The Effects of the Removal of Chief Lymphoid Organs

Abstract

In adult rabbits, chief lymphoid organs such as the mesenterial lymph nodes, vermiform appendix and spleen as well as other several small lymph nodes were removed. The total weight of the removed lymphoid organs amounted to approximately 80per cent of their entire lymphoid organs. In rabbits the mesenterial lymph nodes unites into a large mass called pancreas ASELLI, and its weight is about one half of the total weight of all the other lymph nodes.
Simultaneons extirpation of chief lymphoid organs and several other small lymph nodes resulted in a marked drop in the number of blood lymphocytes, down to 30 to 40per cent of the pre-operative values, and such a pronounced lymphopenia persisted for several weeks. No other remarkable alterations were observed in the blood picture, except for a post-operative granulocytosis which disappeared within 2 or 3 weeks. The continuity of the lymphatic pathway, interrupted by the removal of the mesenterial nodes, was rapidly re-established.
The main factor responsible for the reduction of the number of blood lymphocytes was the removal of mesenterial nodes, and accordingly these nodes are considered to be the most important source of blood lymphocytes.
In the absence of the chief lymphoid organs, there appeared a compensatory new formation of lymphoid tissues in the periportal areas of the liver, often on a large scale and, though to a much lesser extent, also in the bone marrow. In the remaining lymph nodes there was no remarkable hyperplasia of lymphatic tissue, except in the remaining portions of the resected mesenterial nodes.
The removal of the chief lymphoid organs did not induce anyspecific alteration of myelopoietic tissues in the bone marrow, except for the formation of a few small lymphoid foci therein.