Rat-liver cell compartition as revealed by correlations between redox-quotient changes following alloxan treatment, starvation, carbohydrate- and fat-diet.
As reported elsewhere (FERAUDI, 1976a & b), we have studied the mathematical relations between metabolite concentrations in the rat liver at various redox states and expressed them algebraically. In the present work we have measured the liver-cell concentrations of lactate, pyruvate, glycerol 3-phosphate, dihydroxyacetone phosphate, malate, oxaloacetate, beta-hydroxybutyrate, acetoacetate, 2-oxoglutarate, ribulose 5-phosphate as pentose phosphates, gluconate 6-phosphate, isocitrate, aspartate in untreated and treated rats (alloxan-diabetic, insulin-treated alloxan-diabetic or starved rats as well as rats fed on carbohydrate- or fat diet). Through analysis of the algebraic correlation between metabolite concentrations, we arrived at the following statements: 1. Under certain physiological conditions the concentration of some metabolites in one compartment determines their total quantity in the cell; 2. NADP and NADPH are comparted within the cytosol; 3. Reduced cosubstrate/oxidized cosubstrate ratios of some enzymic reactions are under certain physiological conditions in mutual equilibrium; 4. Such relationships are first verified after treatment and therefore characterize the metabolite status.
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004734:Energy Metabolism; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008291:Malate Dehydrogenase / Q000378:metabolism; D008297:Male; D008433:Mathematics; D009243:NAD / Q000378:metabolism*; D009249:NADP / Q000378:metabolism*; D010084:Oxidation-Reduction; D051381:Rats; D013217:Starvation; D013347:Subcellular Fractions / Q000378:metabolism
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D009243:NAD; D009249:NADP; D007770:L-Lactate Dehydrogenase; D008291:Malate Dehydrogenase