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Sun X, Tang S, Hou B, Duan Z, Liu Z, Li Y, He S, Wang Q, Chang Q. Overexpression of P-glycoprotein, MRP2, and CYP3A4 impairs intestinal absorption of octreotide in rats with portal hypertension. BMC Gastroenterol 2021; 21:2. [PMID: 33407159 PMCID: PMC7789354 DOI: 10.1186/s12876-020-01532-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 11/09/2020] [Indexed: 02/08/2023] Open
Abstract
Background Portal hypertension (PH) is the main cause of complications and death in liver cirrhosis. The effect of oral administration of octreotide (OCT), a drug that reduces PH by the constriction of mesenteric arteries, is limited by a remarkable intestinal first-pass elimination.
Methods The bile duct ligation (BDL) was used in rats to induce liver cirrhosis with PH to examine the kinetics and molecular factors such as P-glycoprotein (P-gp), multidrug resistance-associated protein 2 (MRP2) and cytochrome P450 3A4 (CYP3A4) influencing the intestinal OCT absorption via in situ and in vitro experiments on jejunal segments, transportation experiments on Caco-2 cells and experiments using intestinal microsomes and recombinant human CYP3A4. Moreover, RT-PCR, western blot, and immunohistochemistry were performed. Results Both in situ and in vitro experiments in jejunal segments showed that intestinal OCT absorption in both control and PH rats was largely controlled by P-gp and, to a lesser extent, by MRP2. OCT transport mediated by P-gp and MRP2 was demonstrated on Caco-2 cells. The results of RT-PCR, western blot, and immunohistochemistry suggested that impaired OCT absorption in PH was in part due to the jejunal upregulation of these two transporters. The use of intestinal microsomes and recombinant human CYP3A4 revealed that CYP3A4 metabolized OCT, and its upregulation in PH likely contributed to impaired drug absorption. Conclusions Inhibition of P-gp, MRP2, and CYP3A4 might represent a valid option for decreasing intestinal first-pass effects on orally administered OCT, thereby increasing its bioavailability to alleviate PH in patients with cirrhosis.
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Affiliation(s)
- Xiaoyu Sun
- Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, 0086-116011, China
| | - Shunxiong Tang
- Department of Invasive Technology, Affiliated Zhongshan Hospital of Dalian University, Dalian, China
| | - Binbin Hou
- Department of Dermatology, Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Zhijun Duan
- Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, 0086-116011, China.
| | - Zhen Liu
- Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, 0086-116011, China
| | - Yang Li
- Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, China.,Department of Breast Surgery, Hospital of Chinese Medical University, Liaoning Provincial Cancer Institute and Hospital, Shenyang, China
| | - Shoucheng He
- Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, 0086-116011, China
| | - Qiuming Wang
- Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, 0086-116011, China
| | - Qingyong Chang
- Department of Neurosurgery, Affiliated Zhongshan Hospital of Dalian University, Dalian, China.
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Prabhala BK, Rahman M, Nour-Eldin HH, Jørgensen FS, Mirza O. PTR2/POT/NPF transporters: what makes them tick? ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2020; 123:219-240. [PMID: 33485485 DOI: 10.1016/bs.apcsb.2020.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PTR2/POT/NPF are a family of primarily proton coupled transporters that belong to the major facilitator super family and are found across most kingdoms of life. They are involved in uptake of nutrients, hormones, ions and several orally administered drug molecules. A wealth of structural and functional data is available for this family; the similarity between the protein structural features have been discussed and investigated in detail on several occasions, however there are no reports on the unification of substrate information. In order to fill this gap, we have collected information about substrates across the entire PTR2/POT/NPF family in order to provide key insights into what makes a molecule a substrate and whether there are common features among confirmed substrates. This review will be of particular interest for researchers in the field trying to probe the mechanisms responsible for the different selectivity of these transporters at a molecular resolution, and to design novel substrates.
