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Kenichi Inui - One of the best experts on this subject based on the ideXlab platform.
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Transcellular Transport of organic cations in double transfected mdck cells expressing human organic cation Transporters hoct1 hmate1 and hoct2 hmate1
Biochemical Pharmacology, 2008Co-Authors: Tomoko Sato, Satohiro Masuda, Toshiya Katsura, Atsushi Yonezawa, Yuko Tanihara, Kenichi InuiAbstract:Abstract To clarify the Transcellular Transport of organic cations via basolateral and apical Transporters, we established double-transfected Madin–Darby canine kidney (MDCK) cells expressing both human organic cation Transporter hOCT1 and hMATE1 (MDCK-hOCT1/hMATE1), and hOCT2 and hMATE1 (MDCK-hOCT2/hMATE1) as models of human hepatocytes and renal epithelial cells, respectively. Using the specific antibodies, hOCT1 and hMATE1 or hOCT2 and hMATE1 were found to be localized in the basolateral and apical membranes of MDCK-hOCT1/hMATE1 or MDCK-hOCT2/hMATE1 cells, respectively. A representative substrate, [ 14 C]tetraethylammonium, was Transported unidirectionally from the basolateral to apical side in these double transfectants. The optimal pH was showed to be 6.5 for the Transcellular Transport of [ 14 C]tetraethylammonium, when the pH of the incubation medium on the apical side was varied from 5.5 to 8.5. The basolateral-to-apical Transport also decreased in the presence of 10 mM 1-methyl-4-phenylpyridinium or 1 mM levofloxacin on the basolateral side of both double transfectants. In MDCK-hOCT2/hMATE1 cell monolayers, but not in MDCK-hOCT1/hMATE1 cell monolayers, the accumulation of [ 14 C]tetraethylammonium was decreased in the presence of 10 mM 1-methyl-4-phenylpyridinium, but significantly increased in the presence of 1 mM levofloxacin. The uptake of [ 14 C]tetraethylammonium, [ 3 H]1-methyl-4-phenylpyridinium, [ 14 C]metformin and [ 3 H]cimetidine, but not of [ 14 C]procainamide and [ 3 H]quinidine, by HEK293 cells was stimulated by expression of the hOCT1, hOCT2 or hMATE1 compared to control cells. However, Transcellular Transport of [ 14 C]procainamide and [ 3 H]quinidine was clearly observed in both double-transfectants. These cells could be useful for examining the routes by which compounds are eliminated, or predicting Transporter-mediated drug interaction.
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Transcellular Transport of organic cations in double-transfected MDCK cells expressing human organic cation Transporters hOCT1/hMATE1 and hOCT2/hMATE1.
Biochemical Pharmacology, 2008Co-Authors: Tomoko Sato, Satohiro Masuda, Toshiya Katsura, Atsushi Yonezawa, Yuko Tanihara, Kenichi InuiAbstract:Abstract To clarify the Transcellular Transport of organic cations via basolateral and apical Transporters, we established double-transfected Madin–Darby canine kidney (MDCK) cells expressing both human organic cation Transporter hOCT1 and hMATE1 (MDCK-hOCT1/hMATE1), and hOCT2 and hMATE1 (MDCK-hOCT2/hMATE1) as models of human hepatocytes and renal epithelial cells, respectively. Using the specific antibodies, hOCT1 and hMATE1 or hOCT2 and hMATE1 were found to be localized in the basolateral and apical membranes of MDCK-hOCT1/hMATE1 or MDCK-hOCT2/hMATE1 cells, respectively. A representative substrate, [ 14 C]tetraethylammonium, was Transported unidirectionally from the basolateral to apical side in these double transfectants. The optimal pH was showed to be 6.5 for the Transcellular Transport of [ 14 C]tetraethylammonium, when the pH of the incubation medium on the apical side was varied from 5.5 to 8.5. The basolateral-to-apical Transport also decreased in the presence of 10 mM 1-methyl-4-phenylpyridinium or 1 mM levofloxacin on the basolateral side of both double transfectants. In MDCK-hOCT2/hMATE1 cell monolayers, but not in MDCK-hOCT1/hMATE1 cell monolayers, the accumulation of [ 14 C]tetraethylammonium was decreased in the presence of 10 mM 1-methyl-4-phenylpyridinium, but significantly increased in the presence of 1 mM levofloxacin. The uptake of [ 14 C]tetraethylammonium, [ 3 H]1-methyl-4-phenylpyridinium, [ 14 C]metformin and [ 3 H]cimetidine, but not of [ 14 C]procainamide and [ 3 H]quinidine, by HEK293 cells was stimulated by expression of the hOCT1, hOCT2 or hMATE1 compared to control cells. However, Transcellular Transport of [ 14 C]procainamide and [ 3 H]quinidine was clearly observed in both double-transfectants. These cells could be useful for examining the routes by which compounds are eliminated, or predicting Transporter-mediated drug interaction.
