Morphological alterations of the spleen of rats (Rattus norvegicus) treated with arsenic trioxide

In Latin America, the presence of arsenic in the environment and water sources for human consumption is due to natural geological factors and anthropogenic activities. Arsenic in natural waters is mainly found as trivalent (arsenite) or pentavalent (arsenate). The aim of this study was to determine the alterations causing arsenic trioxide-level morphology of the spleen of rats (Rattus norvegicus - Sprague-Dawley). Were used 24 rats of both sexes of 55 days of life. The rats were weighed and divided into 3 groups (4 females and 4 males). The treated groups were injected with 5 mg and 10 mg of As₂O₃ respectively, intraperitoneally daily dosing for 15 days. The control group was administered arsenic-free distilled water. After treatment the animals were euthanized conventionally, and spleen was removed, which was washed, weighed and sectioned into four parts, which were fixed in 10% buffered formalin. Histological technique using four serial samples were obtained from each spleen of 5 microns thick with a spacing of 100 microns between them. Subsequently these were stained with H-E. We analyzed 30 fields (120 fields per organ). The data obtained indicates that rats treated with arsenic trioxide have an altered level of the compartments of the spleen, with an increased red pulp chamber, depletion in the size and number of lymphoid follicles and marginal zone. Furthermore, loss of cellularity of periarteriolar lymphoid sheath (PALS) was observed.