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Ye F, Li X, Ni J, Xu X, Luo J, Zhong Y, Wang Y, Wang S, Zhang Y, Hu G, Qian J. Gene Polymorphisms and Drug-Drug Interactions Determine the Metabolic Profile of Blonanserin. J Pharmacol Exp Ther 2024; 388:190-200. [PMID: 37863485 DOI: 10.1124/jpet.123.001767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 09/29/2023] [Accepted: 10/04/2023] [Indexed: 10/22/2023] Open
Abstract
This study aimed to evaluate the effects of cytochrome P450 3A4 (CYP3A4) gene polymorphism and drug interaction on the metabolism of blonanserin. Human recombinant CYP3A4 was prepared using the Bac-to-Bac baculovirus expression system. A microsomal enzyme reaction system was established, and drug-drug interactions were evaluated using Sprague-Dawley rats. Ultra-performance liquid chromatography-tandem mass spectrometry was used to detect the concentrations of blonanserin and its metabolite. Compared with wild type CYP34A, the relative clearance of blonanserin by CYP3A4.29 significantly increased to 251.3%, while it decreased notably with CYP3A4.4, 5, 7, 8, 9, 10, 12, 13, 14, 16, 17, 18, 23, 24, 28, 31, 33, and 34, ranging from 6.09% to 63.34%. Among 153 tested drugs, nimodipine, felodipine, and amlodipine were found to potently inhibit the metabolism of blonanserin. Moreover, the inhibitory potency of nimodipine, felodipine, and amlodipine varied with different CYP3A4 variants. The half-maximal inhibitory concentration and enzymatic kinetics assay demonstrated that the metabolism of blonanserin was noncompetitively inhibited by nimodipine in rat liver microsomes and was inhibited in a mixed manner by felodipine and amlodipine in both rat liver microsomes and human liver microsomes. When nimodipine and felodipine were coadministered with blonanserin, the area under the blood concentration-time curve (AUC)(0-t), AUC(0-∞), and C max of blonanserin increased. When amlodipine and blonanserin were combined, the C max of blonanserin C increased remarkably. The vast majority of CYP3A4 variants have a low ability to catalyze blonanserin. With combined administration of nimodipine, felodipine, and amlodipine, the elimination of blonanserin was inhibited. This study provides the basis for individualized clinical use of blonanserin. SIGNIFICANCE STATEMENT: The enzyme kinetics of novel CYP3A4 enzymes for metabolizing blonanserin were investigated. Clearance of blonanserin by CYP3A4.4, 5, 7-10, 12-14, 16-18, 23-24, 28, 31, 33, and 34 decreased notably, but increased with CYP3A4.29. Additionally, we established a drug interaction spectrum for blonanserin, in which nimodipine, felodipine, and amlodipine kinetics exhibited mixed inhibition. Moreover, their inhibitory potencies decreased with CYP3A4.4 and 5 compared to CYP3A4.1. This study provides essential data for personalized clinical use of blonanserin.
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Affiliation(s)
- Feng Ye
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xinyue Li
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jinhuan Ni
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiaoyu Xu
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jianchao Luo
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yunshan Zhong
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yahui Wang
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Shiyu Wang
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yuqing Zhang
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Guoxin Hu
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jianchang Qian
- Institute of Molecular Toxicology and Pharmacology, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China
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Gao S, Yan N. Structural Basis of the Modulation of the Voltage-Gated Calcium Ion Channel Ca v 1.1 by Dihydropyridine Compounds*. Angew Chem Int Ed Engl 2021; 60:3131-3137. [PMID: 33125829 PMCID: PMC7898392 DOI: 10.1002/anie.202011793] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/28/2020] [Indexed: 12/29/2022]
Abstract
1,4-Dihydropyridines (DHP), the most commonly used antihypertensives, function by inhibiting the L-type voltage-gated Ca2+ (Cav ) channels. DHP compounds exhibit chirality-specific antagonistic or agonistic effects. The structure of rabbit Cav 1.1 bound to an achiral drug nifedipine reveals the general binding mode for DHP drugs, but the molecular basis for chiral specificity remained elusive. Herein, we report five cryo-EM structures of nanodisc-embedded Cav 1.1 in the presence of the bestselling drug amlodipine, a DHP antagonist (R)-(+)-Bay K8644, and a titration of its agonistic enantiomer (S)-(-)-Bay K8644 at resolutions of 2.9-3.4 Å. The amlodipine-bound structure reveals the molecular basis for the high efficacy of the drug. All structures with the addition of the Bay K8644 enantiomers exhibit similar inactivated conformations, suggesting that (S)-(-)-Bay K8644, when acting as an agonist, is insufficient to lock the activated state of the channel for a prolonged duration.