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Transcellular Transport of creatinine in renal tubular epithelial cell line llc pk1
Drug Metabolism and Pharmacokinetics, 2005Co-Authors: Yumiko Urakami, Naoko Kimura, Masahiro Okuda, Satohiro Masuda, Toshiya Katsura, Kenichi InuiAbstract:Summary: Background /Aim Creatinine is excreted into urine via tubular secretion in addition to glomerular filtration. In the present study, characteristics of the creatinine Transport in renal epithelial cells were investigated. Methods The Transcellular Transport and accumulation of [ 14 C]creatinine and [ 14 C]tetraethylammonium (TEA) were assessed using LLC-PK 1 cell monolayers cultured on porous membrane filters. Results [ 14 C]Creatinine was Transported directionally from the basolateral to apical side of LLC-PK 1 cell monolayers. Basolateral uptake of [ 14 C]creatinine was dependent on membrane potential, and was saturable with apparent K m and V max values of 13.2±2.8 mM and 13.1 ± 3.1 nmol/mg protein/5min, respectively. Concomitant administration of organic cations (1 mM) such as cimetidine, quinidine and trimethoprim inhibited both the Transcellular Transport and accumulation of [ 14 C]creatinine. Furthermore, apical excretion of [ 14 C]creatinine was not dependent on acidification of the apical medium. Conclusions Creatinine was subjected to directional Transport across renal epithelial cells from the basolateral to apical side. The organic cation Transporter should be involved in the basolateral uptake of creatinine.
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Secretory mechanisms of grepafloxacin and levofloxacin in the human intestinal cell line caco-2.
Journal of Pharmacology and Experimental Therapeutics, 2000Co-Authors: Hiroaki Yamaguchi, Yukiya Hashimoto, Ikuko Yano, Kenichi InuiAbstract:Grepafloxacin and levofloxacin Transport by Caco-2 cell monolayers was examined to characterize the intestinal behavior of these quinolones. The levels of Transcellular Transport of [14C]grepafloxacin and [14C]levofloxacin from the basolateral to the apical side were greater than those in the opposite direction. The unidirectional Transport was inhibited by the presence of excess unlabeled quinolones, accompanied by increased accumulation. The inhibitory effects of cyclosporin A plus grepafloxacin on basolateral-to-apical Transcellular Transport and cellular accumulation of [14C]grepafloxacin were comparable to those of cyclosporin A alone, indicating that the Transport of grepafloxacin across the apical membrane was mainly mediated by P-glycoprotein. On the other hand, basolateral-to-apical Transcellular Transport of [14C]levofloxacin in the presence of cyclosporin A was decreased by unlabeled levofloxacin, grepafloxacin, and enoxacin, accompanied by significantly increased cellular accumulation. The organic cation cimetidine, organic anion p -aminohippurate, and the multidrug resistance-related protein (MRP) modulator probenecid did not affect the Transcellular Transport of [14C]grepafloxacin or [14C]levofloxacin in the presence of cyclosporin A. The basolateral-to-apical Transcellular Transport of levofloxacin in the presence of cyclosporin A showed concentration-dependent saturation with an apparent Michaelis constant of 5.6 mM. In conclusion, these results suggested that basolateral-to-apical flux of quinolones was mediated by P-glycoprotein and a specific Transport system distinct from organic cation and anion Transporters and MRP.
