The Effects of Acute Bisphenol A Toxicity on the Hematological Parameters, Hematopoiesis, and Kidney Histology of Zebrafish (Danio rerio)

Simple Summary Bisphenol A (BPA) is an organic compound used in the manufacture of plastic products and is considered a common pollutant in the aquatic environment. Its impact on aquatic organisms is manifested in several reactions, particularly in changes in peripheral blood and disorders of hematopoiesis. In the present study, the effects of high concentrations of BPA on several indices of zebrafish blood were investigated. Differences in the effects of high and low concentrations on blood composition and disorders in hematopoietic organs were identified. The genotoxic effect of BPA at concentrations of 6 and 8 mg/L was confirmed. The test parameters most affected by the toxicant, such as the number of young erythrocytes in peripheral blood, nuclear anomalies of erythrocytes, and disturbances in hematopoiesis processes in the head kidney, expressed as changes in the ratio of immature/undifferentiated cell elements, were determined. Abstract In this study, the results of evaluating the acute toxicity of Bisphenol A on Danio rerio are presented, encompassing peripheral blood parameters, the composition of hematopoietic cells of erythroid and myeloid lines in the head kidney, and data from histological studies. The LC50 values of Bisphenol A for adult zebrafish individuals for 12, 24, and 48–96 h were determined, which were 18.04, 7.55, and 6.22 mg/L, respectively. The study includes data on the morphology and quantitative frequency of specific cells in the hematopoietic tissue of the head kidney, along with the consideration of adaptive mechanisms in hematopoiesis under BPA exposure. The application of polynomial regression analysis to reveal the concentration–effect relationship for some hematological and histological parameters was demonstrated. Significant increases in the frequency of erythrocyte nuclear abnormalities were observed at BPA concentrations of 6 and 8 mg/L, which indicates a genotoxic effect. BPA’s impact on fish peripheral blood parameters manifested as an increase in the number of erythrocytes (RBC) and immature erythrocytes, as well as a decrease in the number of lymphocytes. The most notable pathological changes in the head kidney’s hematopoietic tissue included circulatory disturbances and the formation of inflammation/degradation foci, as confirmed by histopathologic indices. At BPA concentrations of 2 and 4 mg/L, the observed changes were compensated for by hematopoietic adaptation mechanisms; however, at concentrations of 6 and 8 mg/L, acute systemic toxicity was evident.