[Morphological and immunohistochemical characteristics of the thymus during chemical carcinogenesis induced by 1,2-dimethylhydrazine administration].

The aim of the study was to examine the histological and immunohistochemical characteristics of the thymus 5 months after the intraperitoneal administration of the carcinogen (1,2-dimethylhydrazine in the dose of 20 mg/kg once a week for 2 weeks). The study was conducted on 50 outbred albino male rats. Paraffin sections of the thymus were stained with hematoxylin-eosin and were processed by an immunohistochemical method using antibodies against CD3, CD30, CD68, synaptophysin, S-100 protein, p53, bcl-2, Ki-67, as well as against IgM and IgG. It was found that carcinogen administration resulted in the increased number of thymic cells expressing bcl-2, S-100 and Ki-67, active T-lymphocytes and thymopoietic microenvironment cells, as well as in the change of the correlation between medullary and cortical CD3(+)-thymocytes with a predominance of the latter. Thus, the malignant tumor, developing in the colon, on the one hand, inhibits the supply of the precursors of thymopoiesis to the thymus, while on the other--enhances the proliferation and differentiation of thymocytes into mature forms.