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Affiliation(s)
- Bala K Prabhala
- Institute of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense, Denmark
| | - Moazur Rahman
- School of Biological Sciences, University of the Punjab, Lahore, Punjab, Pakistan; Drug Discovery and Structural Biology Group, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Punjab, Pakistan
| | - Hussam H Nour-Eldin
- DynaMo Center, Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Flemming Steen Jørgensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Osman Mirza
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Kamiya Y, Otsuka S, Miura T, Yoshizawa M, Nakano A, Iwasaki M, Kobayashi Y, Shimizu M, Kitajima M, Shono F, Funatsu K, Yamazaki H. Physiologically Based Pharmacokinetic Models Predicting Renal and Hepatic Concentrations of Industrial Chemicals after Virtual Oral Doses in Rats. Chem Res Toxicol 2020; 33:1736-1751. [PMID: 32500706 DOI: 10.1021/acs.chemrestox.0c00009] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Recently developed high-throughput in vitro assays in combination with computational models could provide alternatives to animal testing. The purpose of the present study was to model the plasma, hepatic, and renal pharmacokinetics of approximately 150 structurally varied types of drugs, food components, and industrial chemicals after virtual external oral dosing in rats and to determine the relationship between the simulated internal concentrations in tissue/plasma and their lowest-observed-effect levels. The model parameters were based on rat plasma data from the literature and empirically determined pharmacokinetics measured after oral administrations to rats carried out to evaluate hepatotoxic or nephrotic potentials. To ensure that the analyzed substances exhibited a broad diversity of chemical structures, their structure-based location in the chemical space underwent projection onto a two-dimensional plane, as reported previously, using generative topographic mapping. A high-throughput in silico one-compartment model and a physiologically based pharmacokinetic (PBPK) model consisting of chemical receptor (gut), metabolizing (liver), central (main), and excreting (kidney) compartments were developed in parallel. For 159 disparate chemicals, the maximum plasma concentrations and the areas under the concentration-time curves obtained by one-compartment models and modified simple PBPK models were closely correlated. However, there were differences between the PBPK modeled and empirically obtained hepatic/renal concentrations and plasma maximal concentrations/areas under the concentration-time curves of the 159 chemicals. For a few compounds, the lowest-observed-effect levels were available for hepatotoxicity and nephrotoxicity in the Hazard Evaluation Support System Integrated Platform in Japan. The areas under the renal or hepatic concentration-time curves estimated using PBPK modeling were inversely associated with these lowest-observed-effect levels. Using PBPK forward dosimetry could provide the plasma/tissue concentrations of drugs and chemicals after oral dosing, thereby facilitating estimates of nephrotoxic or hepatotoxic potential as a part of the risk assessment.
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Affiliation(s)
- Yusuke Kamiya
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, 3-3165 Higashi-tamagawa Gakuen, Machida, Tokyo 194-8543, Japan
| | - Shohei Otsuka
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, 3-3165 Higashi-tamagawa Gakuen, Machida, Tokyo 194-8543, Japan
| | - Tomonori Miura
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, 3-3165 Higashi-tamagawa Gakuen, Machida, Tokyo 194-8543, Japan
| | - Manae Yoshizawa
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, 3-3165 Higashi-tamagawa Gakuen, Machida, Tokyo 194-8543, Japan
| | - Ayane Nakano
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, 3-3165 Higashi-tamagawa Gakuen, Machida, Tokyo 194-8543, Japan
| | - Miyu Iwasaki
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, 3-3165 Higashi-tamagawa Gakuen, Machida, Tokyo 194-8543, Japan
| | - Yui Kobayashi
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, 3-3165 Higashi-tamagawa Gakuen, Machida, Tokyo 194-8543, Japan
| | - Makiko Shimizu
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, 3-3165 Higashi-tamagawa Gakuen, Machida, Tokyo 194-8543, Japan
| | - Masato Kitajima
- Fujitsu Kyusyu Systems, Higashi-hie, Hakata-ku, Fukuoka 812-0007, Japan
| | - Fumiaki Shono
- Department of Chemical System Engineering, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kimito Funatsu
- Department of Chemical System Engineering, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Hiroshi Yamazaki
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, 3-3165 Higashi-tamagawa Gakuen, Machida, Tokyo 194-8543, Japan