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MESH Headings
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/chemistry
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/metabolism
- Amlodipine/chemistry
- Amlodipine/metabolism
- Binding Sites
- Calcium Channel Agonists/chemistry
- Calcium Channel Agonists/metabolism
- Calcium Channel Blockers/chemistry
- Calcium Channel Blockers/metabolism
- Calcium Channels, L-Type/chemistry
- Calcium Channels, L-Type/metabolism
- Cryoelectron Microscopy
- Dihydropyridines/chemistry
- Dihydropyridines/metabolism
- Molecular Dynamics Simulation
- Nanostructures/chemistry
- Protein Structure, Tertiary
- Stereoisomerism
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Affiliation(s)
- Shuai Gao
- Department of Molecular BiologyPrinceton UniversityPrincetonNJ08544USA
| | - Nieng Yan
- Department of Molecular BiologyPrinceton UniversityPrincetonNJ08544USA
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Courlet P, Spaggiari D, Desfontaine V, Cavassini M, Alves Saldanha S, Buclin T, Marzolini C, Csajka C, Decosterd LA. UHPLC-MS/MS assay for simultaneous determination of amlodipine, metoprolol, pravastatin, rosuvastatin, atorvastatin with its active metabolites in human plasma, for population-scale drug-drug interactions studies in people living with HIV. J Chromatogr B Analyt Technol Biomed Life Sci 2019; 1125:121733. [PMID: 31374423 DOI: 10.1016/j.jchromb.2019.121733] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 07/02/2019] [Accepted: 07/24/2019] [Indexed: 11/17/2022]
Abstract
Thanks to highly active antiretroviral treatments, HIV infection is now considered as a chronic condition. Consequently, people living with HIV (PLWH) live longer and encounter more age-related chronic co-morbidities, notably cardiovascular diseases, leading to polypharmacy. As the management of drug-drug interactions (DDIs) constitutes a key aspect of the care of PLWH, the magnitude of pharmacokinetic DDIs between cardiovascular and anti-HIV drugs needs to be more thoroughly characterized. To that endeavour, an UHPLC-MS/MS bioanalytical method has been developed for the simultaneous determination in human plasma of amlodipine, metoprolol, pravastatin, rosuvastatin, atorvastatin and its active metabolites. Plasma samples were subjected to protein precipitation with methanol, followed by evaporation at room temperature under nitrogen of the supernatant, allowing to attain measurable plasma concentrations down to sub-nanogram per milliliter levels. Stable isotope-labelled analytes were used as internal standards. The five drugs and two metabolites were analyzed using a 6-min liquid chromatographic run coupled to electrospray triple quadrupole mass spectrometry detection. The method was validated over the clinically relevant concentrations ranging from 0.3 to 480 ng/mL for amlodipine, atorvastatin and p-OH-atorvastatin, and 0.4 to 480 ng/mL for pravastatin, 0.5 to 480 ng/mL for rosuvastatin and o-OH-atorvastatin, and 3 to 4800 ng/mL for metoprolol. Validation performances such as trueness (95.4-110.8%), repeatability (1.5-13.4%) and intermediate precision (3.6-14.5%) were in agreement with current international recommendations. Accuracy profiles (total error approach) were lying within the limits of ±30% accepted in bioanalysis. This rapid and robust UHPLC-MS/MS assay allows the simultaneous quantification in plasma of the major currently used cardiovascular drugs and offers an efficient analytical tool for clinical pharmacokinetics as well as DDIs studies.
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Affiliation(s)
- Perrine Courlet
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland.
| | - Dany Spaggiari
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland.
| | - Vincent Desfontaine
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland.
| | - Matthias Cavassini
- Service of Infectious Diseases, Lausanne University Hospital and University of Lausanne, Switzerland.
| | - Susana Alves Saldanha
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland.
| | - Thierry Buclin
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland.
| | - Catia Marzolini
- Departments of Medicine and Clinical Research, University Hospital of Basel and University of Basel, Switzerland.
| | - Chantal Csajka
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland; School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Switzerland.
| | - Laurent-Arthur Decosterd
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland.
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Imaoka A, Seki K, Akiyoshi T, Ohtani H. The extent of drug-drug interaction between amlodipine and activated charcoal is attenuated by food intake in rats. Drug Metab Pharmacokinet 2018; 34:108-110. [PMID: 30415897 DOI: 10.1016/j.dmpk.2018.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 08/14/2018] [Accepted: 08/23/2018] [Indexed: 11/19/2022]
Abstract
Activated charcoal decreases gastrointestinal absorption of concomitantly administered drugs. The absorption of amlodipine (AML) was reported as almost completely attenuated by 25 g of activated charcoal under a fasted condition, but not affected by 2 g of activated charcoal under a fed condition. However, it is not clear whether this difference resulted from the food intake or the dose of activated charcoal. The aim of this study was to quantitatively evaluate the effect of food intake on drug interactions caused by adsorption to activated charcoal in the gastrointestinal tract in rats. The rats were orally administered 0.08 mg/kg of AML, with or without 33 mg/kg of activated charcoal, under the fasted or fed condition and the plasma concentration profiles of AML were monitored. For the fed group, the standard breakfast used in clinical studies was smashed and administered at a dose of 11 g/kg. The AUC value of AML under the fasted condition was significantly decreased to 24.8% by coadministration of activated charcoal. On the other hand, activated charcoal moderately decreased the AUC value of AML to 74.8% under the fed condition. These results suggest that the extent of drug interactions caused by activated charcoal is attenuated by food intake.
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Affiliation(s)
- Ayuko Imaoka
- Division of Clinical Pharmacokinetics, Keio University Faculty of Pharmacy, 1-5-30, Shibakoen Minato-ku, Tokyo, 105-8512, Japan
| | - Kohei Seki
- Division of Clinical Pharmacokinetics, Keio University Faculty of Pharmacy, 1-5-30, Shibakoen Minato-ku, Tokyo, 105-8512, Japan
| | - Takeshi Akiyoshi
- Division of Clinical Pharmacokinetics, Keio University Faculty of Pharmacy, 1-5-30, Shibakoen Minato-ku, Tokyo, 105-8512, Japan
| | - Hisakazu Ohtani
- Division of Clinical Pharmacokinetics, Keio University Faculty of Pharmacy, 1-5-30, Shibakoen Minato-ku, Tokyo, 105-8512, Japan.
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Abstract
BACKGROUND AND OBJECTIVE Ginkgo leaf tablet (GLT) is an effective traditional Chinese multi-herbal formula, which is often combined with amlodipine for treating senile hypertension in clinic. The aim of this study was to study the pharmacokinetics of amlodipine after oral administration of amlodipine and GLT and to investigate the potential for pharmacokinetic herb-drug interactions between GLT and amlodipine in rats. METHODS A liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical method was developed for quantification of amlodipine in rat plasma. The accuracy, precision, linearity, selectivity and recovery were all within an acceptable range. Male Sprague-Dawley rats were randomly assigned to two groups: amlodipine group and amlodipine + GLT group. Plasma concentrations of amlodipine were determined at the designated time points after oral administration by using the developed LC-MS/MS method, and the main pharmacokinetic parameters were calculated and compared. As ginkgolides A, ginkgolides B, bilobalide, quercetin and kaempferol were the main components of GLT, the effects of these ingredients in GLT on metabolism of amlodipine were further investigated in rat liver microsomes. RESULTS The pharmacokinetic parameters, maximum plasma concentration (C max), time to reach C max (T max), area under the concentration-time curve (AUC), area under the first moment plasma concentration-time curve (AUMC) and elimination half-life (t 1/2), of amlodipine were significantly increased in amlodipine + GLT group, which suggested that GLT may influence the pharmacokinetic behavior after oral co-administration with amlodipine. Amlodipine is metabolized by cytochrome P450 (CYP) 3A4, so it was speculated that GLT may change the pharmacokinetic parameters of amlodipine through modulating the metabolism of CYP3A4 enzymes. When ginkgolides B, bilobalide, or quercetin and amlodipine were co-incubated in the rat liver microsomes, the metabolic rate of amlodipine was prolonged to 533.1, 216.1 and 407.6 min, respectively, from 73.7 min. CONCLUSIONS These results suggested that these components in GLT inhibit the metabolism of amlodipine. So it can be speculated that the herb-drug interactions between GLT and amlodipine resulted from inhibiting the metabolism of amlodipine by GLT when they were co-administered.