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Transport of Quinolone Antibacterial Drugs in a Kidney Epithelial Cell Line, LLC-PK1
Journal of Pharmacology and Experimental Therapeutics, 1998Co-Authors: Yumiko Matsuo, Yukiya Hashimoto, Ikuko Yano, Kenichi InuiAbstract:The Transport of quinolone antibacterial drugs by LLC-PK 1 monolayers was examined to characterize the renal tubular secretion of these drugs. The Transcellular Transport of levofloxacin and grepafloxacin from the basolateral to apical side was larger than the Transport in the opposite direction. The basal-to-apical Transcellular Transport and uptake from the basolateral side of levofloxacin showed concentration dependent saturation with an apparent Michaelis constant ( K m ) of 0.6 and 13 mM, respectively. Various quinolones (1 mM) inhibited the Transcellular Transport of levofloxacin, and this inhibition was accompanied by a marked increase of cellular accumulation. These results indicated that quinolones interacted more strongly with the Transport system on the apical than the basolateral membrane. Neither tetraethylammonium nor cyclosporin A affected the basal-to-apical Transcellular Transport and accumulation of levofloxacin. The basal-to-apical Transcellular Transport of levofloxacin was not influenced by either lowering the pH of the apical side or pretreatment of apical membrane with p -chloromercuribenzene sulfonate. These findings indicate that quinolones are specifically Transported from the basolateral to apical side by LLC-PK 1 monolayers and have higher affinity for the Transport system in the apical membrane, a system distinct from H + /organic cation antiport system.
Toshiya Katsura - One of the best experts on this subject based on the ideXlab platform.
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Transcellular Transport of organic cations in double transfected mdck cells expressing human organic cation Transporters hoct1 hmate1 and hoct2 hmate1
Biochemical Pharmacology, 2008Co-Authors: Tomoko Sato, Satohiro Masuda, Toshiya Katsura, Atsushi Yonezawa, Yuko Tanihara, Kenichi InuiAbstract:Abstract To clarify the Transcellular Transport of organic cations via basolateral and apical Transporters, we established double-transfected Madin–Darby canine kidney (MDCK) cells expressing both human organic cation Transporter hOCT1 and hMATE1 (MDCK-hOCT1/hMATE1), and hOCT2 and hMATE1 (MDCK-hOCT2/hMATE1) as models of human hepatocytes and renal epithelial cells, respectively. Using the specific antibodies, hOCT1 and hMATE1 or hOCT2 and hMATE1 were found to be localized in the basolateral and apical membranes of MDCK-hOCT1/hMATE1 or MDCK-hOCT2/hMATE1 cells, respectively. A representative substrate, [ 14 C]tetraethylammonium, was Transported unidirectionally from the basolateral to apical side in these double transfectants. The optimal pH was showed to be 6.5 for the Transcellular Transport of [ 14 C]tetraethylammonium, when the pH of the incubation medium on the apical side was varied from 5.5 to 8.5. The basolateral-to-apical Transport also decreased in the presence of 10 mM 1-methyl-4-phenylpyridinium or 1 mM levofloxacin on the basolateral side of both double transfectants. In MDCK-hOCT2/hMATE1 cell monolayers, but not in MDCK-hOCT1/hMATE1 cell monolayers, the accumulation of [ 14 C]tetraethylammonium was decreased in the presence of 10 mM 1-methyl-4-phenylpyridinium, but significantly increased in the presence of 1 mM levofloxacin. The uptake of [ 14 C]tetraethylammonium, [ 3 H]1-methyl-4-phenylpyridinium, [ 14 C]metformin and [ 3 H]cimetidine, but not of [ 14 C]procainamide and [ 3 H]quinidine, by HEK293 cells was stimulated by expression of the hOCT1, hOCT2 or hMATE1 compared to control cells. However, Transcellular Transport of [ 14 C]procainamide and [ 3 H]quinidine was clearly observed in both double-transfectants. These cells could be useful for examining the routes by which compounds are eliminated, or predicting Transporter-mediated drug interaction.
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Transcellular Transport of organic cations in double-transfected MDCK cells expressing human organic cation Transporters hOCT1/hMATE1 and hOCT2/hMATE1.
