Disappearance Rate of Normal Bactericidins in Irradiated Mice.

Summary X-irradiated CF-1 mice lacking normal serum bactericidal activity for Escherichia coli were injected intravenously with highly bactericidal mouse serum. Passively transferred bactericidins were lost so rapidly from the circulating blood as to be undetectable 20-30 minutes later. Following 2 intravenous injections 30 minutes apart, bactericidins disappeared almost as quickly as after a single injection. The disappearance rates of normal bactericidins and immune hemagglutinins were compared under identical experimental conditions by injecting a mouse antiserum to sheep cells which was also bactericidal. The half-disappearance time of sheep cell agglutinins in mice was approximately 2 days, that of normal bactericides, only a few minutes. The authors are indebted to Dr. William H. Taliaferro for his interest in this work, and for many valuable suggestion.