Elemental characterization of injuries in fish liver

Abstract Fish liver is the primary organ related to the biotransformation of organic contaminants and metals. This organ is very sensitive to organic and inorganic contaminants and can accumulate them in higher amounts relative to the environment itself and to other organs. One of the most common injuries is a histopathology called melanomacrophage centers, characterized as modifications of the cellular structure of the tissue and usually accompanied by pigmented cells. The aim of this study is to apply micro-PIXE in combination with conventional PIXE as a qualitative and quantitative analysis of elements to characterize histopathologies in the liver of fishes. Micro-PIXE results show that there is a higher concentration of Fe, P, K, Ti, Cr, Ni, Cu and Zn in melanomacrophage centers. On healthy tissue, the distribution of these elements is homogeneous. In cases where the histopathological study showed injuries without melanomacrophage centers, the micro-PIXE analysis showed much smaller clusters with higher concentrations of these elements, suggesting the presence of melanomacrophage centers which are too small to be detected by histopathological conventional methods. Broad PIXE results showed that the concentration of Si, Cl, K, Ti, Fe and Cu are directly related to the presence of melanomacrophage centers. Moreover, it could be observed that the concentration of Cr, Mn and Ni is directly related to the injuries but not to melanomacrophage centers.