Glucose uptake in Oesophagostomum dentatum and the effect of oxfendazole

Abstract

The uptake of 14 C -glucose by adult Oesophagostomum dentatum was characterised. The uptake was a non-linear function of external glucose concentration. The maximum velocity of uptake ( V max) was 0.964 nmol/100 mg dry weight (dw)/5 min, and the transport constant ( K t) was 10.02 μM. When phlorizin, phloretin and 3- O-methylglucose were tested for their effects on the uptake of 14 C -glucose, phloretin and 3- O-methylglucose produced significant inhibitions, indicating that the uptake was mediated and occurred by facilitated diffusion. Exposure of the worms to oxfendazole prior to incubation with 14 C -glucose did not affect the uptake of glucose. In another experiment worms were incubated with unlabelled glucose and the external glucose concentration was measured enzymatically. During a 7 h incubation period, the quantity of glucose remaining in the incubation medium of oxfendazole exposed worms was significantly greater than in the control group. It was concluded that oxfendazole did not influence the process of 14 C -glucose uptake, but might induce changes in the parasite leading to a reduced ability to deplete the incubation medium of glucose.