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Ameen Ismail A, Sadek S, Hatata R, Kamal M. Effect of brimonidine on vascular density and imagej-derived flow index of optic nerve head and macula in primary open angle glaucoma. Int Ophthalmol 2024; 44:311. [PMID: 38963456 DOI: 10.1007/s10792-024-03221-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 06/16/2024] [Indexed: 07/05/2024]
Abstract
PURPOSE To study the effect of brimonidine on vascular density and flow index of optic nerve head (ONH) and macula in primary open angle glaucoma (POAG) using optical coherence tomography angiography (OCTA). METHODS Twenty-three brimonidine-naïve POAG patients were started on brimonidine. They underwent OCTA ONH and macula before commencing brimonidine and one month thereafter. Systemic arterial blood pressure (SABP) and intraocular pressure (IOP) were measured at each visit to calculate mean ocular perfusion pressure (MOPP). The OCT angiograms were analyzed using ImageJ software to calculate ONH and macular flow indices. RESULTS Thirty-seven eyes (23 patients) with a mean age of 56.7 ± 12.49 years were included of whom 60.8% were males. Brimonidine was associated with an increase in the superficial flow index (SFI) (P-value = 0.02) and optic nerve head flow index (ONHFI) (P-value = 0.01). Also, superficial vascular density (SVD) for whole image, superior-hemi and fovea increased (P-value = 0.03, 0.02, 0.03 respectively). ONH inferior-hemi vascular density decreased (P-value = 0.01) despite an increase in inferior quadrant retinal nerve fiber layer thickness (RNFLT) (P-value = 0.03). There was no statistically significant correlation between flow indices and MOPP at baseline and follow-up. A moderate negative correlation was found between SVD and DVD at the fovea and MOPP at baseline and follow-up (P-value = 0.03, 0.05) (P-value = 0.02, 0.01) respectively. CONCLUSIONS Brimonidine was associated with an increase in SFI, ONHFI and SVD indicating improved GCC and RNFL perfusion in POAG. Despite the increase in inferior quadrant RNFLT, the concomitant decrease in inferior-hemi ONHVD precluded a conclusion of hemodynamically-mediated improvement of RNFLT.
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Affiliation(s)
- Ahmed Ameen Ismail
- Department of Ophthalmology, Faculty of Medicine, Fayoum University, Al-Fayoum, Egypt.
| | - Sherin Sadek
- Department of Ophthalmology, Faculty of Medicine, Fayoum University, Al-Fayoum, Egypt
| | - Ragai Hatata
- Department of Ophthalmology, Faculty of Medicine, Fayoum University, Al-Fayoum, Egypt
| | - Mahmoud Kamal
- Department of Ophthalmology, Faculty of Medicine, Fayoum University, Al-Fayoum, Egypt
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Ruan Y, Buonfiglio F, Gericke A. Adrenoceptors in the Eye - Physiological and Pathophysiological Relevance. Handb Exp Pharmacol 2024; 285:453-505. [PMID: 38082203 DOI: 10.1007/164_2023_702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
The autonomic nervous system plays a crucial role in the innervation of the eye. Consequently, it comes as no surprise that catecholamines and their corresponding receptors have been extensively studied and characterized in numerous ocular structures, including the cornea, conjunctiva, lacrimal gland, trabecular meshwork, uvea, and retina. These investigations have unveiled substantial clinical implications, particularly in the context of treating glaucoma, a progressive neurodegenerative disorder responsible for irreversible vision loss on a global scale. The primary therapeutic approaches for glaucoma frequently involve the modulation of α1-, α2-, and β-adrenoceptors, making them pivotal targets. In this chapter, we offer a comprehensive overview of the expression, distribution, and functional roles of adrenoceptors within various components of the eye and its associated structures. Additionally, we delve into the pivotal role of adrenoceptors in the pathophysiology of glaucoma. Furthermore, we provide a concise historical perspective on adrenoceptor research, examine the distinct contributions of individual adrenoceptor subtypes to the treatment of various ocular conditions, and propose potential future avenues of exploration in this field.
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Affiliation(s)
- Yue Ruan
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Francesco Buonfiglio
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Adrian Gericke
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Mainz, Germany.
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3
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Orii Y, Kunikane E, Yamada Y, Morioka M, Iwasaki K, Arimura S, Mizuno A, Inatani M. Ocular Distribution of Brimonidine and Brinzolamide after Topical Instillation of a 0.1% Brimonidine Tartrate and 1% Brinzolamide Fixed-Combination Ophthalmic Suspension: An Interventional Study. J Clin Med 2023; 12:4175. [PMID: 37445209 DOI: 10.3390/jcm12134175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/08/2023] [Accepted: 06/16/2023] [Indexed: 07/15/2023] Open
Abstract
PURPOSE To evaluate the concentrations of brimonidine and brinzolamide in the vitreous and aqueous humor after instillation of a 0.1% brimonidine tartrate and 1% brinzolamide fixed-combination ophthalmic suspension. METHODS The present investigation involved patients with macular holes or idiopathic epiretinal membranes who were planning to undergo vitrectomy. One week prior to surgery, the patients received twice-daily topical treatment with 0.1% brimonidine tartrate and 1% brinzolamide fixed-combination ophthalmic suspension. Before vitrectomy, vitreous and aqueous humor samples were collected, and the mean concentrations of brimonidine and brinzolamide were determined through liquid chromatography-tandem spectrometry. RESULTS Ten eyes (nine phakic and one pseudophakic eyes; 10 patients) were examined. The concentration of brimonidine in vitreous and aqueous humor samples was 5.02 ± 2.24 and 559 ± 670 nM, respectively. The concentration of brimonidine in the vitreous humor, which is needed to activate α2 receptors, was >2 nM in all patients. The concentration of brinzolamide was 8.96 ± 4.65 and 1100 ± 813 nM, respectively. However, there was no significant correlation between the concentrations of brimonidine in the vitreous and aqueous humor samples. CONCLUSIONS Sufficient concentrations of brimonidine were detected in all vitreous samples. The dissociated correlation of the drug concentrations between aqueous and vitreous humors implies the possibility of another pathway to vitreous humor, different from the pathway to aqueous humor.
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Affiliation(s)
- Yusuke Orii
- Department of Ophthalmology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | | | - Yutaka Yamada
- Department of Ophthalmology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Masakazu Morioka
- Department of Ophthalmology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Kentaro Iwasaki
- Department of Ophthalmology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Shogo Arimura
- Department of Ophthalmology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Akemi Mizuno
- Senju Pharmaceutical Co., Ltd., Osaka 541-0048, Japan
| | - Masaru Inatani
- Department of Ophthalmology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
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Bozkan Z, Yaygingul R, Bulut O, Belge A. Measuring the Effects of Detomidine and Medetomidine Alone and in Combination with Ketamine on Tear Production and Intraocular Pressure in Common Buzzards (Buteo buteo). J Avian Med Surg 2022; 36:242-249. [DOI: 10.1647/21-00064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Connell AR, Hookham MB, Fu D, Brazil DP, Lyons TJ, Yu JY. Comparisons of α2-Adrenergic Agents, Medetomidine and Xylazine, with Pentobarbital for Anesthesia: Important Pitfalls in Diabetic and Nondiabetic Rats. J Ocul Pharmacol Ther 2021; 38:156-166. [PMID: 34964655 PMCID: PMC8971989 DOI: 10.1089/jop.2021.0084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Purpose: Anesthesia is necessary to conduct rodent electroretinograms (ERGs). We evaluated utility of the α2-agonist medetomidine versus xylazine for ERG studies in nondiabetic and diabetic rats. Pentobarbital was included as a comparator. Methods: Male Sprague-Dawley rats, with and without streptozotocin (STZ)-induced diabetes, were anesthetized with medetomidine (1 mg/kg), xylazine (10 mg/kg) (both with ketamine 75 mg/kg), or pentobarbital (70 mg/kg). The depth of anesthesia was assessed, and if adequate, scotopic ERGs were recorded. Blood glucose was monitored. Results: In nondiabetic rats, all three agents induced satisfactory anesthesia, but with differing durations: medetomidine > pentobarbital > xylazine. ERG responses were similar under medetomidine and xylazine, but relatively reduced under pentobarbital. Both α2-agonists (but not pentobarbital) elicited marked hyperglycemia (peak values 316.1 ± 42.6 and 300.3 ± 29.5 mg/dL, respectively), persisting for 12 h. In diabetic rats, elevated blood glucose concentrations were not affected by any of the agents, but the depth of anesthesia under medetomidine and xylazine was inadequate for ERG recording. Conclusions: In nondiabetic rats, medetomidine and xylazine elicited comparable effects on ERGs that differ from pentobarbital, but both perturbed glucose metabolism, potentially confounding experimental outcomes. In STZ-diabetic rats, neither α2-agent provided adequate anesthesia, while pentobarbital did so. Problems with α2-anesthetic agents, including medetomidine, must be recognized to ensure meaningful interpretation of experimental results.
