Abstract

A rat model of immediate pulmonary hypersensitivity was used to investigate the permeability changes in the tracheal epithelium produced by aerosol challenge with antigen. The rats were sensitised by the intraperitoneal injection of antigen (dinitrophenyl (DNP19) ovalbumin). Sensitised and control animals were then challenged for 60 minutes with an aerosol of the same antigen, which also contained the electron dense pore marker lanthanum. Histological examination and x ray probe microanalysis showed a greater intercellular concentration of lanthanum in the tracheal epithelium in sensitised than in control animals. The results show that in sensitised rats increased intercellular penetrance of antigen can occur after antigen challenge.