Investigations on the biochemical characteristics of chronically underperfused muscle

During operation, biopsies from the gastrocnemius muscle and, in some cases, from the sartorius muscle were taken from 32 patients with peripheral arterial occlusive disease and from 5 subjects with normal peripheral circulation. In patients with inadequate circulation only during exercise, when compared with the control group, increased activities of enzymes involved in oxidative metabolism (malate dehydrogenase, nicotinamide adenine dinucleotide phosphate-dependent isocitrate dehydrogenase, cytochrome C oxidase, creatine kinase), in amino acid metabolism (asparate aminotransferase, alanine aminotransferase), and in anaerobic glycoysis (lactate dehydrogenase) were found. In patients with circulatory disturbances that manifested themselves already at rest, enzyme activities were, with the exception of LDH, lower than those of patients with exclusively exercise-related insufficiency. By means of intraindividual comparisons with the corresponding enzyme activities in the sartorius muscle, the author was able to show that the changes found were not simply the result of differences in training conditions. The diminished concentrations of energy-rich phosphate are an expression of the anaerobic metabolic state in patients with inadequate circulation at rest. It is concluded that chronic ischemia of muscle leads to changes in the energy metabolism of the cell. In the presence of more nearly adequate circulation at rest, the portion of oxidative potential of the total energy metabolism increases. In contrast, if there is an inadequate circulation at rest, the mainly anaerobic glycolysis becomes quantitatively predominant.