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Affiliation(s)
- Anna R Connell
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Northern Ireland, United Kingdom
| | - Michelle B Hookham
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Northern Ireland, United Kingdom
| | - Dongxu Fu
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Northern Ireland, United Kingdom.,Division of Endocrinology, Diabetes, and Metabolic Diseases, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA.,Diabetes Free South Carolina, BlueCross BlueShield of South Carolina, Columbia, South Carolina, USA
| | - Derek P Brazil
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Northern Ireland, United Kingdom
| | - Timothy J Lyons
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Northern Ireland, United Kingdom.,Division of Endocrinology, Diabetes, and Metabolic Diseases, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA.,Diabetes Free South Carolina, BlueCross BlueShield of South Carolina, Columbia, South Carolina, USA
| | - Jeremy Y Yu
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Northern Ireland, United Kingdom.,Division of Endocrinology, Diabetes, and Metabolic Diseases, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
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Tamhane M, Luu KT, Attar M. Ocular Pharmacokinetics of Brimonidine Drug Delivery System in Monkeys and Translational Modeling for Selection of Dose and Frequency in Clinical Trials. J Pharmacol Exp Ther 2021; 378:207-214. [PMID: 34210753 DOI: 10.1124/jpet.120.000483] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 06/28/2021] [Indexed: 01/07/2023] Open
Abstract
Brimonidine, a selective α 2-adrenoceptor agonist, displays putative retinal cyto- and neuroprotective activity in vitro and in vivo. An intravitreal sustained-release brimonidine implant, Brimonidine Posterior Segment Drug Delivery System (brimonidine DDS), allowing targeted drug delivery to the retina has been developed for potential clinical application. This study evaluates the in vivo posterior segment pharmacokinetics of brimonidine DDS implant in the monkey eye and applies translational pharmacokinetic modeling to predict tissue exposure in the human eye. Anesthetized cynomolgus monkeys received a single intravitreal injection of brimonidine DDS 400 µg implant before removal of study eyes at days 7, 30, 60, 92, 120, and 150 postimplant (three to four animals per time point) for assay of brimonidine in aqueous humor, vitreous, and retina samples. Brimonidine concentrations in the human eye were modeled using a linear, three-compartment model assuming bidirectional distribution to/from the aqueous humor and retina and elimination from the aqueous humor. Monkey tissue volumes were scaled up to human values; intercompartmental and elimination rate constants were assumed to be identical in the two species. Modeling and simulations were performed using NONMEM v. 7.3, R 3.5.1. Brimonidine exposure was highest in the monkey vitreous and retina; concentrations in the central (macula) and peripheral retina were maintained at high levels (>100 ng/g) for 3 to 4 months. Simulated brimonidine concentration-time profiles in human macula indicated that brimonidine DDS 400 µg implant would deliver effective drug concentrations (20.7‒82.2 ng/g, based on animal pharmacology) for approximately 3 months. Accordingly, administration of the 400 µg implant at 3-month intervals is recommended. SIGNIFICANCE STATEMENT: Brimonidine, an α 2-adrenoceptor agonist, is cyto- and neuroprotective in animal models of retinal/optic nerve injury. Brimonidine Posterior Segment Drug Delivery System (brimonidine DDS) is an intravitreal sustained-release implant with potential ophthalmological applications. This study explores the pharmacokinetics of brimonidine DDS 400 µg implant in the monkey eye and uses compartmental modeling to predict human ocular tissue exposure. Targeted retinal brimonidine delivery from vitreous was demonstrated in monkeys. Simulated tissue concentration-time profiles indicated persistence of pharmacologically effective brimonidine concentrations for ≈3 months in human retina.
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Lelescu CA, Dumitras DA, Iurian S, Staffieri F, Muresan C. Effects of topical application of tramadol with/without dexmedetomidine and proparacaine on corneal sensitivity in rats. Int Ophthalmol 2021; 41:465-473. [PMID: 33095346 DOI: 10.1007/s10792-020-01596-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 10/01/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To evaluate the corneal anesthetic effect following topical application of tramadol alone and in combination with dexmedetomidine, and compare it to proparacaine, in clinically healthy rats. METHODS A randomized, crossover study was performed. Twenty Wistar albino rats (n = 40 eyes) were used. Corneal touch threshold (CTT) measurements (in mm) were obtained using a Cochet-Bonnet aesthesiometer. CTT measurements were obtained at baseline, 1-min following application of the topical anesthetic agent, and repeated at 5-min intervals up to 75 min. The topical protocol involved 3 treatment conditions, separated by a 2-week washout period: proparacaine, tramadol alone, and tramadol in combination with dexmedetomidine. RESULTS CTT values were significantly decreased compared to baseline at each timepoint until completion of the 75-min evaluation in all treated eyes, regardless of the assigned treatment (p < 0.0083). With tramadol, complete corneal anesthesia (CTT = 0) was achieved within 1-5 min in 18 eyes and ranged from 5 to 25 min. Co-administration of dexmedetomidine to tramadol resulted in significantly increased CTT values from 5 to 20 min following topical application, compared to tramadol alone (p < 0.0083), and complete corneal anesthesia was achieved in only 14 out of 20 treated eyes. CONCLUSION Tramadol might be a useful alternative to topical anesthetic agents, providing a dose-related corneal anesthetic effect. Co-administration of dexmedetomidine does not potentiate its anesthetic effect. The underlying mechanism(s) of drug antagonism between tramadol and dexmedetomidine remains to be determined.
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Affiliation(s)
- Cristina A Lelescu
- Modis Competence Center, Modis Life Sciences Belgium, Mureșului 9, 400000, Cluj-Napoca, Romania
| | - Daria A Dumitras
- Department of Biochemistry, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine, Calea Mănăştur 3-5, 400372, Cluj-Napoca, Romania
| | - Sonia Iurian
- Department of Pharmaceutical Technology and Biopharmaceutics, Faculty of Pharmacy, University of Medicine and Pharmacy "Iuliu Hațieganu", V. Babeș 41, 400012, Cluj-Napoca, Romania
| | - Francesco Staffieri
- Division of Veterinary Surgery, Department of Emergency and Organ Transplantation, Faculty of Veterinary Medicine, University "Aldo Moro" of Bari, SP Per Casamassima Km. 3, 70010, Valenzano, Bari, Italy
| | - Cosmin Muresan
- Department of Surgery, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine, Calea Mănăştur 3-5, 400372, Cluj-Napoca, Romania.
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8
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The Role of Adrenoceptors in the Retina. Cells 2020; 9:cells9122594. [PMID: 33287335 PMCID: PMC7761662 DOI: 10.3390/cells9122594] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 11/29/2020] [Accepted: 12/01/2020] [Indexed: 01/16/2023] Open
Abstract
The retina is a part of the central nervous system, a thin multilayer with neuronal lamination, responsible for detecting, preprocessing, and sending visual information to the brain. Many retinal diseases are characterized by hemodynamic perturbations and neurodegeneration leading to vision loss and reduced quality of life. Since catecholamines and respective bindings sites have been characterized in the retina, we systematically reviewed the literature with regard to retinal expression, distribution and function of alpha1 (α1)-, alpha2 (α2)-, and beta (β)-adrenoceptors (ARs). Moreover, we discuss the role of the individual adrenoceptors as targets for the treatment of retinal diseases.
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Rodrigo MJ, Cardiel MJ, Fraile JM, Mendez-Martinez S, Martinez-Rincon T, Subias M, Polo V, Ruberte J, Ramirez T, Vispe E, Luna C, Mayoral JA, Garcia-Martin E. Brimonidine-LAPONITE® intravitreal formulation has an ocular hypotensive and neuroprotective effect throughout 6 months of follow-up in a glaucoma animal model. Biomater Sci 2020; 8:6246-6260. [PMID: 33016285 DOI: 10.1039/d0bm01013h] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Intravitreal administration is widely used in ophthalmological practice to maintain therapeutic drug levels near the neuroretina and because drug delivery systems are necessary to avoid reinjections and sight-threatening side effects. However, currently there is no intravitreal treatment for glaucoma. The brimonidine-LAPONITE® formulation was created with the aim of treating glaucoma for extended periods with a single intravitreal injection. Glaucoma was induced by producing ocular hypertension in two rat cohorts: [BRI-LAP] and [non-bri], with and without treatment, respectively. Eyes treated with brimonidine-LAPONITE® showed lower ocular pressure levels up to week 8 (p < 0.001), functional neuroprotection explored by scotopic and photopic negative response electroretinography (p = 0.042), and structural protection of the retina, retinal nerve fibre layer and ganglion cell layer (p = 0.038), especially on the superior-inferior axis explored by optical coherence tomography, which was corroborated by a higher retinal ganglion cell count (p = 0.040) using immunohistochemistry (Brn3a antibody) up to the end of the study (week 24). Furthermore, delayed neuroprotection was detected in the contralateral eye. Brimonidine was detected in treated rat eyes for up to 6 months. Brimonidine-LAPONITE® seems to be a potential sustained-delivery intravitreal drug for glaucoma treatment.
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Affiliation(s)
- M J Rodrigo
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain.
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Chang CY, Chen HA, Chien YJ, Wu MY. Attenuation of the increase in intraocular pressure with dexmedetomidine: Systematic review with meta-analysis and trial sequential analysis. J Clin Anesth 2020; 68:110065. [PMID: 33032125 DOI: 10.1016/j.jclinane.2020.110065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/16/2020] [Accepted: 09/19/2020] [Indexed: 11/16/2022]
Abstract
STUDY OBJECTIVE Whether dexmedetomidine effectively attenuates the increase in intraocular pressure (IOP) remains inconclusive. We aim to evaluate the effects of dexmedetomidine on IOP in adult patients undergoing surgery which requires general anesthesia and endotracheal intubation. DESIGN Systematic review and meta-analysis. INTERVENTIONS Intravenous administration of dexmedetomidine during surgery. MEASUREMENTS Intraocular pressure. METHODS We searched PubMed, Embase, Scopus, Web of Science, Cochrane Library, Google Scholar, Wanfang Data, and China National Knowledge Infrastructure from the inception through April 14, 2020. Randomized control trials which involved adult patients undergoing surgery that required general anesthesia and endotracheal intubation, which compared intravenous administration of dexmedetomidine with placebo regarding the IOP levels, which also provided sufficient information for meta-analysis were considered eligible. MAIN RESULTS Twenty-nine randomized control trials were included. The IOP levels are significantly lower in patients receiving dexmedetomidine after the administration of dexmedetomidine [mean difference (MD), -2.04 mmHg; 95% confidence interval (CI), -2.40 mmHg to -1.67 mmHg], after the injection of succinylcholine (MD, -3.84 mmHg; 95% CI, -4.80 mmHg to -2.88 mmHg), after endotracheal intubation (MD, -3.64 mmHg; 95% CI, -4.46 mmHg to -2.82 mmHg), after pneumoperitoneum (MD, -3.12 mmHg; 95% CI, -3.93 mmHg to -2.30 mmHg), and after the patients being placed in a steep Trendelenburg position (MD, -4.12 mmHg; 95% CI, -5.39 mmHg to -2.85 mmHg). Trial sequential analyses for these outcomes are conclusive. CONCLUSIONS Dexmedetomidine effectively attenuates the increase in IOP levels, and should be considered especially for at-risk patients.
