A COMPARISON OF THE MAST-CELL AND EOSINOPHIL RESPONSES OF SHEEP AND GOATS TO GASTROINTESTINAL NEMATODE INFECTIONS

The mucosal mast cell and eosinophil responses of goats and sheep to a mixed gastrointestinal nematode infection were compared. Groups of ei ght does and nine ewes, previously maintained on pasture and treated w ith anthelmintic when they were housed and five worm-free lambs were c hallenged with 10,000 Trichostriongylus vitrinus third stage larvae (L (3)) and 10,000 Teladorsagia circumcincta L(3). Eleven days after chal lenge, the ewes had significantly (P<0.001) lower burdens of abomasal and intestinal worms than the does or naive lambs, but significantly h igher (P<0.001) tissue concentrations of mast cell proteinase. Toluidi ne blue-stained sections indicated a paucity of mast cells in the does compared with the ewes, whereas the immunolocalisation of sheep mast cell proteinase revealed similar numbers of stained cells in the two s pecies. This discrepancy was due to the relatively high proportion of globule leucocytes (77 and 91 per cent in the jejunum and abomasum, re spectively) in the does compared with the ewes (7 and 24 per cent in t he jejunum and abomasum, respectively). No differences were detected b etween the numbers of circulating or tissue eosinophils in the ewes an d does.