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Mahmoud MR, Shahien MM, Ibrahim S, S Alenazi F, Hussein W, Abdallah MH, Aljadani A, Alreshidi F, E El-Horany H, M Osman Elhussein GE, Abdeen H Abdalla R, H Elhaj A, M Khalifa A. Novel Insights in the Hypertension Treatment & Type 2 Diabetics Induced by Angiotensin Receptor Blockers: MD Simulation Studies & Molecular Docking of Some Promising Natural Therapies. ACS OMEGA 2024; 9:21234-21244. [PMID: 38764667 PMCID: PMC11097153 DOI: 10.1021/acsomega.4c01319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/18/2024] [Accepted: 04/23/2024] [Indexed: 05/21/2024]
Abstract
Angiotensin receptor blockers (ARBs) are commonly used to treat hypertension that target the hormonal system (renin-angiotensin system (RAS)), which regulates various physiological functions in the body. ARBs work by blocking the binding of angiotensin II to its receptor, thereby preventing a rise in blood pressure. These drugs not only normalize the overactivation of RAS but also provide protective effects against cardiovascular, renal, and type 2 diabetic patients. Inappropriate RAS activity has been linked to insulin resistance of type 2 diabetes. Olmesartan, as an ARB, was found to have a beneficial role in reducing postprandial glucose levels in type 2 diabetes. However, ARBs can cause side effects, prompting a search for new compounds that have fewer adverse effects. This study explores the potential of natural metabolites, specifically eugenol, gallic acid, myricetin, p-cymene, quercetin, and kaempferol, as ARB inhibitors compared to the current standard, olmesartan. Using in silico studies, the binding affinity of these natural substances to the ARB receptor was evaluated. The results showed that myricetin and kaempferol had affinities higher than those of olmesartan, suggesting that they could serve as promising ARB inhibitors for hypertension treatment. These natural compounds could provide an alternative approach to conventional antihypertensive drugs, which may have fewer side effects. However, more research is needed to validate the efficacy and safety of these natural compounds as antihypertensive drugs. Further in vitro and in vivo studies are needed to confirm their effectiveness and safety. This study provides a promising starting point for future investigations into the potential of natural metabolites as alternative treatments for hypertension. The findings also highlight the importance of exploring natural alternative treatments for hypertension and the protective effects of ARBs on early stage type-2 diabetics.
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Affiliation(s)
- Madiha R. Mahmoud
- Department
of Pharmacology, College of Medicine, University
of Ha’il, Ha’il 81442, Saudi Arabia
- Department
of Pharmacology, TBRI, Ministry of Higher
Education and Scientific Research, Giza 12411, Egypt
| | - Mona M. Shahien
- Department
of Pediatrics, College of Medicine, University
of Ha’il, Ha’il 81442, Saudi Arabia
| | - Somia Ibrahim
- Department
of Pediatrics, College of Medicine, University
of Ha’il, Ha’il 81442, Saudi Arabia
| | - Fahaad S Alenazi
- Department
of Pharmacology, College of Medicine, University
of Ha’il, Ha’il 81442, Saudi Arabia
| | - Weiam Hussein
- Department
of Pharmaceutical Chemistry, College of
Pharmacy, University of Ha’il, Ha’il 81442, Saudi
Arabia
- Department
of Pharmaceutical Chemistry, College of
Pharmacy, Aden University, Aden 6075, Yemen
| | - Marwa H. Abdallah
- Department
of Pharmaceutics, College of Pharmacy, University
of Ha’il, Ha’il 81442, Saudi Arabia
- Department
of Pharmaceutics, Faculty of Pharmacy, Zagazig
University, Zagazig 44519, Egypt
| | - Ahmed Aljadani
- Department
of Psychiatry, College of Medicine, University
of Ha’il, Ha’il 81442, Saudi Arabia
| | - Fayez Alreshidi
- Department
of Family Medicine, College of Medicine,
University of Ha’il, Ha’il 81442, Saudi Arabia
| | - Hemat E El-Horany
- Department
of Biochemistry, College of Medicine, University
of Ha’il, Ha’il 81442, Saudi Arabia
- Medical
Biochemistry Department, Faculty of Medicine, Tanta University, Tanta 31527, Egypt
| | | | - Rania Abdeen H Abdalla
- Obstetric
and Gynecology Department, College of Medicine,
University of Ha’il, Ha’il 81442, Saudi Arabia
| | - Abeer H Elhaj
- Family
and Community Medicine Department, College
of Medicine, University of Ha’il, Ha’il 81442, Saudi Arabia
| | - Amany M Khalifa
- Medical
Parasitology, Pathology Department, College
of Medicine, University of Ha’il, Ha’il 81442, Saudi Arabia
- Medical
Parasitology Department, Faculty of Medicine, Alexandria University, Alexandria 5424041, Egypt
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Paik SH, Chi YH, Lee JH, Han HS, Lee KT. Pharmacological Profiles of a Highly Potent and Long-Acting Angiotensin II Receptor Antagonist, Fimasartan, in Rats and Dogs after Oral Administration. Biol Pharm Bull 2018; 40:992-1001. [PMID: 28674263 DOI: 10.1248/bpb.b16-00987] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The pharmacological profile of fimasartan, [2-n-butyl-5-dimethylamino-thiocarbonyl-methyl-6-methyl-3-{[2-(1H-tetrazole-5-yl)biphenyl-4-yl]methyl}-pyrimidin-4(3H)-one, a new non-peptide angiotensin type 1 (AT1)-selective angiotensin receptor antagonist, has been investigated in a variety of in vitro and in vivo experimental models. In the present study, fimasartan showed slow dissociation and irreversible binding to AT1 subtype receptors in membrane fractions of HEK-293 cells with a Kd of 0.03 nM and a T1/2 of 63.7 min. The inhibitory effect of fimasartan on angiotensin II (Ang II)-induced contraction persisted longer after washout than that of losartan or candesartan. In conscious rats, a single dose of fimasartan (0.3, 1, or 3 mg/kg; per os (p.o.)) dose-dependently antagonized Ang II-induced pressor responses. Both orally administrated fimasartan and losartan dose-dependently decreased mean arterial pressure in furosemide-treated rats and dogs, and fimasartan administered orally at 1, 3, or 10 mg/kg reduced blood pressure in conscious spontaneously hypertensive rats. Taken together, these findings indicate that fimasartan has potent and sustained binding affinity at the AT1 receptor subtype, and reveal the molecular basis responsible for the marked lowering of blood pressure in various conscious rats and dogs models after its oral administration.