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Affiliation(s)
- Chun-Yu Chang
- Department of Anesthesiology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan; Department of Anesthesiology, School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Hsuan-An Chen
- Department of Emergency Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan
| | - Yung-Jiun Chien
- Department of Physical Medicine and Rehabilitation, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan; Department of Physical Medicine and Rehabilitation, School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Meng-Yu Wu
- Department of Emergency Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan; Department of Emergency Medicine, School of Medicine, Tzu Chi University, Hualien, Taiwan.
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11
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Ophthalmic artery resistance index after peribulbar block in the presence of epinephrine. Int Ophthalmol 2020; 41:203-210. [PMID: 32857309 DOI: 10.1007/s10792-020-01567-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 08/17/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE There are controversies regarding ophthalmic artery (OA) flow after peribulbar block in the presence of epinephrine. Therefore, we aimed to evaluate OA flow via echo-Doppler before and after peribulbar block with lidocaine in the presence or absence of epinephrine. METHODS Fifty-six patients who had an American Society of Anesthesiologists (ASA) classification of I, II or III and were eligible for cataract phacoemulsification surgery were selected. Patients with other eye diseases were excluded. Patients were divided into two groups: group 1-peribulbar block with lidocaine and 1/200,000 epinephrine; group 2-peribulbar block with lidocaine in the absence of epinephrine. The resistance index (RI), peak systolic velocity (PSV), end diastolic velocity (EDV) of the OA were evaluated using echo-Doppler before and 10 min after the peribulbar block. RESULTS No differences between groups were observed in the RI before the peribulbar block as well regarding the presence of hypertension and the age or gender of the patient. After the peribulbar block, we observed a decrease in the RI in group 1 (p = 0.038, Cohen's d = 0.336) and no difference in the RI in group 2 (p = 0.109, Cohen's d = 0.172). When comparing group 1 and group 2, we observed a decrease in the RI in group 1 (p = 0.028, Cohen's d = 0,583). There was no difference between groups regarding the PSV and EDV after the peribulbar block. CONCLUSIONS A decrease in RI was observed in the OA after peribulbar block with a vasoconstrictor, an effect that could be a benefit in some ocular surgeries.
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Krzyczmonik A, Keller T, López-Picón FR, Forsback S, Kirjavainen AK, Takkinen JS, Wasilewska A, Scheinin M, Haaparanta-Solin M, Sączewski F, Solin O. Radiosynthesis and Preclinical Evaluation of an α 2A-Adrenoceptor Tracer Candidate, 6-[ 18F]Fluoro-marsanidine. Mol Imaging Biol 2020; 21:879-887. [PMID: 30710261 DOI: 10.1007/s11307-019-01317-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE The α2-adrenoceptors mediate many effects of norepinephrine and epinephrine, and participate in the regulation of neuronal, endocrine, cardiovascular, vegetative, and metabolic functions. Of the three receptor subtypes, only α2A and α2C are found in the brain in significant amounts. Subtype-selective positron emission tomography (PET) imaging of α2-adrenoceptors has been limited to the α2C subtype. Here, we report the synthesis of 6-[18F]fluoro-marsanidine, a subtype-selective PET tracer candidate for α2A-adrenoceptors, and its preclinical evaluation in rats and mice. PROCEDURES 6-[18F]Fluoro-marsanidine was synthesized using electrophilic F-18 fluorination with [18F]Selectfluor bis(triflate). The tracer was evaluated in Sprague Dawley rats and in α2A-knockout (KO) and wild-type (WT) mice for subtype selectivity. In vivo PET imaging and ex vivo brain autoradiography were performed to determine the tracer distribution in the brain. The specificity of the tracer for the target was determined by pretreatment with the subtype-non-selective α2-agonist medetomidine. The peripheral biodistribution and extent of metabolism of 6-[18F]fluoro-marsanidine were also analyzed. RESULTS 6-[18F]Fluoro-marsanidine was synthesized with [18F]Selectfluor bis(triflate) in a radiochemical yield of 6.4 ± 1.7 %. The molar activity was 3.1 to 26.6 GBq/μmol, and the radiochemical purity was > 99 %. In vivo studies in mice revealed lower uptake in the brains of α2A-KO mice compared to WT mice. The results for selectivity were confirmed by ex vivo brain autoradiography. Blocking studies revealed reduced uptake in α2A-adrenoceptor-rich brain regions in pretreated animals, demonstrating the specificity of the tracer. Metabolite analyses revealed very rapid metabolism of 6-[18F]fluoro-marsanidine with blood-brain barrier-permeable metabolites in both rats and mice. CONCLUSION 6-[18F]Fluoro-marsanidine was synthesized and evaluated as a PET tracer candidate for brain α2A-adrenoceptors. However, rapid metabolism, extensive presence of labeled metabolites in the brain, and high non-specific uptake in mouse and rat brain make 6-[18F]fluoro-marsanidine unsuitable for α2A-adrenoceptor targeting in rodents in vivo.
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Affiliation(s)
- Anna Krzyczmonik
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland
| | - Thomas Keller
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland
| | - Francisco R López-Picón
- PET Preclinical Imaging Laboratory, Turku PET Centre, University of Turku, Turku, Finland.,MediCity Research Laboratory, University of Turku, Turku, Finland
| | - Sarita Forsback
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland.,Department of Chemistry, University of Turku, Turku, Finland
| | - Anna K Kirjavainen
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland
| | - Jatta S Takkinen
- PET Preclinical Imaging Laboratory, Turku PET Centre, University of Turku, Turku, Finland.,MediCity Research Laboratory, University of Turku, Turku, Finland
| | - Aleksandra Wasilewska
- Department of Chemical Technology of Drugs, Faculty of Pharmacy, Medical University of Gdańsk, Gdańsk, Poland
| | - Mika Scheinin
- Institute of Biomedicine, University of Turku, and Unit of Clinical Pharmacology, Turku University Hospital, Turku, Finland
| | - Merja Haaparanta-Solin
- PET Preclinical Imaging Laboratory, Turku PET Centre, University of Turku, Turku, Finland.,MediCity Research Laboratory, University of Turku, Turku, Finland
| | - Franciszek Sączewski
- Department of Chemical Technology of Drugs, Faculty of Pharmacy, Medical University of Gdańsk, Gdańsk, Poland
| | - Olof Solin
- Radiopharmaceutical Chemistry Laboratory, Turku PET Centre, University of Turku, Turku, Finland. .,Department of Chemistry, University of Turku, Turku, Finland. .,Accelerator Laboratory, Turku PET Centre, Åbo Akademi University, Kiinamyllynkatu 4-8, FI-20520, Turku, Finland.
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13
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Zhou X, Zhang T, Wu J. Brimonidine enhances inhibitory postsynaptic activity of OFF- and ON-type retinal ganglion cells in a Wistar rat chronic glaucoma model. Exp Eye Res 2019; 189:107833. [PMID: 31618613 DOI: 10.1016/j.exer.2019.107833] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 06/07/2019] [Accepted: 10/09/2019] [Indexed: 10/25/2022]
Abstract
Glaucoma is a multifactorial disease in which retinal ganglion cells (RGCs) undergo excitotoxic damage, leading to their degeneration. The α2-adrenoceptor (α2-AR) agonist brimonidine exerts a neuroprotective effect by regulating postsynaptic excitatory N-methyl-D-aspartate (NMDA) receptor activity in RGCs. However, researchers have not clearly determined whether or how brimonidine regulates inhibitory synaptic transmission in rat models of chronic glaucoma. Whole-cell voltage-clamp and current-clamp recordings were performed in ON- and OFF-type RGCs in retinal slices. Brimonidine directly and acutely enhanced γ-aminobutyric acidergic (GABAergic) transmission mediated by ionotropic GABAA receptors in ON- and OFF-type RGCs in rat retinal slices; this effect occurred at the synaptic terminals and was independent of action potentials and multi-synaptic connections. The highly selective α2-AR antagonist yohimbine blocked the effects of brimonidine. Regarding the postsynaptic GABA receptor sensitivity, brimonidine also increased the amplitude of the GABA-induced current. Additionally, compared to RGCs from the control group, the frequencies and amplitudes of spontaneous excitatory postsynaptic currents (sEPSCs) and miniature excitatory postsynaptic currents (mEPSCs) did not change after brimonidine gravity perfusion. Brimonidine significantly decreased the spontaneous firing frequency of rat RGCs with intact synaptic inputs and decreased the resting membrane potential of RGCs, changes that were blocked by the highly selective GABAA receptor antagonist SR95531. SR95531 alone increased spontaneous action potentials and the resting membrane potential. Based on these findings, an α2-AR agonist facilitated the frequency of the GABAergic inhibitory postsynaptic currents (IPSCs), directly increased the amplitude of the postsynaptic GABA-induced current (GABA receptor reactivity/sensitivity), suppressed the firing frequency of spontaneous action in RGCs with intact synaptic inputs and decreased the resting membrane potential of RGCs, thus deactivating RGCs from the neural network level and reducing the excitotoxic damage occurring during the pathological process of chronic glaucoma.
