[Effects of bisphenol A on the placental function and reproduction in rats].
OBJECTIVE
The aim of this study was to investigate the effects of bisphenol A (BPA), an estrogen-like environmental endocrine disrupter, on the placental function and reproduction in rats. The mRNA levels of the placental prolactin-growth hormone(PRL-GH) gene family, placental trophoblast cell frequency and reproductive data were analyzed.


METHODS
The pregnancies of F344 Fisher rats (160 g +/-20 g) were detected by the presence of the copulatory plug or sperm in the vaginal smear, which marked Day 0 of pregnancy. Pregnant rats were divided into three groups. The control group was intraperitoneally injected with a sesame oil vehicle. The two remaining groups were injected with 50 or 500 mg/kg B.W/day of BPA, resuspended in sesame oil, on either days 7 to 11 or 16 to 20 of pregnancy, with the rats sacrificed on either day 11 or 20, respectively. The mRNA levels of PRL-GH and Pit-1a and b isotype genes were analyzed by Northern blot hybridization and reverse transcription-polymerase chain reaction. The hormone concentrations were analyzed by radioimmunoassay, and the frequency of the placental trophoblast cells observed by a histochemical study. Reproductive data, such as the placental weight and litter size, were surveyed on day 20. The fetal weight was surveyed for 4 weeks after birth. A statistical analysis was carried out using the SAS program (version 8.1).


RESULTS
The mRNA levels of the PRL-GH gene family, such as placental lactogen I, Iv and II, prolactin like protein A, C and Cv, and decidual prolactin-related protein were significantly reduced due to BPA exposure. The mRNA levels of the Pit-1a and b isotype genes, which induce the expression of the PRL-GH gene family in the rat placenta, were also reduced due to BPA exposure. The PL-Iv and PL-II concentrations were reduced in the BPA exposed group. During the middle to last stage of pregnancy (Days 11-20), a high dose of BPA exposure reduced the frequency of spongiotrophoblast cells, which are responsible for the secretion of the PRL-GH hormones. Reproductive data, such as the placental and fetal weights and the litter size, were reduced, but that of the pregnancy period was extended in the BPA exposed compared to the control group.


CONCLUSIONS
BPA disrupts the placental functions in rats, which leads to reproductive disorders.
Lee
Chae-Kwan
CK
Institute of Industrial Medicine & Department of Occupational & Environmental Medicine. lck3303@inje.ac.kr
Kim
Seog-Hyun
SH
Moon
Deog-Hwan
DH
Kim
Jeong-Ho
JH
Son
Byung-Chul
BC
Kim
Dae-Hwan
DH
Lee
Chang-Hee
CH
Kim
Hwi-Dong
HD
Kim
Jung-Won
JW
Kim
Jong-Eun
JE
Lee
Chae-Un
CU
D000818:Animals; D001559:Benzhydryl Compounds; D052244:Endocrine Disruptors / Q000494:pharmacology*; D005260:Female; D007723:Korea; D010636:Phenols / Q000494:pharmacology*; D010920:Placenta / Q000187:drug effects* / Q000502:physiology; D011247:Pregnancy; D011388:Prolactin / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011916:Rats, Inbred F344; D012098:Reproduction / Q000187:drug effects*; D000098826:Bisphenol A Compounds
D001559:Benzhydryl Compounds; D052244:Endocrine Disruptors; D010636:Phenols; D011388:Prolactin; D012333:RNA, Messenger; C006780:bisphenol A; D000098826:Bisphenol A Compounds