[The differences in absorption and metabolism of bisphenol A between rats and mice].
OBJECTIVE
To investigate the mechanism of the different levels of serum bisphenol A (BPA) between rat and mouse after oral administration.


METHODS
A total of 18 specific pathogen free (SPF) male rats and 18 mice were treated with 300 mg/kg BPA by oral administration, blood samples were taken from rats and mice after BPA administration at 0.5, 1.0, 12.0 h time points (n = 6 at each point). Serum BPA levels were quantified using fluorescence-high performance liquid chromatography (FL-HPLC) analysis. The rats and mice (n = 6, respectively) were perfused with 100 ml of 0.1 mmol/L BPA by intestinal absorption in situ, then the BPA levels of perfusion fluid at 0.5, 1.0, 2.0 h time points and serum at 2.0 h after BPA perfusion were determined by FL-HPLC analysis. The levels of UDP-glucuronosyltransferase 2B1 (UGT2B1) mRNA expression in the liver of rats and mice were analyzed by semi-quantitative RT-PCR and UGT2B1 enzymatic activity was determined by FL-HPLC method. The rats and mice (n = 6, respectively) were treated with 300 mg/kg BPA by oral administration after fasting 24 h, the feces were collected during 24 h and the levels of BPA in feces were determined by FL-HPLC analysis.


RESULTS
At 0.5, 1.0, 12.0 h after oral administration at 300 mg/kg BPA, the levels of serum BPA in mice ((66.57 ± 14.95), (51.16 ± 16.06), (22.73 ± 5.00) µg/ml, respectively) were significantly higher than in rats ((15.63 ± 5.65), (18.34 ± 5.02), (7.65 ± 2.58) µg/ml, respectively) (F values were 50.660, 17.957, 8.420, respectively, P < 0.05), the rates of absorption in mice small intestine during 0 h-, 0.5 h-, 1.0 - 2.0 h ((10.20 ± 4.20), (1.49 ± 0.67), (1.31 ± 0.55) µg × cm(-2) × min(-1), respectively) were higher than that in rats ((1.87 ± 0.69), (0.47 ± 0.13), (0.36 ± 0.08) µg × cm(-2) × min(-1), respectively) (F values were 14.954, 8.877, 11.536, respectively, P < 0.05), the serum BPA levels in mice ((22.64 ± 4.35) µg/ml) were significantly higher than in rats ((4.13 ± 0.83) µg/ml) after 2 h perfusion with 0.1 mmol/L BPA (F = 74.643, P = 0.000), the levels of UGT2B1 mRNA expression and enzymatic activity in the rats liver were obviously higher than in the mice liver. After oral administration at 300 mg/kg BPA, the feces BPA levels of rats ((1.50 ± 0.32) mg/g) were significantly higher than that of the mice ((0.57 ± 0.35) mg/g) (F = 21.215, P = 0.001) during 24 h.


CONCLUSIONS
The serum BPA level of mouse is significantly higher than the rat after oral administration at 300 mg/kg BPA, which may be caused by BPA high absorption rate of mouse small intestine and strong ability of BPA glucuronidation and excretion of the rat.
Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226007, China.
Chun-yan
CY
Huang
Chen-juan
CJ
Yao
Jing-yun
JY
Ju
Shao-cong
SC
Pan
Fei-lin
FL
Ren
Gang
G
Chen
D000818:Animals; D001559:Benzhydryl Compounds; D007408:Intestinal Absorption; D007928:Lethal Dose 50; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR / Q000378:metabolism*; D010636:Phenols / Q000097:blood* / Q000378:metabolism* / Q000633:toxicity; D051381:Rats; D017207:Rats, Sprague-Dawley / Q000378:metabolism*; D000098826:Bisphenol A Compounds
D001559:Benzhydryl Compounds; D010636:Phenols; C006780:bisphenol A; D000098826:Bisphenol A Compounds