Biochemical Pharmacology, 2008Co-Authors: Tomoko Sato, Satohiro Masuda, Toshiya Katsura, Atsushi Yonezawa, Yuko Tanihara, Kenichi InuiAbstract:Abstract To clarify the Transcellular Transport of organic cations via basolateral and apical Transporters, we established double-transfected Madin–Darby canine kidney (MDCK) cells expressing both human organic cation Transporter hOCT1 and hMATE1 (MDCK-hOCT1/hMATE1), and hOCT2 and hMATE1 (MDCK-hOCT2/hMATE1) as models of human hepatocytes and renal epithelial cells, respectively. Using the specific antibodies, hOCT1 and hMATE1 or hOCT2 and hMATE1 were found to be localized in the basolateral and apical membranes of MDCK-hOCT1/hMATE1 or MDCK-hOCT2/hMATE1 cells, respectively. A representative substrate, [ 14 C]tetraethylammonium, was Transported unidirectionally from the basolateral to apical side in these double transfectants. The optimal pH was showed to be 6.5 for the Transcellular Transport of [ 14 C]tetraethylammonium, when the pH of the incubation medium on the apical side was varied from 5.5 to 8.5. The basolateral-to-apical Transport also decreased in the presence of 10 mM 1-methyl-4-phenylpyridinium or 1 mM levofloxacin on the basolateral side of both double transfectants. In MDCK-hOCT2/hMATE1 cell monolayers, but not in MDCK-hOCT1/hMATE1 cell monolayers, the accumulation of [ 14 C]tetraethylammonium was decreased in the presence of 10 mM 1-methyl-4-phenylpyridinium, but significantly increased in the presence of 1 mM levofloxacin. The uptake of [ 14 C]tetraethylammonium, [ 3 H]1-methyl-4-phenylpyridinium, [ 14 C]metformin and [ 3 H]cimetidine, but not of [ 14 C]procainamide and [ 3 H]quinidine, by HEK293 cells was stimulated by expression of the hOCT1, hOCT2 or hMATE1 compared to control cells. However, Transcellular Transport of [ 14 C]procainamide and [ 3 H]quinidine was clearly observed in both double-transfectants. These cells could be useful for examining the routes by which compounds are eliminated, or predicting Transporter-mediated drug interaction.
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Transcellular Transport of creatinine in renal tubular epithelial cell line llc pk1
Drug Metabolism and Pharmacokinetics, 2005Co-Authors: Yumiko Urakami, Naoko Kimura, Masahiro Okuda, Satohiro Masuda, Toshiya Katsura, Kenichi InuiAbstract:Summary: Background /Aim Creatinine is excreted into urine via tubular secretion in addition to glomerular filtration. In the present study, characteristics of the creatinine Transport in renal epithelial cells were investigated. Methods The Transcellular Transport and accumulation of [ 14 C]creatinine and [ 14 C]tetraethylammonium (TEA) were assessed using LLC-PK 1 cell monolayers cultured on porous membrane filters. Results [ 14 C]Creatinine was Transported directionally from the basolateral to apical side of LLC-PK 1 cell monolayers. Basolateral uptake of [ 14 C]creatinine was dependent on membrane potential, and was saturable with apparent K m and V max values of 13.2±2.8 mM and 13.1 ± 3.1 nmol/mg protein/5min, respectively. Concomitant administration of organic cations (1 mM) such as cimetidine, quinidine and trimethoprim inhibited both the Transcellular Transport and accumulation of [ 14 C]creatinine. Furthermore, apical excretion of [ 14 C]creatinine was not dependent on acidification of the apical medium. Conclusions Creatinine was subjected to directional Transport across renal epithelial cells from the basolateral to apical side. The organic cation Transporter should be involved in the basolateral uptake of creatinine.
Satohiro Masuda - One of the best experts on this subject based on the ideXlab platform.
