title: Anaphylactic reactions to endotoxin in guinea-pig tissues: relationship to endotoxin toxicity.
abstract: 1 A lipopolysaccharide extract of Escherichia coli 026:B6 cells (026:B6(B) endotoxin) was shown to be toxic to normal adult guinea-pigs. 2 The agent had no action on isolated preparations of ileum and heart taken from normal adult guinea-pigs. 3 Ileal segments from animals actively immunized against 026:B6(B) endotoxin showed dose-dependent contractions when exposed to endotoxin. Desensitization phenomena were demonstrated. 4 Reactivity of 026:B6(B) endotoxin was transferred to isolated preparations of ileum and heart from normal animals by passive transfer of immune serum. 5 Tissue responses to 026:B6(B) were associated with release of ileal spasmogen into the bath medium. Mepyramine blocked the effects of this spasmogen at bath concentrations which caused little change in ileal responses to carbachol. 6 It is concluded that E. coli endotoxin can elicit anaphylactic reactions, and that this process may potentiate endotoxin toxicity in sensitized animals. However, endotoxin toxicity in guinea-pigs does not appear to depend on this kind of allergic process.
mesh_terms: D000707:Anaphylaxis / Q000139:chemically induced*; D000818:Animals; D004731:Endotoxins / Q000494:pharmacology* / Q000633:toxicity; D004926:Escherichia coli; D006168:Guinea Pigs; D006339:Heart Rate / Q000187:drug effects; D007082:Ileum / Q000187:drug effects; D007106:Immune Sera / Q000494:pharmacology; D007112:Immunity, Maternally-Acquired; D007114:Immunization; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects
chemical_list: D004731:Endotoxins; D007106:Immune Sera