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TMAO Suppresses Megalin Expression and Albumin Uptake in Human Proximal Tubular Cells Via PI3K and ERK Signaling. Int J Mol Sci 2022; 23:ijms23168856. [PMID: 36012119 PMCID: PMC9407713 DOI: 10.3390/ijms23168856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/22/2022] [Accepted: 07/23/2022] [Indexed: 11/23/2022] Open
Abstract
Trimethylamine-N-oxide (TMAO) is a uremic toxin, which has been associated with chronic kidney disease (CKD). Renal tubular epithelial cells play a central role in the pathophysiology of CKD. Megalin is an albumin-binding surface receptor on tubular epithelial cells, which is indispensable for urine protein reabsorption. To date, no studies have investigated the effect of TMAO on megalin expression and the functional properties of human tubular epithelial cells. The aim of this study was first to identify the functional effect of TMAO on human renal proximal tubular cells and second, to unravel the effects of TMAO on megalin-cubilin receptor expression. We found through global gene expression analysis that TMAO was associated with kidney disease. The microarray analysis also showed that megalin expression was suppressed by TMAO, which was also validated at the gene and protein level. High glucose and TMAO was shown to downregulate megalin expression and albumin uptake similarly. We also found that TMAO suppressed megalin expression via PI3K and ERK signaling. Furthermore, we showed that candesartan, dapagliflozin and enalaprilat counteracted the suppressive effect of TMAO on megalin expression. Our results may further help us unravel the role of TMAO in CKD development and to identify new therapeutic targets to counteract TMAOs effects.
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Evaluation of the high affinity [ 18F]fluoropyridine-candesartan in rats for PET imaging of renal AT 1 receptors. Nucl Med Biol 2021; 96-97:41-49. [PMID: 33798796 DOI: 10.1016/j.nucmedbio.2021.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 03/01/2021] [Accepted: 03/11/2021] [Indexed: 11/23/2022]
Abstract
INTRODUCTION Alterations in the expression of the Angiotensin II type 1 receptors (AT1R) have been demonstrated in the development of several heart and renal diseases. The aim of this study was to evaluate the novel compound [18F]fluoropyridine-candesartan as a PET imaging tracer of AT1R in rat kidneys. METHODS Competition binding assays were carried out with membranes from CHO-K1 cells expressing human AT1R. Binding to plasma proteins was assessed by ultrafiltration. Radiolabeled metabolites in rat plasma and kidneys of control and pretreated animals (candesartan 10 mg/kg or losartan 30 mg/kg) were analyzed by column-switch HPLC. Dynamic PET/CT images of [18F]fluoropyridine-candesartan in male Sprague-Dawley rats were acquired for 60 min at baseline, pre-treatment with the AT1R antagonist losartan (30 mg/kg) or the AT2R antagonist PD123,319 (5 mg/kg). RESULTS Fluoropyridine-candesartan bound with a high affinity for AT1R (Ki = 5.9 ± 1.1 nM), comparable to fluoropyridine-losartan but lower than the parent compound candesartan (Ki = 0.4 ± 0.1 nM). [18F]Fluoropyridine-candesartan bound strongly to plasma proteins (99.3%) and was mainly metabolized to radiolabeled hydrophilic compounds, displaying minimal interference on renal AT1R binding with 82% of unchanged tracer in the kidneys at 20 min post-injection. PET imaging displayed high renal and liver accumulations and slow clearances, with maximum tissue-to-blood ratios of 14 ± 3 and 54 ± 12 in kidney cortex and liver, respectively, at 10 min post-injection. Binding specificity for AT1R was demonstrated with marked reductions in kidney cortex (-84%) and liver (-93%) tissue-to-blood ratios at 20 min post-injection, when blocking with AT1R antagonist losartan (30 mg/kg). No change was observed in kidney cortex of rats pre-treated with AT2R antagonist PD 123,319 (5 mg/kg), confirming binding selectivity for AT1 over AT2 receptors. CONCLUSION High kidney-to-blood ratios and binding selectivity to renal AT1R combined with tracer in vivo stability displaying minimal interference from labeled metabolites support further PET imaging studies with [18F]fluoropyridine-candesartan.
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IJzerman AP, Guo D. Drug-Target Association Kinetics in Drug Discovery. Trends Biochem Sci 2019; 44:861-871. [PMID: 31101454 DOI: 10.1016/j.tibs.2019.04.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 03/28/2019] [Accepted: 04/08/2019] [Indexed: 02/07/2023]
Abstract
The important role of ligand-receptor binding kinetics in drug design and discovery is increasingly recognized by the drug research community. Over the past decade, accumulating evidence has shown that optimizing the ligand's dissociation rate constant can lead to desirable duration of in vivo target occupancy and, hence, improved pharmacodynamic properties. However, the association rate constant as a pharmacological principle remains less investigated, whereas it can play an equally important role in the selection of drug candidates. This review provides a compilation and discussion of otherwise scarce and dispersed information on this topic, bringing to light the importance of drug-target association in kinetics-directed drug design and discovery.
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Affiliation(s)
- Adriaan P IJzerman
- Division of Drug Discovery and Safety, Leiden Academic Centre for Drug Research (LACDR), Leiden University, P.O. Box 9502, 2300, RA, Leiden, The Netherlands
| | - Dong Guo
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China.
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Zhao D, Liu H, Dong P. A Meta-analysis of antihypertensive effect of telmisartan versus candesartan in patients with essential hypertension. Clin Exp Hypertens 2018; 41:75-79. [PMID: 29589977 DOI: 10.1080/10641963.2018.1445750] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The comparison of antihypertensive effects between telmisartan and candesartan in patients with essential hypertension has been investigated in several small studies. The results were not consistent. We performed this meta-analysis determining the antihypertensive effect of telmisartan versus candesartan in these patients. METHODS We searched Pubmed, Web of Science, and Cochrane Central for all published studies comparing the antihypertensive effects between telmisartan and candesartan in patients with essential hypertension. RESULTS The antihypertensive effects were assessed in 302 patients included in 4 trials with a mean follow-up of 10 ± 4 weeks. There were no significant differences between telmisartan and candesartan in reduction of systolic blood pressure (SBP) and diastolic BP (DBP) in patients with essential hypertension (weighted mean differences (WMD) for SBP 1.98 mm Hg (95% confidence interval (CI), -0.53, 4.49), p > 0.05; WMD for DBP 0.26 mm Hg (95% CI, -1.65, 2.16), p > 0.05), respectively. In a sub-analysis including 2 randomized studies, there was not a significant difference for the reduction of SBP (WMD 0.90 (95% CI, -2.88, 4.68) mm Hg, p > 0.05) or DBP (WMD -0.80 (95% CI, -3.40, 1.81) mm Hg, p > 0.05) treated with telmisartan or candesartan. CONCLUSIONS This meta-analysis provides the evidence that the antihypertensive effects of telmisartan and candesartan are similar on SBP and DBP reduction in patients with essential hypertension, suggesting that strict designed randomized controlled trial would be helpful to compare antihypertensive effects of angiotensin II receptor blockers (ARBs) and improve the choice of ARBs in antihypertensive therapy.
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Affiliation(s)
- Di Zhao
- a Division of Hypertension , the First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology , Luoyang , China
| | - Hui Liu
- b Division of Endocrinology , Luoyang Central Hospital Affiliated to Zhengzhou University , Luoyang , China
| | - Pingshuan Dong
- c Division of Cardiology , the First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology , Luoyang , China
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Guan Q, Sun Q, Wen L, Zha Z, Yang Y, Wang Z. The synthesis of benzimidazoles via a recycled palladium catalysed hydrogen transfer under mild conditions. Org Biomol Chem 2018; 16:2088-2096. [DOI: 10.1039/c8ob00323h] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
An efficient synthesis of benzimidazoles was developed by virtue of a recycled palladium catalyzed hydrogen transfer.