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Affiliation(s)
- Rong Wang
- Department of Pharmacy, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhi Zao Ju Rd, Shanghai, 200011, China
| | - Hai Zhang
- Department of Pharmacy, Eastern Hepatobiliary Surgery Hospital, School of Pharmacy, Second Military Medical University, Shanghai, 200438, China
| | - Sen Sun
- Department of Pharmacy, Eastern Hepatobiliary Surgery Hospital, School of Pharmacy, Second Military Medical University, Shanghai, 200438, China
| | - Yuanyuan Wang
- Department of Pharmacy, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhi Zao Ju Rd, Shanghai, 200011, China
| | - Yifeng Chai
- Department of Pharmaceutical Analysis, School of Pharmacy, Second Military Medical University, Shanghai, 200433, China
| | - Yongfang Yuan
- Department of Pharmacy, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhi Zao Ju Rd, Shanghai, 200011, China.
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Rehman SU, Choi MS, Kim IS, Luo Z, Xue Y, Yao G, Zhang Y, Yoo HH. In Vitro Assessment of CYP-Mediated Drug Interactions for Kinsenoside, an Antihyperlipidemic Candidate. Molecules 2016; 21:molecules21060800. [PMID: 27322236 PMCID: PMC6274256 DOI: 10.3390/molecules21060800] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 06/07/2016] [Accepted: 06/15/2016] [Indexed: 01/08/2023] Open
Abstract
Kinsenoside, the herb-derived medicine isolated from the plant Anoect chilus, has diverse pharmacological actions, and it is considered to be a promising antihyperlipidemic drug candidate. This study evaluates the effects of kinsenoside on CYP enzyme-mediated drug metabolism in order to predict the potential for kinsenoside-drug interactions. Kinsenoside was tested at different concentrations of 0.1, 0.3, 1, 3, 10, 30, and 100 µM in human liver microsomes. The c Cktail probe assay based on liquid chromatography-tandem mass spectrometry was conducted to measure the CYP inhibitory effect of kinsenoside. Subsequently, the metabolism profiles of amlodipine and lovastatin in human liver microsomes were analyzed following co-incubation with kinsenoside. The concentration levels of the parent drug and the major metabolites were compared with the kinsenoside-cotreated samples. The effect of kinsenoside was negligible on the enzyme activity of all the CYP isozymes tested even though CYP2A6 was slightly inhibited at higher concentrations. The drug-drug interaction assay also showed that the concomitant use of kinsenoside has a non-significant effect on the concentration of lovastatin or amlodipine, and their major metabolites. So, it was concluded that there is almost no risk of drug interaction between kinsenoside and CYP drug substrates via CYP inhibition.
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Affiliation(s)
- Shaheed Ur Rehman
- Institute of Pharmaceutical Science and Technology and College of Pharmacy, Hanyang University, Ansan Gyeonggi-do 426-791, Korea.
| | - Min Sun Choi
- Institute of Pharmaceutical Science and Technology and College of Pharmacy, Hanyang University, Ansan Gyeonggi-do 426-791, Korea.
| | - In Sook Kim
- Institute of Pharmaceutical Science and Technology and College of Pharmacy, Hanyang University, Ansan Gyeonggi-do 426-791, Korea.
| | - Zengwei Luo
- School of Pharmacy, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China.
| | - Yongbo Xue
- School of Pharmacy, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China.
| | - Guangming Yao
- School of Pharmacy, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China.
| | - Yonghui Zhang
- School of Pharmacy, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China.
| | - Hye Hyun Yoo
- Institute of Pharmaceutical Science and Technology and College of Pharmacy, Hanyang University, Ansan Gyeonggi-do 426-791, Korea.
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Housaindokht MR, Rouhbakhsh Zaeri Z, Bahrololoom M, Chamani J, Bozorgmehr MR. Investigation of the behavior of HSA upon binding to amlodipine and propranolol: Spectroscopic and molecular modeling approaches. Spectrochim Acta A Mol Biomol Spectrosc 2012; 85:79-84. [PMID: 22024455 DOI: 10.1016/j.saa.2011.09.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2011] [Revised: 09/07/2011] [Accepted: 09/08/2011] [Indexed: 05/31/2023]
Abstract
The interaction between human serum albumin (HSA) and two drugs - amlodipine and propranolol - was investigated using fluorescence, UV absorption and circular dichroism (CD) spectroscopy. In addition, the binding site was established by applying molecular modeling technique. Fluorescence data suggest that amlodipine will quench the intrinsic fluorescence of HSA; whereas propranolol enhances the fluorescence of HSA. The binding constants for the interaction of amlodipine and propranolol with HSA were found to be 3.63×10(5)M(-1) and 2.29×10(4)M(-1), respectively. The percentage of secondary structure feature of each one of the HSA-bound drugs, i.e. the α-helix content, was estimated empirically by circular dichroism. The results indicated that amlodipine causes an increase, and that propranolol leads to a decrease in α-helix content of HSA. The spectroscopic analysis indicates that the binding mechanisms of the two drugs are different from each other. The data obtained by the molecular modeling study indicated that these drugs bind, with different affinity, to different sites located in subdomain IIA and IIIA.
