101
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Moons T, de Roo M, Claes S, Dom G. Relationship between P-glycoprotein and second-generation antipsychotics. Pharmacogenomics 2011; 12:1193-211. [PMID: 21843066 DOI: 10.2217/pgs.11.55] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The membrane transport protein P-glycoprotein (P-gp) is an interesting candidate for individual differences in response to antipsychotics. To present an overview of the current knowledge of P-gp and its interaction with second-generation antipsychotics (SGAs), an internet search for all relevant English original research articles concerning P-gp and SGAs was conducted. Several SGAs are substrates for P-gp in therapeutic concentrations. These include amisulpride, aripiprazole, olanzapine, perospirone, risperidone and paliperidone. Clozapine and quetiapine are not likely to be substrates of P-gp. However, most antipsychotics act as inhibitors of P-gp, and can therefore influence plasma and brain concentrations of other substrates. No information was available for sertindole, ziprasidone or zotepine. Research in animal models demonstrated significant differences in antipsychotic brain concentration and behavior owing to both P-gp knockout and inhibition. Results in patients are less clear, as several external factors have to be accounted for. Patients with polymorphisms which decrease P-gp functionality tend to perform better in clinical settings. There is some variability in the findings concerning adverse effects, and no definitive conclusions can be drawn at this point.
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Affiliation(s)
- Tim Moons
- University Psychiatric Centre, Catholic University Leuven, Herestraat 49, 3000 Leuven, Belgium.
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102
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Li Y, Yan YE, Wang H. Enhancement of placental antioxidative function and P-gp expression by sodium ferulate mediated its protective effect on rat IUGR induced by prenatal tobacco/alcohol exposure. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2011; 32:465-71. [PMID: 22004967 DOI: 10.1016/j.etap.2011.08.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 08/15/2011] [Accepted: 08/30/2011] [Indexed: 05/31/2023]
Abstract
This study was aimed to explore the therapeutic effect of sodium ferulate (SF) on rats with intrauterine growth retardation (IUGR), and then to clarify the corresponding mechanism. Pregnant rats were divided into normal group, tobacco/alcohol exposure group, and tobacco/alcohol+SF groups. Fetal developmental indices, placental weight, histological alteration, oxidative and antioxidative-function (e.g. MDA, SOD, CAT) and Mdr1 levels were assayed. Results showed exposure to tobacco/alcohol resulted in reduced fetal developmental indices and placental histological alteration, as well as the increased MDA content, decreased SOD and CAT activities and decreased Mdr1a level. After SF treatment, fetal developmental indices, and placental weight, histological alteration, oxidative and antioxidative-function and mdr1a levels were reversed. Our study indicated SF may be effective in reversing IUGR production, and its underlying mechanism may be due to enhanced placental antioxidative function and P-gp expression, which may be related to IUGR formation by tobacco/alcohol exposure.
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Affiliation(s)
- Yan Li
- Department of Pharmacology of Basic Medical College, Wuhan University, Wuhan 430071, China
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103
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Ni Z, Mao Q. ATP-binding cassette efflux transporters in human placenta. Curr Pharm Biotechnol 2011; 12:674-85. [PMID: 21118087 DOI: 10.2174/138920111795164057] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Accepted: 04/08/2010] [Indexed: 01/11/2023]
Abstract
Pregnant women are often complicated with diseases including viral or bacterial infections, epilepsy, hypertension, or pregnancy-induced conditions such as depression and gestational diabetes that require treatment with medication. In addition, substance abuse during pregnancy remains a major public health problem. Many drugs used by pregnant women are off label without the necessary dose, efficacy, and safety data required for rational dosing regimens of these drugs. Thus, a major concern arising from the widespread use of drugs by pregnant women is the transfer of drugs across the placental barrier, leading to potential toxicity to the developing fetus. Knowledge regarding the ATP-binding cassette (ABC) efflux transporters, which play an important role in drug transfer across the placental barrier, is absolutely critical for optimizing the therapeutic strategy to treat the mother while protecting the fetus during pregnancy. Such transporters include P-glycoprotein (P-gp, gene symbol ABCB1), the breast cancer resistance protein (BCRP, gene symbol ABCG2), and the multidrug resistance proteins (MRPs, gene symbol ABCCs). In this review, we summarize the current knowledge with respect to developmental expression and regulation, membrane localization, functional significance, and genetic polymorphisms of these ABC transporters in the placenta and their relevance to fetal drug exposure and toxicity.
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Affiliation(s)
- Zhanglin Ni
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, WA 98195, USA
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104
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Petropoulos S, Gibb W, Matthews SG. Glucocorticoid regulation of placental breast cancer resistance protein (Bcrp1) in the mouse. Reprod Sci 2011; 18:631-9. [PMID: 21602547 DOI: 10.1177/1933719110395399] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Placental breast cancer resistance protein (Bcrp1; encoded by the Abcg2 gene) limits maternal-fetal transplacental transfer of numerous endogenous and exogenous substrates; however, the regulation of placental Abcg2 and Bcrp1 and is not well understood. Placental Abcg2 messenger RNA (mRNA) levels decrease with advancing gestation in the mouse, and this corresponds to increasing levels of maternal and fetal plasma glucocorticoid. Glucocorticoids, including dexamethasone (DEX), downregulate Bcrp1 expression and function in both breast cancer cell lines and the blood-brain barrier in vitro; whether this occurs in the placenta is not known. The potential regulatory role of synthetic glucocorticoids on placental Bcrp1 is of interest, given that approximately 10% of pregnant women are treated with synthetic glucocorticoid for threatened preterm labor. We hypothesized that (1) exposure of pregnant mice to DEX will downregulate placental Abcg2 mRNA and Bcrp1 protein, and (2) results in increased fetal accumulation of [(3)H]mitoxantrone. Pregnant mice were treated with DEX (low-dose: 0.1 mg/kg or high-dose: 1 mg/kg) or vehicle (saline) from embryonic day (E) E9.5 to E15.5 or E12.5 to E18.5. In placentae derived from female fetuses, high-dose DEX significantly downregulated Abcg2 mRNA expression on E15.5 (P < .05) and significantly inhibited Bcrp1 function (P < .05). Similarly, high-dose DEX significantly inhibited Bcrp1 function in the placentae derived from male fetuses (P < .05). In conclusion, there is a dose-dependent regulatory effect of synthetic glucocorticoid on placental Abcg2 mRNA and Bcrp1 function in vivo. Further, it appears that, at the level of Abcg2 gene expression, the female-derived placentae are more susceptible to the effects of DEX than male placentae.
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Affiliation(s)
- Sophie Petropoulos
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
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105
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The human placental perfusion model: a systematic review and development of a model to predict in vivo transfer of therapeutic drugs. Clin Pharmacol Ther 2011; 90:67-76. [PMID: 21562489 DOI: 10.1038/clpt.2011.66] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Dual perfusion of a single placental lobule is the only experimental model to study human placental transfer of substances in organized placental tissue. To date, there has not been any attempt at a systematic evaluation of this model. The aim of this study was to systematically evaluate the perfusion model in predicting placental drug transfer and to develop a pharmacokinetic model to account for nonplacental pharmacokinetic parameters in the perfusion results. In general, the fetal-to-maternal drug concentration ratios matched well between placental perfusion experiments and in vivo samples taken at the time of delivery of the infant. After modeling for differences in maternal and fetal/neonatal protein binding and blood pH, the perfusion results were able to accurately predict in vivo transfer at steady state (R² = 0.85, P < 0.0001). Placental perfusion experiments can be used to predict placental drug transfer when adjusting for extra parameters and can be useful for assessing drug therapy risks and benefits in pregnancy.
