BONGIOVANNI guillermina Azucena
congresos y reuniones científicas
Application of XRF and biochemical methods to evaluate the arsenic doses-response in the lymphoid organ spleen
SORIA, ELIO A; QUERALT, IGNASI; PEREZ, ROBERTO D; PEREZ, CARLOS A; BONGIOVANNI, GUILLERMINA A.
Congreso; 21 International Congress on X-Ray Optics and Microanalysis (ICXOM21); 2011
Brazilian Synchrotron Light Laboratory (LNLS) and the National Laboratory of Biosciences (LNBio)
Arsenic is one of the most relevant elements closely associated to human pathologies, given its widespread distribution (mainly by contaminated drinking water) and its multiple biological targets since oxidative stress is triggered into the cells. In some organs, As is retained and accumulated, may still represent a continuing risk for normal physiological processes. Given that immune system function is tightly regulated by the cellular redox status, As exhibits a dangerous immunotoxic potential. However, doses-responses relationship between As distribution and oxidative stress in splenic tissue has not been studied. Here analyze the distribution of As in lyophilized spleens along white and red pulps and their relation with the immunotoxicological process in chronically arsenic-exposed rats. As localization was achieved by SR-µXRF into the DO09B beamline from LNLS, Campinas, Brazil, using a focused white beam (30 µm x 30 ìm), as well as by EDXRF into Fischer XDV-SD spectrometer from Jaume Almera, Institute, Barcelona, Spain with a 50 keV tungsten-anode x-ray tube as radiation source (50 W), 1.0 mm excitation collimated and Titanium filter. A high concentration of As was found in both white and red pulps in a similar extent (Table 1). The As accumulation was accompanied by a decreased in vitro lymphocyte viability and a increased oxidative stress response (Table 1). Therefore, these techniques allow determining the arsenic distribution and the arsenic-associated oxidative stress response in rat spleen. XRF will help to clarify the doseresponse relationship between As exposure levels and adverse health effects with enhanced accuracy.