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Varghese SJ, Johny SK, Paul D, Ravi TK. In vitro interaction study of retinoic acid isomers with telmisartan and amlodipine by equilibrium dialysis method using UV spectroscopy. Spectrochim Acta A Mol Biomol Spectrosc 2011; 79:384-387. [PMID: 21489865 DOI: 10.1016/j.saa.2011.02.047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Accepted: 02/23/2011] [Indexed: 05/30/2023]
Abstract
The in vitro protein binding of retinoic acid isomers (isotretinoin and tretinoin) and the antihypertensive drugs (amlodipine and telmisartan) was studied by equilibrium dialysis method. In this study, free fraction of drugs and the % of binding of drugs in the mixture to bovine serum albumin (BSA) were calculated. The influence of retinoic acid isomers on the % of protein binding of telmisartan and amlodipine at physiological pH (7.4) and temperature (37±0.5°C) was also evaluated. The in vitro displacement interaction study of drugs telmisartan and amlodipine on retinoic acid isomers and also interaction of retinoic acid isomers on telmisartan and amlodipine were carried out.
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Affiliation(s)
- Susheel John Varghese
- Department of Pharmaceutical Analysis, College of Pharmacy, Sri Ramakrishna Institute of Paramedical Sciences, 395 Sarojini Naidu Road, Sidhapudur, Coimbatore 641 044, Tamil Nadu, India.
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Rousu T, Tolonen A. Characterization of cyanide-trapped methylated metabonates formed during reactive drug metabolite screening in vitro. Rapid Commun Mass Spectrom 2011; 25:1382-1390. [PMID: 21504003 DOI: 10.1002/rcm.5005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Reactive metabolites are estimated to be one of the main reasons behind unexpected drug-induced toxicity, by binding covalently to cell proteins or DNA. Due to their high reactivity and short lifespan, reactive metabolites are analyzed after chemical trapping with nucleophilic agents such as glutathione or cyanide. Recently, unexplained and uncharacterized methylated reaction products were reported in a human liver microsome based reactive metabolite trapping assay utilizing potassium cyanide as a trapping agent. Here, a similar assay was utilized to produce mono- or dimethylated and further cyanide-trapped reaction products from propranolol, amlodipine and ciprofloxacin, followed by ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC/TOF-MS) and ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) experiments for their more detailed structural elucidation. Formation of all observed cyanide-trapped products was clearly NADPH-dependent and thus metabolism-mediated. The suggested reaction pathways included N-methylation leading to iminium formation in primary and/or secondary amines preceded by cytochrome P450 (CYP)-mediated reactions. As the methylation reaction was suggested to be involved in formation of the actual reactive iminium ion, the observed cyanide-trapped products were experimental artifacts rather than trapped reactive metabolites. The results stress that to avoid overestimating the formation of reactive metabolites in vitro, this methylation phenomenon should be taken into account when interpreting the results of cyanide-utilizing reactive metabolite trapping assays. This in turn emphasizes the importance of identification of the observed cyano conjugates during such studies. Yet, metabolite identification has a high importance to avoid overestimation of in vitro metabolic clearance in the cases where this kind of metabonate formation has a high impact in the disappearance rate of the compound.
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Affiliation(s)
- Timo Rousu
- Department of Chemistry, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland
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Meier M, Blatter XL, Seelig A, Seelig J. Interaction of verapamil with lipid membranes and P-glycoprotein: connecting thermodynamics and membrane structure with functional activity. Biophys J 2006; 91:2943-55. [PMID: 16877510 PMCID: PMC1578493 DOI: 10.1529/biophysj.106.089581] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Verapamil and amlodipine are calcium ion influx inhibitors of wide clinical use. They are partially charged at neutral pH and exhibit amphiphilic properties. The noncharged species can easily cross the lipid membrane. We have measured with solid-state NMR the structural changes induced by verapamil upon incorporation into phospholipid bilayers and have compared them with earlier data on amlodipine and nimodipine. Verapamil and amlodipine produce a rotation of the phosphocholine headgroup away from the membrane surface and a disordering of the fatty acid chains. We have determined the thermodynamics of verapamil partitioning into neutral and negatively charged membranes with isothermal titration calorimetry. Verapamil undergoes a pK-shift of DeltapK(a) = 1.2 units in neutral lipid membranes and the percentage of the noncharged species increases from 5% to 45%. Verapamil partitioning is increased for negatively charged membranes and the binding isotherms are strongly affected by the salt concentration. The electrostatic screening can be explained with the Gouy-Chapman theory. Using a functional phosphate assay we have measured the affinity of verapamil, amlodipine, and nimodipine for P-glycoprotein, and have calculated the free energy of drug binding from the aqueous phase to the active center of P-glycoprotein in the lipid phase. By combining the latter results with the lipid partitioning data it was possible, for the first time, to determine the true affinity of the three drugs for the P-glycoprotein active center if the reaction takes place exclusively in the lipid matrix.
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Affiliation(s)
- M Meier
- Department of Biophysical Chemistry, Biozentrum, University of Basel, Basel, Switzerland
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Kohlmann O, Oigman W, Mion D, Rocha JC, Gomes MAM, Salgado N, Feitosa GS, Dallaverde E, Ribeiro AB. Estudo "LOTHAR": avaliação de eficácia e tolerabilidade da combinação fixa de anlodipino e losartana no tratamento da hipertensão arterial primária. Arq Bras Cardiol 2006; 86:39-51. [PMID: 16491208 DOI: 10.1590/s0066-782x2006000100007] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE The LOTHAR study evaluated medium and long term (one year) efficacy, tolerability and metabolic effects of the fixed combination of amlodipine and losartan compared to amlodipine or losartan alone. METHODS Brazilian multicenter, randomized, double-blind and comparative trial performed with 198 patients in stage 1 and 2 essential hypertension. RESULTS The fixed combination has a high antihypertensive efficacy that is sustained in the long term with very low percentage of loss of blood pressure control. This percentage is incidentally lower than that of the two monotherapy comparative regimens. In the long term, more than 60% of the patients treated with the fixed combination remained with DBP < or = 85 mmHg, and the antihypertensive effect, when assessed by ABPM persisted for 24 hours with a trough-to-peak ratio of 76.7%. The frequency of adverse events was quite low in this group, and the long-term incidence of leg edema was approximately four-fold lower than that observed with amlodipine alone. The fixed combination did not change glucose and lipid metabolism in the medium or in the long term. CONCLUSION Based on these results, we can say that the combination of amlodipine and losartan--the first fixed combination of a calcium channel blocker and an angiotensin II receptor blocker available in the pharmaceutical market, is an excellent option for the treatment of a wide range of hypertensive patients.