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Affiliation(s)
- Qianqian Guan
- Hefei National Laboratory for Physical Sciences at Microscale
- Center for Excellence in Molecular Synthesis of Chinese Academy of Sciences
- Collaborative Innovation Center of Suzhou Nano Science and Technology & Department of Chemistry
- University of Science and Technology of China
- Hefei
| | - Qi Sun
- Hefei National Laboratory for Physical Sciences at Microscale
- Center for Excellence in Molecular Synthesis of Chinese Academy of Sciences
- Collaborative Innovation Center of Suzhou Nano Science and Technology & Department of Chemistry
- University of Science and Technology of China
- Hefei
| | - Lixian Wen
- Hefei National Laboratory for Physical Sciences at Microscale
- Center for Excellence in Molecular Synthesis of Chinese Academy of Sciences
- Collaborative Innovation Center of Suzhou Nano Science and Technology & Department of Chemistry
- University of Science and Technology of China
- Hefei
| | - Zhenggen Zha
- Hefei National Laboratory for Physical Sciences at Microscale
- Center for Excellence in Molecular Synthesis of Chinese Academy of Sciences
- Collaborative Innovation Center of Suzhou Nano Science and Technology & Department of Chemistry
- University of Science and Technology of China
- Hefei
| | - Yu Yang
- Hefei National Laboratory for Physical Sciences at Microscale
- Center for Excellence in Molecular Synthesis of Chinese Academy of Sciences
- Collaborative Innovation Center of Suzhou Nano Science and Technology & Department of Chemistry
- University of Science and Technology of China
- Hefei
| | - Zhiyong Wang
- Hefei National Laboratory for Physical Sciences at Microscale
- Center for Excellence in Molecular Synthesis of Chinese Academy of Sciences
- Collaborative Innovation Center of Suzhou Nano Science and Technology & Department of Chemistry
- University of Science and Technology of China
- Hefei
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Busse LW, McCurdy MT, Ali O, Hall A, Chen H, Ostermann M. The effect of angiotensin II on blood pressure in patients with circulatory shock: a structured review of the literature. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2017; 21:324. [PMID: 29282149 PMCID: PMC5745607 DOI: 10.1186/s13054-017-1896-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 11/28/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND Circulatory shock is a common syndrome with a high mortality and limited therapeutic options. Despite its discovery and use in clinical and experimental settings more than a half-century ago, angiotensin II (Ang II) has only been recently evaluated as a vasopressor in distributive shock. We examined existing literature for associations between Ang II and the resolution of circulatory shock. METHODS We searched PubMed, MEDLINE, Ovid, and Embase to identify all English literature accounts of intravenous Ang II in humans for the treatment of shock (systolic blood pressure [SBP] ≤ 90 mmHg or a mean arterial pressure [MAP] ≤ 65 mmHg), and hand-searched the references of extracted papers for further studies meeting inclusion criteria. Of 3743 articles identified, 24 studies including 353 patients met inclusion criteria. Complete data existed for 276 patients. Extracted data included study type, publication year, demographics, type of shock, dosing of Ang II or other vasoactive medications, and changes in BP, lactate, and urine output. BP effects were grouped according to type of shock, with additional analyses completed for patients with absent blood pressure. Shock was distributive (n = 225), cardiogenic (n = 38), or from other causes (n = 90). Blood pressure as absent in 18 patients. RESULTS For the 276 patients with complete data, MAP rose by 23.4% from 63.3 mmHg to 78.1 mmHg in response to Ang II (dose range: 15 ng/kg/min to 60 mcg/min). SBP rose by 125.2% from 56.9 mmHg to 128.2 mmHg (dose range: 0.2 mcg/min to a 1500 mcg bolus). A total of 271 patients with complete data were determined to exhibit a BP effect which was directly associated with Ang II. Subgroups (patients with cardiogenic, septic, and other types of shock) exhibited similar increases in BP. In patients with absent BP, deemed to be cardiac arrest, return of spontaneous circulation (ROSC) was achieved, and BP increased by an average of 107.3 mmHg in 11 of 18 patients. The remaining seven patients with cardiac arrest did not respond. CONCLUSIONS Intravenous Ang II is associated with increased BP in patients with cardiogenic, distributive, and unclassified shock. A role may exist for Ang II in restoring circulation in cardiac arrest.
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Affiliation(s)
- Laurence W Busse
- Department of Medicine, Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Emory University, Emory St. Joseph's Hospital, 5665 Peachtree Dunwoody Road, Atlanta, GA, 30342, USA.
| | - Michael T McCurdy
- Division of Pulmonary & Critical Care, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Osman Ali
- Division of Pulmonary & Critical Care, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Anna Hall
- Department of Critical Care, King's College London, Guy's & St Thomas' NHS Foundation Hospital, London, SE1 7EH, UK
| | - Huaizhen Chen
- Department of Medicine, Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Emory University, Emory St. Joseph's Hospital, 5665 Peachtree Dunwoody Road, Atlanta, GA, 30342, USA
| | - Marlies Ostermann
- Department of Critical Care, King's College London, Guy's & St Thomas' NHS Foundation Hospital, London, SE1 7EH, UK
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Zeilinger M, Pichler F, Nics L, Wadsak W, Spreitzer H, Hacker M, Mitterhauser M. New approaches for the reliable in vitro assessment of binding affinity based on high-resolution real-time data acquisition of radioligand-receptor binding kinetics. EJNMMI Res 2017; 7:22. [PMID: 28271461 PMCID: PMC5340791 DOI: 10.1186/s13550-016-0249-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 12/15/2016] [Indexed: 12/02/2022] Open
Abstract
Background Resolving the kinetic mechanisms of biomolecular interactions have become increasingly important in early-phase drug development. Since traditional in vitro methods belong to dose-dependent assessments, binding kinetics is usually overlooked. The present study aimed at the establishment of two novel experimental approaches for the assessment of binding affinity of both, radiolabelled and non-labelled compounds targeting the A3R, based on high-resolution real-time data acquisition of radioligand-receptor binding kinetics. A novel time-resolved competition assay was developed and applied to determine the Ki of eight different A3R antagonists, using CHO-K1 cells stably expressing the hA3R. In addition, a new kinetic real-time cell-binding approach was established to quantify the rate constants kon and koff, as well as the dedicated Kd of the A3R agonist [125I]-AB-MECA. Furthermore, lipophilicity measurements were conducted to control influences due to physicochemical properties of the used compounds. Results Two novel real-time cell-binding approaches were successfully developed and established. Both experimental procedures were found to visualize the kinetic binding characteristics with high spatial and temporal resolution, resulting in reliable affinity values, which are in good agreement with values previously reported with traditional methods. Taking into account the lipophilicity of the A3R antagonists, no influences on the experimental performance and the resulting affinity were investigated. Conclusions Both kinetic binding approaches comprise tracer administration and subsequent binding to living cells, expressing the dedicated target protein. Therefore, the experiments resemble better the true in vivo physiological conditions and provide important markers of cellular feedback and biological response.
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Affiliation(s)
- Markus Zeilinger
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Radiopharmacy and Experimental Nuclear Medicine, Waehringer Guertel 18-20, 1090, Vienna, Austria.,Faculty of Engineering, University of Applied Sciences Wiener Neustadt, Wiener Neustadt, Austria
| | - Florian Pichler
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Radiopharmacy and Experimental Nuclear Medicine, Waehringer Guertel 18-20, 1090, Vienna, Austria.,Faculty of Engineering, University of Applied Sciences Wiener Neustadt, Wiener Neustadt, Austria
| | - Lukas Nics
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Radiopharmacy and Experimental Nuclear Medicine, Waehringer Guertel 18-20, 1090, Vienna, Austria
| | - Wolfgang Wadsak
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Radiopharmacy and Experimental Nuclear Medicine, Waehringer Guertel 18-20, 1090, Vienna, Austria.,Department of Inorganic Chemistry, University of Vienna, Vienna, Austria
| | - Helmut Spreitzer
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Marcus Hacker
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Radiopharmacy and Experimental Nuclear Medicine, Waehringer Guertel 18-20, 1090, Vienna, Austria
| | - Markus Mitterhauser
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Radiopharmacy and Experimental Nuclear Medicine, Waehringer Guertel 18-20, 1090, Vienna, Austria. .,Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Vienna, Austria. .,Ludwig Boltzmann Institute for Applied Diagnostics, Vienna, Austria.
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van Rodijnen WF, van Lambalgen TA, van Teijlingen ME, Tangelder GJ, ter Wee PM. Comparison of the AT1-receptor blockers candesartan, irbesartan and losartan for inhibiting renal microvascular constriction. J Renin Angiotensin Aldosterone Syst 2016; 2:S204-S210. [DOI: 10.1177/14703203010020013601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Angiotensin II (Ang II) type 1 (AT1) receptor blockers differ in their affinity for the AT1-receptor, suggesting a dissimilar potency for inhibiting Ang II-induced vascular constriction. In the present study, we compared the effects of candesartan, irbesartan and losartan on the renal microvascular constriction to locally-formed Ang II, using isolated, perfused hydronephrotic rat kidneys. Addition of 1 nmol/L angiotensin I (Ang I, the precursor of Ang II) significantly reduced the diameters of interlobular arteries (ILAs; -47.6±2.6%), afferent arterioles (AAs; -43.6±2.3%) and efferent arterioles (EAs; -31.6±2.4%). Candesartan and irbesartan were more potent in antagonising the constriction to Ang I than losartan. By contrast, candesartan and irbesartan differed only slightly in potency. After a washing period of 60 minutes with drug-free medium, a second application of Ang I failed to induce vasoconstriction only in candesartan-treated kidneys. Pretreatment of hydronephrotic kidneys with candesartan, to further explore its antagonistic properties, shifted the dose-response curves of Ang II approximately 2 log units to the right without reducing the maximal Ang II-induced constriction of ILAs, AAs or EAs. Additionally, dose-response curves of Ang II were similar after short (10 minutes) and prolonged (60 minutes) preincubation with candesartan. Our findings indicate that candesartan and irbesartan are more potent inhibitors of renal microvascular constriction to locally-formed Ang II than losartan. The inhibitory effect of candesartan is more prolonged, suggesting a slow dissociation from the AT1-receptor. Additionally, candesartan was found to block the Ang II-induced constriction of renal microvessels in a surmountable manner.
