The aim of the present study was to investigate the expression, localization, and function of organic cation transporter 3 (Oct3, Slc22a3) and multidrug and toxin extrusion protein 1 (Mate1, Slc47a1) in the rat placenta. Using qRT-PCR and Western blotting techniques, we demonstrated abundant Oct3 and Mate1 mRNA and protein expression achieving significantly higher levels than those in the maternal kidney (positive control). Immunohistochemical visualization revealed preferential localization of Oct3 on the basolateral, i.e., fetus facing side of the placenta, whereas Mate1 positivity was located in the labyrinth area predominantly on the apical, i.e., maternal side of the placenta. To investigate the role of these transporters in the transplacental pharmacokinetics, the in situ method of dually perfused rat term placenta was employed in open- and closed-circuit arrangements; 1-methyl-4-phenylpyridinium (MPP(+)) was used as a model substrate of both Oct3 and Mate1. We provide evidence that Oct3 and Mate1 cause considerable asymmetry between maternal-to-fetal and fetal-to-maternal transport of MPP(+) in favor of fetomaternal direction. Using closed-circuit experimental setup, we further describe the capacity of Oct3 and Mate1 to transport their substrate from fetus to mother even against a concentration gradient. We conclude that Oct3, in a concentration-dependent manner, takes up MPP(+) from the fetal circulation into the placenta, whereas Mate1, on the other side of the barrier, is responsible for MPP(+) efflux from placenta to the maternal circulation. These two transport proteins, thus, form an efficient transplacental eliminatory pathway and play an important role in fetal protection and detoxication.

• MeSH
• 1-methyl-4-fenylpyridinium farmakokinetika   MeSH
• antiportéry fyziologie   MeSH
• buněčné linie MeSH
• imunohistochemie MeSH
• krysa rodu rattus MeSH
• maternofetální výměna látek MeSH
• placenta metabolismus   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• potkani Wistar MeSH
• proteiny přenášející organické kationty fyziologie   MeSH
• těhotenství MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Amphotericin B (AmB) is excreted via the renal excretion route. This excretion process may result in nephrotoxicity. However, relevant information on the precise renal excretion mechanisms is not available. The aim of the study was to analyze the possible interaction of AmB or its prodrug AmB deoxycholate (AmB-DOC) with the typical renal organic anion transporters (OATs) and organic cation transporters (OCTs), using cellular and organ models. The relevant transport systems were then investigated in terms of the drug-drug interactions of AmB-DOC with antivirals that might potentially be used concomitantly. To analyze the renal excretion mechanisms of [(3)H]AmB, perfused rat kidney was employed. HeLa and MDCK II cells transiently transfected with human OAT1 (hOAT1) or hOCT2 were used as the cellular models. A significant tubular secretion of AmB was demonstrated in the perfused rat kidney. The cellular studies performed confirmed the active transport of AmB into cells. AmB did not interact with hOAT1 but strongly inhibited hOCT2. In contrast, AmB-DOC inhibited both hOAT1 and hOCT2. However, [(3)H]AmB cellular uptake by hOAT1 and hOCT2 was not found. AmB-DOC interacted significantly with adefovir, tenofovir, and cidofovir in hOAT1-transfected cells at supratherapeutic concentrations. In conclusion, the significant potency of AmB and AmB-DOC for inhibiting the transporters was demonstrated in this study. The secretion of AmB in the renal tubules is likely not related to the transporters here, since the drug was not proven to be a substrate for them. Drug-drug interactions of AmB and the antivirals used in this study on the investigated transporters are not probable.

