Intraperitoneal Injections of Pneumococcus in Animals Primarily Receiving Leucocytic Stimulating Antigens.

Abstract

In a previous communication we reported the difference in leucocytic response to the injection in animals of various antigenic substances. The differences were of a marked character, not only for the different antigens used but also for the route of injection chosen. Killed cultures of B. typhosus and Staph. aureus injected intraperitoneally resulted in the formation of the highest leucocytic increase. The peak of the rise appeared in from 6 to 8 hours. We also called attention to the phenomenon of local leucocytosis as a possible misleading factor in making such observations. Some allusion to this feature had previously been made by Garrey and Butler., Steinberg reports that 4 intraperitoneal injections of heat killed B. coli at daily intervals, protects 65% of animals against an artificially produced peritonitis caused by a living B. coli suspension administered on the 5th day. Gay and Clapole have shown that the “carrier state” in rabbits can be prevented if previously immunized rabbits are injected with a live suspension of B. typhosus. Their experiments show that there is a much greater leucocytic response when immunized rabbits are injected than when normal rabbits are used and in the latter case the “carrier state” cannot be prevented. To ascertain the protective influence of induced leucocytosis, 47 white mice received intraperitoneal injections of the following antigenic substances for the purpose of producing leucocytic reactions in approximately 6 hours as controlled by the previously reported experiments: (1) Suspension of killed B. typhosus. (2) Suspension of killed Staphylococcus aureus. (3) Detoxicated suspension of killed pneumococcus. (4) Sterile milk. After 6 to 8 hours these animals were injected intraperitoneally with lethal doses of Pneumococci types I, II, and III.