US EPA

799704 

Journal Article 

Abstract 

Transport Of Mono-Phthalates Across The Human Placenta; Perfusion Method And Pilot-Tests 

Mikkelsen, TD; Mortensen, GK; Knudsen, LE 

2005 

1 

Reproductive Toxicology
ISSN: 0890-6238
EISSN: 1873-1708 

DART/TER/5001487 

20 

3 

473-474 

English 

Phthalates are widely used as plasticizers in plastics of polyvinyl chloride (PVC) and in the cosmetic industry to provide the products with more suitable properties. Phthalates are not covalently bound to PVC, which enables migration from the products to the environment, e.g. from milk rubber tubes to milk or from plastic toys to sucking children. Pregnant women are exposed to phthalate and the question is, if phthalates crosses the human placenta. Di-2-ethyl-hexylphthalate has been detected in human placental tissue [1], but perfusion studies with the human placenta are not reported in the literature. Perfusion study with Guinea-pig placenta has shown foetal exposure to diethylhexyl-phthalate dependent on perfusion media [2]. Maternal–fetal transfer studies of di-2-ethylhexyl-phthalate and di-ethyl-phthalate in pregnant rats demonstrated both phthalates and/or their metabolic products in the placenta, amniotic fluid and fetus. Reduction of phthalates concentration was found to fit a first order excretion curve; half-life 2.2 days suggesting that repetitive maternal exposure during pregnancy, can lead to accumulation of phthalates in the fetus [3]. Dual perfusion of a single cotyledon in the human placenta can contribute to a better understanding of the placental barrier, transportrate and -mechanisms of different substances and placental metabolism. Immediately after birth the foetal circulation in a single cotyledon is re-established by cannulation of foetal artery and vein. The maternal arteries are connected in the intervillous space and the cotyledon is placed in a perfusion chamber where temperature, pH, pressure and pO2 are controlled to ensure the integrity of the tissue. Because maternal and foetal perfusion solutions circulate it is possible to measure exchanges in substance concentration over time. Antipyrin rapidly diffuses across the placenta and is therefore used as a marker when assessing the transfer rate of other substances. Maternal–fetal transport of mono-phthalates across the human placenta is to be tested. Preliminary studies show that the perfusion liquids after perfusion contain the following mono-phthalates; monomethyl-phthalat, monoethylphthalat, monobutyl-phthalat, monobenzyl-phthalat and mono-2-ethylhexyl-phthalat. The liquids did not contain mono-2-ethyl-5-hydroxy-hexyl-phthalate, monooctylphthalat and monoisononyl-phthalate. The analysis is done in collaboration with the Department of Growth and Reproduction and the results support former findings, by the department, on mono-phthalates in placenta tissue. 

Humans; In Vitro; Pilot Projects; Placenta/METABOLISM; Phthalic Acids/PHARMACOKINETICS; Maternal-Fetal Exchange; Biological Transport; Research Support, Non-U.S. Gov't; NO CAS RN; 88-99-3 

Annual Meeting of the Teratology Society 

Tucson, AZ