Effects of prometryne on apoptosis and necrosis in thymus, lymph node and spleen in mice.

Prometryne is a methylthio-s-triazine herbicide. Significant traces are documented in environment, mainly waters, soil and plants used for nutrition. The aim of this study was to estimate prometryne immunotoxic properties through induction of apoptotic and/or necrotic changes in thymocytes, splenocytes and lymph node cells after repeated subchronical exposure. Three different doses of prometryne (185, 375, 555mgkg(-1)) were applied per os every 48h, over 28 days. Flow cytometry assay (annexinV-FITC and PI) was conducted to record apoptotic and necrotic damage. In the spleen significant changes in the percentage of apoptotic cells were not detected between treated and control groups respectively. In thymus and lymph node, within the lowest dose group (185mgkg(-)1), an increase in percentage of early apoptosis without any significant increase in necrosis was detected. Medium (375mgkg(-1)) as well as high dose triggered increase in late apoptosis in lymph node while in thymus; late apoptosis was increased only in animals exposed to the highest dose (555mgkg(-1)). The highest applied dose, in thymus and lymph node respectively, caused a general decrease in percentage of vital cells in favour of marked increase of percentages of all types of dying cells (apoptotic, late apoptotic/early necrotic and necrotic). Prometryne caused disbalance in major organs of immune system, markedly lymph nodes and thymus, by induction of early apoptotic changes in dose/time specific manner.