Volume 55 (2005) Issue: 2005 No#2-3

Phenotypic characteristics of thymic microenvironment in WR-638-protected rats after whole-body irradiation: epithelial cells

Author(s): Dragojević-Simić Viktorija, Gašić Sonja, Čolić M, Bokonjić D

Keywords:epithelial cells, radiation, radioprotection, rats, thymus,WR-638

Phenotypic changes of thymic epithelial cells (TEC) were studied in male Wistar rats subjected to radioprotector WR-638 (358 mg/kg b.w. ip) and/or whole body X-ray irradiation (3.5 Gy) 15 days after its application. Phenotypic changes were identified in situ on cryostat thymic sections using immunohistochemical staining by a panel of monoclonal anti-cytokeratin antibodies. It was shown that WR-638 significantly reduced changes in the structure of the thymus caused by X-ray irradiation. In the primary involution phase some phenotypic characteristic changes of TEC can be explained mostly by lymphoid destruction, although factors directly connected to the protector can not be excluded. However, in the primary regenerative phase WR-638 caused prominent changes of antigen expression on subcapsular and medullary TEC in irradiated rats. Therefore, WR-638 not only protects thymocytes, but also causes alterations of phenotypic characteristics of TEC which may contribute to its beneficial radioprotective effect on the irradiated rat thymus.