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Ersoy C, Imamoğlu S, Budak F, Tuncel E, Ertürk E, Oral B. Effect of amlodipine on insulin resistance & tumor necrosis factor-alpha levels in hypertensive obese type 2 diabetic patients. Indian J Med Res 2004; 120:481-8. [PMID: 15591634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023] Open
Abstract
BACKGROUND & OBJECTIVES Tumour necrosis factor-alpha (TNF-alpha) has been suggested to play a key role in insulin resistance (IR) in obesity and may contribute to the development of type 2 diabetes mellitus. Recently, studies are focused on the effect of antihypertensive drugs on insulin sensitivity and cytokines. We undertook this study to evaluate the effect of amlodipine, a long-acting dihydropyridine calcium channel blocker treatment on TNF-alpha, homeostasis model assessment (HOMA) IR and leptin levels in obese hypertensive type 2 diabetic patients. METHODS Amlodipine 5-10 mg for 12 wk was given to type 2 diabetic patients in the amlodipine group. Pre- and post-treatment values of laboratory parameters in the amlodipine group were compared with those of normotensive nondiabetic obese controls. At baseline blood pressures (BP) and metabolic parameters were measured in all patients and repeated after 12 wk in the amlodipine group. RESULTS Basal waist-to-hip ratio, systolic and diastolic BPs, fasting glucose, TNF-alpha and HOMAIR values of the amlodipine group were higher than the control group. No difference was detected in body mass index, fasting insulin, hemoglobin A1c and leptin values between groups. The systolic and diastolic BPs, fasting glucose, HOMA-IR and TNF-alpha values decreased significantly after the treatment. But, there was no correlation between percentage change in TNF-alpha and HOMA-IR. INTERPRETATION & CONCLUSION Besides reducing BP, amlodipine seemed to improve IR and decrease TNF-alpha levels. In this context, these properties may provide additional benefits of antihypertensive drug regimens chosen for this population, but larger group interventions are needed.
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Affiliation(s)
- Canan Ersoy
- Department of Endocrinology & Metabolism, Uludağ University Medical School, Bursa, Turkey.
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13
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Libhaber EN, Libhaber CD, Candy GP, Sliwa K, Kachope J, Hlatshwayo NM, Puane MO, Woodiwiss AJ, Norton GR, Essop MR, Sareli P. Effect of slow-release indapamide and perindopril compared with amlodipine on 24-hour blood pressure and left ventricular mass in hypertensive patients of African ancestry. Am J Hypertens 2004; 17:428-32. [PMID: 15110902 DOI: 10.1016/j.amjhyper.2004.02.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2003] [Accepted: 02/10/2004] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND In the treatment of hypertension in subjects of African origins, although hydrochlorothiazide (HCTZ) is not as effective as calcium channel blockers, indapamide is superior to HCTZ. In the present study we therefore compared the effects of slow release (SR) indapamide with the calcium channel blocker amlodipine, when used as initial therapy, on blood pressure (BP) and left ventricular mass (LVM) during 6 months of treatment in this group. METHODS Patients with a mean daytime ambulatory diastolic BP > or =90 mm Hg and < or =110 mm Hg (n = 125, aged 53 +/- 11 years, 68% women) were randomized to receive open-label 1.5 mg of indapamide SR or 5 mg of amlodipine. If daytime ambulatory diastolic BP at 1 month was >/=90 mm Hg, 4 mg of perindopril was added to indapamide SR or the dose of amlodipine was increased to 10 mg. RESULTS After 1 month of therapy, there was an equivalent decline in systolic and diastolic BP in both groups (P <.0001). In the indapamide-treated group (n = 62) the daytime BP decreased from 153 +/- 12/101 +/- 6 mm Hg to 138 +/- 15/92 +/- 10 mm Hg and for amlodipine (n = 58), it decreased from 152 +/- 13/99 +/- 5 mm Hg to 138 +/- 12/91 +/- 8 mm Hg. At 6 months daytime ambulatory BP decreased to 130 +/- 15/86 +/- 8 mm Hg and to 129 +/- 11/85 +/- 5 mm Hg for the indapamide SR (n = 42) and amlodipine (n = 44) treatment groups, respectively. Both groups showed equivalent regression of LVM index and relative wall thickness. CONCLUSIONS These data suggest that in hypertensive patients of African ancestry initiating therapy with 1.5 mg of indapamide SR and then adding 4 mg of perindopril is equally as effective as amlodipine therapy at reducing BP, and modifying target organ damage.
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Affiliation(s)
- Elena N Libhaber
- Department of Cardiology, Chris-Hani Baragwanath Hospital, University of the Witwatersrand, PO Bertsham, Johannesburg 2013, South Africa.
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Wu YJ, Pan YX, Zeng S. [Determination of amlodipine in CYP3A4 cDNA-expressed cells by HPLC]. Zhejiang Da Xue Xue Bao Yi Xue Ban 2004; 32:510-3. [PMID: 14712515 DOI: 10.3785/j.issn.1008-9292.2003.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To establish a RP-HPLC method for the determination of amlodipine after metabolism by cytochrome P450 cDNA-expressed cells. METHODS The determination was performed on a C(18) reversed phase column with a mobile phase composed of acetonitrile phosphates buffer (45:55, v/v, pH 4.5) with UV detection (lambda250nm). Propranolol was used as the internal standard. RESULT The standard curve was linear over the concentration range of 0.2 - 30.0 microg/ml (r=0.9993), and the limits of determination was 20 ng/ml (S/N >or=3), the limits of quantity was 0.2 microg/ml (recovery 104.0%, RSD 11.4%, n=5). The recovery for this assay was (98.2+/-2.4)%, precision for inter-assay and intra-assay was <10 % and 6 %, respectively. CONCLUSION The HPLC method established is simple, accurate and suitable for the determination of amlodipine in cytochrome p450 cDNA-expressed cells.
