Antigen-induced release of histamine from rat tissues in vitro: dissociation in development of serosal mast cell, lung tissue, and tracheal tissue response capacity.

We examined the temporal development and the fading in Sprague Dawley rats, actively sensitized to ovalbumin (OA), of the capacity of serosal mast cells, chopped lung tissue, and occasionally chopped tracheal tissue, to respond at antigen challenge in vitro with histamine release. Response capacity of both serosal mast cells and lung tissue developed within 2-3 weeks after injection of 1 microgram OA or more together with 100 mg of alum. Maximum response capacity was observed in cells and tissue from animals injected with 10 micrograms OA, part of the response capacity then remained until 3 months after immunization. Development of serosal mast cell reactivity was occasionally dissociated from that of lung tissue. When low amounts of alum (1 or 10 mg) were employed as adjuvant, lung tissue reactivity could be induced in the virtual absence of serosal mast cell response capacity. Silica gel was less efficient than alum as an adjuvant for induction of a primary response, but 'secondary' tissue responses could be induced when silica gel was used as an adjuvant. Pretreatment of the animals with cyclophosphamide before the booster injection enhanced and prolonged the response capacity of lung tissue. Animals injected with OA together with Freund's complete adjuvant did not provide responding serosal mast cells; response capacity of lung tissue varied with immunization dose of antigen. Antigen-induced histamine release from chopped tracheal tissue did not correlate to response capacity of lung tissue. Thus, the development in the rat of response capacity with respect to antigen-induced histamine release dissociates from serosal mast cells, lung tissue, and tracheal tissue.