title: Production of rat homocytotropic antibodies using low dose, long term oral exposure to penicillin G.
abstract: Sera from 15 patients with immediate hypersensitivity reactions to penicillin G gave positive responses in the rat mast cell test (RMCT) indicating the presence of IgE-type antibodies in the sera. Five sera were from patients who had had reactions to penicillin 15 to 22 years previously without known re-exposure to this antigen. To explore the possibility that non-therapeutic exposure to penicillin may have produced continued sensitization in these patients, an animal model system was developed to explore the efficacy of low dose, long term oral exposure to penicillin G in rats for producing homocytotropic antibodies in these animals. It was found that when rats were given penicillin G in their drinking water at concentrations of 0.1 to 1 U/ml over a period of 1 to 3 months they produced serum IgE and IgGa antibodies. In addition, IgE antibodies were actively bound to the peritoneal mast cells of these animals. The presence of circulating or cell bound antibodies was detected using the rat mast cell test. It was also shown that rats given penicillin G orally for 1 month were more prone to antibody production after a single intramuscular injection of penicillin G compared to a control group receiving only the intramuscular injection of this antigen. The results of this study are discussed in terms of possible non-therapeutic sensitization towards penicillin G in the human population.
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000917:Antibody Formation; D004342:Drug Hypersensitivity; D006801:Humans; D007106:Immune Sera; D007111:Immunity, Cellular; D007073:Immunoglobulin E / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007273:Injections, Intramuscular; D007518:Isoantibodies; D008407:Mast Cells / Q000276:immunology*; D008954:Models, Biological; D010400:Penicillin G / Q000008:administration & dosage / Q000276:immunology*; D051381:Rats; D013997:Time Factors
chemical_list: D007106:Immune Sera; D007074:Immunoglobulin G; D007518:Isoantibodies; D007073:Immunoglobulin E; D010400:Penicillin G