RESUMO
Some studies in animals suggest that TBT may constitute a risk factor for cardiovascular diseases. Hence, the main purpose of this study was to investigate in human umbilical artery (HUA) the effect of TBT on vascular reactivity, manly in serotonin (5-HT) and histamine receptors. Using standard organ bath techniques, rings of HUA without endothelium were contracted by 5-HT and histamine. We also investigated the effect of TBT on the expression of the receptors using Real-time PCR. The results show that TBT short term effects include concentration-dependent relaxation. Moreover, at long term exposures, the arteries treated with 100⯵M of TBT do not have contraction capacity when 5-HT is added, and the gene expression of 5-HT2A receptor decrease. Regarding histamine, it was demonstrated that TBT induces a concentration-dependent relaxation and the H1 gene expression levels decrease. In conclusion TBT modifies the activity and expression of 5-HT and histamine receptors.
