Gamma globulin production in germfree rats after bacterial contamination.

The earlier observed pronounced hypogammaglobulinemia in germfree rats of different ages has been confirmed. Using an immunologic technique the concentration of immunologic gamma globulins were found to vary between 10 and 15 per cent of the values observed in ordinary rats. Upon contamination of germfree rats with the normal microbial flora a pronounced lag phase was noted before the gamma globulin level became normal. This lag phase was most pronounced in growing rats. Newborn rats seem to start gamma globulin production more rapidly than older germfree rats. The response with regard to gamma globulin production on contamination of germfree rats with different types of bacterial cells through the natural routes is not identical.