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Affiliation(s)
| | - Yong Ha Chi
- Central Research Institute, Boryung Pharm. Co., Ltd
| | - Joo Han Lee
- Central Research Institute, Boryung Pharm. Co., Ltd
| | - Hee-Soo Han
- Department of Pharmaceutical Biochemistry College of Pharmacy, Kyung Hee University.,Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University
| | - Kyung-Tae Lee
- Department of Pharmaceutical Biochemistry College of Pharmacy, Kyung Hee University.,Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University
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Neuroprotective effects of AT1 receptor antagonists after experimental ischemic stroke: what is important? Naunyn Schmiedebergs Arch Pharmacol 2017; 390:949-959. [PMID: 28669009 DOI: 10.1007/s00210-017-1395-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 06/16/2017] [Indexed: 12/25/2022]
Abstract
The present study conducted in rats defines the requirements for neuroprotective effects of systemically administered AT1 receptor blockers (ARBs) in acute ischaemic stroke. The inhibition of central effects to angiotensin II (ANG II) after intravenous (i.v.) treatment with candesartan (0.3 and 3 mg/kg) or irbesartan and losartan (3 and 30 mg/kg) was employed to study the penetration of these ARBs across the blood-brain barrier. Verapamil and probenecid were used to assess the role of the transporters, P-glycoprotein and the multidrug resistance-related protein 2, in the entry of losartan and irbesartan into the brain. Neuroprotective effects of i.v. treatment with the ARBs were investigated after transient middle cerebral artery occlusion (MCAO) for 90 min. The treatment with the ARBs was initiated 3 h after the onset of MCAO and continued for two consecutive days. Blood pressure was continuously recorded before and during MCAO until 5.5 h after the onset of reperfusion. The higher dose of candesartan completely abolished, and the lower dose of candesartan and higher doses of irbesartan and losartan partially inhibited the drinking response to intracerebroventricular ANG II. Only 0.3 mg/kg candesartan improved the recovery from ischaemic stroke, and 3 mg/kg candesartan did not exert neuroprotective effects due to marked blood pressure reduction during reperfusion. Both doses of irbesartan and losartan had not any effect on the stroke outcome. An effective, long-lasting blockade of brain AT1 receptors after systemic treatment with ARBs without extensive blood pressure reductions is the prerequisite for neuroprotective effects in ischaemic stroke.
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Maillard MP, Centeno C, Frostell-Karlsson Å, Brunner HR, Burnier M. Does protein binding modulate the effect of angiotensin II receptor antagonists? J Renin Angiotensin Aldosterone Syst 2016; 2:S54-S58. [DOI: 10.1177/14703203010020010901] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Introduction Angiotensin II AT 1-receptor antagonists are highly bound to plasma proteins (≥ 99%). With some antagonists, such as DuP-532, the protein binding was such that no efficacy of the drug could be demonstrated clinically. Whether protein binding interferes with the efficacy of other antagonists is not known. We have therefore investigated in vitro how plasma proteins may affect the antagonistic effect of different AT1-receptor antagonists. Methods A radio-receptor binding assay was used to analyse the interaction between proteins and the ability of various angiotensin II (Ang II) antagonists to block AT1-receptors. In addition, the Biacore technology, a new technique which enables the real-time monitoring of binding events between two molecules, was used to evaluate the dissociation rate constants of five AT1-receptor antagonists from human serum albumin. Results The in vitro AT 1-antagonistic effects of different Ang II receptor antagonists were differentially affected by the presence of human plasma, with rightward shifts of the IC50 ranging from one to several orders of magnitude. The importance of the shift correlates with the dissociation rate constants of these drugs from albumin. Our experiments also show that the way that AT1-receptor antagonists bind to proteins differs from one compound to another. These results suggest that the interaction with plasma proteins appears to modulate the efficacy of some Ang II antagonists. Conclusion Although the high binding level of Ang II receptor antagonist to plasma proteins appears to be a feature common to this class of compounds, the kinetics and characteristics of this binding is of great importance. With some antagonists, protein binding interferes markedly with their efficacy to block AT1-receptors.
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Affiliation(s)
- Marc P Maillard
- Division of Hypertension and Vascular Medicine, Lausanne
University Hospital, CH-1011 Lausanne, Switzerland,
| | - Catherine Centeno
- Division of Hypertension and Vascular Medicine, Lausanne
University Hospital, CH-1011 Lausanne, Switzerland
| | | | - Hans R Brunner
- Division of Hypertension and Vascular Medicine, Lausanne
University Hospital, CH-1011 Lausanne, Switzerland
| | - Michel Burnier
- Division of Hypertension and Vascular Medicine, Lausanne
University Hospital, CH-1011 Lausanne, Switzerland
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Ytterberg H, Edvinsson L. Evidence for a cyclic AMP-dependent pathway in angiotensin AT1-receptor activation of human omental arteries. J Renin Angiotensin Aldosterone Syst 2016; 2:S42-S47. [DOI: 10.1177/14703203010020010701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Enhanced responses to vasoconstriction induced by neuropeptide Y and α2-adrenoceptor agonists have been seen following pharmacological activation of the adenylyl cyclase (AC) system. Since preliminary studies revealed only minor responses to angiotensin II (Ang II) in human omental arteries, we have investigated whether enhanced activity of AC may unravel further functional Ang II receptors. Human omental arteries were obtained in conjunction with elective gut surgery. After dissection of the vessel, the endothelium was removed by 10 sec of Triton X-100 treatment. Ring segments (1—2 mm long) were mounted on a myograph and studied. Ang II produced small contractions, 27±5% relative to the response elicited by 60 mM K+. However, enhanced Ang II (105±10%, p<0.001) responses were seen during AC activation by forskolin (0.1—1 µM). This enhanced contractile response to Ang II was not inhibited by the angiotensin II type 2 (AT2-receptor antagonist PD 123319 (0.1 µM), but was blocked in an insurmountable way by the angiotensin II type 1 (AT1)-receptor antagonist candesartan (1 nM) and in a surmountable manner by losartan (0.1 µM) and irbesartan (0.1 µM). Pertussis toxin (a Gi-protein blocker) and the protein kinase C inhibitor, RO31—8220 (0.01, 0.1 and 1 µM), markedly reduced this response, while the protein kinase A inhibitor, H89 (1, 10 µM), had no effect. RT-PCR provided evidence for the presence of mRNA for both AT1- and AT2-receptors. The results suggest that both a cAMP-dependent and a cAMP-independent mechanism are involved in the contractile responses to Ang II in human omental arteries and that both responses are mediated via the AT1-receptor.
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Affiliation(s)
- Hoa Ytterberg
- Department of Internal Medicine, University Hospital,
Lund, Sweden,
| | - Lars Edvinsson
- Department of Internal Medicine, University Hospital,
Lund, Sweden
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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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Ytterberg H, Edvinsson L. Characterisation of angiotensin II receptors in isolated human subcutaneous resistance arteries. J Renin Angiotensin Aldosterone Syst 2016; 2:S37-S41. [DOI: 10.1177/14703203010020010601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Subcutaneous arteries have been used as a model for resistance arteries, which are potentially involved in enhanced blood pressure (BP) regulation in man. Angiotensin II (Ang II) is an important regulator of tone, acting via type 1 (AT1-) and type 2 (AT2-) receptor subtypes. The aim of this study was to characterise the Ang II receptors in isolated human subcutaneous arteries, using pharmacological and molecular methods. Subcutaneous arteries were obtained from patients undergoing elective gut surgery and were carefully dissected from the abdominal wall. Cylindrical segments were mounted on two L-shaped metal prongs, one of which was connected to a force-displacement transducer for continuous recording of isometric tension. Concentration-response curves to Ang II were constructed in the presence and absence of various selective AT1-receptor antagonists, candesartan, EXP3174, irbesartan and losartan, and the AT2-receptor antagonist, PD 123319. Responses to Ang II were measured as increases in force (mN) and expressed as a percentage of the response to 60 mM of KCl. Ang II caused a concentration-dependent contraction (pEC50=9.45±0.48, Emax=120±13%). Candesartan and EXP3174 caused concentration-dependent depression of the Emax of Ang II without any major shift of pEC50. Losartan and irbesartan caused a significant, dose-dependent rightward shift of the Ang II contraction-response curve in human subcutaneous arteries. The results show that contractile responses of human subcutaneous arteries are mediated via the AT1-receptor. The AT1-receptor antagonists, candesartan and EXP3174, acted in an insurmountable manner, while losartan and irbesartan were surmountable AT1-receptor antagonists. The AT2-receptor antagonist, PD 123319, (10, 100 nM) had no effect on Ang II-induced contraction. This is supported by the positive identification of mRNA for the human AT 1-receptor by RT-PCR.