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Affiliation(s)
- Yong-jiang Wu
- Department of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310031, China
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15
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Cominacini L, Fratta Pasini A, Garbin U, Pastorino AM, Davoli A, Nava C, Campagnola M, Rossato P, Lo Cascio V. Antioxidant activity of different dihydropyridines. Biochem Biophys Res Commun 2003; 302:679-84. [PMID: 12646222 DOI: 10.1016/s0006-291x(03)00158-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lacidipine, a dihydropyridine-based calcium antagonist (DHP), has already been demonstrated to possess antioxidant activity and to reduce the intracellular production of reactive oxygen species (ROS). To verify if this effect is a peculiarity of this molecule, or belongs to other DHPs, the activity of lacidipine was compared with those of amlodipine, lercanidipine, nimodipine, and nifedipine. The DHPs were incorporated in bovine aortic endothelial cells (BAECs). Cu(2+)-oxidized LDL (ox-LDL, 5 microM) was incubated with BAECs for 5 min. 2',7'-Dichlorofluorescein (DCF) as expression of intracellular ROS production was measured by flow cytometry. Ox-LDL induced a strong increase in intracellular ROS formation (p<0.001) that was significantly reduced only with lacidipine and lercanidipine (p from <0.05 to <0.01); the effect of lacidipine, however, resulted in being much more evident than lercanidipine (p<0.01); amlodipine, nimodopine, and nifedipine had no effect on ROS formation. The lowest IC50s, i.e. the concentrations determining the 50% reduction of ROS, were obtained with lacidipine (p<0.01). The inhibitory effect of lacidipine on ox-LDL-induced ROS production in endothelial cells is a peculiarity of this molecule through its antioxidant activity.
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Affiliation(s)
- Luciano Cominacini
- Dipartimento di Scienze Biomediche Chirurgiche, c/o Medicina Interna D-Ospedale Policlinico, Università di Verona, Verona 37134 Italy.
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16
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Szász G. [Pharmaceutical chemistry of "dipines"]. Acta Pharm Hung 2003; 72:156-65. [PMID: 12494786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
The paper gives an overview on the pharmaceutical chemistry of of dihydropyridine Ca-antagonists through the chapters of history and preparation, structure and properties, metabolism, therapeutical use and analysis. In the author's concept the paper represents a model for postgraduate education. Consequently, after proper volume-cutting, it covers the complete material for undergraduate courses.
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Affiliation(s)
- György Szász
- Semmelweis Egyetem, Gyógyszerészi Kémiai Intézet, Budapest, Hógyes E. u. 9.-1092
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Yamada S, Nakajima M, Kusaka T, Uchida S, Kimura R. In vivo receptor binding of benidipine and amlodipine in mesenteric arteries and other tissues of spontaneously hypertensive rats. Life Sci 2002; 70:1999-2011. [PMID: 12148692 DOI: 10.1016/s0024-3205(01)01541-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The present study was undertaken to characterize the in vivo 1,4-dihydropyridine (DHP) receptor binding of long-acting 1,4-DHP calcium channel antagonists in the mesenteric artery and other tissues of SHR. In vivo specific binding of (+)-[3H]PN 200-110 in the SHR mesenteric artery was significantly (36.6-49.7 %) reduced 1-8 h after oral administration of benidipine (1.84 micromol/kg). A greater reduction in (+)-[3H]PN 200-110 binding in the mesenteric artery was observed at a higher dose (5.53 micromol/kg) of this drug. This dose of benidipine also reduced significantly the in vivo specific (+)-[3H]PN 200-110 binding in the aorta but not in the myocardium and cerebral cortex. Following oral administration of amlodipine (17.6 micromol/kg), a significant (51.7-94.2 %) reduction in (+)-[3H]PN 200-110 binding was seen at 1-18 h in the mesenteric artery and at 1-12 h in the aorta. Only a slight reduction in myocardial and cerebral cortical (+)-[3H]PN 200-110 binding was seen following amlodipine administration. In contrast, oral administration of nifedipine (28.9 micromol/kg) reduced markedly in vivo (+)-[3H]PN 200-110 binding in all the tissues of SHR at 1-6 h, and the degree and time-course of the reduction did not differ significantly among the tissues. The area under the curve (AUC) for the receptor occupancy vs time was calculated from the reduction rate (%) of in vivo specific (+)-[3H]PN 200-110 binding. The ratios of the AUCmesenteric artery to AUCaorta or AUCmesenteric artery to AUCmyocardium after oral administration of benidipine and amlodipine were greater than the corresponding value for nifedipine. The degree and time-course of arterial receptor occupancy by benidipine and amlodipine agreed well with those of their hypotensive effects in the conscious SHR. In conclusion, the present study demonstrates that benidipine and amlodipine may occupy, in a more selective and sustained manner, 1,4-DHP receptors in arterial tissues than in other tissues of SHR, and thus, such receptor binding specificity may be responsible for the long-lasting hypotensive effects of these drugs.
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Affiliation(s)
- Shizuo Yamada
- Department of Biopharmacy, School of Pharmaceutical Sciences, University of Shizuoka, Japan.
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18
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Abstract
Coronary artery disease (CAD) is the result of atherosclerosis, a vascular disorder characterized by abnormalities in vasoconstriction and endothelial function, ultimately leading to partial or complete vessel occlusion. Because the atherosclerotic plaque is marked by changes in calcium regulation, there has been interest in a potential antiatherosclerotic role for calcium antagonists. In support of this hypothesis, a recent clinical study demonstrated in patients with CAD that treatment with the lipophilic dihydropyridine-type calcium antagonist amlodipine resulted in significantly fewer cardiovascular procedures and events. The Prospective Randomized Evaluation of the Vascular Effects of Norvasc Trial (PREVENT) evaluated the effects of amlodipine on the development and progression of atherosclerotic lesions in coronary and carotid arteries in 825 patients with documented CAD. The results of PREVENT showed that patients receiving amlodipine had marked reductions in hospitalization for revascularization and unstable angina compared with placebo in a population consisting of either normotensive or controlled hypertensive patients. Ultrasound approaches determined that amlodipine therapy was also associated with significant slowing in carotid atherosclerosis-an important surrogate marker for CAD-over the 3-year period. This vascular-wall benefit associated with amlodipine treatment was not related to changes in blood pressure. The findings from PREVENT were consistent with a second reported study known as the Coronary Angioplasty Amlodipine Restenosis Study (CAPARES). These clinical results have led to an interest in potential plaque-stabilization properties of this lipophilic calcium antagonist. In this article, cellular and molecular mechanisms of action that may contribute to a beneficial role for a calcium antagonist in the treatment of atherosclerosis will be reviewed.
