Clasmatosis: Certain qualitative and quantitative peculiarities of this phenomenon in the lymphoid organs of the rat

Summary Clasmatosis in the spleen, thymus, submaxillary lymph nodes, Peyer's patches and bone marrow has been studied in Wistar male rats by standard cytological methods, and a method of obtaining a fraction of cytoplasmic fragments (leptons) from the spleen has been elaborated. A conjectural scheme of the successive stages of this phenomenon has been drawn up; according to this scheme, the lepton detached from the clasmatocyte undergoes a series of transformations and again splits off a fragment from itself (secondary clasmatosis).Micrometric measurements of the diameters of free lymphocytes, clasmatocytes, and bound and free leptons have made it possible to establish that: 1. the size of the lepton does not depend on the size of its producer cell; 2. the largest percentage of clasmatocytes occurs among cells with a diameter of 9 (about 35%); 3. the lymphocytes of the spleen are smaller than the clasmatocytes of the same organ, and the free leptons are smaller than the bound leptons. The assumption is made that this difference is due in the former case to clasmatosis itself, and in the latter to formation of secondary leptons.Clasmatosis is traced in all stages of differentiation of lymphoid cells, which lose their pyroninophilic granularity along with their loss of cytoplasm.The different lymphoid organs have been compared according to their relative content of clasmatocytes and free leptons. The second, more distinct index increases in the following succession: thymus, submaxillary lymph nodes, spleen, Peyer's patches. The difference between the first and the last is 15.In the bone marrow of intact rats clasmatosis is practically absent.The results have been discussed in relation to the possible connection of clasmatosis with the differentiation of lymphoid cells.The authors are very grateful to N. S.Nikishova for her help in the cytological part of this work and to M. L.Kopnova for the microphotographs.