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Affiliation(s)
- Hoa Ytterberg
- Department of Experimental Vascular Research, Department
of Internal Medicine, Lund University Hospital, Lund, Sweden,
| | - Lars Edvinsson
- Department of Experimental Vascular Research, Department
of Internal Medicine, Lund University Hospital, Lund, Sweden
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8
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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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Morgan T, Anderson A, Bertram D, MacInnis RJ. Effect of candesartan and lisinopril alone and in combination on blood pressure and microalbuminuria. J Renin Angiotensin Aldosterone Syst 2016; 5:64-71. [PMID: 15295717 DOI: 10.3317/jraas.2004.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Background Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blocking drugs (ARB) block the effect of angiotensin II by different mechanisms. It has been suggested that combined therapy may be more effective at reducing blood pressure (BP) than higher doses of either drug. Methods Twenty-three elderly patients with systolic hypertension completed a double-blind crossover study comparing placebo, candesartan (C) 16 mg, C32 mg, lisinopril (L) 20 mg, L40 mg and C16 mg + L20 mg. Treatment periods were one month and ambulatory BP measurements were performed at the end of each period. The effects on albumin excretion in eight patients with microalbuminuria were determined. Results All treatments lowered BP. The falls in systolic and diastolic BP with C16, C32, L20 and L40 were similar. Plasma renin rose to a similar extent. A plateau effect was reached with C16 and L20. Systolic BP on the combination of C16 + L20 was lower than on each monotherapy (C16, 3.8 mmHg [p=0.002]; C32, 6.4 [0.0003]; L20, 2.9 [0.05]; L40, 3.3 [0.003]). The additional fall in BP with the combination appeared to be due to recruitment of non-responders, rather than to an additive effect in most patients. All treatments reduced microalbuminuria to a similar extent. The combination was well tolerated and there was no deterioration in renal function. Conclusion When patients are on a plateau dose of an ACE inhibitor or an ARB, addition of the other drug class has a small but significant incremental effect on BP in the overall group. However, some patients respond better to one drug class than to the other and this may explain the results. This study lends no support to the use of these two drugs in combination to treat hypertension.
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Affiliation(s)
- Trefor Morgan
- Department of Physiology, University of Melbourne, Victoria, 3010, Australia.
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Yan WH, Pan CY, Dou JT, Meng JH, Wang BA, Mu YM. Candesartan cilexetil prevents diet-induced insulin resistance via peroxisome proliferator-activated receptor-γ activation in an obese rat model. Exp Ther Med 2016; 12:272-278. [PMID: 27347049 PMCID: PMC4906785 DOI: 10.3892/etm.2016.3297] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 04/08/2016] [Indexed: 12/28/2022] Open
Abstract
Angiotensin II type 1 receptor (AT1R) blockers (ARBs) have been shown to reduce the incidence of type 2 diabetes mellitus; however, the underlying molecular mechanism is unknown. Peroxisome proliferator-activated receptor γ (PPARγ) is the central regulator of insulin and glucose metabolism, which improves insulin sensitivity. Whether candesartan cilexetil, as a prodrug of the AT1R blocker candesartan, has PPARγ-activating properties remains to be elucidated. The aim of the present study was to investigate the effects of oral administration of candesartan cilexetil on glucose tolerance and the actions of PPARγ on liver and adipose tissue in the insulin-resistant obese rat induced by high-fat diet. Animals treated with candesartan cilexetil showed an improved glucose tolerance after oral glucose challenge. Whole-body insulin sensitivity was evaluated using the hyperinsulinemic-euglycemic clamp technique. During high-fat feeding in high-fat diet (HF) rats, the glucose infusion rate (GIR) was 52.3% lower than that in normal chow (NC) rats. However, the GIR was significantly enhanced following candesartan cilexetil treatment. Angiotensin II receptor antagonism also resulted in significant increases in PPARγ protein expression in adipose and liver tissue. These results indicate that PPARγ activation by candesartan cilexetil may provide novel therapeutic options in the treatment of patients with metabolic syndrome.
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Affiliation(s)
- Wen-Hua Yan
- Department of Endocrinology, Chinese People's Liberation Army General Hospital, Beijing 100853, P.R. China
| | - Chang-Yu Pan
- Department of Endocrinology, Chinese People's Liberation Army General Hospital, Beijing 100853, P.R. China
| | - Jing-Tao Dou
- Department of Endocrinology, Chinese People's Liberation Army General Hospital, Beijing 100853, P.R. China
| | - Jun-Hua Meng
- Department of Endocrinology, Chinese People's Liberation Army General Hospital, Beijing 100853, P.R. China
| | - Bao-An Wang
- Department of Endocrinology, Chinese People's Liberation Army General Hospital, Beijing 100853, P.R. China
| | - Yi-Ming Mu
- Department of Endocrinology, Chinese People's Liberation Army General Hospital, Beijing 100853, P.R. China
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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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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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Spasov AA, Yakovlev DS, Bukatina TM, Brigadirova AA. In vitro method of studying the angiotensin activity of chemical compounds. Bull Exp Biol Med 2014; 158:115-7. [PMID: 25403411 DOI: 10.1007/s10517-014-2705-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Indexed: 10/24/2022]
Abstract
We developed and tested an experimental model to study in vitro the type 1 angiotensin antagonistic activity of compounds on the isolated portal vein of rats. The reliability of this method was confirmed in tests with saralasin (nonselective antagonist of angiotensin receptors) and losartan (selective antagonist of type 1 angiotensin receptors) in concentrations of 10(-9)-10(-5) mol/liter. The half-maximal inhibitory concentrations (IC50) of these substances were calculated.
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Affiliation(s)
- A A Spasov
- Volgograd State Medical University, Ministry of Health of the Russian Federation; Volgograd Medical Scientific Center, Volgograd, Russia
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Stetskaia TA, Bushueva OI, Bulgakova IV, Vialykh EK, Shuteeva TV, Biriukov AE, Ivanov VP, Polonikov AV. [Association of T174M polymorphism of the angiotensinogen gene with the higher risk of cerebral stroke in women]. TERAPEVT ARKH 2014; 86:66-71. [PMID: 25804043 DOI: 10.17116/terarkh2014861266-71] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
AIM To study the association of M235T (rs699) and T174M (rs4762) polymorphisms of the angiotensinogen (AGT) gene with the risk of cerebral stroke (CS) in the Russians of the Central Chernozem Region. MATERIALS AND METHODS A total of 638 DNA samples obtained from 353 patients with CS and 285 sex- and age-matched healthy individuals were examined. The polymorphisms were genotyped by polymerase chain reaction (T174M) and TaqMan allelic discrimination (M235T) assays. RESULTS Heterozygous AGT 174TM genotype carriers were found to be at a higher risk for CS (odd ratio (OR) = 1.52; 95% confidence interval (CI), 1.08-2.15; p = 0.02). A gender-stratified analysis showed that the mutant 174M allele (OR = 1.86; 95% CI, 1.14-3.03, p = 0.01) and variant 174TM and 174MM genotypes (OR = 1.86; 95% CI, 1.09-3.20; p = 0.02) were associated with the higher risk of cerebral stroke in women. CONCLUSION The association of AGT T174M polymorphism with the risk of CS was first found; but the higher risk of the disease in the carriers of variant alleles and genotypes was observed in the women only.
