Systemic and Local Anaphylaxis in the Albino Rat

Abstract

Summary and Conclusions Lethal anaphylactic shock has been elicited in rats sensitized with bovine serum albumin combined with adjuvants. Of 10 rats sensitized with bovine serum albumin combined with paraffin oil adjuvants containing mycobacteria, 6 died after intravenous injection of the antigen. Of 9 rats sensitized with bovine serum albumin combined with adjuvants without mycobacteria, 1 died after intravenous injection of the antigen. Skin reactions were elicited in rats sensitized with bovine serum albumin or egg albumin in paraffin oil emulsions. The reactions in animals receiving tubercle bacilli in the emulsion were more extensive and of longer duration than in rats sensitized without mycobacteria. The histologic changes in the sites of intense skin reactions were similar to those in the Arthus reaction in the rabbit. Rats immunized with bovine serum albumin with adjuvant emulsions produced relatively large amounts of precipitating antibody. The high incidence of anaphylactic death and the intense skin reactions in rats so immunized are probably referable to the high antibody titers. Relatively large amounts of antigen used in skin tests frequently did not elicit skin reactions in sensitized rats; the injection of more dilute antigen solutions caused reactions. When several skin tests were made simultaneously, a high dose at one site inhibited the reactions at the sites of injection of lower doses of antigen. In rats similarly sensitized, tests made with only the lower dosages showed intense skin reactions. This may be due to desensitization caused by antigen entering the general circulation and combining with the available antibodies.