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Sun XY, Duan ZJ, Liu Z, Tang SX, Li Y, He SC, Wang QM, Chang QY. Inhibition of P-glycoprotein, multidrug resistance-associated protein 2 and cytochrome P450 3A4 improves the oral absorption of octreotide in rats with portal hypertension. Exp Ther Med 2017; 12:3716-3722. [PMID: 28105103 DOI: 10.3892/etm.2016.3808] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 07/28/2016] [Indexed: 12/28/2022] Open
Abstract
The aim of the present study was to increase the intestinal transport of octreotide (OCT) by targeting the first-pass impact to identify a potential method for decreasing portal vein pressure (PVP) using oral OCT. Thus, the bioavailability of intestinally absorbed OCT was evaluated in normal rats and rats with portal hypertension (PH) that had been administered P-glycoprotein/multidrug resistance-associated protein 2/cytochrome P450 3A4 (P-gp/MRP2/CYP3A4) inhibitors. The mRNA and protein expression levels of P-gp, MRP2 and CYP3A4 were evaluated in normal and PH rats with or without OCT and the inhibitors using RT-PCR, western blot and immunohistochemical analyses. The potential effects of the inhibitor administration on PVP were also examined. The results suggest that P-gp, MRP2 and CYP3A4 play important roles in prohibiting the enteral absorption of OCT, particularly under a PH environment. Moreover, inhibitors of P-gp, MRP2 and CYP3A4 decrease the first-pass effects of OCT and effectively reduce PVP under PH conditions. Therefore, the present results suggest P-gp, MRP2 and CYP3A4 are key factors in the intestinal absorption of OCT. The inhibition of P-gp, MRP2 and CYP3A4 can markedly decrease the first-pass effects of OCT, and their use may facilitate the use of orally administered OCT.
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Affiliation(s)
- Xiao-Yu Sun
- Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Zhi-Jun Duan
- Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Zhen Liu
- Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Shun-Xiong Tang
- Department of Invasive Technology, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning 116001, P.R. China
| | - Yang Li
- Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning 116023, P.R. China; Department of Breast Surgery, Liaoning Cancer Hospital & Institute, Shenyang, Liaoning 110042, P.R. China
| | - Shou-Cheng He
- Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Qiu-Ming Wang
- Department of Gastroenterology, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Qing-Yong Chang
- Department of Neurosurgery, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning 116001, P.R. China
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Wang H, Sun P, Wang C, Meng Q, Liu Z, Huo X, Sun H, Ma X, Peng J, Liu K. Liver uptake of cefditoren is mediated by OATP1B1 and OATP2B1 in humans and Oatp1a1, Oatp1a4, and Oatp1b2 in rats. RSC Adv 2017. [DOI: 10.1039/c7ra03537c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
OATPs and Oatps mediated liver uptake of cefditoren in humans and in rats.
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Dioscin protects against ANIT–induced cholestasis via regulating Oatps, Mrp2 and Bsep expression in rats. Toxicol Appl Pharmacol 2016; 305:127-135. [DOI: 10.1016/j.taap.2016.06.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 06/04/2016] [Accepted: 06/13/2016] [Indexed: 12/17/2022]
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Peters SA, Jones CR, Ungell AL, Hatley OJD. Predicting Drug Extraction in the Human Gut Wall: Assessing Contributions from Drug Metabolizing Enzymes and Transporter Proteins using Preclinical Models. Clin Pharmacokinet 2016; 55:673-96. [PMID: 26895020 PMCID: PMC4875961 DOI: 10.1007/s40262-015-0351-6] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Intestinal metabolism can limit oral bioavailability of drugs and increase the risk of drug interactions. It is therefore important to be able to predict and quantify it in drug discovery and early development. In recent years, a plethora of models-in vivo, in situ and in vitro-have been discussed in the literature. The primary objective of this review is to summarize the current knowledge in the quantitative prediction of gut-wall metabolism. As well as discussing the successes of current models for intestinal metabolism, the challenges in the establishment of good preclinical models are highlighted, including species differences in the isoforms; regional abundances and activities of drug metabolizing enzymes; the interplay of enzyme-transporter proteins; and lack of knowledge on enzyme abundances and availability of empirical scaling factors. Due to its broad specificity and high abundance in the intestine, CYP3A is the enzyme that is frequently implicated in human gut metabolism and is therefore the major focus of this review. A strategy to assess the impact of gut wall metabolism on oral bioavailability during drug discovery and early development phases is presented. Current gaps in the mechanistic understanding and the prediction of gut metabolism are highlighted, with suggestions on how they can be overcome in the future.