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Gualtierotti R, Zoppi A, Mugellini A, Derosa G, D'Angelo A, Fogari R. Effect of naproxen and acetaminophen on blood pressure lowering by ramipril, valsartan and aliskiren in hypertensive patients. Expert Opin Pharmacother 2013; 14:1875-84. [PMID: 23883161 DOI: 10.1517/14656566.2013.816286] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently used for reducing pain and other symptoms in osteoarthritis (OA). NSAIDs have been associated with an increase in blood pressure (BP) in both normotensive and hypertensive individuals and a blunting effect on various anti-hypertensive medications. Acetaminophen effects on anti-hypertensive treatment, instead, are still a matter of debate. OBJECTIVES To assess the effect of naproxen versus acetaminophen on ramipril, valsartan and aliskiren therapy in hypertensive patients with OA in a double-blind, cross-over study, by measuring clinic, ambulatory BP and heart rate (HR). RESULTS One hundred seventy four patients were randomly treated with ramipril, valsartan or aliskiren for 8 weeks and 135 patients with normalized BP were randomized to receive naproxen or acetaminophen for 2 weeks. Naproxen significantly increased clinic and ambulatory systolic/diastolic BP (SBP/DBP) values in patients treated with ramipril (p < 0.01) or valsartan (p < 0.05), but did not affect aliskiren effects. Also acetaminophen slightly but significantly affected clinic and ambulatory SBP/DBP in all three groups and, surprisingly, it also produced a slight increase in HR (+3.1, +3.3 and +3.4 b/min day-time HR values, for ramipril, valsartan and aliskiren, respectively; p < 0.05). CONCLUSIONS Both naproxen and acetaminophen can affect anti-hypertensive therapy with ramipril, valsartan or aliskiren with a different extent. When acetaminophen is chosen for OA management in subjects with hypertension, patients should be evaluated as carefully as when traditional NSAIDs are given.
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Affiliation(s)
- Roberta Gualtierotti
- University of Milan, Division of Rheumatology, Istituto G. Pini, Department of Clinical Sciences and Community Health , P.za Cardinal Ferrari 1, 20122 Milan , Italy +3958296272 ; +3958296315 ;
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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: 211] [Impact Index Per Article: 19.2] [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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Deo AK, Theil FP, Nicolas JM. Confounding Parameters in Preclinical Assessment of Blood–Brain Barrier Permeation: An Overview With Emphasis on Species Differences and Effect of Disease States. Mol Pharm 2013; 10:1581-95. [DOI: 10.1021/mp300570z] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Anand K. Deo
- UCB Pharma S.A., Chemin du Foriest, B-1420 Braine-l’Alleud,
Belgium
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Borghi C, Cicero AFG. The role of irbesartan in the treatment of patients with hypertension: a comprehensive and practical review. High Blood Press Cardiovasc Prev 2012; 19:19-31. [PMID: 22670584 DOI: 10.2165/11632100-000000000-00000] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Irbesartan is an orally active angiotensin II type 1 receptor antagonist (angiotensin receptor blocker [ARB]) whose pharmacological profile differs significantly from those of many other compounds of the same class. In particular, according to its pharmacokinetic and pharmacodynamic profile, irbesartan has a high bioavailability, a long duration of action and a small potential for pharmacological interactions due to the nature of the enzymatic pathway involved in its metabolic process. Morbidity data with irbesartan have been mainly accumulated in patients with renal impairment where the drug has demonstrated the most remarkable evidence of efficacy among the ARBs class, regardless of the stage of the renal disease (from early to late) and the length of the observational period. The efficacy of irbesartan has also been demonstrated in patients with left ventricular hypertrophy and congestive heart failure. The drug is indicated for the treatment of hypertension and renal impairment in patients with type 2 diabetes mellitus (T2D) and hypertension, and its tolerability and safety profile have been extensively investigated and reported to be similar to placebo. From the pharmacoeconomic point of view, treating patients with T2D, hypertension and overt nephropathy using irbesartan was both a cost- and life-saving procedure compared with the use of amlodipine and standard antihypertensive treatment in an Italian setting. The role of irbesartan in the management of hypertension with or without T2D and renal impairment is clearly recognized by national and international guidelines and largely acknowledged by the medical community according to the efficacy of the drug in the prevention of cardiovascular risk in addition to and beyond kidney prevention.
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Affiliation(s)
- Claudio Borghi
- Department of Medicine, Aging and Clinical Nephrology, University of Bologna, Bologna, Italy.
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Toischer K, Kochhäuser S, Nguyen van P, Leineweber K, Hasenfuss G, Kögler H. Mechanical load-dependent cardiac ER stress in vitro and in vivo: Effects of preload and afterload. FEBS Lett 2012; 586:1363-9. [DOI: 10.1016/j.febslet.2012.03.055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 03/27/2012] [Indexed: 11/16/2022]
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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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Baker WL, White WB. Azilsartan medoxomil: a new angiotensin II receptor antagonist for treatment of hypertension. Ann Pharmacother 2011; 45:1506-15. [PMID: 22116996 DOI: 10.1345/aph.1q468] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To evaluate the efficacy, safety, and clinical role of azilsartan medoxomil, an angiotensin II receptor blocker (ARB) that recently gained Food and Drug Administration approval for lowering of blood pressure (BP) in patients with hypertension. DATA SOURCES A systematic review of the literature was performed through August 2011 using MEDLINE, Web of Science, and International Pharmaceutical Abstracts and the key words and MeSH terms azilsartan, azilsartan medoxomil, TAK-491, TAK-536, and Edarbi. Abstracts presented in the last 2 years from the annual meetings of appropriate medical societies were reviewed in addition to a search of clinicaltrials.gov. STUDY SELECTION AND DATA EXTRACTION Studies eligible for inclusion were in vitro or in vivo evaluations of azilsartan medoxomil, with no restrictions on patient population or indication. Data related to the patient populations and outcomes of interest were extracted from each publication. DATA SYNTHESIS Three trials are available in full publication form with others available only as abstracts. Azilsartan medoxomil 40 mg and 80 mg daily significantly improves both systolic and diastolic BP from baseline compared with placebo, and the 80-mg dose has greater efficacy than other ARBs, including olmesartan 40 mg daily and valsartan 320 mg daily. Improvements in both 24-hour BP using ambulatory monitoring and clinic monitoring have been seen with azilsartan medoxomil as well as a higher proportion of patients reaching the goal level. Additional information shows added BP lowering when azilsartan medoxomil is combined with chlorthalidone. Adverse events are similar with azilsartan medoxomil versus other ARBs and include headache, dizziness, urinary tract infections, and fatigue. CONCLUSIONS Azilsartan medoxomil is a safe and effective ARB with a unique pharmacologic profile versus other agents, including slowed angiotensin II type 1 receptor dissociation rates and improved receptor specificity. Studies have shown azilsartan medoxomil 80 mg once daily to reduce BP to a greater extent than valsartan and olmesartan, with similar safety and tolerability.
