Abstract: This study was aimed at elucidating the interplay between the parasiticide ivermectin and haemonchiasis on the hepatic activities of some drug-metabolizing enzymes in Nubian goats. The in vitro experiments were confirmed in vivo by estimating the effect of ivermectin on hexobarbitone-induced sleeping time in rats. The in vivo experiments showed that there was no substantial influence of ivermectin on Hexobarbital Sleeping Time (HST) in rats, whether administered at its recommended therapeutic dose (200 ug kg-1 body weight) or two times the recommended dose. But there was significant decrease in HST 24 h post administration of the double dose, although all other values of HST from day 2 to day 15 were within the normal range. In in vitro experiments, the enzymes studied in goat liver were hexobarbitone oxidase, p-nitroreductase and UDP-glucuronyl transferase. Ivermectin given at a dose rate of 200 ug kg-1 body weight did not produce alterations in the activities of drug-metabolizing enzymes investigated, nor did it affect microsomal protein contents or liver weight. The activities of hexobarbitone oxidase, P-nitroreductase and UDP-glucuronyl transferase were significantly decreased three weeks post infection, also there was significant decrease in microsomal protein contents.Ivermectin when given at a dose rate of 200 µg kg-1 body weight subcutaneously resulted in a significant increase in the activities of hexobarbitone oxidase, P-nitroreductase and UDP-glyucuronyl transferase in infected animals given the drug three weeks post infection and killed one week later.
El A.D. Inaam , Idris. B. El Tayeb , Sania, A. Shadad and T. Hassan , 2007. The Effect of Haemonchus Contortus Infection and Treatment with Ivermectin on Drug-Metabolizing Enzymes. Journal of Animal and Veterinary Advances, 6: 123-128.