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Affiliation(s)
| | | | | | | | - Piet M ter Wee
- Department of Nephrology, Institute for Cardiovascular
Research (ICaR-VU), Vrije Universiteit, Amsterdam, The Netherlands
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9
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Distinctions between non-peptide angiotensin II AT1-receptor antagonists. J Renin Angiotensin Aldosterone Syst 2016; 2:S24-S31. [DOI: 10.1177/14703203010020010401] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A far-reaching understanding of the molecular action mechanism of AT1-receptor antagonists (AIIAs) was obtained by using CHO cells expressing transfected human AT 1-receptors. In this model, direct [3H]-antagonist binding and inhibition of agonist-induced responses (inositol phosphate accumulation) can be measured under identical experimental conditions. Whereas preincubation with a surmountable AIIA (losartan) causes parallel shifts of the angiotensin II (Ang II) concentration-response curve, insurmountable antagonists also cause partial (i.e., 30% for irbesartan, 50% for valsartan, 70% for EXP3174,) to almost complete (95% for candesartan) reductions of the maximal response. The main conclusions are that all investigated antagonists are competitive with respect to Ang II. They bind to a common or overlapping site on the receptor in a mutually exclusive way. Insurmountable inhibition is related to the slow dissociation rate of the antagonist-receptor complex (t 1/2 of 7 minutes for irbesartan, 17 minutes for valsartan, 30 minutes for EXP3174 and 120 minutes for candesartan). Antagonist-bound AT1-receptors can adopt a fast and a slow reversible state. This is responsible for the partial nature of the insurmountable inhibition. The long-lasting effect of candesartan, the active metabolite of candesartan cilexetil, in vascular smooth muscle contraction studies, as well as in in vivo experiments on rat and in clinical studies, is compatible with its slow dissociation from, and continuous recycling between AT1-receptors. This recycling, or `rebinding' takes place because of the very high affinity of candesartan for the AT1-receptor.
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Jugdutt BI, Menon V. Upregulation of Angiotensin II Type 2 Receptor and Limitation of Myocardial Stunning by Angiotensin II Type 1 Receptor Blockers during Reperfused Myocardial Infarction in the Rat. J Cardiovasc Pharmacol Ther 2016; 8:217-26. [PMID: 14506547 DOI: 10.1177/107424840300800307] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Background: We have previously shown that angiotensin II type 1 receptor blockers induce cardioprotection and upregulate angiotensin II type 2 receptor during in vivo postischemicreperfusion in dogs. Whether angiotensin II type 1 receptor blockers upregulate angiotensin II type 2 receptors in rats is controversial, and whether surmountable and insurmountable angiotensin II type 1 receptor blockers exert similar protective effects during reperfused myocardial infarction is not known. Methods: We assessed the effects of the surmountable angiotensin receptor blocker valsartan, and the insurmountable angiotensin receptor blocker irbesartan, on hemodynamics and left ventricular systolic and diastolic function (echocardiography/Doppler) in vivo and infarct size (triphenyl tetrazolium chloride method), and regional angiotensin II type 1 receptor and angiotensin II type 2 receptor expression (immunoblots) ex vivo, after anterior reperfused myocardial infarction in rats. The rats were randomized to four groups: intravenous valsartan (10 mg/kg, n = 8), irbesartan (10 mg/kg, n = 8), or saline vehicle (controls, n = 14) over 30 minutes before reperfused myocardial infarction, and sham (n = 8). Angiotensin II type 1 receptor blockade was assessed by the inhibition of angiotensin II pressor responses. Results: Compared with the control group, both angiotensin receptor blockers significantly decreased infarct size, limited the increase in left atrial pressure, improved positive left ventricular dP/dtm,x and dP/dtm,,, improved left ventricular ejection fraction and diastolic function, and limited infarct expansion after reperfused myocardial infarction. Both angiotensin receptor blockers increased angiotensin II type 2 receptor protein in the postischemic-reperfused zone, with no change in angiotensin II type 1 receptor protein. There were no changes in the sham group. Conclusion: The overall results indicate that the angiotensin receptor blockers valsartan and irbesartan both induce cardioprotection, limit myocardial stunning, and upregulate angiotensin II type 2 receptor protein expression after reperfused myocardial infarction in the rat. Patients who are already receiving angiotensin receptor blockers and develop acute coronary syndromes might benefit from these cardioprotective effects during reperfusion therapy.
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Affiliation(s)
- Bodh I Jugdutt
- Division of Cardiology, Department of Medicine and the Cardiovascular Research Group, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada.
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Michel MC, Brunner HR, Foster C, Huo Y. Angiotensin II type 1 receptor antagonists in animal models of vascular, cardiac, metabolic and renal disease. Pharmacol Ther 2016; 164:1-81. [PMID: 27130806 DOI: 10.1016/j.pharmthera.2016.03.019] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 03/30/2016] [Indexed: 02/07/2023]
Abstract
We have reviewed the effects of angiotensin II type 1 receptor antagonists (ARBs) in various animal models of hypertension, atherosclerosis, cardiac function, hypertrophy and fibrosis, glucose and lipid metabolism, and renal function and morphology. Those of azilsartan and telmisartan have been included comprehensively whereas those of other ARBs have been included systematically but without intention of completeness. ARBs as a class lower blood pressure in established hypertension and prevent hypertension development in all applicable animal models except those with a markedly suppressed renin-angiotensin system; blood pressure lowering even persists for a considerable time after discontinuation of treatment. This translates into a reduced mortality, particularly in models exhibiting marked hypertension. The retrieved data on vascular, cardiac and renal function and morphology as well as on glucose and lipid metabolism are discussed to address three main questions: 1. Can ARB effects on blood vessels, heart, kidney and metabolic function be explained by blood pressure lowering alone or are they additionally directly related to blockade of the renin-angiotensin system? 2. Are they shared by other inhibitors of the renin-angiotensin system, e.g. angiotensin converting enzyme inhibitors? 3. Are some effects specific for one or more compounds within the ARB class? Taken together these data profile ARBs as a drug class with unique properties that have beneficial effects far beyond those on blood pressure reduction and, in some cases distinct from those of angiotensin converting enzyme inhibitors. The clinical relevance of angiotensin receptor-independent effects of some ARBs remains to be determined.
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Affiliation(s)
- Martin C Michel
- Dept. Pharmacology, Johannes Gutenberg University, Mainz, Germany; Dept. Translational Medicine & Clinical Pharmacology, Boehringer Ingelheim, Ingelheim, Germany.
| | | | - Carolyn Foster
- Retiree from Dept. of Research Networking, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, CT, USA
| | - Yong Huo
- Dept. Cardiology & Heart Center, Peking University First Hospital, Beijing, PR China
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12
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Vauquelin G, Van Liefde I, Swinney DC. Radioligand binding to intact cells as a tool for extended drug screening in a representative physiological context. DRUG DISCOVERY TODAY. TECHNOLOGIES 2015; 17:28-34. [PMID: 26724334 DOI: 10.1016/j.ddtec.2015.09.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 09/04/2015] [Accepted: 09/09/2015] [Indexed: 06/05/2023]
Abstract
Radioligand binding assays on intact cells offer distinct advantages to those on membrane suspensions. Major pharmacological properties like drug affinity and binding kinetics are more physiologically relevant. Complex mechanisms can be studied with a wider choice of experimental approaches and so provide insights into induced-fit type binding, receptor internalisation and even into pharmacomicrokinetic phenomena like drug rebinding and partitioning into the membrane. Hence, intact cell binding constitutes a valuable addition to the pharmacologist's toolbox.
