Bactericidal Activity of Fixed Phagocytes in Irradiated and Unirradiated Mice Treated with RNA. ∗

Abstract

Summary

CF1 female mice 9–10 weeks old were injected intravenously with RNA 30 minutes before or on the 4th day after exposure to a sublethal dose of X-irradiation (550 r). Simultaneously an equal number of irradiated mice were injected intravenously with buffered saline to serve as controls. On the 5th day post-irradiation all mice were injected intravenously with Ps. aeruginosa followed one minute later by intravenous polymyxin or colymycin. The next day all mice were killed and heart's blood cultured. Livers and spleens were removed, ground separately in tissue grinders and appropriate dilutions plated. The results of the bacterial counts indicated that the mean number of pseudomonads in livers and spleens of mice injected with RNA were slightly lower than the mean number in livers and spleens of controls but the difference was not significant. Similar results were obtained among unirradiated mice injected with RNA 4 days before challenge with Ps. aeruginosa.