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Affiliation(s)
- Sheila Annie Peters
- Translational Quantitative Pharmacology, BioPharma, R&D Global Early Development, Merck KGaA, Frankfurter Str. 250, F130/005, 64293, Darmstadt, Germany.
| | | | - Anna-Lena Ungell
- Investigative ADME, Non-Clinical Development, UCB New Medicines, BioPharma SPRL, Braine l'Alleud, Belgium
| | - Oliver J D Hatley
- Simcyp Limited (A Certara Company), Blades Enterprise Centre, Sheffield, UK
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8
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Benzylpenicillin inhibits the renal excretion of acyclovir by OAT1 and OAT3. Pharmacol Rep 2014; 65:505-12. [PMID: 23744435 DOI: 10.1016/s1734-1140(13)71026-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 11/02/2012] [Indexed: 11/23/2022]
Abstract
BACKGROUND Acyclovir is acyclic guanosine derivative. Benzylpenicillin (PCG) is a β-lactam antibiotic. The purpose of this study was to investigate the pharmacokinetic drug-drug interaction (DDI) between PCG and acyclovir. METHOD When acyclovir and PCG were co-administered, plasma concentration of acyclovir, urinary excretion of acyclovir in vivo, uptake of acyclovir in kidney slices and uptake of acyclovir in human (h) OAT1/hOAT3- HEK293 cells were determined to examine the effect of PCG on urinary excretion of acyclovir. RESULTS The plasma concentration of acyclovir was increased markedly and accumulative renal excretion and renal clearance of acyclovir were decreased significantly after intravenous administration of acyclovir in combination with PCG. PCG could decrease the uptake of acyclovir in kidney slices and in hOAT1-/hOAT3-human embryonic kidney (HEK293) cells. CONCLUSIONS It indicates that acyclovir is a substrate for OAT1 and OAT3. PCG inhibits the renal excretion of acyclovir by inhibiting renal transporters OAT1 and OAT3 in vivo and in vitro. These results suggest important information for DDI between PCG and acyclovir in kidney.
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9
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Intestinal drug transporters: an overview. Adv Drug Deliv Rev 2013; 65:1340-56. [PMID: 23041352 DOI: 10.1016/j.addr.2012.09.042] [Citation(s) in RCA: 203] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 09/21/2012] [Accepted: 09/24/2012] [Indexed: 02/07/2023]
Abstract
The importance of drug transporters as one of the determinants of pharmacokinetics has become increasingly evident. While much research has been conducted focusing the role of drug transporters in the liver and kidney less is known about the importance of uptake and efflux transporters identified in the intestine. Over the past years the effects of intestinal transporters have been studied using in vivo models, in situ organ perfusions, in vitro tissue preparations and cell lines. This review aims to describe up to date findings regarding the importance of intestinal transporters on drug absorption and bioavailability, highlighting areas in need of further research. Wu and Benet proposed a Biopharmaceutics Drug Disposition Classification System (BDDCS) that allows the prediction of transporter effects on the drug disposition of orally administered drugs. This review also discusses BDDCS predictions with respect to the role of intestinal transporters and intestinal transporter-metabolizing enzyme interplay on oral drug pharmacokinetics.