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106
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Abramov JP, Wells PG. Embryonic catalase protects against endogenous and phenytoin‐enhanced DNA oxidation and embryopathies in acatalasemic and human catalase‐expressing mice. FASEB J 2011; 25:2188-200. [DOI: 10.1096/fj.11-182444] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Peter G. Wells
- Faculty of PharmacyUniversity of TorontoTorontoOntarioCanada
- Department of Pharmacology and ToxicologyUniversity of TorontoTorontoOntarioCanada
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107
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SCHRICKX JA, FINK-GREMMELS J. A porcine lymphocyte model for P-gp inhibition studies. J Vet Pharmacol Ther 2011; 34:499-501. [DOI: 10.1111/j.1365-2885.2011.01270.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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108
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Teratogenic and cytogenetic effects of ivermectin and its interaction with P-glycoprotein inhibitor. Res Vet Sci 2011; 90:116-23. [DOI: 10.1016/j.rvsc.2010.05.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Revised: 04/30/2010] [Accepted: 05/14/2010] [Indexed: 12/11/2022]
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109
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P-glycoprotein is functionally expressed in the placenta-derived bovine caruncular epithelial cell line 1 (BCEC-1). Placenta 2011; 32:146-52. [DOI: 10.1016/j.placenta.2010.11.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Revised: 11/09/2010] [Accepted: 11/10/2010] [Indexed: 01/16/2023]
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110
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Pollex EK, Hutson JR. Genetic polymorphisms in placental transporters: implications for fetal drug exposure to oral antidiabetic agents. Expert Opin Drug Metab Toxicol 2011; 7:325-39. [DOI: 10.1517/17425255.2011.553188] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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111
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Slåtsve A, Ravna A, Lyså R, Sager G. ABC-transportørenes betydning for effekt og omsetning av legemidler. TIDSSKRIFT FOR DEN NORSKE LEGEFORENING 2011; 131:1084-7. [DOI: 10.4045/tidsskr.10.0675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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112
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113
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Rebuelto M, Loza ME. Antibiotic Treatment of Dogs and Cats during Pregnancy. Vet Med Int 2010; 2010:385640. [PMID: 21253497 PMCID: PMC3021871 DOI: 10.4061/2010/385640] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 08/24/2010] [Accepted: 11/02/2010] [Indexed: 01/16/2023] Open
Abstract
The use of pharmacological agents in pregnant females poses a major clinical challenge due to the marked physiological changes that may modify the pharmacokinetics of drugs and to the potential effects on the fetus. The purpose of this paper is to review briefly our knowledge on the use of antibacterial drugs during pregnancy and to provide information for the judicious selection of an antimicrobial treatment for use in pregnant bitches and queens. The risk to the fetus is a result of the ability of a drug to reach the fetal circulation and to produce toxic effects. The placenta functions as a barrier that protects the fetus due to the presence of transporters and metabolising enzymes; however, during pregnancy, the presence and activity of both enzymes and transporters may change. Antimicrobial agents that have been shown to be safe for use during pregnancy include betalactams, macrolides, and lincosamides. Pharmacotherapy during pregnancy in all species may affect adversely the developing fetus; therefore, it should be avoided when possible.
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Affiliation(s)
- Marcela Rebuelto
- Farmacología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Chorroarín 280, 1427 Buenos Aires, Argentina
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114
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Gahir SS, Piquette-Miller M. Gestational and pregnane X receptor-mediated regulation of placental ATP-binding cassette drug transporters in mice. Drug Metab Dispos 2010; 39:465-71. [PMID: 21127142 DOI: 10.1124/dmd.110.034983] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The ATP-binding cassette (ABC) drug transporters in the placenta are involved in controlling the exchange of endogenous and exogenous moieties. Pregnane X receptor (PXR) is a nuclear receptor that regulates the hepatic expression of several key ABC transporters, but it is unclear whether PXR is involved in the regulation of these transporters in the placenta. This study explores the role of PXR in the regulation of placental drug transporters. The placental mRNA expression of Mdr1a, Bcrp, and Mrp1, 2, and 3 was examined in PXR knockout (-/-), heterozygote (+/-), and wild-type (+/+) mice by quantitative PCR. The impact of PXR activation was examined in pregnant pregnane-16α-carbonitrile (PCN)-treated mice. Compared with that in controls, the basal expression of Mdr1a, Bcrp, Mrp1, and Mrp2 was significantly higher in (+/-) and (-/-) mice. Alterations in the expression of mdr1a, bcrp, and mrp1, 2, and 3 between gestational day (GD) 10 and GD 17 was dissimilar between (+/+) and (-/-) mice. Although PCN treatment induced maternal and fetal hepatic expression of Cyp3a11; placental expression of transporters were not significantly changed. Overall, our results suggest a repressive role of PXR in the basal expression of several placental transporters and a tissue-specific induction of these target genes after PXR activation.
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Affiliation(s)
- Sarabjit S Gahir
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
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115
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Wang L, He K, Maxwell B, Grossman SJ, Tremaine LM, Humphreys WG, Zhang D. Tissue distribution and elimination of [14C]apixaban in rats. Drug Metab Dispos 2010; 39:256-64. [PMID: 21071521 DOI: 10.1124/dmd.110.036442] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Apixaban, a potent and highly selective factor Xa inhibitor, is currently under development for treatment of arterial and venous thrombotic diseases. The distribution, metabolism, and elimination of [(14)C]apixaban were investigated in male, female, pregnant, and lactating rats after single oral doses. Tissue distribution of radioactivity in rats was measured using quantitative whole-body autoradiography. After a single oral administration, radioactivity distributed quickly in rats with C(max) at 1 h for most tissues. The elimination t(1/2) of radioactivity in blood was 1.7 to 4.2 h. The blood area under the plasma concentration-time curve of radioactivity was similar between male and female rats and was slightly higher in pregnant rats and lower in lactating rats. The radioactivity concentration in tissues involved in elimination was greater than that in blood with the highest concentration in the gastrointestinal tract, liver, and urinary bladder/contents and lowest level in brains. In pregnant rats, the whole-body autoradiogram showed that low levels of radioactivity were present in fetal blood, liver, and kidney and were much lower than the radioactivity in the respective maternal organs. The fecal route was the major pathway (74% of dose), and the urinary route was the minor pathway (14%) for apixaban elimination. After single oral doses of [(14)C]apixaban to lactating rats, apixaban exhibited extensive lacteal excretion with apixaban as the major component. In summary, tissue distribution of apixaban in rats was extensive but with limited transfer to fetal and brain tissues and extensive secretion into rat milk with the parent drug as the major component. Milk excretion could account for 10% of apixaban dose, which was comparable to urinary elimination in rats. Tissue distribution and drug excretion of apixaban are consistent with those for a moderately permeable drug that is a substrate for P-glycoprotein and breast cancer resistance protein efflux transporters.
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Affiliation(s)
- Lifei Wang
- Pharmaceutical Candidate Optimization , Bristol-Myers Squibb, P.O. Box 4000, Princeton, NJ 08543, USA
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116
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Pérez R, Palma C, Núñez MJ, Urrutia P, Salazar A, Morales L, Vera D, Cox J. Influence of verapamil on pharmacokinetics and transplacental transfer of ivermectin in sheep. Small Rumin Res 2010. [DOI: 10.1016/j.smallrumres.2010.05.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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117
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Hahnova-Cygalova L, Ceckova M, Staud F. Fetoprotective activity of breast cancer resistance protein (BCRP, ABCG2): expression and function throughout pregnancy. Drug Metab Rev 2010; 43:53-68. [DOI: 10.3109/03602532.2010.512293] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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118
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Modulation of endocrine and transport functions in human trophoblasts by saquinavir and nelfinavir. Eur J Obstet Gynecol Reprod Biol 2010; 152:55-9. [PMID: 20591557 DOI: 10.1016/j.ejogrb.2010.05.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Revised: 03/19/2010] [Accepted: 05/24/2010] [Indexed: 02/03/2023]
Abstract
OBJECTIVES The distribution of drugs to the maternal-fetal interface is influenced by the expression of various efflux transporters. Among these transporters, P-glycoprotein (P-gp) is responsible for the efflux of a great number of drugs such as protease inhibitors of the human immunodeficiency virus, thus reducing the chemical exposure of the fetus. STUDY DESIGN The effects of saquinavir and nelfinavir were evaluated on human trophoblast functions and integrity by investigating their effect on human chorionic gonadotropin (hCG) secretion and on P-gp expression and functionality. RESULTS Nelfinavir significantly reduced hCG secretion by 30% after a 48-h treatment but it had no effect on syncytia formation. Saquinavir had no effect on hCG secretion but significantly increased both expression (to a 2-fold extent) and functionality (by 17.9%) of P-gp, whereas nelfinavir only increased functionality (by 23.1%) with a dissociation of P-gp from caveolin-1. CONCLUSION These results suggest that the effects of saquinavir and nelfinavir differ on trophoblast functions.