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Affiliation(s)
- Georges Vauquelin
- Dept. of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
| | - Isabelle Van Liefde
- Dept. of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - David C Swinney
- Institute for Rare and Neglected Diseases Drug Discovery, 897 Independence Ave, Suite 2C, Mountain View, CA 94043, United States
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13
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Karnik SS, Unal H, Kemp JR, Tirupula KC, Eguchi S, Vanderheyden PML, Thomas WG. International Union of Basic and Clinical Pharmacology. XCIX. Angiotensin Receptors: Interpreters of Pathophysiological Angiotensinergic Stimuli [corrected]. Pharmacol Rev 2015; 67:754-819. [PMID: 26315714 PMCID: PMC4630565 DOI: 10.1124/pr.114.010454] [Citation(s) in RCA: 207] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The renin angiotensin system (RAS) produced hormone peptides regulate many vital body functions. Dysfunctional signaling by receptors for RAS peptides leads to pathologic states. Nearly half of humanity today would likely benefit from modern drugs targeting these receptors. The receptors for RAS peptides consist of three G-protein-coupled receptors—the angiotensin II type 1 receptor (AT1 receptor), the angiotensin II type 2 receptor (AT2 receptor), the MAS receptor—and a type II trans-membrane zinc protein—the candidate angiotensin IV receptor (AngIV binding site). The prorenin receptor is a relatively new contender for consideration, but is not included here because the role of prorenin receptor as an independent endocrine mediator is presently unclear. The full spectrum of biologic characteristics of these receptors is still evolving, but there is evidence establishing unique roles of each receptor in cardiovascular, hemodynamic, neurologic, renal, and endothelial functions, as well as in cell proliferation, survival, matrix-cell interaction, and inflammation. Therapeutic agents targeted to these receptors are either in active use in clinical intervention of major common diseases or under evaluation for repurposing in many other disorders. Broad-spectrum influence these receptors produce in complex pathophysiological context in our body highlights their role as precise interpreters of distinctive angiotensinergic peptide cues. This review article summarizes findings published in the last 15 years on the structure, pharmacology, signaling, physiology, and disease states related to angiotensin receptors. We also discuss the challenges the pharmacologist presently faces in formally accepting newer members as established angiotensin receptors and emphasize necessary future developments.
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Affiliation(s)
- Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Jacqueline R Kemp
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Kalyan C Tirupula
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Satoru Eguchi
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Patrick M L Vanderheyden
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Walter G Thomas
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
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Vauquelin G. On the 'micro'-pharmacodynamic and pharmacokinetic mechanisms that contribute to long-lasting drug action. Expert Opin Drug Discov 2015; 10:1085-98. [PMID: 26165720 DOI: 10.1517/17460441.2015.1067196] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Optimal drug therapy often requires continuing high levels of target occupancy. Besides the traditional pharmacokinetic (PK) contribution thereto, drug-target interactions that comprise successive 'microscopic' steps as well as the intervention of the cell membrane and other 'micro'-anatomical structures nearby may help attaining this objective. AREAS COVERED This article reviews the 'micro'-pharmacodynamic (PD) and PK mechanisms that may increase a drug's residence time. Special focus is on induced-fit- and bivalent ligand binding models as well as on the ability of the plasma membrane surrounding the target to act as a repository for the drug (e.g., microkinetic model), to actively participate in the binding process (e.g., exosite model) and, along with microanatomical elements like synapses and interstitial spaces, to act on the drug's diffusion properties (reduction in dimensionality and drug-rebinding models). EXPERT OPINION The PK profile, as well as the target dissociation kinetics of a drug, may fail to account for its long-lasting efficiency in intact tissues and in vivo. This lacuna could potentially be alleviated by incorporating some of the enumerated 'microscopic' mechanisms and, to unveil them, dedicated experiments on sufficiently physiologically relevant biological material like cell monolayers can already be implemented early on in the lead optimization process.
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Affiliation(s)
- Georges Vauquelin
- a Free University Brussels (VUB), Molecular and Biochemical Pharmacology Department , Pleinlaan 2, B-1050 Brussels, Belgium +32 2 6291955 ; +32 2 6291358 ;
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Kim JH, Kim JM, Cho YZ, Na JH, Kim HS, Kim HA, Kang HW, Baik SK, Kwon SO, Cha SH, Kim YJ, Kim MY. Effects of candesartan and propranolol combination therapy versus propranolol monotherapy in reducing portal hypertension. Clin Mol Hepatol 2014; 20:376-83. [PMID: 25548744 PMCID: PMC4278069 DOI: 10.3350/cmh.2014.20.4.376] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 12/08/2014] [Accepted: 12/09/2014] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND/AIMS Angiotensin receptor blockers (ARBs) inhibit activated hepatic stellate cell contraction and are thought to reduce the dynamic portion of intrahepatic resistance. This study compared the effects of combined treatment using the ARB candesartan and propranolol versus propranolol monotherapy on portal pressure in patients with cirrhosis in a prospective, randomized controlled trial. METHODS Between January 2008 and July 2009, 53 cirrhotic patients with clinically significant portal hypertension were randomized to receive either candesartan and propranolol combination therapy (26 patients) or propranolol monotherapy (27 patients). Before and 3 months after the administration of the planned medication, the hepatic venous pressure gradient (HVPG) was assessed in both groups. The dose of propranolol was subsequently increased from 20 mg bid until the target heart rate was reached, and the candesartan dose was fixed at 8 mg qd. The primary endpoint was the HVPG response rate; patients with an HVPG reduction of >20% of the baseline value or to <12 mmHg were defined as responders. RESULTS The mean portal pressure declined significantly in both groups, from 16 mmHg (range, 12-28 mmHg) to 13.5 mmHg (range, 6-20 mmHg) in the combination group (P<0.05), and from 17 mmHg (range, 12-27 mmHg) to 14 mmHg (range, 7-25 mmHg) in the propranolol monotherapy group (P<0.05). However, the medication-induced pressure reduction did not differ significantly between the two groups [3.5 mmHg (range, -3-11 mmHg) vs. 3 mmHg (range, -8-10 mmHg), P = 0.674]. The response rate (55.6% vs. 61.5%, P = 0.435) and the reductions in mean blood pressure or heart rate also did not differ significantly between the combination and monotherapy groups. CONCLUSIONS The addition of candesartan (an ARB) to propranolol confers no benefit relative to classical propranolol monotherapy for the treatment of portal hypertension, and is thus not recommended.
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Affiliation(s)
- Jae Hyun Kim
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Jung Min Kim
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Youn Zoo Cho
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Ji Hoon Na
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Hyun Sik Kim
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Hyoun A Kim
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Hye Won Kang
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Soon Koo Baik
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea. ; Department of Cell Therapy and Tissue Engineering, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Sang Ok Kwon
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Seung Hwan Cha
- Department of Radiology, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Young Ju Kim
- Department of Radiology, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Moon Young Kim
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea. ; Department of Cell Therapy and Tissue Engineering, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, Wonju, Korea
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McKelvie RS. The CHARM program: the effects of candesartan for the management of patients with chronic heart failure. Expert Rev Cardiovasc Ther 2014; 7:9-16. [DOI: 10.1586/14779072.7.1.9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Michel MC, Foster C, Brunner HR, Liu L. A systematic comparison of the properties of clinically used angiotensin II type 1 receptor antagonists. Pharmacol Rev 2013; 65:809-48. [PMID: 23487168 DOI: 10.1124/pr.112.007278] [Citation(s) in RCA: 205] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Angiotensin II type 1 receptor antagonists (ARBs) have become an important drug class in the treatment of hypertension and heart failure and the protection from diabetic nephropathy. Eight ARBs are clinically available [azilsartan, candesartan, eprosartan, irbesartan, losartan, olmesartan, telmisartan, valsartan]. Azilsartan (in some countries), candesartan, and olmesartan are orally administered as prodrugs, whereas the blocking action of some is mediated through active metabolites. On the basis of their chemical structures, ARBs use different binding pockets in the receptor, which are associated with differences in dissociation times and, in most cases, apparently insurmountable antagonism. The physicochemical differences between ARBs also manifest in different tissue penetration, including passage through the blood-brain barrier. Differences in binding mode and tissue penetration are also associated with differences in pharmacokinetic profile, particularly duration of action. Although generally highly specific for angiotensin II type 1 receptors, some ARBs, particularly telmisartan, are partial agonists at peroxisome proliferator-activated receptor-γ. All of these properties are comprehensively reviewed in this article. Although there is general consensus that a continuous receptor blockade over a 24-hour period is desirable, the clinical relevance of other pharmacological differences between individual ARBs remains to be assessed.
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Affiliation(s)
- Martin C Michel
- Department of Clinical Development & Medical Affairs, Boehringer Ingelheim, 55216 Ingelheim, Germany.
