Effects of concurrent administration of monensin and selenium on erythrocyte glutathione peroxidase activity and liver selenium concentration in broiler chickens.

Different toxic doses of selenium and monensin preparations were administered to broiler chickens. The two substances were given by oral route, alone or concurrently, for variable periods. Erythrocyte glutathione peroxidase (GSH-Px) activity was found to be elevated after the administration of the drugs. This increase was considerably higher when selenium and monensin were administered concurrently, indicating the occurrence of strong interaction between them. Administration of selenium led to a rapid increase in the liver selenium concentration. This increase, in turn, was enhanced by concurrent application of monensin. Monensin given alone did not have any significant effect on the changes of liver selenium concentration. Further results suggest that administration of monensin increases erythrocyte GSH-Px activity, even in the absence of supplemental selenium or during increased liver selenium concentration.