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Affiliation(s)
- William L Baker
- School of Pharmacy, University of Connecticut, Farmington, CT, USA.
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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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Casimiro-Garcia A, Filzen GF, Flynn D, Bigge CF, Chen J, Davis JA, Dudley DA, Edmunds JJ, Esmaeil N, Geyer A, Heemstra RJ, Jalaie M, Ohren JF, Ostroski R, Ellis T, Schaum RP, Stoner C. Discovery of a Series of Imidazo[4,5-b]pyridines with Dual Activity at Angiotensin II Type 1 Receptor and Peroxisome Proliferator-Activated Receptor-γ. J Med Chem 2011; 54:4219-33. [DOI: 10.1021/jm200409s] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Agustin Casimiro-Garcia
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Gary F. Filzen
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Declan Flynn
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Christopher F. Bigge
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Jing Chen
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Jo Ann Davis
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Danette A. Dudley
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Jeremy J. Edmunds
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Nadia Esmaeil
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Andrew Geyer
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Ronald J. Heemstra
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Mehran Jalaie
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Jeffrey F. Ohren
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Robert Ostroski
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Teresa Ellis
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Robert P. Schaum
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
| | - Chad Stoner
- Pfizer Global Research and Development, Groton Laboratories, Eastern Point Rd, Groton, Connecticut 06340, United States
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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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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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Han SH, Kang EW, Yoon SJ, Yoon HS, Lee HC, Yoo TH, Choi KH, Han DS, Kang SW. Combined vascular effects of HMG-CoA reductase inhibitor and angiotensin receptor blocker in non-diabetic patients undergoing peritoneal dialysis. Nephrol Dial Transplant 2011; 26:3722-8. [DOI: 10.1093/ndt/gfr108] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Li L, Zhou N, Gong H, Wu J, Lin L, Komuro I, Ge J, Zou Y. Comparison of angiotensin II type 1-receptor blockers to regress pressure overload-induced cardiac hypertrophy in mice. Hypertens Res 2010; 33:1289-97. [DOI: 10.1038/hr.2010.182] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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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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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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Efficacy, safety and pharmacokinetics of candesartan cilexetil in hypertensive children from 1 to less than 6 years of age. J Hypertens 2010; 28:1083-90. [DOI: 10.1097/hjh.0b013e328336b86b] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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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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Trachtman H, Hainer JW, Sugg J, Teng R, Sorof JM, Radcliffe J. Efficacy, safety, and pharmacokinetics of candesartan cilexetil in hypertensive children aged 6 to 17 years. J Clin Hypertens (Greenwich) 2009; 10:743-50. [PMID: 19090875 DOI: 10.1111/j.1751-7176.2008.00022.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
This 4-week randomized, double blind, placebo-controlled study (N=240), 1-year open label trial (N=233), and single-dose pharmacokinetic study (N=22) evaluated candesartan cilexetil (3 doses) in hypertensive children aged 6 to 17 years. Seventy-one percent were 12 years of age or older, 71% were male, and 47% were black. Systolic (SBP)/diastolic (DBP) blood pressure declined 8.6/4.8-11.2/8.0 mm Hg with candesartan and 3.7/1.8 mm Hg with placebo (P<.01 compared to placebo for SBP and for the mid and high doses for DBP; placebo-corrected 4.9/3.0-7.5/6.2 mm Hg). The slopes for dose were not, however, different from zero (P>.05). The response rate (SBP and DBP <95th percentile) after 1 year was 53%. The pharmacokinetic profiles in 6- to 12- and 12- to 17-year-olds were similar and were comparable to adults. Eight candesartan patients discontinued treatment because of an adverse event. Candesartan is an effective, well-tolerated antihypertensive agent for children aged 6 to 17 years and has a pharmacokinetic profile that is similar to that in adults.
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Affiliation(s)
- Howard Trachtman
- Division of Pediatric Nephrology, Schneider Children's Hospital, New Hyde Park, NY, USA
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Bramlage P, Schönrock E, Odoj P. Metabolic effects of an AT1-receptor blockade combined with HCTZ in cardiac risk patients: a non interventional study in primary care. BMC Cardiovasc Disord 2008; 8:30. [PMID: 19000308 PMCID: PMC2588554 DOI: 10.1186/1471-2261-8-30] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Accepted: 11/10/2008] [Indexed: 12/20/2022] Open
Abstract
Background The reduction of blood pressure alone does not eliminate the increased risk of arterial hypertension. Whilst concomitant metabolic risk factors have been shown to be responsible, the available pharmacotherapy has differential effects on these metabolic risk factors. For example, diuretics and betablockers worsen glucose metabolism, hence the starting point of the current subanalysis of the CHILI (Candesartan in patients with HIgher cardiovascuLar rIsk) study was the assumption that an angiotensin receptor blocker may counterbalance the metabolic effects of a low dose diuretic in patients with several metabolic risk factors. Methods The present study was performed as a non-interventional observational study in Germany. Patients with previously uncontrolled hypertension with at least one further risk factor in which physicians deemed a treatment with 16 mg Candesartan/12.5 mg HCTZ to be necessary were included. The risk factors were calculated in patient subgroups with diabetes, the metabolic syndrome (MetSyn) and neither condition (control). The risk of cardiovascular mortality within the next 10 years was calculated using the SCORE algorithm of the ESC. Results Between August 2006 and February 2007 a total of 3,787 patients were included into the non-interventional trial. Patients were 62.2 ± 11.3 years old, 48.1% were female, 97.5% had at least one additional risk factor. Blood pressure was reduced by -27.2/-13.4 mmHg with only minor non significant variations between patient groups. Waist circumference was reduced (P < 0.0001) and HDL-C elevated (P < 0.05) in every subgroup except the control subgroup. Fasting blood glucose was reduced by -5.6 ± 21.6% (P < 0.0001 vs. baseline and vs. control) as well as triglycerides (-4.9 ± 29.4%; P < 0.0001 vs. baseline and vs. control). The SCORE value was reduced substantially (-8.7, -3.2 and -2.7% in patients with diabetes, the metabolic syndrome or neither). Conclusion The present study demonstrates that a 16 mg candesartan/12.5 mg HCTZ based treatment results in a pronounced blood pressure reduction and was associated with a favourable change in metabolic risk factors such as HDL cholesterol, triglycerides and blood glucose. These data indicate that metabolic effects observed in clinical trials like ALPINE, SCOPE or CHARM can also be observed in an unselected patient population in primary care.
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Affiliation(s)
- Peter Bramlage
- Institute for Clinical Pharmacology, Medical Faculty Carl Gustav Carus, TU Dresden, Germany.