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Transcellular Transport of organic cations in double transfected mdck cells expressing human organic cation Transporters hoct1 hmate1 and hoct2 hmate1
Biochemical Pharmacology, 2008Co-Authors: Tomoko Sato, Satohiro Masuda, Toshiya Katsura, Atsushi Yonezawa, Yuko Tanihara, Kenichi InuiAbstract:Abstract To clarify the Transcellular Transport of organic cations via basolateral and apical Transporters, we established double-transfected Madin–Darby canine kidney (MDCK) cells expressing both human organic cation Transporter hOCT1 and hMATE1 (MDCK-hOCT1/hMATE1), and hOCT2 and hMATE1 (MDCK-hOCT2/hMATE1) as models of human hepatocytes and renal epithelial cells, respectively. Using the specific antibodies, hOCT1 and hMATE1 or hOCT2 and hMATE1 were found to be localized in the basolateral and apical membranes of MDCK-hOCT1/hMATE1 or MDCK-hOCT2/hMATE1 cells, respectively. A representative substrate, [ 14 C]tetraethylammonium, was Transported unidirectionally from the basolateral to apical side in these double transfectants. The optimal pH was showed to be 6.5 for the Transcellular Transport of [ 14 C]tetraethylammonium, when the pH of the incubation medium on the apical side was varied from 5.5 to 8.5. The basolateral-to-apical Transport also decreased in the presence of 10 mM 1-methyl-4-phenylpyridinium or 1 mM levofloxacin on the basolateral side of both double transfectants. In MDCK-hOCT2/hMATE1 cell monolayers, but not in MDCK-hOCT1/hMATE1 cell monolayers, the accumulation of [ 14 C]tetraethylammonium was decreased in the presence of 10 mM 1-methyl-4-phenylpyridinium, but significantly increased in the presence of 1 mM levofloxacin. The uptake of [ 14 C]tetraethylammonium, [ 3 H]1-methyl-4-phenylpyridinium, [ 14 C]metformin and [ 3 H]cimetidine, but not of [ 14 C]procainamide and [ 3 H]quinidine, by HEK293 cells was stimulated by expression of the hOCT1, hOCT2 or hMATE1 compared to control cells. However, Transcellular Transport of [ 14 C]procainamide and [ 3 H]quinidine was clearly observed in both double-transfectants. These cells could be useful for examining the routes by which compounds are eliminated, or predicting Transporter-mediated drug interaction.
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Transcellular Transport of organic cations in double-transfected MDCK cells expressing human organic cation Transporters hOCT1/hMATE1 and hOCT2/hMATE1.
Biochemical Pharmacology, 2008Co-Authors: Tomoko Sato, Satohiro Masuda, Toshiya Katsura, Atsushi Yonezawa, Yuko Tanihara, Kenichi InuiAbstract:Abstract To clarify the Transcellular Transport of organic cations via basolateral and apical Transporters, we established double-transfected Madin–Darby canine kidney (MDCK) cells expressing both human organic cation Transporter hOCT1 and hMATE1 (MDCK-hOCT1/hMATE1), and hOCT2 and hMATE1 (MDCK-hOCT2/hMATE1) as models of human hepatocytes and renal epithelial cells, respectively. Using the specific antibodies, hOCT1 and hMATE1 or hOCT2 and hMATE1 were found to be localized in the basolateral and apical membranes of MDCK-hOCT1/hMATE1 or MDCK-hOCT2/hMATE1 cells, respectively. A representative substrate, [ 14 C]tetraethylammonium, was Transported unidirectionally from the basolateral to apical side in these double transfectants. The optimal pH was showed to be 6.5 for the Transcellular Transport of [ 14 C]tetraethylammonium, when the pH of the incubation medium on the apical side was varied from 5.5 to 8.5. The basolateral-to-apical Transport also decreased in the presence of 10 mM 1-methyl-4-phenylpyridinium or 1 mM levofloxacin on the basolateral side of both double transfectants. In MDCK-hOCT2/hMATE1 cell monolayers, but not in MDCK-hOCT1/hMATE1 cell monolayers, the accumulation of [ 14 C]tetraethylammonium was decreased in the presence of 10 mM 1-methyl-4-phenylpyridinium, but significantly increased in the presence of 1 mM levofloxacin. The uptake of [ 14 C]tetraethylammonium, [ 3 H]1-methyl-4-phenylpyridinium, [ 14 C]metformin and [ 3 H]cimetidine, but not of [ 14 C]procainamide and [ 3 H]quinidine, by HEK293 cells was stimulated by expression of the hOCT1, hOCT2 or hMATE1 compared to control cells. However, Transcellular Transport of [ 14 C]procainamide and [ 3 H]quinidine was clearly observed in both double-transfectants. These cells could be useful for examining the routes by which compounds are eliminated, or predicting Transporter-mediated drug interaction.