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Affiliation(s)
- Xujiao Zhou
- Eye Institute, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, 200032, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200032, China; NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences (Fudan University), Shanghai, 200032, China.
| | - Ting Zhang
- Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200032, China; NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences (Fudan University), Shanghai, 200032, China; Research Center, Eye & ENT Hospital, Fudan University, Shanghai, 200032, China.
| | - Jihong Wu
- Eye Institute, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, 200032, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200032, China; NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences (Fudan University), Shanghai, 200032, China; Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Fudan University, Shanghai, 200032, China.
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14
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Himmel H, Eriksson Faelker T. Pupillary function test in rat: Establishment of imaging setup and pharmacological validation within modified Irwin test. J Pharmacol Toxicol Methods 2019; 99:106588. [DOI: 10.1016/j.vascn.2019.106588] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 04/26/2019] [Accepted: 05/23/2019] [Indexed: 01/23/2023]
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15
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Carr BJ, Mihara K, Ramachandran R, Saifeddine M, Nathanson NM, Stell WK, Hollenberg MD. Myopia-Inhibiting Concentrations of Muscarinic Receptor Antagonists Block Activation of Alpha2A-Adrenoceptors In Vitro. Invest Ophthalmol Vis Sci 2019; 59:2778-2791. [PMID: 29860464 DOI: 10.1167/iovs.17-22562] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Myopia is a refractive disorder that degrades vision. It can be treated with atropine, a muscarinic acetylcholine receptor (mAChR) antagonist, but the mechanism is unknown. Atropine may block α-adrenoceptors at concentrations ≥0.1 mM, and another potent myopia-inhibiting ligand, mamba toxin-3 (MT3), binds equally well to human mAChR M4 and α1A- and α2A-adrenoceptors. We hypothesized that mAChR antagonists could inhibit myopia via α2A-adrenoceptors, rather than mAChR M4. Methods Human mAChR M4 (M4), chicken mAChR M4 (cM4), or human α2A-adrenergic receptor (hADRA2A) clones were cotransfected with CRE/promoter-luciferase (CRE-Luc; agonist-induced luminescence) and Renilla luciferase (RLuc; normalizing control) into human cells. Inhibition of normalized agonist-induced luminescence by antagonists (ATR: atropine; MT3; HIM: himbacine; PRZ: pirenzepine; TRP: tropicamide; OXY: oxyphenonium; QNB: 3-quinuclidinyl benzilate; DIC: dicyclomine; MEP: mepenzolate) was measured using the Dual-Glo Luciferase Assay System. Results Relative inhibitory potencies of mAChR antagonists at mAChR M4/cM4, from most to least potent, were QNB > OXY ≥ ATR > MEP > HIM > DIC > PRZ > TRP. MT3 was 56× less potent at cM4 than at M4. Relative potencies of mAChR antagonists at hADRA2A, from most to least potent, were MT3 > HIM > ATR > OXY > PRZ > TRP > QNB > MEP; DIC did not antagonize. Conclusions Muscarinic antagonists block hADRA2A signaling at concentrations comparable to those used to inhibit chick myopia (≥0.1 mM) in vivo. Relative potencies at hADRA2A, but not M4/cM4, correlate with reported abilities to inhibit chick form-deprivation myopia. mAChR antagonists might inhibit myopia via α2-adrenoceptors, instead of through the mAChR M4/cM4 receptor subtype.
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Affiliation(s)
- Brittany J Carr
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Inflammation Research Network-Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Koichiro Mihara
- Inflammation Research Network-Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Rithwik Ramachandran
- Inflammation Research Network-Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
| | - Mahmoud Saifeddine
- Inflammation Research Network-Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Neil M Nathanson
- Department of Pharmacology, University of Washington, Seattle, Washington, United States
| | - William K Stell
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Morley D Hollenberg
- Inflammation Research Network-Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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16
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Li T, Yang S, She X, Yan Q, Zhang P, Zhu H, Wang F, Luo X, Sun X. Modulation of α-adrenoceptor signalling protects photoreceptors after retinal detachment by inhibiting oxidative stress and inflammation. Br J Pharmacol 2019; 176:801-813. [PMID: 30588605 DOI: 10.1111/bph.14565] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 11/20/2018] [Accepted: 11/29/2018] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND AND PURPOSE Currently available treatments do not halt progression of photoreceptor death and subsequent visual impairment related to retinal detachment (RD) which is observed in various retinal disorders. This study investigated the neuroprotective effects of two adrenoceptor ligands, the α1 -adrenoceptor antagonist doxazosin and the α2 -adrenoceptor agonist guanabenz, against photoreceptor cell death in RD. EXPERIMENTAL APPROACH We used a model of experimental RD in Brown-Norway rats induced by subretinal injection of sodium hyaluronate. Oxidative stress biomarkers and cytokine production were quantified with elisa. Protein expression levels and immunofluorescent labelling were determined in rats with RD and controls for mechanistic elucidation. The effects of systemic (i.p.) administration of doxazosin or guanabenz on photoreceptor apoptosis, retinal histology and electroretinography were evaluated in rats with RD and compared to the effects in vehicle controls. KEY RESULTS Photoreceptors were the major source of RD-induced ROS overproduction in the rat retina through the regulation of NADPH oxidase. Systemic administration of doxazosin or guanabenz decreased the RD-induced production of ROS and proinflammatory cytokines, including IL-1β and the chemokine CCL2, and suppressed retinal gliosis, resulting in attenuation of photoreceptor death and preservation of retinal structures and functions in RD. CONCLUSIONS AND IMPLICATIONS Our findings point to α-adrenoceptors as novel therapeutic targets to provide photoreceptor protection and suggest that both doxazosin and guanabenz, two FDA-approved drugs, could be further explored to treat retinal diseases.
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Affiliation(s)
- Tong Li
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shiqi Yang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiangjun She
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Quan Yan
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Pengfei Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hong Zhu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Fenghua Wang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Xueting Luo
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Fundus Diseases, Shanghai, China
| | - Xiaodong Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
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17
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Wiciński M, Kaluzny BJ, Liberski S, Marczak D, Seredyka-Burduk M, Pawlak-Osińska K. Association between serotonin-norepinephrine reuptake inhibitors and acute angle closure: What is known? Surv Ophthalmol 2018; 64:185-194. [PMID: 30278181 DOI: 10.1016/j.survophthal.2018.09.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 08/27/2018] [Accepted: 09/17/2018] [Indexed: 10/28/2022]
Abstract
Serotonin-norepinephrine reuptake inhibitors are widely used antidepressants with a relatively safe profile. One of the complications associated with this group of drugs is acute angle closure. The mechanisms linking serotonin-norepinephrine reuptake inhibitors and acute angle closure are complex and may be interlinked with the effects of the drug on the inhibition of serotonin and noradrenaline reuptake, as well as pseudo-anticholinergic effects, dopaminergic effects, and idiosyncratic reactions with the drug molecule in the eye. Individual characteristics, such as polymorphisms of the gene encoding the 2D6 subunit of cytochrome P450, may affect the metabolism of the serotonin-norepinephrine reuptake inhibitor, whereas the combination with other drugs may lead to an increased risk of iridocorneal angle closure and may further exacerbate other mechanisms. Improved knowledge of the mechanisms linking serotonin-norepinephrine reuptake inhibitors and acute angle closure and of the risk factors predisposing to patients to acute angle closure will reduce the number of patients affected by this dangerous complication.
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Affiliation(s)
- Michał Wiciński
- Department of Pharmacology and Therapeutics, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - Bartlomiej J Kaluzny
- Division of Ophthalmology and Optometry, Department of Ophthalmology, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - Sławomir Liberski
- Department of Pharmacology and Therapeutics, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Bydgoszcz, Poland.
| | - Daria Marczak
- Department of Pharmacology and Therapeutics, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - Małgorzata Seredyka-Burduk
- Division of Ophthalmology and Optometry, Department of Ophthalmology, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - Katarzyna Pawlak-Osińska
- Department of Pathophysiology of Hearing and Balance System, Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Bydgoszcz, Poland
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18
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Harun-Or-Rashid M, Hallböök F. Alpha 2-Adrenergic Receptor Agonist Brimonidine Stimulates ERK1/2 and AKT Signaling via Transactivation of EGF Receptors in the Human MIO-M1 Müller Cell Line. Curr Eye Res 2018; 44:34-45. [DOI: 10.1080/02713683.2018.1516783] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Mohammad Harun-Or-Rashid
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - Finn Hallböök
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
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19
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Nikkhah H, Garfami KH, Kanavi MR, Nashtaei EM, Karimi S, Soheilian M. Safety threshold of intravitreal clonidine in rabbit's eyes. Int J Ophthalmol 2018; 11:25-30. [PMID: 29375986 DOI: 10.18240/ijo.2018.01.05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 10/31/2017] [Indexed: 11/23/2022] Open
Abstract
AIM To determine the safe dose of intravitreal clonidine (IVC), a potential drug for neuroprotection and angiogenesis inhibition in rabbits. METHODS A total of 28 rabbits were divided into four groups. Three groups received IVC with concentrations of 15 (Group A), 25 (Group B), and 50 (Group C) µg/0.1 mL and the control group (Group D) received 0.1 mL balanced salt solution (BSS). To investigate IVC safety, electroretinography (ERG) was performed at baseline, then at 1, 4 and 8wk after injection. After last ERG, all rabbits were euthanized, their eyes were enucleated and subjected to routine histopathological evaluation, immunohistochemistry for glial fibrillary acidic protein (GFAP) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) test. RESULTS Based on ERG, histopathology, GFAP and TUNEL assay findings, 15 µg IVC was determined as the safe dose in rabbit eyes. While, the results of routine histopathology and TUNEL assay were unremarkable in all groups, toxic effects attributed to 25 and 50 µg IVC were demonstrated by ERG and GFAP tests. CONCLUSION Totally 15 µg clonidine is determined as the safe dose for intravitreal injection in rabbits. Contribution of IVC in neuroprotection and inhibition of angiogenesis deserve more studies.
