Thyroid hormones affect decidualization and angiogenesis in the decidua and metrial gland of rats / Hormônios tireoidianos afetam a decidualização e a angiogênese na decídua e glândula metrial de ratas

This study aimed to evaluate the effects of thyroid hormone on the decidua and metrial gland of rats and to examine the expression of angiogenic factors. 72 adult, female rats were divided into hypothyroid, T4-treated2, and control groups. At 10, 14 and 19 days of gestation (DG), the decidua and metrial gland were collected for histomorphometric and immunohistochemical evaluation of the expression of VEGF, Flk-1 and Tie-2. Hypothyroidism reduced the area of the decidua at 10 and 19 DG. Furthermore, VEGF was increased at 10 and 14 DG, and Flk-1 only at 14 DG, but both was reduced at 19 DG in the metrial gland without significantly changing the area occupied by blood vessels. Rats treated with T4 showed an increase in the decidua blood vessels at 10 and 19 DG. However, at 10 DG, excess T4 resulted in increased of Flk-1 in the decidua and metrial gland. Hypothyroidism increased the Tie-2 at 10 and 19 DG in the decidua and metrial gland. In conclusion, hypothyroidism reduces the area of the decidua and increases the expression of VEGF, Tie-2 and Flk-1. The excess of T4 promotes tissue angiogenesis by increasing the number of vessels in the decidua because of the increased expression of Flk-1.(AU)

Este estudo teve como objetivo avaliar os efeitos dos hormônios tireoidianos sobre a decídua e a glândula metrial pela análise da expressão de fatores angiogênicos em ratas. 72 ratas adultas, fêmeas foram distribuídas nos grupos hipotiroideo, tratado com T4 e controle. Aos 10, 14 e 19 dias de gestação (DG), a decídua e a glândula metrial foram coletadas para avaliação histomorfométrica e imunoistoquímica da expressão de VEGF, Flk-1 e Tie-2. O hipotireoidismo reduziu a área da decídua aos 10 e 19 DG. Além disso, o VEGF aumentou aos 10 e 14 DG e o Flk-1 apenas aos 14 DG, mas ambos foram reduzidos aos 19 DG na glândula metrial sem alterar significativamente a área ocupada pelos vasos sanguíneos. As ratas tratadas com T4 apresentaram aumento do número de vasos sanguíneos na decídua aos 10 e 19 DG. Além disso, aos 10 DG, o excesso de T4 resultou no aumento de Flk-1 na decídua e na glândula metrial. O hipotireoidismo aumentou o Tie-2 em 10 e 19 DG na decídua e na glândula metrial. Desta forma, pode-se concluir que o hipotireoidismo reduz a área da decídua e aumenta a expressão de VEGF, Tie-2 e Flk-1. O excesso de T4 promove a angiogênese tecidual ao aumentar o número de vasos na decídua devido ao aumento da expressão de Flk-1.(AU)

Production and characterization of tyrosinase activity in Pycnoporus sanguineus CCT-4518 crude extract

Tyrosinase is an enzyme of industrial interest. The production and characterization of tyrosinase from P. sanguineus CCT-4518 were investigated. The selection of inductors, luminosity influence, inoculum size and type of culture medium on the production of tyrosinase and the effect of inhibitors on enzyme activity were performed. Optimum conditions for intracellular tyrosinase production was observed after 2 days using 0.15% L-tyrosine as inducer, in the presence of light, with inoculum size of 10 mycelium discs, using 2% malt extract broth medium, incubated at 30°C, and constant agitation of 150 rpm. Tyrosinase activity was completely inhibited by the addition of 6 mM salicylhydroxamic acid or phenylthiourea, however an inhibition of 4.15% was recorded by the addition of 0.1 mM sodium azide. No inhibition could be detected in case of 0.1 mM phenyl methanesulfonyl fluoride addition. Optimal conditions for intracellular tyrosinase activity using L-dopa as substrate were observed at pH 6.6 and 45°C. Thermal stability studies indicated that the enzyme is stable at 45°C for 15 minutes. Higher temperatures decreased tyrosinase activity. Enzyme production was confirmed by non-denaturing polyacrylamide gel electrophoresis and the protein profile was investigated by denaturing polyacrylamide gel electrophoresis.