[Maximal turnover rates of glycolysis enzymes and of the citrate cycle of separated granulocytes in the postoperative period].

The human granulocyte is easy to obtain and shows a nearly complete enzymatic equipment. It therefore represents an interesting model for in-vitro studies of metabolic disorders under various clinical conditions. In the presented study, the activities of several enzymes of glycolysis and citric cycle are measured in granulocytes separated from surgical patients (n = 10). Blood samples of 20 to 40 ml were drawn 6.5 +/- 4.8 hours after termination of surgical procedure. All patients were artificially respirated and nourished intravenously according to the results of indirect calorimetry. Hexokinase (HK), pyruvate kinase (PK), lactate dehydrogenase (LDH), and isocitrate dehydrogenase (IDH) were measured photometrically in the cell homogenate. The values were compared to those determined in a group of healthy, not-anesthetized persons, nourished and studied identically (n = 12). In granulocytes separated from patients following major surgery we found increased activities of HK (29.8 vs. 24.1 mU/mg protein in controls), LDH (2,484 vs. 1,868 mU/mg protein, p less than 0.01) and IDH (41.5 vs. 35 mU/mg protein, p less than 0.05), and a reduced activity of PK (1,623 vs. 2,265 mU/mg protein, p less than 0.01). Assuming that the alterations in enzyme activities of isolated granulocytes reflect metabolic alterations of the whole organism to a certain extent, the results can be interpreted as a decreased induction of PK by insulin, an increase of lactate recycling via Cori cycle (LDH), and a stimulated substrate flux in citric cycle (IDH). The separated human granulocyte is recommended as a model of posttraumatic metabolic disorders. It should be taken into consideration for studies leading to further improvement of nutrition during posttraumatic glucose mal-utilization.