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Abstract
The number of hospitalizations for heart failure has continued to increase despite rapid and significant advances in cardiovascular care. The mortality rate is lower, but morbidity remains significant. In 2004, over 1 million people were hospitalized for heart failure. Conservative estimates indicate that the United States spends more than $33 billion annually, with hospital and nursing home costs consuming 75% of the total, home health care 10%, care providers 8%, and drugs and medical durables 8%. Angiotensin-converting enzyme inhibitor use confers a 16-20% reduction in mortality. beta-Blocker use also confers a significant reduction in mortality, as well as reduces hospitalizations. Angiotensin II receptor blockers also reduce mortality and morbidity. Appropriate use of drugs can reduce other costs associated with heart failure. During the past 20 years, many trials in patients with heart failure have been conducted. Those that have demonstrated reductions in morbidity and mortality were reviewed in order to identify the important implications for sound clinical care of patients with heart failure. Managed care practitioners and pharmacists who take the time to revisit pertinent studies will understand how each incremental knowledge enhancement builds on previous data. They will also know which agents are preferred based on well-conducted clinical trials, as well as the target doses at which these agents should be used.
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Affiliation(s)
- Mark E Dunlap
- Case Western Reserve University, Louis Stokes Veterans Affairs Medical Center, Cleveland, Ohio 44106, USA.
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Baker KM, Kumar R. Intracellular angiotensin II induces cell proliferation independent of AT1 receptor. Am J Physiol Cell Physiol 2006; 291:C995-1001. [PMID: 16774988 DOI: 10.1152/ajpcell.00238.2006] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We recently reported intracrine effects of angiotensin II (ANG II) on cardiac myocyte growth and hypertrophy that were not inhibited by the ANG II type 1 receptor (AT1) antagonist, losartan. To further determine the role of AT1 in intracrine effects, we studied the effect of intracellular ANG II (iANG II) on cell proliferation in native Chinese hamster ovary (CHO) cells and those stably transfected with AT1 receptor (CHO-AT1). CHO-AT1, but not CHO cells, showed enhanced proliferation following exposure to extracellular ANG II (eANG II). However, when transiently transfected with an iANG II expression vector, both cell types showed significantly enhanced proliferation, compared with those transfected with a scrambled peptide. Losartan blocked eANG II-induced cell proliferation, but not that induced by iANG II. To further confirm these findings, CHO and CHO-AT1 cells were stably transfected for iANG II expression (CHO-iA and CHO-AT1-iA, respectively). Cells grown in serum-free medium were counted every 24 h, up to 72 h. CHO-iA and CHO-AT1-iA cells showed a steeper growth curve compared with CHO and CHO-AT1, respectively. These observations were confirmed by Wst-1 assay. The AT1 receptor antagonists losartan, valsartan, telmisartan, and candesartan did not attenuate the faster growth rate of CHO-iA and CHO-AT1-iA cells. eANG II showed an additional growth effect in CHO-AT1-iA cells, which could be selectively blocked by losartan. These data demonstrate that intracrine ANG II can act independent of AT1 receptors and suggest novel intracellular mechanisms of action for ANG II.
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Affiliation(s)
- Kenneth M Baker
- Cardiovascular Research Institute, The Texas A&M University System Health Science Center, Temple, TX 76504, USA
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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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Zorad S, Dou JT, Benicky J, Hutanu D, Tybitanclova K, Zhou J, Saavedra JM. Long-term angiotensin II AT1 receptor inhibition produces adipose tissue hypotrophy accompanied by increased expression of adiponectin and PPARgamma. Eur J Pharmacol 2006; 552:112-22. [PMID: 17064684 PMCID: PMC1764497 DOI: 10.1016/j.ejphar.2006.08.062] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Revised: 08/10/2006] [Accepted: 08/29/2006] [Indexed: 12/13/2022]
Abstract
To clarify the mechanism of the effects of angiotensin II AT(1) receptor antagonists on adipose tissue, we treated 8 week-old male Wistar Kyoto rats with the angiotensin II AT(1) receptor antagonist Candesartan cilexetil (10 mg/kg/day) for 18 weeks. Candesartan cilexetil reduced body weight gain, decreased fat tissue mass due to hypotrophy of epididymal and retroperitoneal adipose tissue and decreased adipocyte size without changing the number of adipocytes. Candesartan cilexetil decreased serum leptin levels and epididymal leptin mRNA, increased serum adiponectin levels and epididymal adiponectin mRNA, decreased epididymal tumor necrosis factor alpha (TNFalpha) mRNA, and increased fatty acid synthase mRNA. Considered free of peroxisome proliferator-activated receptor gamma (PPARgamma) agonist activity, Candesartan cilexetil increased epididymal expression of PPARgamma mRNA. The effects of Candesartan cilexetil on adipokine production and release may be attributable to PPARgamma activation and/or decrease in adipocyte cell size. In addition, Candesartan cilexetil treatment increased the expression of epididymal angiotensin II AT(2) receptor mRNA and protein and decreased the expression of renin receptor mRNA. These results suggest that Candesartan cilexetil influences lipid metabolism in adipose tissue by promoting adipose tissue rearrangement and modulating adipokine expression and release. These effects are probably consequences of local angiotensin II AT(1) receptor inhibition, angiotensin II AT(2) receptor stimulation, and perhaps additional angiotensin II-independent mechanisms. Our results indicate that the activity of local renin-angiotensin system plays an important role in adipose tissue metabolism. The decrease in the pro-inflammatory cytokine TNFalpha and the increase in the anti-inflammatory adipokine adiponectin indicate that Candesartan cilexetil may exert significant anti-inflammatory properties.
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Affiliation(s)
- Stefan Zorad
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Jing-tao Dou
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892
| | - Julius Benicky
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892
- To whom correspondence should be addressed. Julius BENICKY, Ph.D., Section on Pharmacology, DIRP, NIMH, NIH, DHHS. 10 Center Drive, Bldg. 10, Room 2D-57, Bethesda MD 20892. Telephone: (301)451-8378, Fax (301) 402-0337. E-mail:
| | - Daniel Hutanu
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892
| | - Katarina Tybitanclova
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Jin Zhou
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892
| | - Juan M. Saavedra
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892
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Sullivan SK, Hoare SRJ, Fleck BA, Zhu YF, Heise CE, Struthers RS, Crowe PD. Kinetics of nonpeptide antagonist binding to the human gonadotropin-releasing hormone receptor: Implications for structure–activity relationships and insurmountable antagonism. Biochem Pharmacol 2006; 72:838-49. [PMID: 16930559 DOI: 10.1016/j.bcp.2006.07.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Revised: 06/28/2006] [Accepted: 07/17/2006] [Indexed: 11/21/2022]
Abstract
Numerous nonpeptide ligands have been developed for the human gonadotropin-releasing hormone (GnRH) receptor as potential agents for treatment of disorders of the reproductive-endocrine axis. While the equilibrium binding of these ligands has been studied in detail, little is known of the kinetics of their receptor interaction. In this study we evaluated the kinetic structure-activity relationships (SAR) of uracil-series antagonists by measuring their association and dissociation rate constants. These constants were measured directly using a novel radioligand, [3H] NBI 42902, and indirectly for unlabeled ligands. Receptor association and dissociation of [3H] NBI 42902 was monophasic, with an association rate constant of 93+/-10 microM(-1) min(-1) and a dissociation rate constant of 0.16+/-0.02 h(-1) (t(1/2) of 4.3 h). Four unlabeled compounds were tested with varying substituents at the 2-position of the benzyl group at position 1 of the uracil (-F, -SO(CH3), -SO2(CH3) and -CF3). The nature of the substituent did not appreciably affect the association rate constant but varied the dissociation rate constant >50-fold (t(1/2) ranging from 52 min for -SO(CH3) to >43 h for -CF3). This SAR was poorly resolved in standard competition assays due to lack of equilibration. The functional consequences of the varying dissociation rate were investigated by measuring antagonism of GnRH-stimulated [3H] inositol phosphates accumulation. Slowly dissociating ligands displayed insurmountable antagonism (decrease of the GnRH E(max)) while antagonism by more rapidly dissociating ligands was surmountable (without effect on the GnRH E(max)). Therefore, evaluating the receptor binding kinetics of nonpeptide antagonists revealed SAR, not evident in standard competition assays, that defined at least in part the mode of functional antagonism by the ligands. These findings are of importance for the future definition of nonpeptide ligand SAR and for the identification of potentially useful slowly dissociating antagonists for the GnRH receptor.
