Exposure to Butyl Paraben During Gestation and Lactation in Hsd:Sprague Dawley SD Rats via Dosed Feed

Publication date: Available online 11 September 2016 Source:Toxicology Reports Author(s): Georgia K. Roberts, Suramya Waidyanatha, Grace E. Kissling, Brenda L. Fletcher, Melanie A.R. Silinski, Timothy R. Fennell, Helen C. Cunny, Veronica Godfrey Robinson, Chad R. Blystone Butyl paraben (BPB) is an antimicrobial used in a variety of consumer products. Due to widespread human exposure and reported estrogenic activity, the National Toxicology Program quantified internal exposure during critical periods of development. Time-mated female Hsd:Sprague Dawley SD rats were administered 0, 1500, 5000 or 15000ppm BPB via NIH-07 feed, ad libitum, from gestation day (GD) 6 to postnatal day (PND) 28. Dam plasma, amniotic fluid and fetuses were collected on GD18 and pup and dam plasma were collected on PNDs 4, 10, 14, 21 and 28 and analyzed for free (unconjugated) and total (unconjugated and conjugated) BPB using liquid chromatography-tandem mass spectrometry. Free BPB was below the limit of quantitation in fetuses (LOQ 1.91ng BPB/g fetus) and amniotic fluid (LOQ 0.17ng BPB/mL amniotic fluid) at 1500ppm. Analyte levels in amniotic fluid were less than 1% of maternal plasma, suggesting limited placental transfer. Total BPB in PND4 pup plasma was less than 5% of dam plasma in all exposure groups, suggesting low lactational transfer. However, at nearly all time points and exposure groups, there were higher levels of free BPB in pup versus dam plasma, suggesting limited conjugation i...

Source: Toxicology Reports - September 10, 2016 Category: Toxicology Source Type: research