Effect of perinatal exposure to 4-nonylphenol on adipogenesis in offspring rats

  Objective  To investigate the effect of 4-nonylphenol (4-NP) exposure of maternal rats during and after gestation period on adipogenesis and the expression of estrogen receptor alpha (ERα) in offspring rats.

  Methods   The female Wistar rats were exposed to 4-NP at the dosages of 5, 25, and 125 μg/kg by gavage once a day from the 6th gestation day to 21th postnatal day (PND). The serum samples of some of the offspring rats were collected at the 21th PND and the blood and adipose tissues adjacent to kidney and gonads of the other offspring rats were collected 23 weeks after their births. A control group with 16 rats treated the same as the exposed rats but without 4-NP was established simultaneously.

  Results  The body weight of the offspring rats with maternal exposure to 5, 25, and 125 μg/kg 4-NP were all significantly higher than those of the control rats (male offspring rats: 453 ± 51, 475 ± 57, and 509 ± 29 g vs. 384 ± 43 g, female offspring rats: 260 ± 13, 260 ± 12, and 284 ± 3 g vs. 231 ± 8 g) (P < 0.05 for all). The serum total cholesterol and leptin of the offspring rats with maternal 4-NP exposure were significantly higher than those of the control rats (P < 0.05 for all). Compared to those of the control rats, the areas of adipose tissues of the offspring rats with 5, 25, and 125 μg/kg maternal 4-NP exposure significantly increased (male offspring rats: 10 142 ± 9 209, 17 465 ± 9 830, and 33 854 ± 2 620 μm² vs. 6 307 ± 312 μm², female offspring rats: 10 100 ± 9 095, 15 134 ± 965, and 31 280 ± 4 654 μm² vs. 5 915 ± 287 μm²) (all P < 0.05). Compared with those of the control rats, the expressions of the genes related to the differentiation and proliferation of adipocytes significantly increased (P < 0.05 for all), while the expressions of ERα mRNA and protein were down-regulated for the offspring rats with 4-NP exposure of various dosages.

  Conclusion   Maternal exposure to 4-NP during and after gestation period can affect adipogenesis of both male and female offspring rats and down-regulated expressions of ERα gene and protein may related to the effects.