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Affiliation(s)
- Susan K Sullivan
- Department of Pharmacology and Lead Discovery, Neurocrine Biosciences Inc., 12790 El Camino Real, San Diego, CA 92130, USA
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Vauquelin G, Fierens F, Van Liefde I. Long-lasting angiotensin type 1 receptor binding and protection by candesartan: comparison with other biphenyl-tetrazole sartans. J Hypertens 2006; 24:S23-30. [PMID: 16601569 DOI: 10.1097/01.hjh.0000220403.61493.18] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The ability of biphenyl-tetrazole angiotensin type 1 (AT1) receptor antagonists (BTsartans) to block angiotensin II (Ang II)-mediated responses has been extensively investigated in vascular tissues and, more recently, in cell lines expressing the human AT1-receptor. When pre-incubated, BTsartans acted surmountably (shifting the Ang II concentration-response curve to the right) or insurmountably (also decreasing the maximal response). It was shown that their insurmountable behaviour is due to the formation of tight, long-lasting complexes with the receptor. Partial insurmountable antagonism is due to the co-existence of tight and loose complexes. The proportion of insurmountable antagonism, the potency and the dissociation rate of the BTsartans decreases in the order: candesartan > EXP3174 (losartan's active metabolite) > valsartan > irbesartan >> losartan. OBJECTIVE It is of interest to explore how tight AT1-receptor binding of BTsartans such as candesartan might contribute to their long-lasting clinical effect. METHODS Computer-assisted simulations (COPASI program) were performed to follow the receptor-occupation and protection by different antagonists as a function of time. Free antagonist concentrations were allowed to decrease exponentially with time. RESULTS The simulations suggest that slow dissociation does not tangibly prolong receptor occupancy if the free antagonist is eliminated at a slower pace (as is the case for BTsartans). Yet when surmountable and insurmountable antagonists occupy the same amount of receptors, insurmountable antagonists offer appreciably better protection against fluctuations in natural messenger concentration. CONCLUSION Slow receptor dissociation and slow antagonist elimination are likely to act in synergy to produce long-lasting receptor protection.
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Affiliation(s)
- Georges Vauquelin
- Department of Molecular and Biochemical Pharmacology, Free University of Brussels (VUB), Brussels, Belgium.
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McKelvie RS. Current and future uses of candesartan in the treatment of heart failure. Future Cardiol 2006; 2:391-402. [PMID: 19804175 DOI: 10.2217/14796678.2.4.391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Candesartan is an angiotensin receptor antagonist that is long acting, well absorbed from the gastrointestinal tract and demonstrates an insurmountable receptor antagonism. It is an effective once-daily antihypertensive therapy that maintains good control of blood pressure for over 24 h. More recently, candesartan was shown to be an effective therapy for heart failure patients, producing a significant reduction in mortality and morbidity. Importantly, the studies have demonstrated that candesartan is effective in heart failure patients intolerant to angiotensin-converting enzyme inhibitors (ACE-I), as well as in addition to ACE-I. This paper reviews the data supporting the use of candesartan to treat patients with clinical heart failure.
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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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Schulz R. Interference with the renin-angiotensin system in heart failure. Naunyn Schmiedebergs Arch Pharmacol 2006; 372:331-4. [PMID: 16468022 DOI: 10.1007/s00210-005-0030-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- R Schulz
- Institut für Pathophysiologie, Zentrum für Innere Medizin, Universitätsklinikum Essen, Hufelandstrasse 55, 45122 Essen, Germany.
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Fernandes L, Loiola RA, Tostes RCA, Nigro D, Fortes ZB, de Carvalho MHC. Angiotensin II-induced venoconstriction involves both AT1 and AT2 receptors and is counterbalanced by nitric oxide. Peptides 2005; 26:2458-63. [PMID: 16043265 DOI: 10.1016/j.peptides.2005.05.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2005] [Revised: 05/31/2005] [Accepted: 05/31/2005] [Indexed: 11/21/2022]
Abstract
The venoconstrictor effect of Angiotensin II (Ang II) was investigated in the rat mesenteric venules and portal vein. Mesenteric venules were perfused at a constant rate and reactivity to Ang II (0.1 nmol) was evaluated as changes in the perfusion pressure. Rings of portal vein were mounted in organ baths and curves to Ang II (0.1-100 nmol/L) were generated. In venules, Ang II-contraction (10.6+/-1.1 mmHg) was abolished by losartan (0.9+/-0.3 mmHg*), reduced by PD 123,319 (5.8+/-0.9 mmHg*), increased by L-NAME (16.5+/-1.8 mmHg*) and not altered by indomethacin. In portal veins, curves to Ang II (-logEC50: 8.9+/-0.1 mol/L) were shifted to the right by losartan (-log EC50: 7.5+/-0.1 mol/L*) and by PD 123,319 (-logEC50: 8.0+/-0.1 mol/L*). L-NAME increased the maximal response to Ang II (Emax: 0.91+/-0.1g versus 1.62+/-0.3g*) and indomethacin had no effect. In conclusion, Ang II induces venoconstriction by activating AT1 and AT2 receptors. Data obtained with L-NAME provide evidence that the basal nitric oxide release from the endothelium of the venous system can modulate the Ang II-induced venoconstriction.