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119
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Lee HJ, Cha KE, Hwang SG, Kim JK, Kim GJ. In vitro screening system for hepatotoxicity: Comparison of bone-marrow-derived mesenchymal stem cells and Placenta-derived stem cells. J Cell Biochem 2010; 112:49-58. [DOI: 10.1002/jcb.22728] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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120
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Errasti-Murugarren E, Pastor-Anglada M. Drug transporter pharmacogenetics in nucleoside-based therapies. Pharmacogenomics 2010; 11:809-41. [PMID: 20504255 DOI: 10.2217/pgs.10.70] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
This article focuses on the different types of transporter proteins that have been implicated in the influx and efflux of nucleoside-derived drugs currently used in the treatment of cancer, viral infections (i.e., AIDS) and other conditions, including autoimmune and inflammatory diseases. Genetic variations in nucleoside-derived drug transporter proteins encoded by the gene families SLC15, SLC22, SLC28, SLC29, ABCB, ABCC and ABCG will be specifically considered. Variants known to affect biological function are summarized, with a particular emphasis on those for which clinical correlations have already been established. Given that relatively little is known regarding the genetic variability of the players involved in determining nucleoside-derived drug bioavailability, it is anticipated that major challenges will be faced in this area of research.
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Affiliation(s)
- Ekaitz Errasti-Murugarren
- The Department of Biochemistry and Molecular Biology, Institute of Biomedicine, University of Barcelona, Diagonal 645, 08028 Barcelona, Spain
- Center for Biomedical Research Network in the Subject Area of Liver and Digestive Diseases (CIBERehd), Barcelona 08071, Spain
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121
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Abstract
During pregnancy, the maternal, placental and fetal physiological characteristics constantly evolve and thereby constantly alter drug bioavailability in the mother and feto-placental unit. Gastric emptying time is increased and bowel movements are reduced. Distribution in the maternal body is mainly influenced by body mass variations, water content and fat stores. Metabolic capacity of the liver appears unchanged but renal clearance of drugs is gradually increased. The placental transfer of most drugs mainly consists of passive diffusion between the maternal and fetal circulations, along their respective concentration gradients. Only the free, unbound and non-ionized fraction of the drug readily crosses the membranes. Four anti-hypertensive drugs have been granted a license for the treatment of PE since the year 2000: these are Clonidine (Catapressan), Nicardipine (Loxen+), Labetalol (Trandate), Dihydralazine (Nepressol). Dihydralazine, Labetalol and Nicardipine are not contraindicated in the breast feeding mother. The administration of a long acting Benzodiazepine during pregnancy can lead to new born intoxication of variable severity and duration. These symptoms may precede a withdrawal syndrome (hyper-excitability, tremor, gastro-intestinal upset, such as diarrhea or vomiting). Breast feeding by mothers using benzodiazepines (Nitrazepam and Midazolam) is not recommended. In France, the use of low molecular weight heparins is not recommended during pregnancy whereas in the United States, they are recommended as a prophylactic measure. Their high molecular weight prevents their diffusion across the placental membrane and therefore prevents any fetal or neonatal risk. Bromocriptine is used as an inhibitor of lactation. During the post-partum period, serious accidents have been described: these consist of systemic hypertension, fits, infarcts (cardiac and neurological). It is contraindicated in case of systemic hypertension.
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122
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Vaidya SS, Walsh SW, Gerk PM. Formation and efflux of ATP-binding cassette transporter substrate 2,4-dinitrophenyl-S-glutathione from cultured human term placental villous tissue fragments. Mol Pharm 2010; 6:1689-702. [PMID: 19397308 DOI: 10.1021/mp900019z] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Upon exposure to 1-chloro-2,4-dinitrobenzene (CDNB), the human placental tissue forms its glutathione conjugate 2,4-dinitrophenyl-S-glutathione (DNP-SG). The purpose of this study was to investigate the involvement of human placental ATP-binding cassette (ABC) transporters in the efflux of DNP-SG. Placental tissue samples were obtained from pregnant patients undergoing C-section deliveries following normal pregnancies; villous tissue was cultured in suspension, and DNP-SG formation and efflux upon exposure to 100 microM CDNB were measured by HPLC. DNP-SG efflux decreased by 69.1 (+/-11.3)%, 51.1 (+/-5.4)%, 56.7 (+/-8.3)% and 53.6 (+/-10.8)% (p < 0.05) in the presence of 5 mM sodium orthovanadate (ATPase inhibitor), 100 microM MK571 (MRP-inhibitor), 1 mM dipyridamole (BCRP/P-gp/MRP1-inhibitor) and 100 microM verapamil (P-gp/MRP1 inhibitor) respectively, without any change in DNP-SG formation, total tissue glutathione, GSH/GSSG ratio, tissue integrity or tissue viability. These data clearly established the role of ABC transporters in the human placental efflux of DNP-SG. To investigate the contribution of various ABC transporters toward DNP-SG transport, ATP-dependent transport of 3H-DNP-SG was determined in Sf9 membrane vesicles overexpressing P-gp, BCRP and the MRP proteins. MRP1-mediated DNP-SG transport was inhibited in the presence of sodium orthovanadate, MK571, dipyridamole and verapamil in the presence of glutathione. Furthermore, MRP1-mediated transport [K(t) = 11.3 +/- 1.3 microM and v(max) = 86.7 +/- 1.9 pmol/mg/min] was a high-affinity process compared to MRP2-mediated transport [K(t) = 168 +/- 7 microM and v(max) = 1367 +/- 18 pmol/mg/min]. The inhibition pattern and the kinetics of DNP-SG efflux in the placental villous tissue were consistent with MRP1-mediated DNP-SG efflux, suggesting a functional role and an apical localization for an MRP1-like transporter in the human placental syncytiotrophoblast.
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Affiliation(s)
- Soniya S Vaidya
- Departments of Pharmaceutics and Obstetrics & Gynecology, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, Virginia 23298-0533, USA
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123
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Kalabis GM, Petropoulos S, Gibb W, Matthews SG. Multidrug resistance phosphoglycoprotein (ABCB1) expression in the guinea pig placenta: developmental changes and regulation by betamethasone. Can J Physiol Pharmacol 2010; 87:973-8. [PMID: 19935905 DOI: 10.1139/y09-087] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Placental ABCB1 plays an important role in fetal protection against xenobiotics in the maternal circulation. Limited evidence indicates that glucocorticoids regulate ABCB1 expression in other tissues. Since approximately 10% of pregnant women are treated with synthetic glucocorticoids for threatened preterm labour, the effects of synthetic glucocorticoids on placental ABCB1 are important. We hypothesized that placental levels of ABCB1 are reduced in late gestation in the guinea pig and that synthetic glucocorticoids downregulate ABCB1 production. There was a significant decrease in placental Abcb1 mRNA expression in late gestation. Treatment of guinea pigs with betamethasone (1 mg/kg) on gestational days 40/41 and 50/51 resulted in a significant decrease in placental Abcb1 mRNA and protein expression. No sex differences were observed. Understanding the regulation of ABCB1 function will facilitate the development of treatment strategies for human fetal protection against maternally derived endobiotics and xenobiotics.
