Tributilestanho prejudica ciclo reprodutivo de ratas
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Data
2013-01-25
Autores
Sena, Gabriela Cavati
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Universidade Federal do Espírito Santo
Resumo
Triorganotins, mainly tributyltin (TBT), are environmental contaminants, commonly used in antifouling paints for boats, which suffer bioaccumulation and thus are found in mammals and humans due to ingestion of contaminated food. The importance of TBT as environmental endocrine disrupter and consequent reproductive toxicity in different animal models is well known. However, the adverse effects upon reproductive cycle are less well understood. The potential reproductive toxicity of TBT on regular reproductive cyclicity of female rats was examined. Wistar female rats at 12 weeks of age, weighing approximately 230 g were divided in two groups: Control (treated with vehicle, 0,4% ethanol solution), and TBT (treated with tributyltin, 100 ng/kg/d). The treatment lasted 16 days. TBT changed cycle regularity (%) (of animals with regular cycle), reduced the cycle duration, the proestrus and diestrus phases, and the number of epithelial cells in the vaginal smears collected during proestrous. TBT also increased the duration of metestrus and the number of cornified cells in this phase. The weight of the ovaries and levels of estradiol in serum were decreased, and we found a significant increase in progesterone levels. Histological analysis showed apoptotic cells in corpus luteum and granulosa cells layer of ovarian follicles treated animals, with cystic follicles, high number of atretic follicles and corpus luteum. The expression of the estrogen receptor alpha was reduced on uterine and ovarian tissues on TBT group. The micronucleus test (MN), using Chinese hamster ovary cells, demonstrated a concentration-dependent mutagenic effect of TBT. The toxic potential of TBT over the reproductive cycle may be attributed to changes found in the ovarian weight, unbalanced levels of sexual female hormones, and impaired ovarian follicles development.
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Palavras-chave
Environmental contamination , Tributyltin , Endocrine disruption , Reprodutive impairment , Reprodutive cycle , Toxicity , Contaminação ambiental , Tributilestanho , Desregulação endócrina , Prejuízo reprodutivo , Ciclo reprodutivo , Toxicidade
Citação
SENA, Gabriela Cavati. Tributilestanho prejudica ciclo reprodutivo de ratas. 2013. 91 f. Dissertação (Mestrado em Biotecnologia) - Programa de Pós-Graduação em Biotecnologia, Universidade Federal do Espírito Santo, Vitória, 2013.