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Affiliation(s)
- Homayoun Nikkhah
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran 16666, Iran.,Torfeh Eye Hospital, Shahid Beheshti University of Medical Sciences, Tehran 16666, Iran
| | - Kiumars Heidari Garfami
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran 16666, Iran
| | - Mozhgan Rezaei Kanavi
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran 16666, Iran.,Ocular Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran 16666, Iran
| | - Ebrahim Mohammad Nashtaei
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran 16666, Iran.,Ocular Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran 16666, Iran
| | - Saeed Karimi
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran 16666, Iran.,Torfeh Eye Hospital, Shahid Beheshti University of Medical Sciences, Tehran 16666, Iran
| | - Masoud Soheilian
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran 16666, Iran.,Ocular Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran 16666, Iran.,Labbafinejad Medical Center, Shahid Beheshti University of Medical Sciences, Tehran 16666, Iran
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20
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Jutley G, Luk SM, Dehabadi MH, Cordeiro MF. Management of glaucoma as a neurodegenerative disease. Neurodegener Dis Manag 2017; 7:157-172. [PMID: 28540772 DOI: 10.2217/nmt-2017-0004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Glaucoma is a neurodegenerative disease with an estimated prevalence of 60 million people, and the most common cause of irreversible blindness worldwide. The mainstay of treatment has been aimed at lowering intraocular pressure, currently the only modifiable risk factor. Unfortunately, despite adequate pressure control, many patients go on to suffer irreversible visual loss. We first briefly examine currently established intraocular pressure lowering-treatments, with a discussion of their roles in neuroprotection as demonstrated by both animal and clinical studies. The review then examines currently available intraocular pressure independent agents that have shown promise for possessing neuroprotective effects in the management of glaucoma. Finally, we explore potential future treatments such as immune-modulation, stem cell therapy and neural regeneration as they may provide further protection against the neurodegenerative processes involved in glaucomatous optic neuropathy.
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Affiliation(s)
- Gurjeet Jutley
- Western Eye Hospital, Imperial College Healthcare Trust, London, UK
| | - Sheila Mh Luk
- Medical Retina, Moorfields Eye Hospital, NHS Foundation Trust, London, UK
| | - Mohammad H Dehabadi
- Glaucoma & Retinal Neurodegeneration Research Group, Visual Neuroscience, UCL Institute of Ophthalmology, London, UK.,Medical Retina, Moorfields Eye Hospital, NHS Foundation Trust, London, UK
| | - M Francesca Cordeiro
- Glaucoma & Retinal Neurodegeneration Research Group, Visual Neuroscience, UCL Institute of Ophthalmology, London, UK.,Western Eye Hospital, Imperial College Healthcare Trust, London, UK
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21
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Abstract
Glaucoma is characterized by a slow and progressive degeneration of the optic nerve, including retinal ganglion cell (RGC) axons in the optic nerve head (ONH), leading to visual impairment. Despite its high prevalence, the biological basis of glaucoma pathogenesis still is not yet fully understood, and the factors contributing to its progression are currently not well characterized. Intraocular pressure (IOP) is the only modifiable risk factor, and reduction of IOP is the standard treatment for glaucoma. However, lowering IOP itself is not always effective for preserving visual function in patients with primary open-angle glaucoma. The second messenger cyclic adenosine 3′,5′-monophosphate (cAMP) regulates numerous biological processes in the central nervous system including the retina and the optic nerve. Although recent studies revealed that cAMP generated by adenylyl cyclases (ACs) is important in regulating aqueous humor dynamics in ocular tissues, such as the ciliary body and trabecular meshwork, as well as cell death and growth in the retina and optic nerve, the functional role and significance of cAMP in glaucoma remain to be elucidated. In this review, we will discuss the functional role of cAMP in aqueous humor dynamics and IOP regulation, and review the current medications, which are related to the cAMP signaling pathway, for glaucoma treatment. Also, we will further focus on cAMP signaling in RGC growth and regeneration by soluble AC as well as ONH astrocytes by transmembrane ACs to understand its potential role in the pathogenesis of glaucoma neurodegeneration
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Affiliation(s)
- Myoung Sup Shim
- Hamilton Glaucoma Center and Department of Ophthalmology, Shiley Eye Institute, University of California San Diego, La Jolla, CA 92037, USA
| | - Keun-Young Kim
- Center for Research on Biological Systems, National Center for Microscopy and Imaging Research and Department of Neuroscience, University of California San Diego, La Jolla 92093, CA 92093, USA
| | - Won-Kyu Ju
- Hamilton Glaucoma Center and Department of Ophthalmology, Shiley Eye Institute, University of California San Diego, La Jolla, CA 92037, USA
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22
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Non-amyloidogenic effects of α2 adrenergic agonists: implications for brimonidine-mediated neuroprotection. Cell Death Dis 2016; 7:e2514. [PMID: 27929541 PMCID: PMC5260990 DOI: 10.1038/cddis.2016.397] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 10/18/2016] [Accepted: 10/24/2016] [Indexed: 12/18/2022]
Abstract
The amyloid beta (Aβ) pathway is strongly implicated in neurodegenerative conditions such as Alzheimer's disease and more recently, glaucoma. Here, we identify the α2 adrenergic receptor agonists (α2ARA) used to lower intraocular pressure can prevent retinal ganglion cell (RGC) death via the non-amyloidogenic Aβ-pathway. Neuroprotective effects were confirmed in vivo and in vitro in different glaucoma-related models using α2ARAs brimonidine (BMD), clonidine (Clo) and dexmedetomidine. α2ARA treatment significantly reduced RGC apoptosis in experimental-glaucoma models by 97.7% and 92.8% (BMD, P<0.01) and 98% and 92.3% (Clo, P<0.01)) at 3 and 8 weeks, respectively. A reduction was seen in an experimental Aβ-induced neurotoxicity model (67% BMD and 88.6% Clo, both P<0.01, respectively), and in vitro, where α2ARAs significantly (P<0.05) prevented cell death, under both hypoxic (CoCl2) and stress (UV) conditions. In experimental-glaucoma, BMD induced ninefold and 25-fold and 36-fold and fourfold reductions in Aβ and amyloid precursor protein (APP) levels at 3 and 8 weeks, respectively, in the RGC layer, with similar results with Clo, and in vitro with all three α2ARAs. BMD significantly increased soluble APPα (sAPPα) levels at 3 and 8 weeks (2.1 and 1.6-fold) in vivo and in vitro with the CoCl2 and UV-light insults. Furthermore, treatment of UV-insulted cells with an sAPPα antibody significantly reduced cell viability compared with BMD-treated control (52%), co-treatment (33%) and untreated control (27%). Finally, we show that α2ARAs modulate levels of laminin and MMP-9 in RGCs, potentially linked to changes in Aβ through APP processing. Together, these results provide new evidence that α2ARAs are neuroprotective through their effects on the Aβ pathway and sAPPα, which to our knowledge, is the first description. Studies have identified the need for α-secretase activators and sAPPα-mimetics in neurodegeneration; α2ARAs, already clinically available, present a promising therapy, with applications not only to reducing RGC death in glaucoma but also other neurodegenerative processes involving Aβ.
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23
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Faria‐Silva R, Rezende DCD, Ribeiro JM, Gomes TH, Oliveira BAMFM, Pereira FMR, Almeida Filho IAD, Carvalho Junior AERD. Associação de clonidina e ropivacaína no bloqueio de plexo braquial para artroscopia de ombro. Braz J Anesthesiol 2016. [DOI: 10.1016/j.bjan.2013.06.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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24
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Complement pathway biomarkers and age-related macular degeneration. Eye (Lond) 2015; 30:1-14. [PMID: 26493033 DOI: 10.1038/eye.2015.203] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 09/03/2015] [Indexed: 02/07/2023] Open
Abstract
In the age-related macular degeneration (AMD) 'inflammation model', local inflammation plus complement activation contributes to the pathogenesis and progression of the disease. Multiple genetic associations have now been established correlating the risk of development or progression of AMD. Stratifying patients by their AMD genetic profile may facilitate future AMD therapeutic trials resulting in meaningful clinical trial end points with smaller sample sizes and study duration.