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Transcellular Transport of creatinine in renal tubular epithelial cell line llc pk1
Drug Metabolism and Pharmacokinetics, 2005Co-Authors: Yumiko Urakami, Naoko Kimura, Masahiro Okuda, Satohiro Masuda, Toshiya Katsura, Kenichi InuiAbstract:Summary: Background /Aim Creatinine is excreted into urine via tubular secretion in addition to glomerular filtration. In the present study, characteristics of the creatinine Transport in renal epithelial cells were investigated. Methods The Transcellular Transport and accumulation of [ 14 C]creatinine and [ 14 C]tetraethylammonium (TEA) were assessed using LLC-PK 1 cell monolayers cultured on porous membrane filters. Results [ 14 C]Creatinine was Transported directionally from the basolateral to apical side of LLC-PK 1 cell monolayers. Basolateral uptake of [ 14 C]creatinine was dependent on membrane potential, and was saturable with apparent K m and V max values of 13.2±2.8 mM and 13.1 ± 3.1 nmol/mg protein/5min, respectively. Concomitant administration of organic cations (1 mM) such as cimetidine, quinidine and trimethoprim inhibited both the Transcellular Transport and accumulation of [ 14 C]creatinine. Furthermore, apical excretion of [ 14 C]creatinine was not dependent on acidification of the apical medium. Conclusions Creatinine was subjected to directional Transport across renal epithelial cells from the basolateral to apical side. The organic cation Transporter should be involved in the basolateral uptake of creatinine.
Gus R Rosania - One of the best experts on this subject based on the ideXlab platform.
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Transcellular Transport of heparin coated magnetic iron oxide nanoparticles hep mion under the influence of an applied magnetic field
Pharmaceutics, 2010Co-Authors: Faquan Yu, Victor C Yang, Xinyuan Zhang, Gus R RosaniaAbstract:In this study, magnetic iron oxide nanoparticles coated with heparin (Hep-MION) were synthesized and the Transcellular Transport of the nanoparticles across epithelial cell monolayers on porous polyester membranes was investigated. An externally applied magnetic field facilitated the Transport of the Hep-MION across cell monolayers. However, high Hep-MION concentrations led to an increased aggregation of nanoparticles on the cell monolayer after application of the magnetic field. Our results indicate that magnetic guidance of Hep-MION most effectively promotes Transcellular Transport under conditions that minimize formation of magnetically-induced nanoparticle aggregates. Across cell monolayers, the magnet’s attraction led to the greatest increase in mass Transport rate in dilute dispersions and in high serum concentrations, suggesting that magnetic guidance may be useful for in vivo targeting of Hep-MION.
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cells on pores a simulation driven analysis of Transcellular small molecule Transport
Molecular Pharmaceutics, 2010Co-Authors: Xinyuan Zhang, Nan Zheng, Juan P Hinestroza, Gus R RosaniaAbstract:A biophysical, computational model of cell pharmacokinetics (1CellPK) is being developed to enable prediction of the intracellular accumulation and Transcellular Transport properties of small molecules using their calculated physicochemical properties as input. To test if 1CellPK can generate accurate, quantitative hypotheses and guide experimental analysis of the Transcellular Transport kinetics of small molecules, epithelial cells were grown on impermeable polyester membranes with cylindrical pores and chloroquine (CQ) was used as a Transport probe. The effect of the number of pores and their diameter on Transcellular Transport of CQ was measured in apical-to-basolateral or basolateral-to-apical directions, at pH 7.4 and 6.5 in the donor compartment. Experimental and simulation results were consistent with a phospholipid bilayer-limited, passive diffusion Transport mechanism. In experiments and 1CellPK simulations, intracellular CQ mass and the net rate of mass Transport varied 10-fold, so by normalizing the net rate of mass Transport by the pore area available for Transport, cell permeability on 3µm pore diameter membranes was more than an order of magnitude less than on 0.4µm pore diameter membranes. The results of simulations of Transcellular Transport were accurate for the first four hours of drug exposure, but those of CQ mass accumulation were accurate only for the first five minutes. Upon prolonged incubation, changes in cellular parameters such as lysosome pH rise, lysosome volume expansion, and nuclear shrinkage were associated with excess CQ accumulation. Based on the simulations, lysosome volume expansion alone can partly account for the measured, total intracellular CQ mass increase, while adding the intracellular binding of the protonated, ionized forms of CQ (as reflected in the measured partition coefficient of CQ in detergent-permeabilized cells at physiological pH) can further improve the intracellular CQ mass accumulation prediction.
