| Popis: |
A comparative characterization of the redox condition and phosphate potential of the hepatic cells in rats kept on two experimental diets (low- and high-carbohydrate) is given. Intensification of the glucogenesis in the liver of rats kept on a low-carbohydrate diet is determined by lower values of the ratios /NAD+/: (NADH/ and /ATP/:/ADP/P1, the cells acquiring more marked reducting properties. Incorporation of 1,2-propanediol, as a source of metabolized energy, in the composition of the low-carbohydrate diet (20 per cent of the fat content) produces a rise in the level of glycogen and a fall of the liver lipids. The reducing capacity of the cytoplasma diminishes, this being borne out by the ratio of /NAD+/:/NADH/. An increase of the phosphate potential and of the ratio /NAD+/:/NADH/ is in these conditions similar to the one observed with a greater amount of carbohydrates in the diet. The phosphoenol-pyruvate-carboxykinase activity and concentration of malate in the liver diminish with rising concentration of oxaloacetate. When superimposed upon a high-carbohydrate diet 1,2-propanediol causes an increase of the /NAD+/:/NADH/ and /ATP/:P1/ ratios with the lipids content in the liver mounting too. The significance of shifts in the redox state and of the phosphate potential in regulating the 1,2-propanediol metabolism is discussed. |
