Experimental ovine fasciolosis: antipyrine clearance as indicator of liver damage.

Antipyrine clearance was used to assess microsomal oxidative function in eight female Churra breed sheep at 20, 30, 40, 60, 80 and 100 days after infection by an oral administration of 150 metacercariae of Fasciola hepatica. Experimental infection was ascertained by an ELISA test and by faecal analysis. A significant increase in plasma glutamate dehydrogenase (GLDH) activity from 20 days post-infection and in gamma-glutamyltransferase (GGT) activity from 40 days post-infection was found. Both enzyme activities reached maximum levels in plasma of infected sheep at 80 days post-infection, progressively decreasing thereafter. A significant reduction in the total plasma clearance of antipyrine occurred from 60 to 100 days post-infection and a significant increase in mean residence time occurred by 80 days post-infection. The decrease of antipyrine metabolism coincided with the entrance of parasites in bile ducts and the highest liver damage caused by migrating juvenile flukes.