INDUCTION OF OXIDATIVE STRESS IN LYMPHOID TISSUE FROM MURINE MODELS OF HYPOTHYROIDISM: TREATMENT WITH PROPYLTHIOURACIL VERSUS THYROIDECTOMY

ROMEO H; KLECHA A; CREMASCHI G; BARREIRO ARCOS ML

CABA - VIRTUAL

Congreso; REUNIÓN DE SOCIEDADES DE BIOCIENCIAS 2020; 2020

SAIC

Introduction: Hypothyroidism induced by antithyroid drugs increasesreactive oxygen species (ROS). Some authors attribute the increasein ROS to a decrease in the intracellular concentration ofnon-enzymatic antioxidants and other authors to a cytotoxic effectof the drug in the liver. Objective: 1- Analyze whether the increasein ROS is a pathological condition induced by hypothyroidism or isdue to the direct action of antithyroid drugs; 2- Evaluate the effect ofhypothyroidism on lymphocyte functionality. Methods: Hypothyroidismwas induced in Balb/c mice by treatment with propylthiouracil(PTU; 0.5 g/l drinking water for 15 days) or thyroidectomy. Thyroidhormone levels were quantified by RIA. ROS were evaluated byDCFH-DA staining and flow cytometry. Liver damage was evaluatedin tissue sections stained with hematoxylin-eosin and Masson?s Trichome.The number of lymphoid follicles was determined in sectionsof lymph nodes or spleen stained with hematoxylin-eosin. Apoptosisof lymphoid cells was quantified by flow cytometry and cell proliferationwas evaluated by incorporation of [3H]-thymidine into DNA. Results:We found that both, hypothyroid mice by treatment with PTUand thyroidectomized (Thy) had an increased production of ROSin lymph nodes (LN) and spleen (S) compared to euthyroid mice[% increase (LN) PTU: 68.5±8.4, Thy: 62.2±6.5 and % increase (S)PTU: 50.3±5.8, Thy: 62.6±7.3 (p