Gut hypersensitivity reactions in guinea pigs following vaccination or infection with Trichostrongylus colubriformis.

A quantitative approach to measuring gut hypersensitivity responses to parasite antigens is described. Guinea pigs exposed to infection with Trichostrongylus colubriformis, were sensitised to excretory-secretory products and homogenates of third-stage larvae (L3), fourth-stage larvae (L4) and adult worms. The nature of these responses and their modification by pharmacological agents were typical of immediate-type hypersensitivity reactions. Gut sensitivity was greatest in the anterior half of the small intestine, persisted for at least 12 months and was more pronounced against L3 antigens than against L4 or adult preparations. Guinea pigs injected with homogenates of L3, L4 or adult worms were sensitised to these homogenates, but not to T. colubriformis excretory-secretory products.