A new anthelmintic assay using rats infected with Trichostrongylus colubriformis.
A new anthelmintic assay is described which uses immunosuppressed (60 ppm hydrocortisone acetate in diet) rats infected with the nematode Trichostrongylus colubriformis. Immunosuppressed rats were infected with 1500 T. colubriformis larvae, treated either orally or subcutaneously on Day 14 post-infection and necropsied 4 days after treatment. The worm counts in immunosuppressed control animals averaged 775 worms per rat. A range of benzimidazoles, levamisole hydrochloride, morantel tartrate, 22,23-dihydroavermectin B1a and alpha-milbemycin have been evaluated in the assay. The ED95 values obtained indicate that rats infected with T. colubriformis provide a highly predictive model for assaying the activity of experimental drugs in vivo prior to studies in ruminants.
Gration
K A
KA
Pfizer Central Research, Sandwich, UK.
Bishop
B F
BF
Martin-Short
M R
MR
Herbert
A
A
D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use*; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001562:Benzimidazoles / Q000627:therapeutic use; D004195:Disease Models, Animal; D005243:Feces / Q000469:parasitology; D007165:Immunosuppression Therapy; D007559:Ivermectin / Q000031:analogs & derivatives / Q000627:therapeutic use; D007978:Levamisole / Q000627:therapeutic use; D018942:Macrolides; D008297:Male; D009015:Morantel / Q000627:therapeutic use; D010270:Parasite Egg Count / Q000662:veterinary; D051381:Rats / Q000469:parasitology*; D012418:Ruminants / Q000469:parasitology*; D014253:Trichostrongylosis / Q000188:drug therapy / Q000662:veterinary*
D000871:Anthelmintics; D000900:Anti-Bacterial Agents; D001562:Benzimidazoles; D018942:Macrolides; D007978:Levamisole; D007559:Ivermectin; D009015:Morantel; C052102:22,23-dihydroavermectin B(1)a; C027837:moxidectin