Endocrine Abstracts

Tributyltin (TBT) is a biocide organotin compound widely used as an antifouling in boat paints. This substance is a factor of contamination to water and food, especially marine fish. As an endocrine disruptor, TBT can interact with hormonal pathways and can induce gonadal dysfunction and glycemic dyshomeostasis; however, the effects caused by maternal exposure to TBT are scarce. Here, we investigate maternal exposure to low dose of TBT, considered safe, during pregnancy and lactation on the metabolism of dams as well as male and female offspring. For this, pregnant Wistar rats were exposed on the 7th day of gestation until weaning (21st day of lactation) by gavage to vehicle (0.1% ethanol, Control group) or TBT (100 ng/kg of body weight, bw, TBT group). Morphometric parameters, milk composition and plasma hormone profile from dams and offspring at birth and weaning were evaluated. Analyses of the fragments of pancreas were performed by Transmission Electron Microscopy (TEM) at weaning. Ethical protocol: CEUA/010/2019. Student t test was used to statistical analyses (n=8/group). In dams, TBT exposure increased the body fat at the end of pregnancy (+38%, P=0.007). In the milk, total protein and cholesterol contents were increased (+18%, P=0.03 and +73%, P=0.01 , respectively), lactose was reduced (-30%, P=0.03), but insulin and leptin was unaltered at weaning. Regarding the offspring, females had reduced bw and nasoanal length at birth (-8%; P=0.003; −10%; P<0.0001, respectively), while the males did not show changes of these parameters. Offspring from both sexes have delayed eye opening during development. Only female offspring showed decreased plasma insulin and leptin levels at weaning (-43%; P=0.03; −45%; P=0.04, respectively). The pancreatic islets of dams and offspring from both sexes showed few preserved mitochondria, many granules with crystallized insulin scattered throughout the cytoplasm and endoplasmic reticulum with dilated cistern regions, indicating a reticulum stress process. The amount of our data evidence that tributyltin exposure during gestation and lactation alters insulin and leptin levels of female offspring and causes pancreas impairment in dams and offspring from both sexes at weaning. Thus maternal TBT exposure at a low dose affects mothers and offspring suggesting the development of future chronic diseases, as diabetes mellitus.