acids, lactate dehydrogenase, alpha-hydroxybutyrate dehydrogenase, malate dehydrogenase, creatine phosphokinase. Decrease or delayed increase in the concentration of energy substrates (nonesterified fatty acids and triglycerides) after a standard exercise test is a metabolic manifestation of deconditioning changes induced by head-down tilting. Insufficient supply of a working human body with readily utilizable lipid substrates causes inadequate activation of energy forming enzymes and excessive buildup of metabolites, i. e. lactate and pyruvate. The efficacy of corrective and prophylactic measures was verified by biochemical data.