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Affiliation(s)
- Liliam Fernandes
- Department of Pharmacology, Institute of Biomedical Sciences I-s/213, University of São Paulo, Av. Prof. Lineu Prestes 1524, 05508 900 São Paulo, SP, Brazil
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Mitchell KD, Mullins JJ. Enhanced tubuloglomerular feedback in Cyp1a1-Ren2 transgenic rats with inducible ANG II-dependent malignant hypertension. Am J Physiol Renal Physiol 2005; 289:F1210-6. [PMID: 16033920 DOI: 10.1152/ajprenal.00461.2004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present study was performed to evaluate tubuloglomerular feedback responses in transgenic rats [TGR(Cypa1a1Ren2)] with inducible malignant hypertension and to determine the degree to which feedback responsiveness is modulated by ANG II in these rats. Male Cyp1a1-Ren2 rats were fed a normal diet containing the aryl hydrocarbon indole-3-carbinol (I3C; 0.3%), for 5-6 days to stimulate expression of the Cyp1a1-Ren2 transgene and, thereby, to induce malignant hypertension. Stop-flow pressure (SFP) feedback responses to a late proximal perfusion rate of 40 nl/min were assessed in pentobarbital sodium-anesthetized rats during control conditions and after administration of the AT(1) receptor antagonist candesartan (0.1 mg/kg iv). Rats induced with I3C (n = 6) exhibited elevated mean arterial pressure and increased maximal SFP feedback responses compared with noninduced rats (n = 4; 163 +/- 4 vs. 130 +/- 2 mmHg, P < 0.01 and 16.3 +/- 1.4 vs. 11.7 +/- 0.5 mmHg, P < 0.05, respectively). Systemic candesartan decreased arterial pressure (to 98 +/- 7 and to 101 +/- 5 mmHg, respectively, P < 0.001) and attenuated SFP feedback responses (to 2.0 +/- 0.4 and to 3.3 +/- 0.9 mmHg, respectively, P < 0.01) in both hypertensive and normotensive rats. In additional experiments, peritubular capillary infusion of 10(-3) M candesartan did not alter arterial pressure but attenuated feedback responses in both hypertensive (19.3 +/- 1.4 to 8.8 +/- 0.9 mmHg, P < 0.01, n = 9) and normotensive Cyp1a1-Ren2 rats (9.0 +/- 0.8 to 4.7 +/- 0.6 mmHg, P < 0.01, n = 7). The present findings indicate that Cyp1a1-Ren2 rats with ANG II-dependent malignant hypertension exhibit augmented tubuloglomerular feedback responses. The data also show that AT(1) receptor activation by ANG II contributes to the enhanced feedback responsiveness in Cyp1a1-Ren2 rats with malignant hypertension.
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Affiliation(s)
- Kenneth D Mitchell
- Department of Physiology, Tulane University Health Sciences Center, New Orleans, LA 70112, USA.
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Levine TB, Levine AB. Clinical update: The role of angiotensin II receptor blockers in patients with left ventricular dysfunction (Part II of II). Clin Cardiol 2005; 28:277-80. [PMID: 16028461 PMCID: PMC6654260 DOI: 10.1002/clc.4960280604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Almost 5 million individuals in the United States have chronic heart failure (HF), which is increasing in prevalence. Angiotensin-converting enzyme (ACE) inhibitors are standard therapies for HF, although more than 10% of patients with HF are unable to tolerate these agents. Furthermore, ACE inhibitors may not provide complete blockade of the renin-angiotensin system (RAS) in the long term. Because angiotensin II receptor blockers (ARBs) may block the RAS more completely than ACE inhibitors and are better tolerated, several large-scale ARB trials have been performed exploring their potential role in treating patients with symptomatic HF and left ventricular systolic dysfunction. The Losartan Heart Failure Survival Study (ELITE II) demonstrated no significant differences in morbidity and mortality between the ARB losartan and the ACE inhibitor captopril among elderly patients with HF. The Valsartan Heart Failure Trial (Val-HeFT) demonstrated reductions in hospitalizations for HF with the ARB valsartan when added to standard HF therapy, with no effect on mortality. Both trials suggested a potential negative interaction between ARB and beta-blocker therapy. The Candesartan in Heart failure-Assessment of Reduction in Mortality and morbidity (CHARM) program demonstrated significant reductions in morbidity and mortality with the ARB candesartan in patients with HF due to systolic dysfunction, with or without ACE inhibitors and with or without beta blockers. Thus, the addition of ARBs to the treatment regimen of patients with symptomatic HF should be strongly considered.
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Affiliation(s)
- T Barry Levine
- Division of Cardiology, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212-4772, USA.
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Nascimento EA, Gioli-Pereira L, Carvalho LT, Santos EL, Pesquero JB, Kouyoumdjian M, Borges DR. Hemodynamic and metabolic effects of angiotensin II on the liver. Peptides 2005; 26:315-22. [PMID: 15629544 DOI: 10.1016/j.peptides.2004.09.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2004] [Revised: 09/28/2004] [Accepted: 09/28/2004] [Indexed: 10/26/2022]
Abstract
To ascertain the mechanism of interaction between angiotensins (AI and AII) and the liver, an angiotensin-converting enzyme inhibitor (captopril) and a receptor antagonist (losartan) were used. Monovascular or bivascular liver perfusion was used to assess both hemodynamic (portal and arterial hypertensive responses) and metabolic (glucose production and oxygen consumption) effects. Microphysiometry was used for isolated liver cell assays to assess AII or losartan membrane receptor-mediated interaction. Captopril abolishes portal hypertensive response (PHR) to AI but not the AII effect. AII infused via the portal pathway promotes calcium-dependent PHR but not a hypertensive response in the arterial pathway (AHR); when infused into the arterial pathway AII promotes calcium-dependent PHR and AHR. Losartan infused into the portal vein abolishes PHR to AII but not the metabolic response; when infused via both pathways it abolishes the hypertensive responses and inhibits the metabolic effects. Isolated liver cells specifically respond to AII. Sinusoidal cells, but not hepatocytes, respond to 10 nM losartan. We conclude that AI has to be converted to AII to produce PHR. Quiescent stellate cells interacts in vitro with AII and losartan. Hemodynamic responses to AII are losartan-dependent but metabolic responses are partially losartan-independent. AII hemodynamic actions are mainly presinusoidal.
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Imbs JL, Nisse-Durgeat S. Efficacy and tolerability of candesartan cilexetil vs. amlodipine as assessed by home blood pressure in hypertensive patients. Int J Clin Pract 2005; 59:78-84. [PMID: 15707470 DOI: 10.1111/j.1742-1241.2005.00296.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
This randomised, double-blind study compared the anti-hypertensive efficacy and tolerability of Candesartan cilexetil (CC 8-16 mg) and Amlodipine (AML 5-10 mg) on home blood pressure (HBP) measurements in mild-to-moderate hypertensive patients. After a 2-week wash-out, patients aged 18-74 years, with a sitting diastolic blood pressure (sDBP)=95-115 mmHg, untreated or intolerant to therapy or uncontrolled were randomised to CC 8 mg or AML 5 mg O.D. for 12 weeks (W12). Patients not normalised or not responders at W12 had their dose doubled for the remaining 6 weeks. HBP was measured before each visit, during 5 days (three measurements in the morning, 24 h after last dose and before drug intake and three measurements before bedtime). The primary criterion was the comparison of mean morning sDBP at baseline and post-treatment. A total of 638 patients were enrolled, 540 of whom were randomised to CC or AML. The intent-to-treat and safety analyses were performed in 532 patients while 321 constituted the per protocol population. Baseline characteristics and BP values of the two groups were similar. Morning sDBP did not differ between groups at W12, but AML patients had significantly more adverse events (AEs) than those treated by CC (28 vs. 20%, p=0.03); 6% of AML patients vs. 1% of CC patients were withdrawn due to AEs (p=0.009). CC demonstrates a better tolerability over AML and an equivalent anti-hypertensive efficacy in terms of morning home DBP after 12 weeks of treatment.
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Affiliation(s)
- J-L Imbs
- Service de Cardiologie, CHU, Strasbourg, Laboratoires TAKEDA, Puteaux, France.
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Saavedra JM, Pavel J. Angiotensin II AT1 receptor antagonists inhibit the angiotensin-CRF-AVP axis and are potentially useful for the treatment of stress-related and mood disorders. Drug Dev Res 2005. [DOI: 10.1002/ddr.20027] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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