The effects of PBDE-209 exposure during pregnancy on placental ET-1 and eNOS expression and the birth weight of offspring

•PBDE-209 exposure during pregnancy reduces the birth weight of the offspring rats.•PBDE-209 exposure during pregnancy increases the mRNA level of ET-1 in the placenta.•PBDE-209 exposure during pregnancy reduces the mRNA level of eNOS in the placenta.•PBDE-209 exposure during pregnancy increases the mRNA level of iNOS in the placenta.•The expression pattern of three proteins is consistent with that of mRNA expression.•Total NO is significantly increased after exposure to 5 and 10 ml/kg PBDE-209.

Decabrominated diphenyl ether (PBDE-209) is a persistent organic pollutant. Gestational exposure to PBDE-209 can accumulate in pregnant women and fetuses via the placenta and umbilical cord, affecting perinatal outcome. In this study, pregnant Sprague–Dawley (SD) rats were randomly divided into five groups and intragastrically administered peanut oil (vehicle) 1, 5 and 10 mg/kg by body weight (b.w.) of PBDE-209, or nothing (control) from day 0 (G0) to day 21 (G21) gestation, respectively. Placental samples were collected on G21 by cesarean section. The mRNA and protein expressions of ET-1, eNOS and iNOS in the placenta were examined using qRT-PCR and Western blot, respectively. Total nitric oxide (NO) in the placenta was measured using a specific ELISA kit. Compared with the control and vehicle groups, the mRNA expression of ET-1 and iNOS in the placenta was gradually and significantly increased after exposure to increasing concentrations of PBDE-209 (P < 0.05), while the mRNA level of eNOS in the placenta was gradually and significantly reduced after exposure to increasing concentrations of PBDE-209 (P < 0.05). The expression trends of ET-1, eNOS and iNOS proteins were consistent with those of mRNA expression. Interestingly, the production of total NO was significantly increased after exposure to 5 and 10 mg/kg b.w. PBDE-209 (P < 0.05). Finally, the birth weight of the offspring rats was significantly reduced after maternal exposure to 5 and 10 mg/kg b.w. PBDE-209 compared with the control and vehicle groups (P < 0.05). These results suggest that PBDE-209 exposure during pregnancy upregulates ET-1 and iNOS expression, but decreases eNOS expression in the placenta, as well as reduces the birth weight of offspring.