RESUMO
Persistent organic pollutants (POPs) accumulate in the fat tissue of living organisms and are found in relatively high concentrations in animals at the top of the food chain, such as dolphins. The ability of these compounds to interact with the endocrine system of marine mammals constitutes a risk for the reproduction and conservation of species. The La Plata dolphin, Pontoporia blainvillei, is exclusive to the southwestern Atlantic Ocean and is classified on the IUCN red list as a vulnerable species. Blubber, liver, kidney and muscle samples from four P. blainvillei mother-fetus pairs were analyzed to evaluate the transfer of POPs to fetal tissues through the placenta. The presence of POPs in fetal tissues indicates the maternal transfer of compounds. In the pregnant females, blubber was the tissue with POP highest concentration, followed by the liver, kidneys and muscles. In the fetuses, POP accumulation mainly occurred in the blubber followed by the muscles, liver and kidneys. Polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDTs) were found in all tissues analyzed and had the highest concentrations among all compounds. The main PCB congeners in the fetal samples had five to seven chlorine atoms. The only polybrominated diphenyl ether (PBDE) in the fetal samples was 47 and was found only in blubber. The main DDT metabolite in the fetuses was p,p'-DDE. POP transfer via the placenta occurs in the first months of gestation and increases with fetal development, according to fetus/mother (F/M) ratio: HCB>DDT>PCB>PBDE>Mirex, which may follow the order of the octanol/water partition coefficient (Kow) values.
Assuntos
Golfinhos/metabolismo , Monitoramento Ambiental , Poluentes Químicos da Água/metabolismo , Tecido Adiposo/metabolismo , Animais , Oceano Atlântico , DDT/metabolismo , Diclorodifenil Dicloroetileno/metabolismo , Feminino , Éteres Difenil Halogenados/metabolismo , Hidrocarbonetos Clorados/metabolismo , Exposição Materna/estatística & dados numéricos , Bifenilos Policlorados/metabolismo , GravidezRESUMO
Fluoxetine (FLX) is commonly used to treat anxiety and depressive disorders in pregnant women. Since FLX crosses the placenta and is excreted in milk, maternal treatment with this antidepressant may expose the fetus and neonate to increased levels of serotonin (5-HT). Long-term behavioral abnormalities have been reported in rodents exposed to higher levels of 5-HT during neurodevelopment. In this study we evaluated if maternal exposure to FLX during pregnancy and lactation would result in behavioral and/or stress response disruption in adolescent and adult rats. Our results indicate that exposure to FLX influenced restraint stress-induced Fos expression in the amygdala in a gender and age-specific manner. In male animals, a decreased expression was observed in the basolateral amygdala at adolescence and adulthood; whereas at adulthood, a decrease was also observed in the medial amygdala. A lack of FLX exposure effect was observed in females and also in the paraventricular nucleus of both genders. Regarding the behavioral evaluation, FLX exposure did not induce anhedonia in the sucrose preference test but decreased the latency to feed of both male and female adolescent rats evaluated in the novelty-suppressed feeding test. In conclusion, FLX exposure during pregnancy and lactation decreases acute amygdalar stress response to a psychological stressor in males (adolescents and adults) as well as influences the behavior of adolescents (males and females) in a model that evaluates anxiety and/or depressive-like behavior. Even though FLX seems to be a developmental neurotoxicant, the translation of these findings to human safe assessment remains to be determined since it is recognized that not treating a pregnant or lactating woman may also impact negatively the development of the descendants.