Effects of phospholine iodide on the metabolites of the glycolytic, pentose phosphate and sorbitol pathways in the rabbit lens.
Steady-state concentrations of the key intermediates from the glycolytic, pentose phosphate, and sorbitol pathways as well as the pyridine nucleotides were measured from the lens after 0.25% phospholine iodide had been instilled into rabbits' eyes twice a day for 18 weeks. In the lenses of those rabbits which had received treatment in both eyes fructose-1,6-diphosphate and pyruvate levels were increased, whereas 6-phosphogluconate, sorbitol and alpha-glycer0phosphate concentrations were decreased. alpha-Ketoglutarate and concentrations and ratios of NAD+ and NADH did not show any changes. In contrast, NADPH and total NADP concentrations as well as the NADPH/NADP+ ratio were decreased, and therefore total NAD/total NADP ratio increased after treatment. It appears that instillation of long-acting 0.25% phospholine iodide into rabbits' eyes results in increased glycolytic activity in the lens in response to the increased energy demand, wheras the activities of other metabolic pathways are suppressed.
Effects of phospholine iodide on the metabolites of the glycolytic, pentose phosphate and sorbitol pathways in the rabbit lens. Steady-state concentrations of the key intermediates from the glycolytic, pentose phosphate, and sorbitol pathways as well as the pyridine nucleotides were measured from the lens after 0.25% phospholine iodide had been instilled into rabbits' eyes twice a day for 18 weeks. In the lenses of those rabbits which had received treatment in both eyes fructose-1,6-diphosphate and pyruvate levels were increased, whereas 6-phosphogluconate, sorbitol and alpha-glycer0phosphate concentrations were decreased. alpha-Ketoglutarate and concentrations and ratios of NAD+ and NADH did not show any changes. In contrast, NADPH and total NADP concentrations as well as the NADPH/NADP+ ratio were decreased, and therefore total NAD/total NADP ratio increased after treatment. It appears that instillation of long-acting 0.25% phospholine iodide into rabbits' eyes results in increased glycolytic activity in the lens in response to the increased energy demand, wheras the activities of other metabolic pathways are suppressed.