STUDIES ON THE INHIBITION OF REJECTION OF TRICHOSTRONGYLUS-COLUBRIFORMIS LARVAE FROM IMMUNE SHEEP

A total of 8 drugs were examined for their ability to suppress the rej ection of Trichostrongylus colubriformis infective larvae (L(3)) from immune sheep. Specific antagonists of leukotrienes (piroxicam), prosta glandin (indomethacin) and the immunosuppressant cyclosporin A were gi ven orally, while injectable preparations of dexamethasone, chlorpheni ramine, BN 52051, WEB 2086 (anti-platelet-activating factor) and theop hylline were administered as directed. The drugs sere given for 5 days prior to and 4 days after challenge with 20,000 L(3), when worm count s were done. Corticosteroids inhibited rejection by around 70% in two experiments, and none of the remaining compounds were effective. In th e third study, six of the drugs were given to susceptible sheep and di d not affect the establishment of a primary infection with T. colubrif ormis.