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25
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McAlvin JB, Zhan C, Dohlman JC, Kolovou PE, Salvador-Culla B, Kohane DS. Corneal Anesthesia With Site 1 Sodium Channel Blockers and Dexmedetomidine. Invest Ophthalmol Vis Sci 2015; 56:3820-6. [PMID: 26066750 DOI: 10.1167/iovs.15-16591] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Amino-amide or amino-ester local anesthetics, which are currently used for topical ocular anesthesia, are short acting and may delay corneal healing with long-term use. In contrast, site 1 sodium channel blockers (S1SCBs) are potent local anesthetics with minimal adverse tissue reaction. In this study, we examined topical local anesthesia with two S1SCBs, tetrodotoxin (TTX) or saxitoxin (STX) individually or in combination with α2-adrenergic receptor agonists (dexmedetomidine or clonidine), and compared them with the amino-ester ocular anesthetic proparacaine. The effect of test solutions on corneal healing was also studied. METHODS Solutions of TTX ± dexmedetomidine, TTX ± clonidine, STX ± dexmedetomidine, dexmedetomidine, or proparacaine were applied to the rat cornea. Tactile sensitivity was measured by recording the blink response to probing of the cornea with a Cochet-Bonnet esthesiometer. The duration of corneal anesthesia was calculated. Cytotoxicity from anesthetic solutions was measured in vitro. The effect on corneal healing was measured in vivo after corneal debridement followed by repeated drug administration. RESULTS Addition of dexmedetomidine to TTX or STX significantly prolonged corneal anesthesia beyond that of either drug alone, whereas clonidine did not. Tetrodotoxin or STX coadministered with dexmedetomidine resulted in two to three times longer corneal anesthesia than did proparacaine. S1SCB-dexmedetomidine formulations were not cytotoxic. Corneal healing was not delayed significantly by any of the test solutions. CONCLUSIONS Coadministration of S1SCBs with dexmedetomidine provided prolonged corneal anesthesia without delaying corneal wound healing. Such formulations may be useful for the management of acute surgical and nonsurgical corneal pain.
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Affiliation(s)
- James Brian McAlvin
- Department of Medicine Division of Medicine Critical Care, Harvard Medical School, Boston Children's Hospital, Boston, Massachusetts, United States 2Laboratory for Biomaterials and Drug Delivery, Department of Anesthesiology, Division of Critical Care Med
| | - Changyou Zhan
- Laboratory for Biomaterials and Drug Delivery, Department of Anesthesiology, Division of Critical Care Medicine, Harvard Medical School, Boston Children's Hospital, Boston, Massachusetts, United States
| | - Jenny C Dohlman
- Laboratory for Biomaterials and Drug Delivery, Department of Anesthesiology, Division of Critical Care Medicine, Harvard Medical School, Boston Children's Hospital, Boston, Massachusetts, United States
| | - Paraskevi E Kolovou
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, United States
| | - Borja Salvador-Culla
- Laboratory for Biomaterials and Drug Delivery, Department of Anesthesiology, Division of Critical Care Medicine, Harvard Medical School, Boston Children's Hospital, Boston, Massachusetts, United States 3Department of Ophthalmology, Schepens Eye Research I
| | - Daniel S Kohane
- Laboratory for Biomaterials and Drug Delivery, Department of Anesthesiology, Division of Critical Care Medicine, Harvard Medical School, Boston Children's Hospital, Boston, Massachusetts, United States
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Du Y, Cramer M, Lee CA, Tang J, Muthusamy A, Antonetti DA, Jin H, Palczewski K, Kern TS. Adrenergic and serotonin receptors affect retinal superoxide generation in diabetic mice: relationship to capillary degeneration and permeability. FASEB J 2015; 29:2194-204. [PMID: 25667222 DOI: 10.1096/fj.14-269431] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 01/13/2015] [Indexed: 12/22/2022]
Abstract
Reactive oxygen species play an important role in the pathogenesis of diabetic retinopathy. We studied the role of adrenergic and serotonin receptors in the generation of superoxide by retina and 661W retinal cells in high glucose and of the α1-adrenergic receptor (AR) on vascular lesions of the retinopathy in experimentally diabetic C57Bl/6J mice (and controls) after 2 and 8 months. Compared with 5 mM glucose, incubating cells or retinal explants in 30 mM glucose induced superoxide generation. This response was reduced or ablated by pharmacologic inhibition of the α1-AR (a Gq-coupled receptor) or Gs-coupled serotonin (5-HT2, 5-HT4, 5-HT6, and 5-HT7) receptors or by activation of the Gi-coupled α2-AR. In elevated glucose, the α1-AR produced superoxide via phospholipase C, inositol triphosphate-induced Ca(2+) release, and NADPH oxidase, and pharmacologic inhibition of these reactions prevented the superoxide increase. Generation of retinal superoxide, expression of proinflammatory proteins, and degeneration of retinal capillaries in diabetes all were significantly inhibited with daily doxazosin or apocynin (inhibitors of α1-AR and NADPH oxidase, respectively), but increased vascular permeability was not significantly affected. Adrenergic receptors, and perhaps other GPCRs, represent novel targets for inhibiting the development of important features of diabetic retinopathy.
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Affiliation(s)
- Yunpeng Du
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Megan Cramer
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Chieh Allen Lee
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Jie Tang
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Arivalagan Muthusamy
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - David A Antonetti
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Hui Jin
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Krzysztof Palczewski
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
| | - Timothy S Kern
- *Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Department of Ophthalmology and Visual Sciences, The University of Michigan, Ann Arbor, Michigan, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA; and Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA
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Faria-Silva R, de Rezende DC, Ribeiro JM, Gomes TH, Oliveira BAMFM, Pereira FMR, de Almeida Filho IA, de Carvalho Junior AER. Association of clonidine and ropivacaine in brachial plexus block for shoulder arthroscopy. Braz J Anesthesiol 2014; 66:335-40. [PMID: 27343780 DOI: 10.1016/j.bjane.2013.06.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 06/10/2013] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Arthroscopy for shoulder disorders is associated with severe and difficult to control pain, postoperatively. The addition of clonidine to local anesthetics for peripheral nerve block has become increasingly common, thanks to the potential ability of this drug to reduce the mass of local anesthetic required and to prolonging analgesia postoperatively. The present study aimed to evaluate the success of brachial plexus block for arthroscopic rotator cuff surgery using local anesthetic with or without clonidine. METHOD 53 patients of both genders, between 18 and 70 years old, American Society of Anesthesiologists I or II, who were scheduled to undergo arthroscopic shoulder surgery were selected. Patients were then randomized into two groups. The verbal numerical pain scale and the presence of motor block were obtained in the post-anesthetic recovery room and 6, 12, 18 and 24h postoperatively. RESULTS The association of clonidine (0.15mg) to a solution of 0.33% ropivacaine (30mL) in brachial plexus block for shoulder arthroscopy has not diminished the visual numeric pain scale values, nor the need for opioid rescue postoperatively. There was a lower incidence of nausea/vomiting postoperatively and a significant motor block time prolongation in the group of patients who received clonidine as adjuvant. CONCLUSIONS The use of brachial plexus block with local anesthetic for analgesic postoperative control is well established in the literature. The addition of clonidine in the dose proposed for prolongation of the analgesic effect and reduction of opioid rescue proved unhelpful.
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Shih GC, Calkins DJ. Secondary neuroprotective effects of hypotensive drugs and potential mechanisms of action. EXPERT REVIEW OF OPHTHALMOLOGY 2014; 7:161-175. [PMID: 22737176 DOI: 10.1586/eop.12.13] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Primary open-angle glaucoma, a long-term degenerative ocular neuropathy, remains a significant cause of vision impairment worldwide. While many risk factors have been correlated with increased risk for primary open-angle glaucoma, intraocular pressure (IOP) remains the only modifiable risk factor and primary therapeutic target. Pharmacologic therapies are administered topically; these include α(2)-agonists, β-antagonists, prostaglandin analogs and carbonic anhydrase inhibitors. Some of these topical medications exhibit secondary neuroprotective effects independent of their effect on IOP. This review covers the possible mechanisms of neuroprotection stimulated by drugs currently marketed for the lowering of IOP, based on known literature. While the neuroprotective properties of many glaucoma pharmaceuticals are promising from an experimental standpoint, key challenges for the development of new clinical practices include unknown systemic side effects, limited methods of drug delivery to the retina and optic nerve, and development of extended-release formulations.
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Affiliation(s)
- Grace C Shih
- The Vanderbilt Eye Institute, Department of Ophthalmology and Visual Sciences, Vanderbilt University, School of Medicine, 11435 MRB IV, 2215B Garland Avenue, Nashville, TN 37232, USA
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Chen Y, Palczewska G, Mustafi D, Golczak M, Dong Z, Sawada O, Maeda T, Maeda A, Palczewski K. Systems pharmacology identifies drug targets for Stargardt disease-associated retinal degeneration. J Clin Invest 2013; 123:5119-34. [PMID: 24231350 DOI: 10.1172/jci69076] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 09/12/2013] [Indexed: 12/22/2022] Open
Abstract
A systems pharmacological approach that capitalizes on the characterization of intracellular signaling networks can transform our understanding of human diseases and lead to therapy development. Here, we applied this strategy to identify pharmacological targets for the treatment of Stargardt disease, a severe juvenile form of macular degeneration. Diverse GPCRs have previously been implicated in neuronal cell survival, and crosstalk between GPCR signaling pathways represents an unexplored avenue for pharmacological intervention. We focused on this receptor family for potential therapeutic interventions in macular disease. Complete transcriptomes of mouse and human samples were analyzed to assess the expression of GPCRs in the retina. Focusing on adrenergic (AR) and serotonin (5-HT) receptors, we found that adrenoceptor α 2C (Adra2c) and serotonin receptor 2a (Htr2a) were the most highly expressed. Using a mouse model of Stargardt disease, we found that pharmacological interventions that targeted both GPCR signaling pathways and adenylate cyclases (ACs) improved photoreceptor cell survival, preserved photoreceptor function, and attenuated the accumulation of pathological fluorescent deposits in the retina. These findings demonstrate a strategy for the identification of new drug candidates and FDA-approved drugs for the treatment of monogenic and complex diseases.