• MeSH
• amfotericin B metabolismus   MeSH
• antivirové látky metabolismus   MeSH
• buněčné linie MeSH
• fixní kombinace léků MeSH
• HeLa buňky MeSH
• krysa rodu rattus MeSH
• kyselina deoxycholová metabolismus   MeSH
• ledviny metabolismus   MeSH
• lékové interakce MeSH
• lidé MeSH
• potkani Wistar MeSH
• protein 1 přenášející organické anionty metabolismus   MeSH
• proteiny přenášející organické kationty metabolismus   MeSH
• psi MeSH
• teplota MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• mužské pohlaví MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Members of acyclic nucleoside phosphonates (ANPs) possess antiviral and antiproliferative activities. However, several clinically important ANPs may cause renal injury, most likely due to their active accumulation in the renal tubular cells. The goal of this study was to investigate in vitro relationships between the affinity of several structurally related potent ANPs to selected human transporters and their cytotoxicity. SLC (solute carrier family) transporters (hOAT1, hOCT2, hCNT2, hCNT3) and ABC (ATP-binding cassette) transporters (MDR1, BCRP), which are typically expressed in the kidney, were included in the study. The transport and toxic parameters of the tested compounds were compared to those of two clinically approved ANPs, adefovir and tenofovir. Transport studies with transiently transfected cells were used as the main method in the experiments. Most of the ANPs studied showed the potency to interact with hOAT1. GS-9191, a double prodrug of PMEG, displayed an affinity for hOAT1 comparable with that of adefovir and tenofovir. No significant interaction of the tested ANPs with hOCT2, hCNT2 and hCNT3 was observed. Only GS-9191 was found to be a strong inhibitor for both MDR1 and BCRP. PMEO-DAPy showed the potency to interact with MDR1. Most of the tested substances caused a significant decrease in cellular viability in the cells transfected with hOAT1. Only with the exclusion of GS-9191, a relatively lipophilic compound, did the in vitro cytotoxicity of the ANPs closely correspond to their potential to interact with hOAT1. The increased cytotoxicity of the studied ANPs found in OAT1 transfected cells was effectively reduced by OAT inhibitors probenecid and quercetin. The higher cytotoxicity of the compounds with affinity to hOAT1 proved in the inhibitory experiments evidences that ANPs are not only inhibitors but also substrates of hOAT1. Any clear relationship between the potency of ANPs to inhibit the studied efflux transporters and their cytotoxicity was not demonstrated. In conclusion, the study documented that among the studied transporters hOAT1 seems to be the decisive determinant for renal handling in most of the tested ANPs. This transporter may also play an important role in the mechanism of their potential cytotoxic effects. These facts are in good accordance with previous findings in the clinically used ANPs.

• MeSH
• antivirové látky farmakologie   MeSH
• buňky MDCK MeSH
• HeLa buňky MeSH
• ledviny metabolismus   MeSH
• lidé MeSH
• membránové transportní proteiny metabolismus   MeSH
• organofosfáty farmakologie   MeSH
• psi MeSH
• puriny farmakologie   MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Antivirotika patří k relativně nové skupině léčiv s dosud nedostatečnými informacemi o farmakokinetice a toxicitě. Membránové transportní systémy jsou důležitým faktorem determinujícím dispozici a eliminaci léčiv. Projekt je zaměřen na studium transmembránového transportu novějších nukleosidových antivirotik v ledvinách a placentě. Důvodem je nefrotoxicita a potenciální teratogenita těchto látek. Záměrem je identifikovat transportní systémy odpovědné za přestup studovaných antivirotik přes bariéry v těchto orgánech a zjistit možné ovlivnění transportu a farmakokinetiky těchto léčiv dalšími farmaky, které jsou v klinické praxi podávány současně s nimi. Změny transportu antivirotik v důsledku transportních interakcí budou dále analyzovány z hlediska vlivu na toxicitu pomocí toxicitních buněčných studií. V rámci projektu bude použito ledvinných a placentárních buněčných modelů in vitro a pokročilých molekulárně-biologických metod. Výsledky mohou přispět k bezpečnějšímu užití těchto léčiv.; Antivirals belongs to a relatively new group of drugs with still insufficient information on their pharmacokinetics and toxicity. Membrane transport systems are important factor determining disposition and elimination of drugs. The project is aimed at study of transmembrane transport of novel nucleoside antivirals in the kidney and placenta. The reason is nephrotoxicity and potential teratogenicity of these compounds. The aim is to identify the transport systems responsible for transport of the studiedantivirals through barriers in these organs and detect possible affection of the transport of the antivirals by other compounds potentially administered in clinical practice concomitantly with them. Changes in transport of antivirals due to transport interactions will be also correlated with possible changes in toxicity. Renal and placental cell models in vitro will be used together with advanced methods of molecular biology. Results may contribute to safer use of the antivirals.

• MeSH
• antivirové látky toxicita   MeSH
• diagnostické techniky molekulární metody   MeSH
• ledviny účinky léků   MeSH
• lékové interakce MeSH
• membránové transportní proteiny analýza   MeSH
• placenta účinky léků   MeSH
• teratogeneze MeSH
• toxické účinky MeSH

• Konspekt
• Farmacie. Farmakologie
• NLK Obory
• farmacie a farmakologie
• NLK Publikační typ
• závěrečné zprávy o řešení grantu IGA MZ ČR