Studies on the effect of radiation on electrolyte changes and metabolism of the myocardium. V. Changes in enzyme activities and glycolysis metabloites due to radiation

The behavior of enzyme activities, substrates and metabolites of glycosis as well as of the pentose phosphate shunt following local irradiation (250 to 6000 R surface dose) is biochemically investigated in the guinea-pig's myocardium. During irradiation, an activation of phosphorylase-a is going on while the total phosphorylase content remains unchanged. Enzyme activities of hexokinase and phosphofructokinase are increased in dependence on dosage as well as time. The glycogen content is being reduced; tissular concentration of the metabolites glucose-1-phosphate, glucose-6-phosphate, glyceraldehyde-3-phosphate, glycerol-3-phosphate, and pyruvate increases following irradiation; the content of fructose-1,6-diphosphate, dihydroxyacetonephosphate, and lactate is decreased. The activity of glucose-6-phosphate dehydrogenas is slightly inhibited, whereas 6-phosphogluconate-dehydrogenase remains unaffected.