[Control of glycolysis in magnesium deficiency: studies on intact red cells and hemolysates].

Abstract

The behaviour of glycolytic flux and glycolytic metabolic concentrations was studied under conditions of magnesium deficiency. The Mg-deficiency was produced in whole animals (rats) by feeding a diet almost completely free of Mg and in hemolysates of men by the addition of a chelating agent. The results show that the decrease of the free Mg-level is diminished by partial destruction of ATP and 2,3-DPG. The analysis of the control strength of the overall flux leads to the conclusion that the decrease of the glycolytic rate is caused by an inhibition of the hexokinase-phosphofructokinase-control system. The decrease of the MgATP-Complex and free Mg++-level explains the diminished phosphorylation of glucose by the hexokinase. The ATP-inhibition of the phosphofructokinase is amplified by a small increase of free ATP-concentration and a simultaneous decrease of the Fru-6P-level. The increase of the PEP-level is caused by the diminished free Mg++ and MgATP-complex and does not demonstrate a larger control strength of the pyruvate kinase.