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Xu Q, Wang C, Meng Q, Liu Q, Sun H, Peng J, Ma X, Kaku T, Liu K. OAT1 and OAT3: targets of drug-drug interaction between entecavir and JBP485. Eur J Pharm Sci 2013; 48:650-7. [PMID: 23313623 DOI: 10.1016/j.ejps.2012.12.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 11/24/2012] [Accepted: 12/19/2012] [Indexed: 12/29/2022]
Abstract
Entecavir and JBP485 (a dipeptide) exhibit the antihepatitis activities and it is possible for the two drugs to be coadministered in the treatment of hepatitis. We aimed to elucidate whether entecavir was a substrate of OAT1, OAT3, OCT, and PEPT1 and to investigate the targets of drug-drug interactions between entecavir and JBP485. Plasma and urine concentrations of entecavir following intravenous and oral administration in vivo, uptake of entecavir in kidney slices and transfected cells in vitro, were determined by LC-MS/MS. Following intravenous co-administration of entecavir and JBP485 in rats, entecavir AUC increased 1.93-fold, t1/2β was prolonged 2.08-fold, CLP decreased 49%, CLR decreased 73%, and accumulated urinary excretion decreased 54%. However, following oral co-administration, the entecavir Tmax and Cmax were not affected; the degree of change in other pharmacokinetic parameters (AUC, t1/2β, CLP, and accumulated urinary excretion) was similar to that of intravenous administration. The uptake of entecavir was nearly identical in hPEPT1- as in vector-HELA cells. In rat kidney slices, uptake of entecavir was markedly inhibited by p-aminohippurate, benzylpenicillin, JBP485, and tetraethyl ammonium. In hOAT1- and hOAT3-HEK293 cells, uptake of entecavir was significantly higher compared to vector-HEK293 cells and was markedly inhibited by p-aminohippurate, benzylpenicillin, and JBP485. Km and Vmax values of entecavir were 250 μM and 0.83 nmol/mg protein/30s (OAT1) and 23 μM and 1.1 nmol/mg protein/30 s (OAT3), respectively. Entecavir is the substrate of OAT1, OAT3, and OCT. Moreover, OAT1 and OAT3 are the targets of DDI between entecavir and JBP485.
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Affiliation(s)
- Qinghan Xu
- Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, China
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Miao Q, Liu Q, Wang C, Meng Q, Guo X, Sun H, Peng J, Ma X, Kaku T, Liu K. Inhibitory effect of 1α,25-dihydroxyvitamin D3 on excretion of JBP485 via organic anion transporters in rats. Eur J Pharm Sci 2013. [DOI: 10.1016/j.ejps.2012.11.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Zhu Y, Meng Q, Wang C, Liu Q, Sun H, Kaku T, Liu K. Organic anion transporters involved in the excretion of bestatin in the kidney. Peptides 2012; 33:265-71. [PMID: 22273603 DOI: 10.1016/j.peptides.2012.01.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 01/10/2012] [Accepted: 01/10/2012] [Indexed: 01/11/2023]
Abstract
Bestatin, a dipeptide, a low molecular weight aminopeptidase inhibitor, has been demonstrated to be an immunomodulator with an antitumor activity. However, the transporter-mediated renal excretion of bestatin is not fully understood. The purpose of this study was to elucidate the transporter-mediated renal excretion mechanism for bestatin. The plasma concentration of bestatin was increased markedly and both the accumulative renal excretion and renal clearance of bestatin were decreased significantly after intravenous administration of bestatin in combination with probenecid. p-Aminohippuric acid (PAH), a substrate of organic anion transporter (OAT) 1, benzylpenicillin (PCG), a substrate of OAT3 and JBP485, a substrate of OAT1 and OAT3, reduced the uptake of bestatin in rat kidney slices and in hOAT1- or hOAT3-HEK 293 cells. The accumulation of bestatin in hOAT1-HEK and hOAT3-HEK 293 cells was significantly greater than that in vector-HEK, and the K(m) and V(max) were 0.679 ± 0.007 mM and 0.807 ± 0.006 nmol/mg protein/30s for OAT1, 0.632 ± 0.014 mM and 1.303 ± 0.015 nmol/mg protein/30s for OAT3 respectively. PAH and JBP485 inhibited significantly the uptake of bestatin in hOAT1-HEK with the K(i) values of 92 ± 9 μM and 197 ± 21 μM; and PCG, JBP485 inhibited significantly the uptake of bestatin in hOAT3-HEK 293 cells with the K(i) values of 88 ± 12 μM and 160 ± 16 μM. Our results are novel in demonstrating for the first time that OAT1 and OAT3 are involved in the renal excretion of bestatin.
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Affiliation(s)
- Yanna Zhu
- Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Lvshunkou District, Dalian, China
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