Gamma globulin formation in vitro by various tissues was studied using the incorporation of C14-L-lysine into a protein precipitable by a specific anti rabbit gamma globulin serum prepared in a sheep.
It was demonstrated that the rate of gamma globulin formation in similar numbers of spleen cells is much higher if taken from an immunized rabbit at the height of antibody formation than that in normal spleen cells. Besides spleen, other tissues shown to form gamma globulin in normal adult rabbits were: peripheral lymph nodes, bone marrow, lung, mesenteric lymph nodes, appendix, and thymus.
In tissues from newborn rabbits gamma globulin formation could not be demonstrated. Rabbits 1 week old already showed a beginning of significant gamma globulin formation in appendix tissue, followed approximately 3 weeks later by gamma globulin synthesis in spleen and thymus. Histological observations on these tissues were described and correlated with findings on gamma globulin formation.
In the discussion an attempt has been made to relate these observations on newborn and immature rabbits to those available in the literature on antibody formation in newborn animals.