title: Interactions of radio-detoxified Escherichia coli endotoxin preparations with the complement system.
abstract: Escherichia coli O89 lipopolysaccharide (LPS) was treated with different doses of gamma irradiation (5, 10, 15, and 20 Mrad). Various biological activities such as lethal effect, decrease in arterial blood pressure in dogs, and interaction with the complement system were determined for the parent and irradiated preparations. Irradiation of LPS significantly and in a dose-dependent manner decreased its lethal and blood pressure-depressing effects along with its ability to activate the complement system. In contrast, radio-detoxified LPS fixed more strongly the isolated human C1 than did the parent LPS. The possible connection between the toxicity of endotoxin and endotoxin-induced complement activation is discussed.
mesh_terms: D000818:Animals; D001794:Blood Pressure; D003172:Complement C1 / Q000378:metabolism; D003176:Complement C3 / Q000378:metabolism; D003181:Complement C4 / Q000378:metabolism; D003165:Complement System Proteins / Q000378:metabolism*; D004285:Dogs; D004307:Dose-Response Relationship, Radiation; D004731:Endotoxins / Q000528:radiation effects*; D004926:Escherichia coli; D005260:Female; D005720:Gamma Rays; D006168:Guinea Pigs; D006801:Humans; D066298:In Vitro Techniques; D007928:Lethal Dose 50; D008070:Lipopolysaccharides / Q000528:radiation effects; D008297:Male; D011135:Polysaccharides, Bacterial / Q000528:radiation effects; D051381:Rats
chemical_list: D003172:Complement C1; D003176:Complement C3; D003181:Complement C4; D004731:Endotoxins; D008070:Lipopolysaccharides; D011135:Polysaccharides, Bacterial; D003165:Complement System Proteins