Effect of arsenic on carbohydrate metabolism after single or repeated injection in guinea pigs

Abstract

Divergent pattern in pyruvate efflux from livers perfused with As₂O₃ and livers of animals previously repeatedly treated with the toxicant was observed in earlier experiments (Reichl et al. 1987, 1988). Further studies of the effect of As₂O₃ on carbohydrate metabolism were therefore performed. Male guinea pigs received either a single dose of As₂O₃ 10 mg· kg⁻¹ s.c. or repeated doses of 2.5 mg·kg⁻¹ bis in die (b.i.d.) on 5 consecutive days. One hour after the single dose or 1 h and 16 h after the last injection in the repeated treatment group the animals were sacrificed under anaesthesia. The livers were removed by a freeze-stop technique and the contents of glycogen and glycolysis intermediates were measured. In the single dose group a decrease in fructose-1,6-diphosphate and glycerolaldehyde-3-phosphate and an increase in phosphoenolpyruvate and pyruvate was observed. In the repeat dose, 1-h group a significant decrease in glycogen, glucose-6-phosphate, fructose-6-phosphate, glycerolaldehyde-3-phosphate, dihydroxyacetonephosphate, 2-phosphoglycerate and pyruvate was found. In the repeat dose, 16-h group the contents of glycogen, glucose-6-phosphate, pyruvate and lactate were diminished. The most prominent finding after repeated As₂O₃ administration was a marked depletion in total carbohydrate content. This was due mainly to depletion of glycogen.