Endocrine Abstracts

The ingestion of marine foods is a potential route of contamination by tributyltin (TBT), a biocide organotin used as an antifouling in boat paints. TBT causes a phenomenon known as imposex, that induces, for instance, the irreversible appearance of male sexual characteristics in gastropod females. In mammals, TBT also directly impairs the sexual development. In fact, it is known that TBT can affect women in reproductive age. Our aim was to study whether the maternal exposure to TBT, in a high dose, during pregnancy and lactation can cause long-term hormonal dysfunctions in male and female offspring. Experimental design was approved by the Ethics Committee (protocol: CEUA/010/2019). Wistar rats were mated and after pregnancy detection, females were randomly separated into 2 groups: dams received vehicle (0.1% ethanol; Control group) or TBT (1000 ng/kg of body weight, bw). Exposure occured from the 7th gestational day until the end of lactation (21 days of lactation period) by gavage. We evaluated plasma hormones of male and female offspring at puberty (45 days old) and adulthood (180 days old) by enzyme-linked immunosorbent assay (ELISA). Data were analyzed by Student’s t test (n=7/group). During puberty, male TBT offspring showed a significant reduction of plasma follicle stimulating hormone (FSH) (-42%), luteinizing hormone (LH) (-51%), testosterone (-70%), estradiol (-39%), insulin (-30%) and corticosterone (-78%) levels. No differences were observed in plasma thyroid-stimulating hormone (TSH), thyroxine (T4), triiodothyronine (T3) and leptin. Female TBT offspring presented increase in plasma testosterone and reduction of corticosterone levels (2-fold and -43%, respectively), without changes of other hormones. On the other hand, at adulthood, TBT males displayed higher plasma T3 (2.7-fold), insulin (1.8-fold), corticosterone (3.8-fold) and leptin (+56%) levels when compared to control ones. Adult TBT females only displayed lower plasma corticosterone level (-45%). Taken togheter our data indicate that perinatal exposure to TBT causes endocrine dysfunctions during puberty period and adult life. Interestingly, in this model we evidence a sex dimorphism, since male offspring seem to be more affected than females.