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Affiliation(s)
- R P Mason
- Membrane Biophysics Laboratory, Division of Cardiology, Department of Medicine and Biochemistry, Medical College of Pennsylvania-Hahnemann University School of Medicine, Pittsburgh, Pennsylvania, USA.
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19
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Avdonin PV, Buhler FR, Tkachuk VA. Ca2+-agonistic effect of a T-type Ca-channel blocker mibefradil (Ro 40-5967). Membr Cell Biol 2001; 13:645-55. [PMID: 10987388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Here we report that a Ca2+ antagonist mibefradil (Ro 40-5967) which has been shown to be a selective inhibitor of T-type calcium channels increases free calcium concentration ([Ca2+]i) in the cytoplasm of cultured smooth muscle cells isolated from porcine coronary artery. Smooth muscle cells were loaded with Fura 2 and a videoimage system was used to follow the [Ca2+]i responses. It was shown that at a concentration of 1 nM mibefradil induced a transient [Ca2+]i elevation in individual cells and at a concentration of 100 nM this compound stimulated almost all the cells in monolayer. The [Ca2+]i response did not change with the further increase of the mibefradil concentration up to 10 microM. The half-maximal effect was observed at 10 nM. The increase in [Ca2+]i strongly depended on the presence of Ca in the extracellular medium. Calcium antagonists belonging to three different classes--verapamil (phenylalkylamines), diltiazem (benzothiazepines) and amlodipin (dihydropyridines) neither suppressed the mibefradil effect nor mimicked it. These data indicate that mibefradil increased [Ca2+]i acting via a distinct receptor site. We suggest that these receptors are coupled to calcium channels of plasma membrane.
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Affiliation(s)
- P V Avdonin
- Koltsov Institute of Developmental Biology, Russian Academy of Sciences, Moscow.
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20
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Qu YL, Sugiyama K, Ohnuki T, Hattori K, Watanabe K, Nagatomo T. Comparison of binding affinities of omega-conotoxin and amlodipine to N-type Ca2+ channels in rat brain. Zhongguo Yao Li Xue Bao 1998; 19:97-100. [PMID: 10374627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
AIM To compare the binding affinities of omega-conotoxin (CTX) and amlodipine to N-type Ca2+ channels in rat brains. METHODS Whole rat brains were homogenized in HEPES buffer 50 mmol.L-1 (pH 7.4) and centrifuged at 40,000 x g to obtain the membrane-entriched fraction. 125I-omega-conotoxin (125I-omega-CTX) was used as a radioligand. Using radioligand binding assay Kd and Bmax values of the radioligand were determined by Scatchard analysis. The IC50 value for each drug was obtained from displacement experiments. RESULTS No differences in Bmax values of 125I-omega-CTX binding sites between frozen and fresh tissues were observed. Values of Kd and Bmax of N-type Ca2+ channels were 0.02 +/- 0.01 nmol.L-1 and 1029 +/- 108 pmol/g protein, respectively. The pKi values of omega-CTX and amlodipine were 9.57 and less than 4, respectively. The pKi values of propranolol, prazosin, atropine, and histamine were very low. CONCLUSION The binding affinity of the L-type Ca(2+)-antagonist amlodipine to N-type Ca2+ channels in the rat brain was very low.
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Affiliation(s)
- Y L Qu
- Department of Pharmacology, Niigata College of Pharmacy, Japan
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21
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Dollé F, Hinnen F, Valette H, Fuseau C, Duval R, Péglion JL, Crouzel C. Synthesis of two optically active calcium channel antagonists labelled with carbon-11 for in vivo cardiac PET imaging. Bioorg Med Chem 1997; 5:749-64. [PMID: 9158874 DOI: 10.1016/s0968-0896(97)00024-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
(+/-)-S11568 (1, 3-ethyl-5-methyl-(+/-)-2-[(2-(2-aminoethoxy)ethoxy) methyl]-4-(2,3-dichlorophenyl)-6-methyl-1,4-dihydropyridine-3, 5-dicarboxylate), has an in vitro profile of high potency and of high selectivity for the low-voltage dependent. L-type calcium channel. In in vitro binding studies, it displaced specifically bound (-)-[3H]PN 200-110 (isradipine (2), the reference molecule for in vitro studies) from cardiac and vascular smooth muscle preparations with potencies of 5.6 and 51 nM, respectively. It also appears as a pure pharmacological antagonist acting at a single channel L-type and free of any interaction at the benzothiazepine binding site such as amlodipine (3). Both enantiomers of S11568 have in vitro activities, the dextro isomer S12967 ((+)-1) being 6 to 18-fold less potent than the levo one S12968 ((-)-1). Two couples of optically active labelling precursors of S11568, ((-)-10/(+)-10 and (-)-14/(+)-14) have been synthesized using a modified Hantzsch's dihydropyridine synthesis. In both cases, the enantiomers were separated by preparative chiral HPLC. They both have been independently labelled with carbon-11, using [11C]diazomethane or [11C]iodomethane to give multimilliCurie quantities of (-)-1 (S12968) and (+)-1 (S12967) with high specific activities (500-1000 mCi/mumol, 18.5-37.0 GBq/mumol). Both enantiomers appear suitable for PET experiments: their myocardial concentration increases after a bolus injection to reach a maximum in 2 min and then remains on a plateau with a slight downslope while the blood concentration falls rapidly. Myocardial uptake was threefold higher than lung uptake, leading to a good contrast on PET images. The present preliminary biological results obtained in Beagle dogs showed that both enantiomers have similar myocardial kinetics and in vivo affinity for the left ventricular myocardium.