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Affiliation(s)
- Grazyna M Kalabis
- Department of Physiology, University of Toronto, Medical Sciences Building, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
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124
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Staud F, Ceckova M, Micuda S, Pavek P. Expression and function of p-glycoprotein in normal tissues: effect on pharmacokinetics. Methods Mol Biol 2010; 596:199-222. [PMID: 19949926 DOI: 10.1007/978-1-60761-416-6_10] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
ATP-binding cassette (ABC) drug efflux transporters limit intracellular concentration of their substrates by pumping them out of cell through an active, energy dependent mechanism. Several of these proteins have been originally associated with the phenomenon of multidrug resistance; however, later on, they have also been shown to control body disposition of their substrates. P-glycoprotein (Pgp) is the first detected and the best characterized of ABC drug efflux transporters. Apart from tumor cells, its constitutive expression has been reported in a variety of other tissues, such as the intestine, brain, liver, placenta, kidney, and others. Being located on the apical site of the plasma membrane, Pgp can remove a variety of structurally unrelated compounds, including clinically relevant drugs, their metabolites, and conjugates from cells. Driven by energy from ATP, it affects many pharmacokinetic events such as intestinal absorption, brain penetration, transplacental passage, and hepatobiliary excretion of drugs and their metabolites. It is widely believed that Pgp, together with other ABC drug efflux transporters, plays a crucial role in the host detoxication and protection against xenobiotic substances. On the other hand, the presence of these transporters in normal tissues may prevent pharmacotherapeutic agents from reaching their site of action, thus limiting their therapeutic potential. This chapter focuses on P-glycoprotein, its expression, localization, and function in nontumor tissues and the pharmacological consequences hereof.
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Affiliation(s)
- Frantisek Staud
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech Republic.
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Padowski JM, Pollack GM. Pharmacokinetic and pharmacodynamic implications of P-glycoprotein modulation. Methods Mol Biol 2010; 596:359-384. [PMID: 19949932 DOI: 10.1007/978-1-60761-416-6_16] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Modulation of P-glycoprotein (Pgp)-mediated transport has significant pharmacokinetic implications for Pgp substrates. Pharmacokinetic alterations may be at the systemic (blood concentrations), regional (organ or tissue concentrations), or local (intracellular concentrations) level. Regardless of the particular location of Pgp modulation, changes in substrate pharmacokinetics will have the potential to alter the magnitude and duration of pharmacologic effect (pharmacodynamics). It is important to understand each of the aspects of Pgp modulation for a given Pgp substrate in order to predict the degree to which Pgp modulation may affect that substrate, to minimize untoward effects associated with that modulation, or to exploit that modulation for specific therapeutic advantage.
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Affiliation(s)
- Jeannie M Padowski
- Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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126
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Chung FS, Eyal S, Muzi M, Link JM, Mankoff DA, Kaddoumi A, O'Sullivan F, Hsiao P, Unadkat JD. Positron emission tomography imaging of tissue P-glycoprotein activity during pregnancy in the non-human primate. Br J Pharmacol 2010; 159:394-404. [PMID: 20002098 PMCID: PMC2825361 DOI: 10.1111/j.1476-5381.2009.00538.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 08/02/2009] [Accepted: 09/04/2009] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Changes in tissue P-glycoprotein (P-gp) activity during pregnancy could affect the pharmacokinetics and thus the efficacy and toxicity of many drugs. Therefore, using positron emission tomography (PET) imaging, we tested whether gestational age affects tissue P-gp activity in the pregnant non-human primate, Macaca nemestrina. EXPERIMENTAL APPROACH Mid-gestational (day 75 +/- 13, n= 7) and late-gestational (day 150 +/- 10, n= 5) age macaques were imaged after administration of a prototypic P-gp substrate, (11)C-verapamil (13.7-75.4 MBq.kg(-1)), before and during intravenous infusion of a P-gp inhibitor, cyclosporin A (CsA) (12 or 24 mg.kg(-1).h(-1)). Accumulation of radioactivity in the fetal liver served as a reporter of placental P-gp activity. P-gp activity was expressed as CsA-induced percent change in the ratio of the area (0-9 min) under the (11)C-radioactivity concentration-time curve in the tissue (AUC(tissue)) to that in the maternal plasma (AUC(plasma)). KEY RESULTS The CsA-induced change in AUC(fetal liver)/AUC(maternal)(plasma) of (11)C-radioactivity significantly increased from mid- (35 +/- 25%) to late gestation (125 +/- 66%). Likewise, the CsA-induced change in AUC(maternal brain)/AUC(plasma) increased from mid- (172 +/- 80%) to late gestation (337 +/- 148%). The AUC ratio for the other maternal tissues was not significantly affected. Neither the CsA blood concentrations nor the level of circulating (11)C-verapamil metabolites were significantly affected by gestational age. CONCLUSIONS AND IMPLICATIONS P-gp activity at the blood-brain barrier and the placental barrier in the macaque increased with gestational age. If replicated in humans, the exposure of the fetus and maternal brain to P-gp substrate drugs, and therefore their efficacy and toxicity, will change during pregnancy.
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Affiliation(s)
- F S Chung
- Department of Pharmaceutics, University of Washington, Seattle, Washington 98195, USA
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Feinshtein V, Holcberg G, Amash A, Erez N, Rubin M, Sheiner E, Polachek H, Ben-Zvi Z. Nitrofurantoin transport by placental choriocarcinoma JAr cells: involvement of BCRP, OATP2B1 and other MDR transporters. Arch Gynecol Obstet 2009; 281:1037-44. [PMID: 19924425 DOI: 10.1007/s00404-009-1286-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2009] [Accepted: 11/02/2009] [Indexed: 01/16/2023]
Abstract
OBJECTIVE To determine the role of BCRP in nitrofurantoin (NF) transport in JAr cells and the possible contribution of OATP2B1, P-gp and MRPs to this transport. METHODS Cells were incubated with various BCRP, P-gp, MRPs, organic anion transporting polypeptide (OAT) and OATP2B1 inhibitors for 15 min, followed by incubation for 30 min with NF, with or without the inhibitors mentioned earlier. NF cytotoxicity was examined using neutral red (NR) assay. Intracellular NF levels were analyzed by HPLC. RESULTS NR assay showed that incubation conditions with NF (as carried out in our experiments) were not cytotoxic. Incubation with specific inhibitors of BCRP (FTC, Chrysin and Novobiocin), showed a significant increase in NF accumulation in the cells. Inhibitors of OATP2B1 (EGCG and BSP) had no influence on NF accumulation. Specific inhibitors of P-gp and MRPs (Verapamil and Indomethacin, respectively) also had no influence on NF accumulation in JAr cells. CONCLUSIONS NF is probably a specific substrate of BCRP, and BCRP has a major active role in NF transport in JAr cells. For the first time, we showed, that P-gp, MRPs, and the OATP2B1, probably have a negligible contribution to NF transport in JAr cells.
