Toxicokinetics of the food-toxin IQ in human placental perfusion is not affected by ABCG2 or xenobiotic metabolism
| Autor: | Elina Immonen, Jeanette K.S. Nielsen, Päivi Myllynen, Kirsi Vähäkangas, Maria Kummu, Line Mathiesen, T. Pihlaja, A. Petsalo, Lisbeth E. Knudsen |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
medicine.medical_specialty
Adenosine Placenta Diketopiperazines Heterocyclic Compounds 4 or More Rings Xenobiotics Fetal membrane Pregnancy Internal medicine Tetrahydroisoquinolines medicine Cytochrome P-450 CYP1A1 Toxicokinetics ATP Binding Cassette Transporter Subfamily G Member 2 Humans Maternal-Fetal Exchange Carcinogen chemistry.chemical_classification Fetus biology Obstetrics and Gynecology Cytochrome P450 Neoplasm Proteins Perfusion medicine.anatomical_structure Endocrinology Reproductive Medicine chemistry Heterocyclic amine embryonic structures biology.protein Carcinogens Quinolines Acridines ATP-Binding Cassette Transporters Female Drug metabolism Developmental Biology |
| Zdroj: | Placenta. 31(7) |
| ISSN: | 1532-3102 |
| Popis: | Metabolizing enzymes and transporters affect toxicokinetics of foreign compounds (e.g. drugs and carcinogens) in human placenta. The heterocyclic amine, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) is a food-borne carcinogen being metabolically activated by cytochrome P450 (CYP) enzymes, especially by CYP1A1/2. IQ is also a substrate for ABCG2 transporter. Placental transfer of (14)C-IQ was evaluated in 4-6 h ex vivo human placental perfusions in Finland and Denmark. In Finland placentas were perfused with (14)C-IQ alone (0.5 microM, n = 6) or in combination with GF120918 (inhibitor of ABCG2, 1 microM, n = 6) or Ko143 (specific inhibitor of ABCG2, 2 microM, n = 4) to study the role of ABCG2 inhibition in transfer while in Denmark perfusions were performed with (14)C-IQ alone. Critical parameters (leak from fetal to maternal circulation, pH values, blood gases, glucose consumption, the production of hCG hormone and transport of antipyrine) were analyzed during the perfusions. (14)C-IQ on maternal and fetal sides was determined by liquid scintillation counting. In Finland IQ and its metabolites in final perfusates were determined also by LC/TOF-MS. ABCG2 expression and EROD activity (CYP1A1/2) were analyzed from perfused tissues. (14)C-IQ was easily transferred through the placenta from maternal to fetal side in both laboratories. Neither significant EROD activity nor IQ metabolites were found in placentas from non-smoking mothers. Inhibition of ABCG2 by GF120918 (FM-ratio of IQ 0.95) or Ko143 (FM-ratio of IQ 0.94) did not affect (14)C-IQ transfer (FM-ratio of IQ in IQ only perfusions 0.97), which indicates that placental ABCG2 does not have a significant role in protecting fetus from IQ. |
| Databáze: | OpenAIRE |
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