Effects of detraining on enzymes of energy metabolism in individual human muscle fibers

• DOI: 10.1152/ajpcell.1983.244.3.c276
• Publication Date: 2017-12-24T11:51:56Z
• Authors: M. M. Chi; C. S. Hintz; E. F. Coyle; W. H. Martin; J. L. Ivy; P. M. Nemeth; J. O. Holloszy; O. H. Lowry
• Keywords: Malate dehydrogenase; Creatine kinase; Oxidative enzyme

Muscle biopsies were obtained from three cyclists and four runners at the end of 10-24 mo intensive training after intervals detraining up to 12 wk. Control samples came untrained persons former athletes. Macro mixed fiber assayed for lactate dehydrogenase, adenylate kinase, glycogen phosphorylase, citrate synthase, malate beta-hydroxyacyl-CoA succinate beta-hydroxybutyrate creatine hexokinase, 1-phosphofructokinase, fructosebisphosphatase, protein, total creatine. In case trained two controls, first six enzymes also measured in individual fibers. Before detraining, oxidative metabolism substantially higher than differences levels between type I II fibers smaller. During decreased both types but did not fall control even Phosphorylase increased with types. The same is true dehydrogenase except one individual. Among other (measured samples), only hexokinase was consistently affected (decreased) by detraining.