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Angeli F, Verdecchia P, Pascucci C, Poltronieri C, Reboldi G. Pharmacokinetic evaluation and clinical utility of azilsartan medoxomil for the treatment of hypertension. Expert Opin Drug Metab Toxicol 2013; 9:379-85. [DOI: 10.1517/17425255.2013.769521] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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19
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Minatoguchi S, Aoyama T, Kawai N, Iwasa M, Oda M, Kida K, Kojima S, Goto N, Goto M, Sugishita F, Takai K, Tanaka R, Hiei K, Minagawa T, Yamamoto N, Watanabe I, Yasue T, Kobayashi H. Comparative effect of candesartan and amlodipine, and effect of switching from valsartan, losartan, telmisartan and olmesartan to candesartan, on early morning hypertension and heart rate. Blood Press 2013; 22 Suppl 1:29-37. [PMID: 23330658 DOI: 10.3109/08037051.2013.757844] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Early morning hypertension and a high heart rate are risk factors for cardiovascular disease. The DOHSAM study was designed to evaluate the effect of candesartan on early morning blood pressure (BP) and heart rate in hypertensives. We used a prospective, randomized, open-label design. Protocol 1: Patients with early morning BP more than 135/85 mmHg who were not on any antihypertensive drug or on candesartan were given amlodipine 2.5 mg/day (amlodipine group, n = 22) or added candesartan 4 mg/day (candesartan group, n = 36). Candesartan or amlodipine was added when BP did not fall lower than 135/85 mmHg. Protocol 2: Early morning hypertensives who were on other angiotensin receptor blockers (ARBs) (n = 50) such as valsartan, losartan, telmisartan and olmesartan were switched to candesartan. Early morning BP significantly decreased in the candesartan group compared with the amlodipine group 9 and 12 months after treatment. Switching other ARBs except for olmesartan to candesartan significantly decreased early morning systolic and diastolic BP 3, 6, 9 and 12 months after treatment. Heart rate in the office significantly decreased by switching to candesartan 6, 9 and 12 months after treatment. In conclusion, candesartan significantly decreased early morning hypertension more than amlodipine or other ARBs except olmesartan in early morning hypertensives.
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Affiliation(s)
- Shinya Minatoguchi
- Department of Cardiology, Gifu University Graduate School of Medicine, Yanagido 1-1, Gifu 5011194, Japan.
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Granström O, Levin LÅ, Henriksson M. Cost-effectiveness of candesartan versus losartan in the primary preventive treatment of hypertension. CLINICOECONOMICS AND OUTCOMES RESEARCH 2012; 4:313-22. [PMID: 23144565 PMCID: PMC3493257 DOI: 10.2147/ceor.s35824] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Background Although angiotensin receptor blockers have different receptor binding properties, no comparative randomized studies with cardiovascular event endpoints have been performed for this class of drugs. The aim of this study was to assess the long-term cost-effectiveness of candesartan (Atacand®) versus generic losartan in the primary preventive treatment of hypertension. Methods A decision-analytic model was developed to estimate costs and health outcomes over a patient’s lifetime. Data from a clinical registry study were used to estimate event rates for cardiovascular complications, such as myocardial infarction and heart failure. Costs and quality of life data were from published sources. Costs were in Swedish kronor and the outcome was quality-adjusted life-years (QALYs). Results Due to reduced rates of cardiovascular complications, candesartan was associated with a QALY gain and lower health care costs compared with generic losartan (0.053 QALYs gained and reduced costs of approximately 4700 Swedish kronor for women; and 0.057 QALYs gained and reduced costs of approximately 4250 Swedish kronor for men). This result was robust in several sensitivity analyses. Conclusion When modeling costs and health outcomes based on event rates for cardiovascular complications from a real-world registry study, candesartan appears to bring a QALY gain and a reduction in costs compared with generic losartan in the primary preventive treatment of hypertension in Sweden.
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Affiliation(s)
- Ola Granström
- AstraZeneca Nordic, Södertälje, Linköping University, Linköping, Sweden
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Guo D, van Dorp EJH, Mulder-Krieger T, van Veldhoven JPD, Brussee J, IJzerman AP, Heitman LH. Dual-Point Competition Association Assay. ACTA ACUST UNITED AC 2012; 18:309-20. [DOI: 10.1177/1087057112464776] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The concept of ligand-receptor binding kinetics is emerging as an important parameter in the early phase of drug discovery. Since the currently used kinetic assays are laborious and low throughput, we developed a method that enables fast and large format screening. It is a so-called dual-point competition association assay, which measures radioligand binding at two different time points in the absence or presence of unlabeled competitors. Specifically, this assay yields the kinetic rate index (KRI), which is a measure for the binding kinetics of the unlabeled ligands screened. As a prototypical drug target, the adenosine A1 receptor (A1R) was chosen for assay validation and optimization. A screen with 35 high-affinity A1R antagonists yielded seven compounds with a KRI value above 1.0, which indicated a relatively slow dissociation from the target. All other compounds had a KRI value below or equal to 1.0, predicting a relatively fast dissociation rate. Several compounds were selected for follow-up kinetic quantifications in classical kinetic assays and were shown to have kinetic rates that corresponded to their KRI values. The dual-point assay and KRI value may have general applicability at other G-protein-coupled receptors, as well as at drug targets from other protein families.
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Affiliation(s)
- Dong Guo
- Leiden University, Leiden, the Netherlands
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Bansal Y, Silakari O. The therapeutic journey of benzimidazoles: a review. Bioorg Med Chem 2012; 20:6208-36. [PMID: 23031649 DOI: 10.1016/j.bmc.2012.09.013] [Citation(s) in RCA: 519] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 09/07/2012] [Accepted: 09/07/2012] [Indexed: 01/03/2023]
Abstract
Presence of benzimidazole nucleus in numerous categories of therapeutic agents such as antimicrobials, antivirals, antiparasites, anticancer, anti-inflammatory, antioxidants, proton pump inhibitors, antihypertensives, anticoagulants, immunomodulators, hormone modulators, CNS stimulants as well as depressants, lipid level modulators, antidiabetics, etc. has made it an indispensable anchor for development of new therapeutic agents. Varied substitutents around the benzimidazole nucleus have provided a wide spectrum of biological activities. Importance of this nucleus in some activities like, Angiotensin I (AT(1)) receptor antagonism and proton-pump inhibition is reviewed separately in literature. Even some very short reviews on biological importance of this nucleus are also known in literature. However, owing to fast development of new drugs possessing benzimidazole nucleus many research reports are generated in short span of time. So, there is a need to couple the latest information with the earlier information to understand the current status of benzimidazole nucleus in medicinal chemistry research. In the present review, various derivatives of benzimidazole with different pharmacological activities are described on the basis of substitution pattern around the nucleus with an aim to help medicinal chemists for developing an SAR on benzimidazole derived compounds for each activity. This discussion will further help in the development of novel benzimidazole compounds.
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Affiliation(s)
- Yogita Bansal
- Molecular Modelling Lab, Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, Punjab 147002, India
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Kim MY, Cho MY, Baik SK, Jeong PH, Suk KT, Jang YO, Yea CJ, Kim JW, Kim HS, Kwon SO, Yoo BS, Kim JY, Eom MS, Cha SH, Chang SJ. Beneficial effects of candesartan, an angiotensin-blocking agent, on compensated alcoholic liver fibrosis - a randomized open-label controlled study. Liver Int 2012; 32:977-87. [PMID: 22364262 DOI: 10.1111/j.1478-3231.2012.02774.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 01/28/2012] [Indexed: 12/12/2022]
Abstract
BACKGROUND Recent studies have shown that the renin-angiotensin system is implicated in hepatic fibrogenesis in vitro and in vivo. However, no study was done in humans with alcoholic liver disease. AIM To investigate the antifibrotic effect of angiotensin II type 1 receptor (AT1-R) blocking agents (ARB) in patients with alcoholic liver disease. METHODS The primary outcome was improvement in patients' histological features. Eighty-five patients with compensated alcoholic liver fibrosis (≥ F2) which was confirmed by baseline liver biopsy were randomized (intention-to-treat (ITT)) to receive either ARB, candesartan (8 mg/day) with ursodeoxycholic acid (UDCA) (600 mg/day) (n = 42) or UDCA alone (n = 43) as control for 6 months and follow-up liver biopsies were conducted. RESULTS According to the Laennec fibrosis system, candesartan showed significantly higher rates of histological improvements (ITT, 33.3% vs. 11.6%, P = 0.020). In addition, the fibrosis score was significantly reduced from 3.4 ± 1.4 to 3.1 ± 1.5 (P = 0.005) in the candesartan group. Candesartan also reduced the area of fibrosis and α-smooth muscle actin positive from 11.3 ± 6.0 to 8.3 ± 4.7 and 28.7 ± 10.5 to 23.9 ± 10.3 (%), and the hydroxyproline levels (μg/g liver tissue) from 7.8 ± 2.4 to 6.3 ± 1.7 respectively (P < 0.05). In addition, the relative expression of transforming growth factor-β1(TGF-β1), collagen-1, AT1-R, tissue inhibitor of metalloproteinase 1 (TIMP-1), metalloproteinases2 (MMP2), Rac1 and p22phox by real-time RT-PCR decreased in the candesartan group (P < 0.05). Mean arterial blood pressure in the candesartan group decreased mildly but significantly (P < 0.001). No significant complications and side effects were observed during the present study. CONCLUSIONS Administration of ARB in compensated alcoholic liver disease induces improvement of fibrosis in histological and quantitative measurements.