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MESH Headings
- ATP-Binding Cassette Transporters/deficiency
- ATP-Binding Cassette Transporters/genetics
- Adenine/analogs & derivatives
- Adenine/pharmacology
- Adenine/therapeutic use
- Adenylyl Cyclase Inhibitors
- Adrenergic alpha-Agonists/pharmacology
- Adrenergic alpha-Agonists/therapeutic use
- Adrenergic alpha-Antagonists/pharmacology
- Adrenergic alpha-Antagonists/therapeutic use
- Alcohol Oxidoreductases/deficiency
- Alcohol Oxidoreductases/genetics
- Animals
- Cell Survival
- Disease Models, Animal
- Doxazosin/pharmacology
- Doxazosin/therapeutic use
- Drug Evaluation, Preclinical
- Guanabenz/pharmacology
- Guanabenz/therapeutic use
- Humans
- Light/adverse effects
- Macaca fascicularis
- Macular Degeneration/congenital
- Macular Degeneration/drug therapy
- Macular Degeneration/genetics
- Macular Degeneration/prevention & control
- Mice
- Mice, Inbred BALB C
- Mice, Knockout
- Molecular Targeted Therapy
- Nerve Tissue Proteins/biosynthesis
- Nerve Tissue Proteins/genetics
- Photoreceptor Cells, Vertebrate/drug effects
- Photoreceptor Cells, Vertebrate/pathology
- Photoreceptor Cells, Vertebrate/physiology
- Photoreceptor Cells, Vertebrate/radiation effects
- Reactive Oxygen Species
- Receptor, Serotonin, 5-HT2A/biosynthesis
- Receptor, Serotonin, 5-HT2A/genetics
- Receptors, Adrenergic, alpha-2/biosynthesis
- Receptors, Adrenergic, alpha-2/genetics
- Receptors, G-Protein-Coupled/biosynthesis
- Receptors, G-Protein-Coupled/genetics
- Serotonin Antagonists/pharmacology
- Serotonin Antagonists/therapeutic use
- Signal Transduction
- Stargardt Disease
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Grove K, Dobish J, Harth E, Ingram MC, Galloway RL, Mawn LA. Trans-meningeal drug delivery to optic nerve ganglion cell axons using a nanoparticle drug delivery system. Exp Eye Res 2013; 118:42-5. [PMID: 24184721 DOI: 10.1016/j.exer.2013.10.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 10/21/2013] [Accepted: 10/23/2013] [Indexed: 12/01/2022]
Abstract
The purpose of this study was to investigate if neuroprotective drugs can cross the optic nerve sheath in vitro. Four optic nerves were used for this study. Two porcine nerves were harvested at the time of euthanasia and two human nerves were obtained at the time of therapeutic globe enucleation. The optic nerve sheaths were dissected and placed as a membrane in a two chamber diffusion cell to test meningeal penetration by both brimonidine alone and brimonidine encapsulated in nanoparticle (NP-brimonidine). Brimonidine concentration was assayed by UV-vis spectrometer measurement of absorbance at 389 nm. Increasing concentration of brimonidine on the receiver side of the chamber was measured in both the brimonidine alone and the brimonidine encapsulated experiments. The human data were fitted with a two parameter exponential regression analysis (brimonidine alone donor r(2) = 0.87 and receiver r(2) = 0.80, NP-brimonidine donor r(2) = 0.79 and receiver r(2) = 0.84). Time constant (τ) was 10.2 h (donor) and 13.1 h (receiver) in the brimonidine study, and 24.0 h (donor) and 15.9 h (receiver) in the NP-brimonidine study. Encapsulated brimonidine had a longer time to reach equilibrium. Passage of brimonidine through the optic nerve sheath was demonstrated in the experiments. Increase in time constants when comparing the NP-brimonidine with the brimonidine curves in the human studiesindicates that diffusion is delayed by the initial parameter of drug being loaded in NP. Direct treatment of injured optic nerve axons may be possible by trans-meningeal drug diffusion.
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Affiliation(s)
- Karen Grove
- Vanderbilt Eye Institute, 2311 Pierce Avenue, Nashville, TN 37232-8808, USA.
| | - Julia Dobish
- Chemistry Department, 7619 Stevenson Center, Vanderbilt University, Nashville, TN 37232, USA.
| | - Eva Harth
- Chemistry Department, 7619 Stevenson Center, Vanderbilt University, Nashville, TN 37232, USA.
| | - Martha-Conley Ingram
- Biomedical Engineering, 5824 Stevenson Center, Vanderbilt University, Nashville, TN 37232, USA.
| | - Robert L Galloway
- Biomedical Engineering, 5824 Stevenson Center, Vanderbilt University, Nashville, TN 37232, USA.
| | - Louise A Mawn
- Vanderbilt Eye Institute, 2311 Pierce Avenue, Nashville, TN 37232-8808, USA.
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Neuroprotection of medical IOP-lowering therapy. Cell Tissue Res 2013; 353:245-51. [DOI: 10.1007/s00441-013-1671-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 05/27/2013] [Indexed: 12/30/2022]
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Dal Monte M, Casini G, la Marca G, Isacchi B, Filippi L, Bagnoli P. Eye drop propranolol administration promotes the recovery of oxygen-induced retinopathy in mice. Exp Eye Res 2013; 111:27-35. [DOI: 10.1016/j.exer.2013.03.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 01/25/2013] [Accepted: 03/18/2013] [Indexed: 01/04/2023]
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Razy-Krajka F, Brown ER, Horie T, Callebert J, Sasakura Y, Joly JS, Kusakabe TG, Vernier P. Monoaminergic modulation of photoreception in ascidian: evidence for a proto-hypothalamo-retinal territory. BMC Biol 2012; 10:45. [PMID: 22642675 PMCID: PMC3414799 DOI: 10.1186/1741-7007-10-45] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 05/29/2012] [Indexed: 12/12/2022] Open
Abstract
Background The retina of craniates/vertebrates has been proposed to derive from a photoreceptor prosencephalic territory in ancestral chordates, but the evolutionary origin of the different cell types making the retina is disputed. Except for photoreceptors, the existence of homologs of retinal cells remains uncertain outside vertebrates. Methods The expression of genes expressed in the sensory vesicle of the ascidian Ciona intestinalis including those encoding components of the monoaminergic neurotransmission systems, was analyzed by in situ hybridization or in vivo transfection of the corresponding regulatory elements driving fluorescent reporters. Modulation of photic responses by monoamines was studied by electrophysiology combined with pharmacological treatments. Results We show that many molecular characteristics of dopamine-synthesizing cells located in the vicinity of photoreceptors in the sensory vesicle of the ascidian Ciona intestinalis are similar to those of amacrine dopamine cells of the vertebrate retina. The ascidian dopamine cells share with vertebrate amacrine cells the expression of the key-transcription factor Ptf1a, as well as that of dopamine-synthesizing enzymes. Surprisingly, the ascidian dopamine cells accumulate serotonin via a functional serotonin transporter, as some amacrine cells also do. Moreover, dopamine cells located in the vicinity of the photoreceptors modulate the light-off induced swimming behavior of ascidian larvae by acting on alpha2-like receptors, instead of dopamine receptors, supporting a role in the modulation of the photic response. These cells are located in a territory of the ascidian sensory vesicle expressing genes found both in the retina and the hypothalamus of vertebrates (six3/6, Rx, meis, pax6, visual cycle proteins). Conclusion We propose that the dopamine cells of the ascidian larva derive from an ancestral multifunctional cell population located in the periventricular, photoreceptive field of the anterior neural tube of chordates, which also gives rise to both anterior hypothalamus and the retina in craniates/vertebrates. It also shows that the existence of multiple cell types associated with photic responses predates the formation of the vertebrate retina.
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Affiliation(s)
- Florian Razy-Krajka
- Neurobiology and Development, UPR, Institut de Neurobiologie Alfred Fessard, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France
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Regulation of ocular adrenoceptor genes expression by 5-MCA-NAT: implications for glaucoma treatment. Pharmacogenet Genomics 2011; 21:587-9. [PMID: 21705965 DOI: 10.1097/fpc.0b013e32834910d1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have demonstrated that 5-methoxycarbonylamino-N-acetyltryptamine (5-MCA-NAT), reduces intraocular pressure (IOP) in rabbits. In addition, we have reported a link between hypotensive effect of 5-MCA-NAT and sympathetic nervous system. Moreover, it is known that aqueous humour production is controlled by the activation of adrenoceptors (ADRs) present in the ocular ciliary epithelium. Thus, the aim of this study is to investigate if the hypotensive effect of 5-MCA-NAT is due to a regulation of ciliary ADR genes expression. To confirm this we followed the effect of 5-MCA-NAT on rabbit IOP for 144 consecutive hours. A sustained IOP reduction for up to 72 h (P<0.01) was seen. In addition, changes in ADRB2 and ADRA2A mRNA were measured in cultured rabbit nonpigmented ciliary epithelial cells. After 5-MCA-NAT treatment, a significant downregulation of ADRB2 and upregulation of ADRA2A was observed. These results provide the regulation of ADRs mRNA by 5-MCA-NAT.
