Изменения формирования селезенки в раннем постнатальном периоде у крыс, развивавшихся при низкодозовом воздействии эндокринного дисраптора ДДТ

Abstract

Introduction. Exposure of a developing body to endocrine disrupting chemicals is considered to be a risk factor for organ disorders. Dichlorodiphenyltrichloroethane (DDT) is known as one of the most wide-spread endocrine disruptors, the exposure to which begins in the prenatal period because of its ability to penetrate the placental barrier. The effects of low-dose DDT exposure on the immune system development are poorly studied, so we aimed to evaluate spleen development in the early postnatal period in rats exposed to DDT. Materials and methods. The study was performed on 2 groups of rats. The control one included 16 7-day-old male Wistar rats, whereas the experimental group consisted of 14 offspring of females that consumed a solution of o,p-DDT (20 μg/l) during pregnancy and lactation. We evaluated anatomical and histomorphometric parameters of spleen development and counted B- and T-lymphocytes with flow cytometry. Results. The DDT exposure did not influence the weight of the spleen. The white pulp had periarterial lymphoid sheaths, which were larger in size and had a less dense arrangement of cells. The marginal zone was found in a larger number of lymphoid sheaths and was of a greater area. However, the number of cells in 1 mm2 was lower and we detected no granulocytes. In the red pulp, the number of cells in 1 mm2 (including megakaryocytes) did not differ from the values of the control group, but the content of granulocytes was higher. We observed a reduced number of differentiated B- and T-cells. Conclusion. The spleens of the experimental rats were characterized by a faster formation of the white pulp and slower rates of terminal lymphocyte differentiation and neutrophil migration into the spleen. Keywords: spleen, histogenesis, endocrine disruptor, DDT, lymphocytes