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Affiliation(s)
- Valeria Feinshtein
- Department of Clinical Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Saunders M. Transplacental transport of nanomaterials. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2009; 1:671-84. [DOI: 10.1002/wnan.53] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Vähäkangas K, Myllynen P. Drug transporters in the human blood-placental barrier. Br J Pharmacol 2009; 158:665-78. [PMID: 19788499 DOI: 10.1111/j.1476-5381.2009.00336.x] [Citation(s) in RCA: 183] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Studies on the increasing number of transporters found in the placental barrier are gaining momentum, because of their tissue-specific expression, significance in physiology and disease, and the possible utilization of the emerging knowledge in pharmacology. In the placenta, both syncytiotrophoblast and fetal capillary endothelium express transporters. Fetal exposure is determined by the net effect of combination of transporters, their nature and localization in relation to placental cells and their substrate specificity. Although the significance of placental transporters on human fetal drug exposure is almost an unstudied field so far, their potential use to design drugs that do not cross the placenta is already being pursued. It is thus of interest to review the existing knowledge of human placental transporters. Transporters in all groups which take part in drug transport are found in human placenta. Especially, ATP-binding cassette transporters ABCG2/breast cancer resistance protein, ABCB1/P-glycoprotein and ABCC2/MRP2 are all expressed at the apical surface of syncytiotrophoblast facing maternal blood and are putatively important protective proteins both for placental tissue and the fetus, because they are efflux transporters and their substrates include many drugs and also environmental chemicals. Such protective effect has been shown in animals, but these results cannot be directly extrapolated to humans due to interspecies differences in placental structure and function. Experimental models utilizing human placental tissue, especially human placental perfusion, offer valuable possibilities, which have been insufficiently studied so far.
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Affiliation(s)
- Kirsi Vähäkangas
- Department of Pharmacology and Toxicology, University of Kuopio, Kuopio, Finland.
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130
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Cygalova LH, Hofman J, Ceckova M, Staud F. Transplacental Pharmacokinetics of Glyburide, Rhodamine 123, and BODIPY FL Prazosin: Effect of Drug Efflux Transporters and Lipid Solubility. J Pharmacol Exp Ther 2009; 331:1118-25. [DOI: 10.1124/jpet.109.160564] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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131
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Gulati A, Gerk PM. Role of placental ATP-binding cassette (ABC) transporters in antiretroviral therapy during pregnancy. J Pharm Sci 2009; 98:2317-35. [PMID: 19067393 DOI: 10.1002/jps.21623] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Highly active anti-retroviral therapy (HAART) is used to treat HIV-infected patients and involves administration of multiple antiretroviral drugs acting at different steps of the HIV life cycle. In treating HIV-infected pregnant patients, the aim of therapy is not only to treat the mother but also to prevent the transmission of the virus to the fetus. Among the antiretroviral drugs used, there are differences in the extent of transfer of these drugs across the placenta; HIV protease inhibitors are particularly poorly transferred. Activities of ABC transporters expressed in the human placenta as well as differences in plasma protein binding may account for the poor transplacental transfer of certain drugs. This review discusses factors affecting the extent of placental transfer of antiretroviral drugs during pregnancy. These issues may also apply to drugs in other therapeutic categories.
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Affiliation(s)
- Abhishek Gulati
- Department of Pharmaceutics, Virginia Commonwealth University, Medical College of Virginia Campus, 410 N. 12th Street, PO Box 980533, Richmond, Virginia 23298-0533, USA
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Eyal S, Chung FS, Muzi M, Link JM, Mankoff DA, Kaddoumi A, O'Sullivan F, Hebert MF, Unadkat JD. Simultaneous PET imaging of P-glycoprotein inhibition in multiple tissues in the pregnant nonhuman primate. J Nucl Med 2009; 50:798-806. [PMID: 19403878 DOI: 10.2967/jnumed.108.059360] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED Studies in rodents indicate that the disruption of P-glycoprotein (P-gp) function increases drug distribution into the developing fetus and organs such as the brain. To simultaneously and serially evaluate the effect of P-gp activity and inhibition on the tissue distribution of drugs in a more representative animal model, we tested the feasibility of conducting whole-body PET of the pregnant nonhuman primate (Macaca nemestrina). We used (11)C-verapamil as the prototypic P-gp substrate and cyclosporine A (CsA) as the prototypic inhibitor. METHODS Four pregnant macaques (gestational age, 145-159 d; gestational term, 172 d) were imaged after the intravenous administration of (11)C-verapamil (30-72 MBq/kg) before and during intravenous infusion of CsA (12 or 24 mg/kg/h, n = 2 each). The content of verapamil and its metabolites in plasma samples was determined using a rapid solid-phase extraction method. The plasma and tissue time-radioactivity concentration curves of (11)C were integrated over 0-9 min after each verapamil injection. The tissue or arterial plasma area under the time-concentration curve (AUC(tissue)/AUC(plasma)) served as a measure of the tissue distribution of (11)C radioactivity. CsA effect on (11)C radioactivity distribution was interpreted as P-gp inhibition. The change in the fetal liver AUC ratio served as a reporter of placental P-gp inhibition. RESULTS CsA effect on tissue distribution of (11)C radioactivity (AUC ratios) did not increase with the mean blood concentration of CsA, indicating a near-maximal P-gp inhibition. CsA increased maternal brain and fetal liver distribution of (11)C radioactivity by 276% +/- 88% (P < 0.05) and 122% +/- 75% (P < 0.05), respectively. Changes in other measured tissues were not statistically significant. CONCLUSION These data demonstrate for the first time, to our knowledge, the feasibility of simultaneous, serial, noninvasive imaging of P-gp activity and inhibition in multiple maternal organs and the placenta in the nonhuman primate. Our findings, consistent with previous data in rodents, indicate that the activity of P-gp in the placenta and the blood-brain barrier is high and that the inhibition of P-gp facilitates drug distribution across these barriers.
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Affiliation(s)
- Sara Eyal
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
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Functional role of p-glycoprotein and binding protein effect on the placental transfer of lopinavir/ritonavir in the ex vivo human perfusion model. Obstet Gynecol Int 2009; 2009:726593. [PMID: 19960055 PMCID: PMC2778444 DOI: 10.1155/2009/726593] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Accepted: 02/02/2009] [Indexed: 01/11/2023] Open
Abstract
Aims. To study the influence of P-glycoprotein (P-glycoprotein, ABCB1, MDR1) function on placental transfer of lopinavir with ritonavir at different albumin concentrations. Methods. Cotyledons were perfused with lopinavir, ritonavir, and the internal control antipyrin, at various albumin concentrations (10, 30, 40 g/L). After the control phase of each experiment, the P-glycoprotein inhibitor ciclosporin A was added at middle perfusion (45 minutes). Fetal Transfer Rate (FTR) and Clearance Index (CLI) were compared between the 2 phases. Results. In the control phase, the clearance index of lopinavir decreased from 0.401 +/- 0.058 to 0.007 +/- 0.027, as albumin concentrations increased from 10 g/L to higher concentrations (30, 40 g/L). When adding ciclosporin A at physiological albumin concentrations, the clearance index of lopinavir increased significantly 10.3 fold (95% of CI difference [-0.156, -0.002], P = .046) and became positive for ritonavir. Conclusions. Even at high albumin concentrations, inhibition of placental P-glycoprotein increased placental transfer of lopinavir, suggesting that this efflux pump actively reduces placental transfer of the drug. This mechanism may play a role in fetal exposure to maternal antiretroviral therapy.
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PÉREZ R, PALMA C, NÚÑEZ MJ, NAVAS M, OLMOS G, COX J. Transplacental exchange of moxidectin after maternal or fetal intravenous administration in sheep. J Vet Pharmacol Ther 2009; 32:596-605. [DOI: 10.1111/j.1365-2885.2009.01081.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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135
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Liu CM, Chang CH, Yu CH, Hsu CC, Huang LLH. Hyaluronan substratum induces multidrug resistance in human mesenchymal stem cells via CD44 signaling. Cell Tissue Res 2009; 336:465-75. [PMID: 19350274 DOI: 10.1007/s00441-009-0780-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Accepted: 02/10/2009] [Indexed: 12/19/2022]
Abstract
Little information is available concerning multidrug resistance (MDR) in mesenchymal stem cells, although several studies have reported that MDR is associated with hyaluronan in neoplastic cells. We have evaluated whether a hyaluronan-coated surface modulates MDR in placenta-derived human mesenchymal stem cells (PDMSCs). We have found that PDMSCs cultured on a tissue-culture polystyrene surface coated with 30 microg/cm(2) hyaluronan are more resistant than control PDMSCs to doxorubicin. Inhibiting PI3K/Akt signaling has shown that the PI3K/Akt pathway modulates both P-glycoprotein activity and doxorubicin resistance. In addition, 10 microM verapamil dramatically suppresses the doxorubicin resistance induced by the hyaluronan-coated surface, indicating that P-glycoprotein activity is necessary for MDR. We have further found that PDMSCs treated with CD44 small interfering RNA (siRNA) and grown on a polystyrene surface coated with 30 microg/cm(2) hyaluronan have fewer P-glycoprotein(+) cells and lower CD44 expression levels (less than 60% in both cases) than PDMSCs not treated with CD44 siRNA and grown on the hyaluronan-coated surface. Moreover, treatment with CD44 siRNA suppresses the hyaluronan-substratum-induced doxorubicin resistance. We conclude that a hyaluronan substratum induces MDR in PDMSCs through CD44 signaling.
