RESUMO
Tributyltin (TBT) is a biocide used in the formulation of antifouling paints and it is highly harmful. Despite the ban, the compound persists in the environment, contaminating marine foodstuffs and household products. Therefore, considering the route of exposure to the contaminant, the gastrointestinal tract (GIT) acts as an important barrier against harmful substances and is a potential biomarker for understanding the consequences of these agents. This work aimed to evaluate histological and neuronal alterations in the duodenum of male Wistar rats that received 20 ng/g TBT and 600 ng/g via gavage for 30 consecutive days. After the experimental period, the animals were euthanized, and the duodenum was intended for neuronal histochemistry (total and metabolically active populations) and histological routine (morphometry and histopathology). The results showed more severe changes in neuronal density and intestinal morphometry in rats exposed to 20 ng/g, such as total neuronal density decrease and reduction of intestinal layers. In rats exposed to 600 ng/g of TBT, it was possible to observe only an increase in intraepithelial lymphocytes. We conclude that TBT can be more harmful to intestinal homeostasis when consumed in lower concentrations.
Assuntos
Duodeno , Plasticidade Neuronal , Ratos Wistar , Compostos de Trialquitina , Animais , Compostos de Trialquitina/toxicidade , Masculino , Plasticidade Neuronal/efeitos dos fármacos , Plasticidade Neuronal/fisiologia , Duodeno/efeitos dos fármacos , Duodeno/patologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Ratos , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Sistema Nervoso Entérico/efeitos dos fármacos , Sistema Nervoso Entérico/patologiaRESUMO
Imposex incidence, organotin tissue levels, and sex steroid (free and esterified testosterone and estradiol) levels were assessed in Stramonita haemastoma from Babitonga Bay (Santa Catarina State, Southern Brazil). The imposex levels showed a reduction when compared to a previous evaluation performed in the same area. In spite of that, the detected imposex incidence indicated the occurrence of tributyltin (TBT) inputs that were still able to produce endocrine disruption in local gastropods. In addition, a high level of organotins was observed in tissues of imposexed females. These females also showed a hormonal imbalance, especially in the total testosterone/total estradiol ratio. These findings obtained under realistic field conditions suggest that the steroid pathway could be responsible by the imposex induction after exposure to TBT. In this case, measurements of sex steroid levels can be an additional evidence for monitoring sites and impose affected gastropod populations.
