Perfluorooctane sulfonic acid modulates expression of placental steroidogenesis-associated genes and hormone levels in pregnant rats

Perfluorooctane sulfonate (PFOS) is a widespread and persistent chemical in the environment. Reports show that PFOS is a potential endocrine disruptor; however, the possible effects of PFOS on placental endocrine function are unclear. This study aimed to investigate the endocrine-disrupting effects of PFOS on the placenta in pregnant rats and its potential mechanism. Pregnant rats from gestational days 4-20 were exposed to 0, 10, and 50 mu g/mL PFOS through drinking water followed by analysis of various biochemical parameters. PFOS dose-dependently decreased fetal and placental weight in both sexes, with a specific decrease in weight of labyrinth but not junctional layer. Plasma progesterone (up arrow 166%), aldosterone (up arrow 201%), corticosterone (up arrow 205%), testosterone (up arrow 45%), luteinizing hormone (up arrow 49%) levels were significantly increased, while estradiol (down arrow 27%), prolactin (down arrow 28%) and hCG (down arrow 62%) levels were reduced in groups exposed to higher doses of PFOS. Real-time quantitative reverse transcriptase-polymerase chain reaction analysis revealed a significant increase in mRNA levels of placental steroid biosynthesis enzymes, including Cyp11A1 and 3 beta-HSD1 in male placenta and StAR, Cyp11A1, 17 beta-HSD1 and 17 beta-HSD3 in female placenta of PFOS dams. Cyp19A1 expression in ovaries was significantly decreased in PFOS dams. mRNA levels for placental steroid metabolism enzyme UGT1A1 increased in male but not in female placenta of PFOS dams. These results suggest that the placenta is a target tissue of PFOS and PFOS-induced dysregulation in steroid hormone production might be related to the altered expression of hormone biosynthesis and metabolism enzyme genes in the placenta. This hormone disruption might affect maternal health and fetal growth.

Automated summary

This study aimed to investigate the endocrine-disrupting effects of PFOS on placental function in pregnant rats. Results showed that PFOS dose-dependently decreased fetal and placental weight, specifically in the labyrinth layer. It also caused alterations in hormone levels and gene expression related to steroid hormone biosynthesis and metabolism in the placenta.