ABSTRACT
As a part of EU-project ReProTect, a comparison of the dual re-circulating human placental perfusion system was carried out, by two independent research groups. The detailed placental transfer data of model compounds [antipyrine, benzo(a)pyrene, PhIP (2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine) and IQ (2-amino-3-methylimidazo(4,5-f)quinoline] has been/will be published separately. For this project, a comparative re-analysis was done, by curve fitting the data and calculating two endpoints: AUC(120), defined as the area under the curve between time 0 and time 120 min and as t(0.5), defined as the time when the fetal to maternal concentration ratio is expected to be 0.5. The transport of the compounds from maternal to fetal circulation across the perfused placenta could be ranked in the order of antipyrine>IQ>PhIP in terms of both t(0.5) and AUC(120) by both partners. For benzo(a)pyrene the curve fitting failed. These prevalidation results give confidence for harmonization of the placental perfusion system to be used as one of the test methods in a panel for reproductive toxicology to model placental transfer in humans.
Subject(s)
Laboratories , Maternal-Fetal Exchange , Perfusion , Placenta/metabolism , Placental Circulation , Environmental Pollutants/pharmacokinetics , Environmental Pollutants/toxicity , Female , Humans , In Vitro Techniques , Laboratories/standards , Perfusion/methods , Perfusion/standards , Pregnancy , Reproducibility of Results , Reproduction/drug effects , Toxicity Tests/methods , Toxicity Tests/standardsABSTRACT
Validation of in vitro test systems using the modular approach with steps addressing reliability and relevance is an important aim when developing in vitro tests in e.g. reproductive toxicology. The ex vivo human placental perfusion system may be used for such validation, here presenting the placental perfusion model in Copenhagen including control substances. The positive control substance antipyrine shows no difference in transport regardless of perfusion media used or of terms of delivery (n=59, p<0.05). Negative control studies with FITC marked dextran correspond with leakage criteria (<3 ml h(-1) from the fetal reservoir) when adding 2 (n=7) and 20mg (n=9) FITC-dextran/100 ml fetal perfusion media. Success rate of the Copenhagen placental perfusions is provided in this study, including considerations and quality control parameters. Three checkpoints suggested to determine success rate revealed that 15% of the cannulated placentae received in one year (n=202) were successfully perfused.