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A cell-based molecular Transport simulator for pharmacokinetic prediction and cheminformatic exploration.
Molecular Pharmaceutics, 2006Co-Authors: Xinyuan Zhang, Kerby Shedden, Gus R RosaniaAbstract:In the body, cell monolayers serve as permeability barriers, determining Transport of molecules from one organ or tissue compartment to another. After oral drug administration, for example, Transport across the epithelial cell monolayer lining the lumen of the intestine determines the fraction of drug in the gut that is absorbed by the body. By modeling passive Transcellular Transport properties in the presence of an apical to basolateral concentration gradient, we demonstrate how a computational, cell-based molecular Transport simulator can be used to define a physicochemical property space occupied by molecules with desirable permeability and intracellular retention characteristics. Considering extracellular domains of cell surface receptors located on the opposite side of a cell monolayer as a drug's desired site of action, simulation of Transcellular Transport can be used to define the physicochemical properties of molecules with maximal Transcellular permeability but minimal intracellular retention. ...
Ikumi Tamai - One of the best experts on this subject based on the ideXlab platform.
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experimental evidence for resecretion of pge2 across rat alveolar epithelium by oatp2a1 slco2a1 mediated Transcellular Transport
Journal of Pharmacology and Experimental Therapeutics, 2019Co-Authors: Takeo Nakanishi, Hiroki Takashima, Yuka Uetoko, Hisakazu Komori, Ikumi TamaiAbstract:Prostaglandin Transporter Oatp2a1/Slco2a1 is expressed at the apical (AP) membranes of type-1 alveolar epithelial (AT1) cells. To investigate the role of OATP2A1 in prostaglandin E2 (PGE2) handling by alveolar epithelium, we studied PGE2 Transport across and secretion from monolayers of rat AT1-like (AT1-L) cells obtained by trans-differentiation of type-2 alveolar epithelial cells isolated from male Wistar rats. Rat AT1-L cells expressed Oatp2a1/Slco2a1, together with smaller amounts of Mrp4/Abcc4 and Oct1/Slc22a1. PGE2 uptake was saturable with Km 43.9 ± 21.9 nM. Transcellular Transport of PGE2 across AT1-L cells grown on permeable filters in the AP-to-basolateral (BL) direction was 5-fold greater than that in the reverse direction and was saturable with Km 118 ± 26.8 nM; it was significantly inhibited by OATP inhibitors bromosulfophthalein (BSP) and suramin, and an MRP4 inhibitor, Ceefourin 1. We simultaneously monitored the effects of BSP on the distribution of PGE2 produced by bradykinin-treated AT1-L cells and PGE2-d4 externally added on the AP side of the cells. In the presence of BSP, PGE2 increased more rapidly on the AP side, whereas PGE2-d4 decreased more slowly on the AP side. The decrease in PGE2-d4 from the AP side corresponded well to the increase on the BL side, indicating that intracellular metabolism did not occur. These results suggest that Oatp2a1 and Mrp4 mediate transepithelial Transport of PGE2 in the AP-to-BL direction. Therefore, OATP2A1 may be an important regulator of PGE2 in alveolar epithelium by reducing secretion of PGE2 and facilitating “resecretion” of PGE2 present in the alveolar lumen to the interstitial space or blood.