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Affiliation(s)
- Chi-Mou Liu
- Institute of Biotechnology, National Cheng Kung University, 1 University Road, Tainan, 70101, Taiwan
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136
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Dahan A, Sabit H, Amidon GL. The H2 receptor antagonist nizatidine is a P-glycoprotein substrate: characterization of its intestinal epithelial cell efflux transport. AAPS JOURNAL 2009; 11:205-13. [PMID: 19319690 DOI: 10.1208/s12248-009-9092-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Accepted: 02/07/2009] [Indexed: 11/30/2022]
Abstract
The aim of this study was to elucidate the intestinal epithelial cell efflux transport processes that are involved in the intestinal transport of the H(2) receptor antagonist nizatidine. The intestinal epithelial efflux transport mechanisms of nizatidine were investigated and characterized across Caco-2 cell monolayers, in the concentration range 0.05-10 mM in both apical-basolateral (AP-BL) and BL-AP directions, and the transport constants of P-glycoprotein (P-gp) efflux activity were calculated. The concentration-dependent effects of various P-gp (verapamil, quinidine, erythromycin, ketoconazole, and cyclosporine A), multidrug resistant-associated protein 2 (MRP2; MK-571, probenecid, indomethacin, and p-aminohipuric acid), and breast cancer resistance protein (BCRP; Fumitremorgin C) inhibitors on nizatidine bidirectional transport were examined. Nizatidine exhibited 7.7-fold higher BL-AP than AP-BL Caco-2 permeability, indicative of net mucosal secretion. All P-gp inhibitors investigated displayed concentration-dependent inhibition on nizatidine secretion in both directions. The IC(50) of verapamil on nizatidine P-gp secretion was 1.2 x 10(-2) mM. In the absence of inhibitors, nizatidine displayed concentration-dependent secretion, with one saturable (J(max) = 5.7 x 10(-3) nmol cm(-2) s(-1) and K(m) = 2.2 mM) and one nonsaturable component (K(d) = 7 x 10(-4) microL cm(-2) s(-1)). Under complete P-gp inhibition, nizatidine exhibited linear secretory flux, with a slope similar to the nonsaturable component. V(max) and K(m) estimated for nizatidine P-gp-mediated secretion were 4 x 10(-3) nmol cm(-2) s(-1) and 1.2 mM, respectively. No effect was obtained with the MRP2 or the BCRP inhibitors. Being a drug commonly used in pediatrics, adults, and elderly, nizatidine susceptibility to efflux transport by P-gp revealed in this paper may be of significance in its absorption, distribution, and clearance, as well as possible drug-drug interactions.
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Affiliation(s)
- Arik Dahan
- College of Pharmacy, The University of Michigan, 428 Church Street, Ann Arbor, Michigan 48109-1065, USA
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137
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Dahan A, Amidon GL. Segmental dependent transport of low permeability compounds along the small intestine due to P-glycoprotein: the role of efflux transport in the oral absorption of BCS class III drugs. Mol Pharm 2009; 6:19-28. [PMID: 19248230 DOI: 10.1021/mp800088f] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The purpose of this study was to investigate the role of P-gp efflux in the in vivo intestinal absorption process of BCS class III P-gp substrates, i.e. high-solubility low-permeability drugs. The in vivo permeability of two H (2)-antagonists, cimetidine and famotidine, was determined by the single-pass intestinal perfusion model in different regions of the rat small intestine, in the presence or absence of the P-gp inhibitor verapamil. The apical to basolateral (AP-BL) and the BL-AP transport of the compounds in the presence or absence of various efflux transporters inhibitors (verapamil, erythromycin, quinidine, MK-571 and fumitremorgin C) was investigated across Caco-2 cell monolayers. P-gp expression levels in the different intestinal segments were confirmed by immunoblotting. Cimetidine and famotidine exhibited segmental dependent permeability through the gut wall, with decreased P(eff) in the distal ileum in comparison to the proximal regions of the intestine. Coperfusion of verapamil with the drugs significantly increased the permeability in the ileum, while no significant change in the jejunal permeability was observed. Both drugs exhibited significantly greater BL-AP than AP-BL Caco-2 permeability, indicative of net mucosal secretion. Concentration dependent decrease of this secretion was obtained by the P-gp inhibitors verapamil, erythromycin and quinidine, while no effect was evident by the MRP2 inhibitor MK-571 and the BCRP inhibitor FTC, indicating that P-gp is the transporter mediates the intestinal efflux of cimetidine and famotidine. P-gp levels throughout the intestine were inversely related to the in vivo permeability of the drugs from the different segments. The data demonstrate that for these high-solubility low-permeability P-gp substrates, P-gp limits in vivo intestinal absorption in the distal segments of the small intestine; however P-gp plays a minimal role in the proximal intestinal segments due to significant lower P-gp expression levels in this region.
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Affiliation(s)
- Arik Dahan
- College of Pharmacy, The University of Michigan, Ann Arbor, Michigan 48109-1065, USA
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138
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Abstract
In adults, the hepatobiliary system, together with the kidney, constitute the main routes for the elimination of several endogenous and xenobiotic compounds into bile and urine, respectively. However, during intrauterine life the biliary route of excretion for cholephilic compounds, such as bile acids and biliary pigments, is very poor. Although very early in pregnancy the fetal liver produces bile acids, bilirubin and biliverdin, these compounds cannot be efficiently eliminated by the fetal hepatobiliary system, owing to the immaturity of the excretory machinery in the fetal liver. Therefore, the potentially harmful accumulation of cholephilic compounds in the fetus is prevented by their elimination across the placenta. Owing to the presence of detoxifying enzymes and specific transport systems at different locations of the placental barrier, such as the endothelial cells of chorionic vessels and trophoblast cells, this organ plays an important role in the hepatobiliary-like function during intrauterine life. The relevance of this excretory function in normal fetal physiology is evident in situations where high concentrations of biliary compounds are accumulated in the mother. This may result in oxidative stress and apoptosis, mainly in the placenta and fetal liver, which might affect normal fetal development and challenge the fate of the pregnancy. The present article reviews current knowledge of the mechanisms underlying the hepatobiliary function of the fetal-placental unit and the repercussions of several pathological conditions on this tandem.
