Local Hemorrhagic Reactions in the Mouse and the Rat after Intralabial Injection of Endotoxin; Their Relationship to the Arthus and the Shwartzman Reactions

Abstract

Hemorrhagic reactions were elicited in mice when the lip was used as the site of injection of preparatory endotoxins. Two methods were used to demonstrate the reaction. In the first method, intralabial preparation was followed by the injection of endotoxin 19–21 hr later into the peritoneal cavity or tail vein. The results were not regular using this technique, and with only one of the endotoxin preparations did a small but significant number of mice show typical hemorrhagic reactions. The other method involved the use of mice sensitized to foreign proteins. The injection of the homologous antigen into the endotoxin-prepared lip of sensitized mice 19–21 hr after preparation regularly caused a hemorrhagic reaction in that lip. Hemorrhagic reactions were demonstrated in rats showing strong edematous reactions when the second method was used, but no Shwartzman reactions were obtained in rats prepared in the lip with endotoxin and given an eliciting injection of endotoxin intravenously or intra-abdominally. Hemorrhagic reactions were not elicited in sensitized rats showing weak or transient Arthus reactions in the prepared lip.