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Affiliation(s)
- Moon Young Kim
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, South Korea
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Kusumoto K. [In vitro and in vivo pharmacological profiles of a novel angiotensin type 1-receptor blocker, azilsartan]. Nihon Yakurigaku Zasshi 2012; 139:236-240. [PMID: 22728984 DOI: 10.1254/fpj.139.236] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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Vauquelin G, Bostoen S, Vanderheyden P, Seeman P. Clozapine, atypical antipsychotics, and the benefits of fast-off D2 dopamine receptor antagonism. Naunyn Schmiedebergs Arch Pharmacol 2012; 385:337-72. [PMID: 22331262 DOI: 10.1007/s00210-012-0734-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 01/25/2012] [Indexed: 12/20/2022]
Abstract
Drug-receptor interactions are traditionally quantified in terms of affinity and efficacy, but there is increasing awareness that the drug-on-receptor residence time also affects clinical performance. While most interest has hitherto been focused on slow-dissociating drugs, D(2) dopamine receptor antagonists show less extrapyramidal side effects but still have excellent antipsychotic activity when they dissociate swiftly. Fast dissociation of clozapine, the prototype of the "atypical antipsychotics", has been evidenced by distinct radioligand binding approaches both on cell membranes and intact cells. The surmountable nature of clozapine in functional assays with fast-emerging responses like calcium transients is confirmatory. Potential advantages and pitfalls of the hitherto used techniques are discussed, and recommendations are given to obtain more precise dissociation rates for such drugs. Surmountable antagonism is necessary to allow sufficient D(2) receptor stimulation by endogenous dopamine in the striatum. Simulations are presented to find out whether this can be achieved during sub-second bursts in dopamine concentration or rather during much slower, activity-related increases thereof. While the antagonist's dissociation rate is important to distinguish between both mechanisms, this becomes much less so when contemplating time intervals between successive drug intakes, i.e., when pharmacokinetic considerations prevail. Attention is also drawn to the divergent residence times of hydrophobic antagonists like haloperidol when comparing radioligand binding data on cell membranes with those on intact cells and clinical data.
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Affiliation(s)
- Georges Vauquelin
- Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium.
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Hasegawa H, Takano H, Kameda Y, Kubota A, Kobayashi Y, Komuro I. Effect of switching from telmisartan, valsartan, olmesartan, or losartan to candesartan on morning hypertension. Clin Exp Hypertens 2012; 34:86-91. [PMID: 22251314 DOI: 10.3109/10641963.2011.628729] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The Candesartan Cooperative Research of Therapy Design for Early Morning Hypertension in CHIBA was designed to investigate whether switching from angiotensin II receptor blockers (ARBs) except candesartan to candesartan might be effective in Japanese patients with morning hypertension. Seventy-eight mild to moderate hypertensive patients, who were treated with the standard doses of ARBs except candesartan (losartan, 50 mg; valsartan, 80 mg; telmisartan, 40 mg; or olmesartan, 20 mg), were entered into 12-week treatment period with candesartan 8 mg according to a multicenter, open-label design. Morning and office blood pressures (BPs) were significantly reduced (morning, -10.1 ± 10.5/-4.5 ± 8.4 mm Hg; office, -13.1 ± 17.3/-6.2 ± 11.3 mm Hg) after medication change. Target BPs (morning BPs ≤ 135/85 mm Hg and office BPs ≤ 140/90 mm Hg) achievement rates were 42.9% in the morning and 64.3% at office. No adverse events were recognized in all patients. Candesartan treatment significantly reduced the morning and office BPs compared with other ARBs in Japanese patients with morning hypertension.
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Affiliation(s)
- Hiroshi Hasegawa
- Department of Cardiovascular Science and Medicine, Chiba University Graduate School of Medicine, Chuo-ku, Chiba, Japan
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Kusumoto K, Igata H, Ojima M, Tsuboi A, Imanishi M, Yamaguchi F, Sakamoto H, Kuroita T, Kawaguchi N, Nishigaki N, Nagaya H. Antihypertensive, insulin-sensitising and renoprotective effects of a novel, potent and long-acting angiotensin II type 1 receptor blocker, azilsartan medoxomil, in rat and dog models. Eur J Pharmacol 2011; 669:84-93. [DOI: 10.1016/j.ejphar.2011.07.014] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 06/27/2011] [Accepted: 07/07/2011] [Indexed: 01/11/2023]
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Packeu A, Wennerberg M, Balendran A, Vauquelin G. Estimation of the dissociation rate of unlabelled ligand-receptor complexes by a 'two-step' competition binding approach. Br J Pharmacol 2011; 161:1311-28. [PMID: 20946109 DOI: 10.1111/j.1476-5381.2010.00931.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Because the in vivo effectiveness of ligands may also be determined by the rate by which they dissociate from their target receptors, drug candidates are being increasingly screened for this kinetic property. The dissociation rate of unlabelled ligand-receptor complexes can be estimated indirectly from their ability to slow the association of subsequently added radioligand molecules. EXPERIMENTAL APPROACH We used the 'two-step competition' binding approach consisting of pre-incubating the receptor preparation with a wide range of ligand concentrations, washing off free ligand molecules, adding radioligand and monitoring its receptor binding after a fixed time. Based on the rationale that binding of both ligands is mutually exclusive and that they bind according to the law of mass action to a single class of sites, the unlabelled ligand's dissociation rate can be estimated from the upward shift that the competition curve experiences after washing. KEY RESULTS The relevance of the 'two-step competition' approach was explored by computer simulations and by comparing the dissociation behaviour of unlabelled D(2) dopamine and CB(1) cannabinoid receptor antagonists in this and alternative approaches. Besides providing satisfactory estimations of dissociation rates, the method also detects the ability of the unlabelled ligand molecules to be released from 'sinks' such as the cell membrane. CONCLUSIONS AND IMPLICATIONS As the 'two-step competition' requires rapid intermediate washing steps and needs radioligand binding to be measured at only one time point, this approach is particularly suited for binding studies on intact plated cells. LINKED ARTICLES This article is part of a themed section on Analytical Receptor Pharmacology in Drug Discovery. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2010.161.issue-6.