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139
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Mark PJ, Augustus S, Lewis JL, Hewitt DP, Waddell BJ. Changes in the placental glucocorticoid barrier during rat pregnancy: impact on placental corticosterone levels and regulation by progesterone. Biol Reprod 2009; 80:1209-15. [PMID: 19208548 DOI: 10.1095/biolreprod.108.073650] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Glucocorticoid excess in utero inhibits fetal growth and programs adverse outcomes in adult offspring. Access of maternal glucocorticoid to the glucocorticoid receptor (NR3C1) in the placenta and fetus is regulated by metabolism via the 11beta-hydroxysteroid dehydrogenase (HSD11B) enzymes, as well as multidrug resistance P-glycoprotein (ABCB1)-mediated efflux of glucocorticoids from the syncytiotrophoblast. This study determined expression of genes encoding the two HSD11B isoforms (Hsd11b1 and Hsd11b2), the two ABCB1 isoforms (Abcb1a and Abcb1b), and Nr3c1 in the junctional and labyrinth zones of rat placentas at Days 16 and 22 of normal gestation (Day 23 is term). To assess possible regulation of the Hsd11b and Abcb1 isoforms by glucocorticoids and progesterone, their placental expression was also measured at Day 22 after partial progesterone withdrawal from Day 16 (maternal ovariectomy plus full estrogen and partial progesterone replacement) or after treatment with dexamethasone acetate (1 microg/ml of drinking water from Day 13). Expression of Hsd11b1 mRNA increased in the labyrinth zone (the site of maternal-fetal exchange) from Day 16 to Day 22, whereas that of Hsd11b2 fell dramatically. Consistent with these changes, corticosterone levels increased 10-fold in the labyrinth zone over this period. Expression of both Abcb1a and Abcb1b was markedly higher in the labyrinth zone compared with the junctional zone on both days, consistent with the proposed barrier role of ABCB1 in the placenta. Nr3c1 mRNA expression was similar in the two placental zones at Day 16 but increased 3-fold in the labyrinth zone by Day 22. Partial progesterone withdrawal increased Hsd11b1 mRNA and protein expression in the labyrinth zone but decreased Nr3c1 mRNA expression. These data show that the dynamic expression patterns of the placental HSD11Bs in late gestation are associated with dramatic shifts in placental corticosterone. Moreover, the late gestational rise in labyrinthine Hsd11b1 seems to be driven by the normal prepartum fall in progesterone level.
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Affiliation(s)
- Peter J Mark
- School of Anatomy and Human Biology, The University of Western Australia, Western Australia, Australia.
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Westerlund M, Belin AC, Anvret A, Håkansson A, Nissbrandt H, Lind C, Sydow O, Olson L, Galter D. Association of a polymorphism in the ABCB1 gene with Parkinson's disease. Parkinsonism Relat Disord 2009; 15:422-4. [PMID: 19196542 DOI: 10.1016/j.parkreldis.2008.11.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Revised: 11/17/2008] [Accepted: 11/26/2008] [Indexed: 12/14/2022]
Abstract
The ATP-binding cassette, sub-family B, member 1 (ABCB1) gene encoding the protein P-glycoprotein (P-gp) has been implicated in the pathophysiology of Parkinson's disease (PD) due to its role in regulating transport of endogenous molecules and exogenous toxins. In the present study, we analyzed the ABCB1 single nucleotide polymorphisms (SNPs) 1236C/T (exon 12), 2677G/T/A (exon 21) and 3435C/T (exon 26) in 288 Swedish PD patients and 313 control subjects and found a significant association of SNP 1236C/T with disease (p=0.0159; chi(2)=8.28), whereas the distributions of wild-type and mutated alleles were similar for 2677G/T/A and 3435C/T in patients and controls. Haplotype analysis revealed significant association of the 1236C-2677G haplotype with PD (p=0.026; chi(2)=4.955) and a trend towards association with disease of the 1236C-2677G-3435C haplotype (p=0.072; chi(2)=3.229). Altered ABCB1 and/or P-pg expression was recently shown in PD patients, and impaired drug efflux across barriers such as the gastrointestinal and nasal mucosal linings or the blood-brain barrier, might result in accumulation of drugs and/or endogenous molecules in toxic amounts, possibly contributing to disease. ABCB1 polymorphisms thus constitute an example of how genetic predisposition and environmental influences may combine to increase risk of PD.
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Affiliation(s)
- Marie Westerlund
- Department of Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden.
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141
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Oretti C, Marino S, Mosca F, Colnaghi MR, De Iudicibus S, Drigo I, Stocco G, Bartoli F, Decorti G, Demarini S. Glutathione-S-transferase-P1 I105V polymorphism and response to antenatal betamethasone in the prevention of respiratory distress syndrome. Eur J Clin Pharmacol 2009; 65:483-91. [PMID: 19183974 DOI: 10.1007/s00228-009-0617-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Accepted: 01/08/2009] [Indexed: 01/11/2023]
Abstract
PURPOSE The aim of this pilot study was to assess the association between polymorphisms in genes that encode for proteins involved in the pharmacokinetics/pharmacodynamics of glucocorticoids and the occurrence of respiratory distress syndrome (RDS) in preterm infants born to mothers treated with a complete course of betamethasone. METHODS Sixty-two preterm infants were enrolled. The C1236T, G2677T, and C3435T polymorphisms in the ABCB1 gene, BclI, N363S and ER22/23EK in the NR3C1 gene, I105V in the GST-P1 gene and GST-M1 and GST-T1 deletions were analyzed, and their association with the occurrence of RDS was assessed. RESULTS In univariate analysis, the heterozygous and homozygous presence of the I105V variant in the GST-P1 gene seemed to confer protection against the occurrence of RDS (P = 0.032), while no association for all other polymorphisms was observed. In multivariate analysis, selection from the reference model of independent variables based on AIC (Akaike information criteria) maintained three variables in the model: gestation, C3435T, and GST-P1 genotype. CONCLUSIONS Polymorphisms of the GST-P1 gene may influence the effect of antenatal steroids on the newborn lung.
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Affiliation(s)
- Chiara Oretti
- Division of Neonatology, Burlo Garofolo Children's Hospital, Trieste I-34137, Italy
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Ronaldson PT, Persidsky Y, Bendayan R. Regulation of ABC membrane transporters in glial cells: Relevance to the pharmacotherapy of brain HIV-1 infection. Glia 2008; 56:1711-35. [DOI: 10.1002/glia.20725] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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143
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Expression of multi-drug resistance 1 mRNA in human and rodent tissues: reduced levels in Parkinson patients. Cell Tissue Res 2008; 334:179-85. [PMID: 18855017 DOI: 10.1007/s00441-008-0686-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2008] [Accepted: 08/22/2008] [Indexed: 12/13/2022]
Abstract
The membrane transporter multi-drug resistance 1 (MDR1, P-gp) regulates the bioavailability of endogenous and exogenous compounds and has been implicated in disorders such as Parkinson's disease, cancer, epilepsy, human immunodeficiency virus disease, and inflammatory bowel disease. To promote further understanding of the role of MDR1 in disease, we have characterized cellular MDR1 mRNA expression in post-mortem human and fresh-frozen Sprague-Dawley rat tissues by using radioactive oligonucleotide probe in situ hybridization. We report MDR1 mRNA in human and rat endothelial cells of small vessels in the brain and pia mater. Mdr1 mRNA is also expressed in the blood vessel walls of rat sensory dorsal root and sympathetic ganglia. In peripheral tissues, we have observed MDR1 mRNA in human and rat liver and renal tubules and in human adrenal cortex and the epithelial lining of rat intestine. In female and male reproductive tissues of rat, strong gene activity has been found in steroid-hormone-synthesizing cells. Quantification of MDR1 mRNA in human striatum has revealed reduced levels in Parkinson patients compared with control individuals. The high expression of MDR1 mRNA in blood vessels of the nervous system, in tissues involved in absorption and excretion, and in tissues forming barriers to the environment support the physiological role of MDR1 as a regulator of intracellular levels of endogenous and exogenous compounds.
