Dexamethasone-induced T-lymphocyte apoptosis in different lymphoid organs

Abstract

The aim of our study was the comparison of the synthetic glucocorticoid dexamethasone (DEXA) influence on T-lymphocytes in central (thymus) and peripheral (spleen, lymphatic nodes) immune organs. For that reason therapeutic doses of DEXA were used followed by histological, histochemical (TUNEL) as well as computerized histomorphometrical investigations. In the study 36 young adult Wistar rats performed. 1–7 days after 3 days injection of DEXA (total dose 1,2 mg/rat i.p.) the material was taken for futher investigations. First days after DEXA administration in therapeutic doses the number of apoptotic cells was considerably increased in the cortical part of thymus. No significant changes were in rest of thymus as well as in peripheral immune organs. 7 days after DEXA-induced injury the number of apoptotic cells had decreased almost to the normal level. Our investigations conclude that the most sensitive for the dexamethasone-induced T-lymphocyte apoptosis is cortex of thymus while the changes in medullary area of thymus and peripheral immune organs – spleen and perithymic lymphatic nodes – are less significant. Week after drug cessation the apoptotic changes are almost at normal level in both types of lymphoid organs.