Structure and Immunological Function of Lymphomyeloid Organs in the Bullfrog, Rana Catesbeiana

Anuran amphibians have long been known to have unique lymphoid organs in the branchial region, such as jugular body (ventraler Kiemenrest) (JB), propericardial body (corpus propericardiale) (PPCB) and procoracoid body (corpus procoracoideum) (PCB) (1, 2). Recently, antibody-producing cells and/or plasma cells have been demonstrated in these unique organs, thymus, and bone marrow, as well as in the spleen and kidney (3–10). Accordingly, the respective role of anuran lymphomyeloid (LM) organs in the immune response seems to be considerably different from that of mammalian counterparts. The present report deals with histological structure and immunological function of bullfrog LM organs with special reference to antibody-producing sites and lymphocyte-proliferating sites.