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144
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Unadkat JD, Chung F, Sasongko L, Whittington D, Eyal S, Mankoff D, Collier AC, Muzi M, Link J. Rapid solid-phase extraction method to quantify [(11)C]-verapamil, and its [(11)C]-metabolites, in human and macaque plasma. Nucl Med Biol 2008; 35:911-7. [PMID: 19026953 DOI: 10.1016/j.nucmedbio.2008.08.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Revised: 07/24/2008] [Accepted: 08/09/2008] [Indexed: 01/16/2023]
Abstract
INTRODUCTION P-glycoprotein (P-gp), an efflux transporter, is a significant barrier to drug entry into the brain and the fetus. The positron emission tomography (PET) ligand, [(11)C]-verapamil, has been used to measure in vivo P-gp activity at various tissue-blood barriers of humans and animals. Since verapamil is extensively metabolized in vivo, it is important to quantify the extent of verapamil metabolism in order to interpret such P-gp activity. Therefore, we developed a rapid solid-phase extraction (SPE) method to separate, and then quantify, verapamil and its radiolabeled metabolites in plasma. METHODS Using high-performance liquid chromatography (HPLC), we established that the major identifiable circulating radioactive metabolite of [(11)C]-verapamil in plasma of humans and the nonhuman primate, Macaca nemestrina, was [(11)C]-D-617/717. Using sequential and differential pH elution on C(8) SPE cartridges, we developed a rapid method to separate [(11)C]-verapamil and [(11)C]-D-617/717. Recovery was measured by spiking the samples with the corresponding nonradioactive compounds and assaying these compounds by HPLC. RESULTS Verapamil and D-617/717 recovery with the SPE method was >85%. When the method was applied to PET studies in humans and nonhuman primates, significant plasma concentration of D-617/717 and unknown polar metabolite(s) were observed. The SPE and the HPLC methods were not significantly different in the quantification of verapamil and D-617/717. CONCLUSIONS The SPE method simultaneously processes multiple samples in less than 5 min. Given the short half-life of [(11)C], this method provides a valuable tool to rapidly determine the concentration of [(11)C]-verapamil and its [(11)C]-metabolites in human and nonhuman primate plasma.
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Affiliation(s)
- Jashvant D Unadkat
- Department of Pharmaceutics, University of Washington, Box 357610, Seattle, WA 98195, USA.
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145
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Oswald S, Grube M, Siegmund W, Kroemer HK. Transporter-mediated uptake into cellular compartments. Xenobiotica 2008; 37:1171-95. [DOI: 10.1080/00498250701570251] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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146
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Mao Q. BCRP/ABCG2 in the placenta: expression, function and regulation. Pharm Res 2008; 25:1244-55. [PMID: 18202831 PMCID: PMC2346511 DOI: 10.1007/s11095-008-9537-z] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Accepted: 01/08/2008] [Indexed: 01/16/2023]
Abstract
Knowledge concerning transport of maternally administered drugs across the placental barrier is essential for determining potential toxicity of drugs to the fetus and the value of drug therapy during pregnancy. An important determinant for fetal drug exposure is the expression of efflux transporters in the placenta. Among human tissues, the ATP-binding cassette efflux transporter BCRP (gene symbol ABCG2) is most abundantly expressed in the apical membrane of placental syncytiotrophoblasts. Although the precise physiological role of BCRP in the placenta is still unclear, existing data strongly suggest that BCRP plays an important role in protecting the fetus against the potential toxicity of drugs, xenobiotics, and metabolites by expelling them across the placental barrier. In this review, we summarize the current knowledge with respect to the expression, function, and polymorphisms of BCRP, as well as transcriptional and posttranscriptional regulation of the transporter in the placenta. Finally, clinical significance of BCRP in the placenta for drug therapy in pregnant women is discussed.
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Affiliation(s)
- Qingcheng Mao
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, WA 98195-7610, USA.
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147
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Niang M, Marrama L, Ekala MT, Alioune G, Tall A, Ndiaye JL, Sarr D, Dangou JM, Lehesran JY, Bouchier C, Mercereau-Puijalon O, Jambou R. Accumulation of CVIET Pfcrt allele of Plasmodium falciparum in placenta of pregnant women living in an urban area of Dakar, Senegal. J Antimicrob Chemother 2008; 62:921-8. [PMID: 18682531 DOI: 10.1093/jac/dkn299] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVES Chemoprophylaxis is recommended during pregnancy to reduce the risk of placental infection. However, in areas with increasing drug resistance, it can trigger selection of resistant parasites in the placenta and increase the frequency of placental malaria. The objective of this study was to analyse the selection of drug-resistant parasites in the placenta in an area where chloroquine was still recommended as prophylaxis. PATIENTS AND METHODS We analysed the polymorphism of parasites from matched placental and venous blood samples at the time of delivery from women in Dakar. Polymorphism of the isolates was studied using nested PCR typing of MSA1 and MSA2 genes, and full sequence of PfCRT exon 2. RESULTS Of 692 women recruited at delivery, 72 had placental malaria. Two Pfcrt exon 2 genotypes were found, and 86% of the placentas had monoallelelic CVIET infection compared with 39% that had peripheral blood infection. Mixed parasite populations of CVIET/CVMNK occurred in 53% of the peripheral blood samples but only in 7% of the infected placentas. This selection of CVIET in placenta was not related to a decreased polymorphism of the parasites, as a large diversity of MSA1 and MSA2 was found in both placenta and venous blood. This diversity confirms that a multiplicity of circulation isolates can occur at low parasite transmission. msp1 and msp2 genotyping revealed mostly distinct populations of parasites in venous and placental blood. CONCLUSIONS These data suggest that, even in low transmission areas, diverse parasite populations can accumulate in the placenta during pregnancy despite strong selection at the PfCRT locus due to chemoprophylaxis with chloroquine.
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Affiliation(s)
- Makhtar Niang
- Unité d'Immunologie, Institut Pasteur de Dakar, Sénégal
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Myllynen P, Kummu M, Kangas T, Ilves M, Immonen E, Rysä J, Pirilä R, Lastumäki A, Vähäkangas KH. ABCG2/BCRP decreases the transfer of a food-born chemical carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in perfused term human placenta. Toxicol Appl Pharmacol 2008; 232:210-7. [PMID: 18680760 DOI: 10.1016/j.taap.2008.07.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Revised: 07/06/2008] [Accepted: 07/10/2008] [Indexed: 12/19/2022]
Abstract
We have studied the role of ATP binding cassette (ABC) transporters in fetal exposure to carcinogens using 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) a known substrate for ABC transporters as a model compound. In perfusion of human term placenta, transfer of (14)C-PhIP (2 microM) through the placenta resulted in fetal-to-maternal concentration ratio (FM ratio) of 0.72+/-0.09 at 6 h. The specific ABCG2 inhibitor KO143 increased the transfer of (14)C-PhIP from maternal to fetal circulation (FM ratio 0.90+/-0.08 at 6 h, p<0.05) while the ABCC1/ABCC2 inhibitor probenecid had no effect (FM ratio at 6 h 0.75+/-0.10, p=0.84). There was a negative correlation between the expression of ABCG2 protein in perfused tissue and the FM ratio of (14)C-PhIP (R=-0.81, p<0.01) at the end of the perfusion. The expression of ABCC2 protein did not correlate with FM ratio of PhIP (R: -0.11, p=0.76). In addition, PhIP induced the expression of ABC transporters in BeWo cells at mRNA level. In conclusion, our data indicates that ABCG2 decreases placental transfer of (14)C-PhIP in perfused human placenta. Also, PhIP may modify ABC transporter expression in choriocarcinoma cells.
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Affiliation(s)
- Päivi Myllynen
- Department of Pharmacology and Toxicology, University of Oulu, PO Box 5000, 90014, Oulu, Finland.
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Petrovic V, Wang JH, Piquette-Miller M. Effect of Endotoxin on the Expression of Placental Drug Transporters and Glyburide Disposition in Pregnant Rats. Drug Metab Dispos 2008; 36:1944-50. [DOI: 10.1124/dmd.107.019851] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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150
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Cygalova L, Ceckova M, Pavek P, Staud F. Role of breast cancer resistance protein (Bcrp/Abcg2) in fetal protection during gestation in rat. Toxicol Lett 2008; 178:176-80. [DOI: 10.1016/j.toxlet.2008.03.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Revised: 03/12/2008] [Accepted: 03/13/2008] [Indexed: 01/16/2023]
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