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Krupin T, Liebmann JM, Greenfield DS, Ritch R, Gardiner S. A randomized trial of brimonidine versus timolol in preserving visual function: results from the Low-Pressure Glaucoma Treatment Study. Am J Ophthalmol 2011; 151:671-81. [PMID: 21257146 DOI: 10.1016/j.ajo.2010.09.026] [Citation(s) in RCA: 245] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 09/04/2010] [Accepted: 09/13/2010] [Indexed: 01/16/2023]
Abstract
PURPOSE To compare the alpha2-adrenergic agonist brimonidine tartrate 0.2% to the beta-adrenergic antagonist timolol maleate 0.5% in preserving visual function in low-pressure glaucoma. DESIGN Randomized, double-masked, multicenter clinical trial. METHODS Exclusion criteria included untreated intraocular pressure (IOP) >21 mm Hg, visual field mean deviation worse than -16 decibels, or contraindications to study medications. Both eyes received twice-daily monotherapy randomized in blocks of 7 (4 brimonidine to 3 timolol). Standard automated perimetry and tonometry were performed at 4-month intervals. Main outcome measure was field progression in either eye, defined as the same 3 or more points with a negative slope ≥-1 dB/year at P<5%, on 3 consecutive tests, assessed by pointwise linear regression. Secondary outcome measures were progression based on glaucoma change probability maps (GCPM) of pattern deviation and the 3-omitting method for pointwise linear regression. RESULTS Ninety-nine patients were randomized to brimonidine and 79 to timolol. Mean (± SE) months of follow-up for all patients was 30.0 ± 2. Statistically fewer brimonidine-treated patients (9, 9.1%) had visual field progression by pointwise linear regression than timolol-treated patients (31, 39.2%, log-rank 12.4, P=.001). Mean treated IOP was similar for brimonidine- and timolol-treated patients at all time points. More brimonidine-treated (28, 28.3%) than timolol-treated (9, 11.4%) patients discontinued study participation because of drug-related adverse events (P=.008). Similar differences in progression were observed when analyzed by GCPM and the 3-omitting method. CONCLUSION Low-pressure glaucoma patients treated with brimonidine 0.2% who do not develop ocular allergy are less likely to have field progression than patients treated with timolol 0.5%.
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Affiliation(s)
- Theodore Krupin
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University and the Chicago Center for Vision Research, Chicago, Illinois 60611, USA.
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Lambert WS, Ruiz L, Crish SD, Wheeler LA, Calkins DJ. Brimonidine prevents axonal and somatic degeneration of retinal ganglion cell neurons. Mol Neurodegener 2011; 6:4. [PMID: 21232114 PMCID: PMC3035592 DOI: 10.1186/1750-1326-6-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Accepted: 01/13/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Brimonidine is a common drug for lowering ocular pressure and may directly protect retinal ganglion cells in glaucoma. The disease involves early loss of retinal ganglion cell transport to brain targets followed by axonal and somatic degeneration. We examined whether brimonidine preserves ganglion cell axonal transport and abates degeneration in rats with elevated ocular pressure induced by laser cauterization of the episcleral veins. RESULTS Ocular pressure was elevated unilaterally by 90% for a period of 8 weeks post- cauterization. During this time, brimonidine (1mg/kg/day) or vehicle (phosphate-buffered saline) was delivered systemically and continuously via subcutaneous pump. Animals received bilateral intravitreal injections of fluorescent cholera toxin subunit β (CTB) two days before sacrifice to assess anterograde transport. In retinas from the vehicle group, elevated pressure induced a 44% decrease in the fraction of ganglion cells with intact uptake of CTB and a 14-42% reduction in the number of immuno-labelled ganglion cell bodies, with the worst loss occurring nasally. Elevated pressure also caused a 33% loss of ganglion cell axons in vehicle optic nerves and a 70% decrease in CTB transport to the superior colliculus. Each of these components of ganglion cell degeneration was either prevented or significantly reduced in the brimonidine treatment group. CONCLUSIONS Continuous and systemic treatment with brimonidine by subcutaneous injection significantly improved retinal ganglion cell survival with exposure to elevated ocular pressure. This effect was most striking in the nasal region of the retina. Brimonidine treatment also preserved ganglion cell axon morphology, sampling density and total number in the optic nerve with elevated pressure. Consistent with improved outcome in the optic projection, brimonidine also significantly reduced the deficits in axonal transport to the superior colliculus associated with elevated ocular pressure. As transport deficits to and from retinal ganglion cell projection targets in the brain are relevant to the progression of glaucoma, the ability of brimonidine to preserve optic nerve axons and active transport suggests its neuroprotective effects are relevant not only at the cell body, but throughout the entire optic projection.
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Affiliation(s)
- Wendi S Lambert
- The Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN 37205, USA.
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Gao Y, Sakurai M, Takeda H, Higashide T, Kawase K, Sugiyama K. Association between genetic polymorphisms of adrenergic receptor and diurnal intraocular pressure in Japanese normal-tension glaucoma. Ophthalmology 2010; 117:2359-2364.e1-2. [PMID: 20705341 DOI: 10.1016/j.ophtha.2010.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 03/03/2010] [Accepted: 04/05/2010] [Indexed: 10/19/2022] Open
Abstract
PURPOSE To evaluate the relationship between genetic polymorphisms of the adrenergic receptor (ADR) and diurnal intraocular pressure (IOP) in Japanese normal-tension glaucoma (NTG) patients. DESIGN Prospective, comparative case series. PARTICIPANTS Ninety-two untreated NTG patients. METHODS The IOP of both eyes was measured at 3-hour intervals from 0600 to 2400 hours over 2 consecutive days. We used IOP data from the eye with the greater visual field defect for statistical analysis. The mean IOP over 2 days was used for each time point. Genetic polymorphisms in α1A-, α2A-, α2B-, α2C-, β1-, β2-, and β3-ADR were determined mainly by direct DNA sequencing. The relationship between IOP and genetic polymorphisms was analyzed. MAIN OUTCOME MEASURES The IOP and genotypes of genetic polymorphisms. RESULTS Diurnal mean IOP of the subjects was 14.8 ± 2.1 mmHg (mean value ± standard deviation). For Del 301-303 in α2B-ADR, insertion/insertion (I/I) had a significantly higher diurnal mean IOP (P = 0.017), peak IOP (P = 0.038), and trough IOP (P = 0.046) than deletion (D) carriers. For Del 322-325 in α2C-ADR, I/I had a significantly lower diurnal mean IOP (P = 0.037) and peak IOP (P = 0.029) than D carriers. For S49G (A/G) in β1-ADR, A/A had a significantly higher diurnal mean IOP (P = 0.023), peak IOP (P = 0.019), and trough IOP (P = 0.014) than G carriers. For these 3 polymorphisms, repeated measures analysis of variance showed that the major homozygotes and minor carriers had parallel diurnal IOP curves, but significantly different diurnal IOP levels. CONCLUSIONS Polymorphisms of the ADR gene may alter the untreated IOP level of patients with NTG.
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Affiliation(s)
- Yanlin Gao
- Department of Ophthalmology and Visual Science, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
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Mojumder DK, Wensel TG. Topical mydriatics affect light-evoked retinal responses in anesthetized mice. Invest Ophthalmol Vis Sci 2009; 51:567-76. [PMID: 19661232 DOI: 10.1167/iovs.09-4168] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To characterize effects of the muscarinic antagonist atropine (A) and the alpha-adrenergic agonist, phenylephrine (P), on mydriasis and light-evoked signaling in mice anesthetized by ketamine and xylazine (K+X). METHODS Pupillary areas of anesthetized C57BL/6 mice were measured, with or without topical application of A or A+P. Dark-adapted ERGs were recorded from 2- to 4-month-old C57BL/6 and 7.5-month-old albino hrhoG/hrhoG mice after application of A or P singly or in combination, before or after induction of K+X anesthesia. Effects of GABA were tested in the hrhoG/hrhoG mice. RESULTS K+X anesthesia resulted in maximum mydriasis that was not enhanced by A or A+P. Dark-adapted b-wave amplitudes (-1.3 log sc td s) after K+X anesthesia were similar with or without A or P. A+P in the presence of K+X produced a slow growth in b-wave amplitude, reaching a plateau of twofold enhancement in 1 hour. Recordings of responses to varying flash energies revealed that the effects of A+P were on the maximum amplitude of the a- and b-waves and not on their sensitivity. Scotopic threshold responses were augmented as well. In photoreceptor-degenerated mice (hrhoG/hrhoG), an electronegative ERG wave recorded with K+X+A, was converted to a gamma-aminobutyric acid (GABA)-sensitive response with two electropositive components with A+P after K+X. CONCLUSIONS Topical administration of A and P together, but not separately, in the presence of K+X, leads to a slow, dramatic enhancement of a- and b-waves by an unknown mechanism independent of pupil dilation.
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Affiliation(s)
- Deb Kumar Mojumder
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
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Fairbanks CA, Stone LS, Wilcox GL. Pharmacological profiles of alpha 2 adrenergic receptor agonists identified using genetically altered mice and isobolographic analysis. Pharmacol Ther 2009; 123:224-38. [PMID: 19393691 DOI: 10.1016/j.pharmthera.2009.04.001] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Accepted: 04/09/2009] [Indexed: 12/24/2022]
Abstract
Endogenous, descending noradrenergic fibers impose analgesic control over spinal afferent circuitry mediating the rostrad transmission of pain signals. These fibers target alpha 2 adrenergic receptors (alpha(2)ARs) on both primary afferent terminals and secondary neurons, and their activation mediates substantial inhibitory control over this transmission, rivaling that of opioid receptors which share a similar pattern of distribution. The terminals of primary afferent nociceptive neurons and secondary spinal dorsal horn neurons express alpha(2A)AR and alpha(2C)AR subtypes, respectively. Spinal delivery of these agents serves to reduce their side effects, which are mediated largely at supraspinal sites, by concentrating the drugs at the spinal level. Targeting these spinal alpha(2)ARs with one of five selective therapeutic agonists, clonidine, dexmedetomidine, brimonidine, ST91 and moxonidine, produces significant antinociception that can work in concert with opioid agonists to yield synergistic antinociception. Application of several genetically altered mouse lines had facilitated identification of the primary receptor subtypes that likely mediate the antinociceptive effects of these agents. This review provides first an anatomical description of the localization of the three subtypes in the central nervous system, second a detailed account of the pharmacological history of each of the six primary agonists, and finally a comprehensive report of the specific interactions of other GPCR agonists with each of the six principal alpha(2)AR agonists featured.
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Affiliation(s)
- Carolyn A Fairbanks
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA
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