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Affiliation(s)
- A Packeu
- Department of Molecular and Biochemical Pharmacology, Free University of Brussels (VUB), Brussels, Belgium
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29
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Fotakis C, Christodouleas D, Zoumpoulakis P, Kritsi E, Benetis NP, Mavromoustakos T, Reis H, Gili A, Papadopoulos MG, Zervou M. Comparative Biophysical Studies of Sartan Class Drug Molecules Losartan and Candesartan (CV-11974) with Membrane Bilayers. J Phys Chem B 2011; 115:6180-92. [DOI: 10.1021/jp110371k] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Charalambos Fotakis
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, Vas. Constantinou 48, Athens 11635, Greece
- Chemistry Department, National and Kapodistrian University of Athens, Panepistimiopolis Zographou 15771, Greece
| | - Dionysios Christodouleas
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, Vas. Constantinou 48, Athens 11635, Greece
- Chemistry Department, National and Kapodistrian University of Athens, Panepistimiopolis Zographou 15771, Greece
| | - Panagiotis Zoumpoulakis
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, Vas. Constantinou 48, Athens 11635, Greece
| | - Eftichia Kritsi
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, Vas. Constantinou 48, Athens 11635, Greece
- Chemistry Department, National and Kapodistrian University of Athens, Panepistimiopolis Zographou 15771, Greece
| | - Nikolas-Ploutarch Benetis
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, Vas. Constantinou 48, Athens 11635, Greece
| | - Thomas Mavromoustakos
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, Vas. Constantinou 48, Athens 11635, Greece
- Chemistry Department, National and Kapodistrian University of Athens, Panepistimiopolis Zographou 15771, Greece
| | - Heribert Reis
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, Vas. Constantinou 48, Athens 11635, Greece
| | - Argiro Gili
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, Vas. Constantinou 48, Athens 11635, Greece
- School of Applied Mathematical and Physical Science, National Technical University of Athens, Zographou Campus, 15700 Athens, Greece
| | - Manthos G. Papadopoulos
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, Vas. Constantinou 48, Athens 11635, Greece
| | - Maria Zervou
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, Vas. Constantinou 48, Athens 11635, Greece
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Zhenfeng Zheng, Huilan Shi, Junya Jia, Dong Li, Shan Lin. A systematic review and meta-analysis of candesartan and losartan in the management of essential hypertension. J Renin Angiotensin Aldosterone Syst 2011; 12:365-74. [PMID: 21421652 DOI: 10.1177/1470320310391503] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Candesartan is a relatively novel antihypertensive agent of the angiotensin receptor blocker (ARB). Several clinical trials have compared candesartan with losartan in the management of essential hypertension. However, systematic assessment of efficacy and safety between candesartan and losartan is still lacking. METHODS We reviewed randomised controlled trials (RCTs) comparing candesartan with losartan for net reduction in blood pressure from baseline, response and control rates, and incidences of common and serious adverse events.Weighted mean differences (WMD), and relative risk (RR) with 95% confidence intervals (CI) were calculated for continuous and dichotomous data, respectively. RESULTS A total of 12 RCTs with 3644 patients were included in this meta-analysis. When comparing the efficacy of candesartan and losartan in reducing systolic blood pressure (SBP) and diastolic blood pressure (DBP) at the end of the follow-up period, results with candesartan were superior to losartan in the reduction SBP and DBP (WMD, -2.97; 95% CI, -4.18 - -1.77; p < 0.001; WMD, -1.76; 95% CI, -2.57 - -0.96; p < 0.001; respectively). Candesartan had better response and control rates than losartan. (RR, 1.12; 95% CI, 1.06-1.18; p < 0.01; RR, 1.26; 95% CI, 1.06-1.50; p = 0.008). Reported common adverse events for the two agents were not significantly different (RR, 0.98; 95% CI, 0.86-1.12; p = 0.78). The incidence of serious adverse events for candesartan was lower than for losartan (RR, 0.48; 95% CI, 0.25-0.92; p = 0.03). The net reduction of DBP showed negative correlation with baseline DBP in both candesartan and losartan groups (regression coefficient -1.81, p = 0.03 and regression coefficient -1.56, p = 0.02, respectively). CONCLUSIONS Candesartan is superior to losartan in reducing blood pressure. Candesartan also causes fewer serious adverse events than losartan.
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Affiliation(s)
- Zhenfeng Zheng
- Department of Nephrology, The First Affiliated Hospital of Tianjin Medical University, China.
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31
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Wennerberg M, Cheng L, Hjorth S, Clapham JC, Balendran A, Vauquelin G. Binding properties of antagonists to Cannabinoid receptors in intact cells. Fundam Clin Pharmacol 2011; 25:200-10. [DOI: 10.1111/j.1472-8206.2010.00843.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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32
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Russell D, Stålhammar J, Bodegard J, Hasvold P, Thuresson M, Kjeldsen SE. Cardiovascular events in subgroups of patients during primary treatment of hypertension with candesartan or losartan. J Clin Hypertens (Greenwich) 2010; 13:189-97. [PMID: 21366850 DOI: 10.1111/j.1751-7176.2010.00410.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Merging data from existing electronic patient records, and electronic hospital discharge and cause of death registers, is a fast and relatively inexpensive method for comparing different treatments with regard to clinical outcome. This study compared the effects of antihypertensive treatment with candesartan or losartan on cardiovascular disease (CVD) using Swedish registers. Patients without previous CVD who were prescribed candesartan (n=7329) or losartan (n=6771) for hypertension during 1999-2007 at 72 Swedish primary care centers were followed for up to 9 years. Both medications were given according to current recommendations, and there was no difference observed in achieved blood pressures. The authors have previously shown that candesartan lowered the risk of all CVD (primary composite end point) more so than losartan (adjusted hazard ratio, 0.86; 95% confidence interval, 0.77-0.96). Candesartan also had a significantly better effect with regards to reducing the development of heart failure, cardiac arrhythmias, and peripheral arterial disease. In the present analysis, the authors found that candesartan, compared with losartan, reduced the risk of all CVD, irrespective of sex, age, previous antihypertensive treatment, baseline blood pressure, and presence of diabetes. These clinical findings may reflect differences between candesartan and losartan in their binding characteristics to the angiotensin type 1 receptor.
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Affiliation(s)
- David Russell
- Department of Neurology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
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33
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Naik P, Murumkar P, Giridhar R, Yadav MR. Angiotensin II receptor type 1 (AT1) selective nonpeptidic antagonists—A perspective. Bioorg Med Chem 2010; 18:8418-56. [DOI: 10.1016/j.bmc.2010.10.043] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Revised: 10/14/2010] [Accepted: 10/15/2010] [Indexed: 10/18/2022]
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Ojima M, Igata H, Tanaka M, Sakamoto H, Kuroita T, Kohara Y, Kubo K, Fuse H, Imura Y, Kusumoto K, Nagaya H. In Vitro Antagonistic Properties of a New Angiotensin Type 1 Receptor Blocker, Azilsartan, in Receptor Binding and Function Studies. J Pharmacol Exp Ther 2010; 336:801-8. [DOI: 10.1124/jpet.110.176636] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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Vauquelin G, Charlton SJ. Long-lasting target binding and rebinding as mechanisms to prolong in vivo drug action. Br J Pharmacol 2010; 161:488-508. [PMID: 20880390 PMCID: PMC2990149 DOI: 10.1111/j.1476-5381.2010.00936.x] [Citation(s) in RCA: 206] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 05/17/2010] [Accepted: 06/10/2010] [Indexed: 11/28/2022] Open
Abstract
An increasing number of examples in the literature suggest that the in vivo duration of drug action not only depends on macroscopic pharmacokinetic properties like plasma half-life and the time needed to equilibrate between the plasma and the effect compartments, but is also influenced by long-lasting target binding and rebinding. The present review combines information from different research areas and simulations to explore the nature of these mechanisms and the conditions in which they are most prevalent. Simulations reveal that these latter phenomena become especially influential when there is no longer sufficient free drug around to maintain high levels of receptor occupancy. There is not always a direct link between slow dissociation and long-lasting in vivo target protection, as the rate of free drug elimination from the effect compartment is also a key influencing factor. Local phenomena that hinder the diffusion of free drug molecules away from their target may allow them to consecutively bind to the same target and/or targets nearby (denoted as 'rebinding') even when their concentration in the bulk phase has already dropped to insignificant levels. The micro-anatomic properties of many effect compartments are likely to intensify this phenomenon. By mimicking the complexity of tissues, intact cells offer the opportunity to investigate both mechanisms under the same, physiologically relevant conditions.
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Affiliation(s)
- Georges Vauquelin
- Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Brussels, Belgium.
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36
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Vauquelin G. Rebinding: or why drugs may act longer in vivo than expected from their in vitro target residence time. Expert Opin Drug Discov 2010; 5:927-41. [PMID: 22823988 DOI: 10.1517/17460441.2010.512037] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
IMPORTANCE OF THE FIELD It is well established that the in vivo duration of drug action not only depends on macroscopic pharmacokinetic properties like its plasma half-life, but also on the residence time of the drug-target complexes. However, drug 'rebinding' (i.e., the consecutive binding of dissociated drug molecules to the original target and/or targets nearby) can be influential in vivo as well. AREAS COVERED IN THIS REVIEW Information about rebinding is available since the 1980s but it is dispersed in the life sciences literature. This review compiles this information. In this respect, neurochemists and biopohysicians advance the same equations to describe drug rebinding. WHAT THE READER WILL GAIN The rebinding mechanism is explained according to the prevailing viewpoint in different life science disciplines. There is a general consensus that high target densities, high association rates and local phenomena that hinder the diffusion of free drug molecules away from their target all promote rebinding. TAKE HOME MESSAGE Simulations presented here for the first time suggest that rebinding may increase the duration and even the constancy of the drug's clinical action. Intact cell radioligand dissociation and related ex vivo experiments offer useful indications about a drug's aptitude to experience target rebinding.