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Experimental Evidence for Resecretion of PGE2 across Rat Alveolar Epithelium by OATP2A1/SLCO2A1-Mediated Transcellular Transport.
Journal of Pharmacology and Experimental Therapeutics, 2018Co-Authors: Takeo Nakanishi, Hiroki Takashima, Yuka Uetoko, Hisakazu Komori, Ikumi TamaiAbstract:Prostaglandin Transporter Oatp2a1/Slco2a1 is expressed at the apical (AP) membranes of type-1 alveolar epithelial (AT1) cells. To investigate the role of OATP2A1 in prostaglandin E2 (PGE2) handling by alveolar epithelium, we studied PGE2 Transport across and secretion from monolayers of rat AT1-like (AT1-L) cells obtained by trans-differentiation of type-2 alveolar epithelial cells isolated from male Wistar rats. Rat AT1-L cells expressed Oatp2a1/Slco2a1, together with smaller amounts of Mrp4/Abcc4 and Oct1/Slc22a1. PGE2 uptake was saturable with Km 43.9 ± 21.9 nM. Transcellular Transport of PGE2 across AT1-L cells grown on permeable filters in the AP-to-basolateral (BL) direction was 5-fold greater than that in the reverse direction and was saturable with Km 118 ± 26.8 nM; it was significantly inhibited by OATP inhibitors bromosulfophthalein (BSP) and suramin, and an MRP4 inhibitor, Ceefourin 1. We simultaneously monitored the effects of BSP on the distribution of PGE2 produced by bradykinin-treated AT1-L cells and PGE2-d4 externally added on the AP side of the cells. In the presence of BSP, PGE2 increased more rapidly on the AP side, whereas PGE2-d4 decreased more slowly on the AP side. The decrease in PGE2-d4 from the AP side corresponded well to the increase on the BL side, indicating that intracellular metabolism did not occur. These results suggest that Oatp2a1 and Mrp4 mediate transepithelial Transport of PGE2 in the AP-to-BL direction. Therefore, OATP2A1 may be an important regulator of PGE2 in alveolar epithelium by reducing secretion of PGE2 and facilitating “resecretion” of PGE2 present in the alveolar lumen to the interstitial space or blood.
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Stereoselective and Carrier-Mediated Transport of Monocarboxylic Acids Across Caco-2 Cells
Pharmaceutical Research, 1996Co-Authors: Takuo Ogihara, Hitomi Takanaga, Ikumi Tamai, Akira TsujiAbstract:Purpose. To characterize the Transport mechanism of monocarboxylic acids across intestinal epithelial cells by examining the stereoselectivity of the Transcellular Transport of several chiral monocarboxylic acids.
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Transcellular Transport of benzoic acid across caco 2 cells by a ph dependent and carrier mediated Transport mechanism
Pharmaceutical Research, 1994Co-Authors: Akira Tsuji, Hitomi Takanaga, Ikumi Tamai, Tetsuya TerasakiAbstract:The pH-dependent Transcellular Transport of [14 C]benzoic acid across a Caco-2 cell monolayer is shown to be mediated by a monocarboxylic acid-specific carrier-mediated Transport system, localized on the apical membrane. Evidence for the carrier-mediated Transport of benzoic acid includes (a) the significant temperature and concentration dependence, (b) the metabolic energy dependence, (c) the inhibition by unlabeled benzoic acid and other monocarboxylic acids, (d) counterTransport effects on the uptake of [14C]benzoic acid, and (e) effects of a proteinase (papain) and amino acid-modifying reagents. Furthermore, since carbonylcyanide p-trifluoromethoxyphenylhydrazone and nigericin significantly inhibited the Transport of [14C] benzoic acid, the direct driving force for benzoic acid Transport is suggested to be the inwardly directed proton gradient. From these results, together with previous observations using intestinal brush border membrane vesicles, the pH dependence of the Transcellular Transport of certain organic weak acids across Caco-2 cells is considered to result mainly from a proton gradient-dependent, carrier-mediated Transport mechanism, rather than passive diffusion according to the pH-partition theory.