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Affiliation(s)
- F Dollé
- Service Hospitalier Frédéric Joliot, CEA, Orsay, France
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22
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Abstract
Drug metabolism input to the discovery process had historically been on an empirical case-by-case basis, since, detailed descriptors of the effect on pharmacokinetics of a change in structure or physicochemical property were not available. Considerable advances have been made in recent years, such that basic rules can be applied to predict the behavior of a compound in man based on physicochemistry and structure. This is particularly true in the areas of absorption, distribution, and clearance. In particular, knowledge of the reactions catalyzed by the enzymes of drug metabolism, including the cytochrome P450 super family, can be used in the design of new chemical entities, together with the usual pharmacological-derived SAR. The combination of both pharmacokinetics and pharmacodynamics at the discovery stage leads to drugs with optimum performance characteristics. Such drugs are easier to develop, representing a huge saving in resources. Moreover, the marketed compound is much more likely to find high clinical utilization. This review uses dofetilide, fluconazole, and amlodipine to highlight the multifaceted consequences of changing chemical structure, in terms of drug disposition, and reinforces these principles with examples from the literature.
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Affiliation(s)
- D A Smith
- Department of Drug Metabolism, Pfizer Central Research, Sandwich, Kent, U.K
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23
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Sugiyama K, Qu YL, Maruyama K, Hattori K, Watanabe K, Nagatomo T. Slow dissociation of long-acting Ca2+ antagonist amlodipine from 3H-PN200-110 binding sites in membranes of rat hearts and brains. Biol Pharm Bull 1996; 19:195-8. [PMID: 8850304 DOI: 10.1248/bpb.19.195] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The dissociation rate of amlodipine ((+/-)-3-ethyl 5-methyl 2-[(2-aminoethoxy)methyl]-4-(o-chlorophenyl)-1,4-dihydro-6-methyl- 3,5- pyridinedicarboxylate benzenesulfonate) from rat heart and brain membranes preincubated with drugs and washed out with buffer was assessed by radioligand binding assay using 3H-PN200-110 as a radioligand. The remaining KCl-induced contraction in rat aortic strips washed out after treatment with this drug and the pKi (inhibition constant) values of the drug were compared with those of nisoldipine, nifedipine, manidipine and benidipine. The inhibition of 3H-PN200-110 binding induced by nifedipine was reversed by washing, whereas that induced by amlodipine, manidipine, and benidipine was not readily reversed under these conditions. When rat aortic strips were pretreated with Ca2+ antagonists, the rank order of the inhibition of contractions induced by 50 mM KCl was manidipine = benidipine > amlodipine > nisoldipine > nifedipine, even though Ca2+ antagonists were not present in the extracellular medium. The pKi values of amlodipine in the heart and brain were 6.86 and 7.41, respectively, and these values were lower than those of the other Ca2+ antagonists. There was a good correlation between the potency of the inhibition of 3H-PN200-110 binding by drugs after the washout of membranes and the inhibition exerted by the drugs in contractions induced by 50 mM KCl after the washout of tissues, although this residual inhibition was not correlated with pKi values. Thus, these results suggest that amlodipine has a very slow rate of dissociation from 3H-PN200-110 binding sites, as do manidipine and benidipine, and this property may explain its long-lasting antihypertensive effect.
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Affiliation(s)
- K Sugiyama
- Department of Pharmacology, Niigata College of Pharmacy, Japan
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24
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Qu YL, Sugiyama K, Hattori K, Yamamoto A, Watanabe K, Nagatomo T. Slow association of positively charged Ca2+ channel antagonist amlodipine to dihydropyridine receptor sites in rat brain membranes. Gen Pharmacol 1996; 27:137-40. [PMID: 8742511 DOI: 10.1016/0306-3623(95)00085-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
1. No significant differences were observed in Kd and Bmax values between pH 7.2 (0.16 +/- 0.01 nM and 155.36 +/- 16.07 fmol/mg protein) and pH 10.0 (0.15 +/- 0.01 nM and 158.63 +/- 13.80 fmol/mg protein) in rat brain membranes. 2. The IC50 ratios at 0- and 270-min preincubations of amlodipine and manidipine at pH 7.2 were 23.09 and 10.25, respectively, whereas these ratios for these two drugs at pH 10.0 were 2.63 and 1.34, respectively. 3. In contrast, on treatment with nisoldipine, benidipine, SM-6586 and nifedipine, no significant differences were observed in the IC50 ratios between 0- and 270-min preincubations at pH 7.2 and 10.0.
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Affiliation(s)
- Y L Qu
- Department of Pharmacology, Niigata College of Pharmacy, Japan
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25
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Abstract
1. In an isolated perfused rat liver (IPRL) model, the extensive hepatic uptake and subsequent slow redistribution of amlodipine into the perfusate have been demonstrated. The apparent liver volume for amlodipine was 920 ml compared with 38ml for nitrendipine. 2. Metabolism is the major clearance mechanism of amlodipine and nitrendipine in animals and man. In the IPRL, the intrinsic (metabolic) clearance and first-pass extraction values for amlodipine are similar to those of nitrendipine. This is in contrast with in vitro metabolic stability data in rat liver microsomes which indicate about 40-fold greater metabolic stability for amlodipine. 3. The discrepancy between relative clearance rates for the two preparations may be explained by consideration of the hepatic volume of the two compounds, with the higher liver volume of amlodipine amplifying the whole organ clearance.
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Affiliation(s)
- D K Walker
- Department of Drug Metabolism, Pfizer Central Research, Sandwich, UK
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26
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Abstract
The present study was undertaken to examine whether plasma concentrations of amlodipine, a calcium antagonist, and its diuretic effects vary with the time of dosage. Pharmacokinetic study; 20 mg/kg of amlodipine was given orally to rats at 10 am (day trial) or 10 pm (night trial), and blood samples were obtained during a 24-hour period. Pharmacodynamic study; two doses (10 and 20 mg/kg) of amlodipine were given orally at 10 am or 10 pm by a cross-over design, and urine was collected for 12 hours after dosage. Rats were maintained under condition of light from 7 am to 7 pm. The following results were obtained; The tmax of amlodipine was shorter and the Cmax was greater in the night trial than in the day trial. Its diuretic effects were greater in the night trial. These results suggest that the pharmacokinetic and pharmacodynamic profiles of amlodipine vary with its time of dosage.
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Affiliation(s)
- A Fujimura
- Department of Clinical Pharmacology, Jichi Medical School Tochigi, Japan
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