A Study of Type I Hypersensitivity (Anaphylaxis)

Abstract

Type I hypersensitivity reactions were studied in vitro using the Schulz-Dale Assay. This assay involved the suspension of pieces of sensitized mouse ileum (smooth muscle of the gut) in an organ bath to allow exposure to different treatments. Each piece of ileum represented an atopic animal. Specifically, the effects of histamine were investigated. Ovalbumin, the sensitizing antigen, induced anaphylactic reaction in the pieces of ileum, and antihistamines were added to determine their effectiveness in counteracting the anaphylactic response. Tripelennamine (an ethylenediamine) and chlorpheniramine (an alkylamine) were used as antagonists. Both counteracted the anaphylactic reactions produced by histamine and seemed to be acting as histamine Hl-receptor blocking drugs. The assay shows promise for further investigation of the mechanisms and treatments of type I hypersensitivity.