Oral feeding of ovalbumin can make rats tolerant to an intraperitoneal injection of dinitrophenylated ovalbumin and Bordetella pertussis vaccine [proceedings].

Materials and nzethods The Hooded Lister inbred rats used have been described as good responders (Jarrett & Steward, 1974; Bazin, 1977) for reaginic antibodies to dinitrophenylated ovalbumin. The animals were bred in this laboratory and were reared in Makrolon cages. They were fed with water and commercial food (UAR, Villemoisson-sur-Orge, France) shown by testing to contain no ovalbumin. Details of the techniques used in the preparation of dinitrophenylated compounds, the immunization and blood-sampling procedures have been described previously (Bazin & Platteau, 1976; Bazin, 1977). The antibody concentrations were determined by the technique of passive cutaneous anaphylaxis, carried out as described by Bazin & Platteau (1976).