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Affiliation(s)
- Georges Vauquelin
- Free University Brussels (VUB), Department of Molecular and Biochemical Pharmacology, Building E.5.10, Pleinlaan 2, B-1050 Brussels, Belgium +32 2 6291955 ; +32 2 6291358 ;
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Unal H, Jagannathan R, Bhat MB, Karnik SS. Ligand-specific conformation of extracellular loop-2 in the angiotensin II type 1 receptor. J Biol Chem 2010; 285:16341-50. [PMID: 20299456 DOI: 10.1074/jbc.m109.094870] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The orientation of the second extracellular loop (ECL2) is divergent in G-protein coupled receptor (GPCR) structures determined. This discovery provoked the question, is the ECL2 conformation differentially regulated in the GPCRs that respond to diffusible ligands? We have determined the conformation of the ECL2 of the angiotensin II type 1 receptor by reporter-cysteine accessibility mapping in different receptor states (i.e. empty, agonist-bound and antagonist-bound). We introduced cysteines at each position of ECL2 of an N-terminal epitope-tagged receptor surrogate lacking all non-essential cysteines and then measured reaction of these with a cysteine-reactive biotin probe. The ability of biotinylated mutant receptors to react with a steptavidin-HRP-conjugated antibody was used as the basis for examining differences in accessibility. Two segments of ECL2 were accessible in the empty receptor, indicating an open conformation of ECL2. These segments were inaccessible in the ligand-bound states of the receptor. Using the accessibility constraint, we performed molecular dynamics simulation to predict ECL2 conformation in different states of the receptor. Analysis suggested that a lid conformation similar to that of ECL2 in rhodopsin was induced upon binding both agonist and antagonist, but exposing different accessible segments delimited by the highly conserved disulfide bond. Our study reveals the ability of ECL2 to interact with diffusing ligands and to adopt a ligand-specific lid conformation, thus, slowing down dissociation of ligands when bound. Distinct conformations induced by the bound agonist and the antagonist around the conserved disulfide bond suggest an important role for this disulfide bond in producing different functional states of the receptor.
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Affiliation(s)
- Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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38
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Okpechi IG, Rayner BL. Update on the role of candesartan in the optimal management of hypertension and cardiovascular risk reduction. Integr Blood Press Control 2010; 3:45-55. [PMID: 21949620 PMCID: PMC3172071 DOI: 10.2147/ibpc.s9963] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Indexed: 01/13/2023] Open
Abstract
Hypertension is the most prevalent cardiovascular disease of adults and is a major risk factor for cardiovascular (CV) and cerebrovascular morbidity and mortality worldwide. Treatment of hypertension leads to reduction of CV morbidity and mortality through blood pressure reduction. The role of renin–angiotensin–aldosterone system (RAAS) in the pathophysiology of hypertension is mainly through generation of potent vasoconstrictor angiotensin II, stimulation of aldosterone secretion, and increase in sympathetic activation. Angiotensin II receptor blockers such as candesartan, a long-acting agent, alter this system by blocking the activation of angiotensin I receptors. Several important clinical trials have tested the efficacy of candesartan with placebo, antihypertensive agents, or other agents that block the RAAS for the control of hypertension and reduction of key CV risk factors such as microalbuminuria, heart failure, retinopathy, and carotid intima medial thickness. Candesartan has been shown to be a well-tolerated and effective antihypertensive agent with positive metabolic characteristics and additional benefits on CV and cerebrovascular outcomes. The aim of this review is to discuss the pharmacology, efficacy, and safety of candesartan, with an overview of key hypertension and CV studies involving candesartan.
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Affiliation(s)
- Ikechi G Okpechi
- Department of Medicine, Division of Nephrology and Hypertension, Groote Schuur Hospital and University of Cape Town, Observatory, Cape Town 7925, South Africa
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39
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Kjeldsen SE, Stålhammar J, Hasvold P, Bodegard J, Olsson U, Russell D. Effects of losartan vs candesartan in reducing cardiovascular events in the primary treatment of hypertension. J Hum Hypertens 2009; 24:263-73. [PMID: 19890371 PMCID: PMC2834374 DOI: 10.1038/jhh.2009.77] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Although angiotensin receptor blockers have different receptor binding properties no comparative studies with cardiovascular disease (CVD) end points have been performed within this class of drugs. The aim of this study was to test the hypothesis that there are blood pressure independent CVD-risk differences between losartan and candesartan treatment in patients with hypertension without known CVD. Seventy-two primary care centres in Sweden were screened for patients who had been prescribed losartan or candesartan between the years 1999 and 2007. Among the 24 943 eligible patients, 14 100 patients were diagnosed with hypertension and prescribed losartan (n=6771) or candesartan (n=7329). Patients were linked to Swedish national hospitalizations and death cause register. There was no difference in blood pressure reduction when comparing the losartan and candesartan groups during follow-up. Compared with the losartan group, the candesartan group had a lower adjusted hazard ratio for total CVD (0.86, 95% confidence interval (CI) 0.77–0.96, P=0.0062), heart failure (0.64, 95% CI 0.50–0.82, P=0.0004), cardiac arrhythmias (0.80, 95% CI 0.65–0.92, P=0.0330), and peripheral artery disease (0.61, 95% CI 0.41–0.91, P=0.0140). No difference in blood pressure reduction was observed suggesting that other mechanisms related to different pharmacological properties of the drugs may explain the divergent clinical outcomes.
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Affiliation(s)
- S E Kjeldsen
- Department of Cardiology, Oslo University Hospital, Ullevål, Oslo, Norway
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40
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Kusumoto K, Mori M, Tanokashira J, Totsuka N. [Pharmacological and clinical properties of ECARD combination tablets LD & HD, fixed-dose combination of candesartan cilexetil and hydrochlorothiazide]. Nihon Yakurigaku Zasshi 2009; 134:217-224. [PMID: 19828927 DOI: 10.1254/fpj.134.217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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41
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SEVER PETERS. Improving Antihypertensive Efficacy while Maintaining Placebo-like Tolerability. Blood Press 2009; 9:19-22. [DOI: 10.1080/080370500439173] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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42
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UNGER THOMAS. Differences Among Angiotensin II Type 1 Receptor Blockers: Characteristics of Candesartan Cilexetil. Blood Press 2009; 9:14-18. [DOI: 10.1080/080370500439164] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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43
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MEREDITH PETER. Achieving Quality 24-h Blood Pressure Control with Candesartan Cilexetil. Blood Press 2009; 9:23-26. [DOI: 10.1080/080370500439182] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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44
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RUILOPE LUIS. Improving Prognosis in Hypertension: Exploring the Benefits of Angiotensin II Type 1 Receptor Blockade. Blood Press 2009; 9:31-35. [DOI: 10.1080/080370500439209] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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45
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46
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ZANNAD FAIEZ. Preserving Target-organ Function with Candesartan Cilexetil in Patients with Hypertension. Blood Press 2009; 9:36-39. [DOI: 10.1080/080370500439218] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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47
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Åberg O, Lindhe Ö, Hall H, Hellman P, Kihlberg T, Långström B. Synthesis and biological evaluation of [carboxyl-11C]eprosartan. J Labelled Comp Radiopharm 2009. [DOI: 10.1002/jlcr.1598] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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48
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49
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McKelvie RS. Candesartan for the management of heart failure: more than an alternative. Expert Opin Pharmacother 2006; 7:1945-56. [PMID: 17020420 DOI: 10.1517/14656566.7.14.1945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Candesartan is a long-acting angiotensin receptor antagonist that is well absorbed from the gastrointestinal tract, with insurmountable receptor binding abilities. Recent studies have shown candesartan to be an effective therapy for heart failure patients, producing a significant reduction in mortality and morbidity. Importantly, studies have demonstrated that candesartan is effective in heart failure patients who are intolerant to angiotensin-converting enzyme inhibitors, in patients already receiving angiotensin-converting enzyme inhibitors and for heart failure patients with preserved systolic function. The primary end point in the latter group failed to achieve statistical significance due to the small number of events. This paper will review the data supporting the use of candesartan to treat all heart failure patients, regardless of their ejection fraction.
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Affiliation(s)
- Robert S McKelvie
- HHSC-General Division, 237 Barton Street East, Hamilton, Ontario, L8L 2X2, Canada.
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50
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Copeland RA, Pompliano DL, Meek TD. Drug-target residence time and its implications for lead optimization. Nat Rev Drug Discov 2006; 5:730-9. [PMID: 16888652 DOI: 10.1038/nrd2082] [Citation(s) in RCA: 1027] [Impact Index Per Article: 57.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Much of drug discovery today is predicated on the concept of selective targeting of particular bioactive macromolecules by low-molecular-mass drugs. The binding of drugs to their macromolecular targets is therefore seen as paramount for pharmacological activity. In vitro assessment of drug-target interactions is classically quantified in terms of binding parameters such as IC(50) or K(d). This article presents an alternative perspective on drug optimization in terms of drug-target binary complex residence time, as quantified by the dissociative half-life of the drug-target binary complex. We describe the potential advantages of long residence time in terms of duration of pharmacological effect and target selectivity.
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Affiliation(s)
- Robert A Copeland
- Department of Enzymology and Mechanistic Pharmacology, at GlaxoSmithKline, UP1345, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, USA.
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