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α1 receptor blockade

Stefan P Mortensen, Stuart Egginton, Mads Madsen, Jonas B Hansen, Gregers D W Munch, Ulrik Winning Iepsen, Thorbjörn Åkerström, Bente K Pedersen, Ylva Hellsten
AIM: To investigate the effect of elevated basal shear stress on angiogenesis in humans, and the role of enhanced skeletal muscle capillarisation on blood flow and O2 extraction. METHODS: Limb haemodynamics and O2 extraction was measured at rest and during one-leg knee-extensor exercise (12 and 24W) in 10 healthy untrained young men before and after 4 weeks treatment with an α1 receptor-antagonist (Terazosin, 1-2 mg day(-1) ). Corresponding biopsies were taken from the m...
February 15, 2017: Acta Physiologica
Yasushi Okura, Tadashi Namisaki, Kei Moriya, Mitsuteru Kitade, Kosuke Takeda, Kosuke Kaji, Ryuichi Noguchi, Norihisa Nishimura, Kenichiro Seki, Hideto Kawaratani, Hiroaki Takaya, Shinya Sato, Yasuhiko Sawada, Naotaka Shimozato, Masanori Furukawa, Keisuke Nakanishi, Saikawa Soichiro, Takuya Kubo, Kiyoshi Asada, Hitoshi Yoshiji
AIM: Dipeptidyl peptidase-4 (DPP4) inhibitors (DPP4-I) are oral glucose-lowering drugs for type 2 diabetes mellitus. Previously, we demonstrated that DPP4-I (sitagliptin) exerted suppressive effects on experimental liver fibrosis in rats. Blockade of the renin-angiotensin system by angiotensin-II type 1 receptor blocker (ARB: losartan), commonly used in the management of hypertension, has been shown to significantly alleviate hepatic fibrogenesis and carcinogenesis. We aimed to elucidate the effects and possible mechanisms of a sitagliptin + losartan combination on the progression of nondiabetic nonalcoholic steatohepatitis (NASH) in a rat model...
December 28, 2016: Hepatology Research: the Official Journal of the Japan Society of Hepatology
Mark Moran
: Obstructive sleep apnea (OSA) is characterized by repeated involuntary closure of the pharyngeal airspace during sleep. Normal activity of the genioglossus (GG) muscle is important in maintaining airway patency, and inhibition of GG activity can contribute to airway closure. Neurons in the hypoglossal motor nucleus (HMN) regulate GG activity. Adrenergic tone is an important regulator of HMN neuronal excitability. In laboratory models α1-adrenergic antagonists inhibit HMN neurons and GG activity, suggesting that α1-adrenergic antagonism might adversely affect patients with OSA...
2016: Respiratory Medicine Case Reports
Toby N Weingarten, Tasha L Welch, Tamara L Moore, Gulshat F Walters, Joni L Whipple, Alexandre Cavalcante, Irina Bancos, William F Young, Lucinda M Gruber, Muhammad Z Shah, Travis J McKenzie, Darrell R Schroeder, Juraj Sprung
OBJECTIVE: To determine whether, despite pharmacologic adrenergic receptor blockade, higher preoperative levels of catecholamines and metanephrines (adrenergic activity) are associated with increased intraoperative complications. MATERIALS AND METHODS: Records of patients undergoing paraganglioma and pheochromocytoma (PGL-PCC) resection from January 1, 2000, to June 30, 2015, were reviewed for preoperative levels of adrenergic activity, intraoperative variability in blood pressure and heart rate (range), and postoperative outcomes (hypotension requiring treatment)...
October 18, 2016: Urology
David John Webb
Treatment-resistant hypertension (TRH) is defined as the failure to achieve an office BP target of <140/90 mmHg (<130/80 mmHg in patients with chronic kidney disease (CKD) or diabetes) in patients with hypertension (HT), despite adherence to at least 3 antihypertensive medications at optimal tolerated doses, ideally including a diuretic (Calhoun et al., Circulation 2008). TRH identifies patients with hard-to-treat HT, who might benefit from specialist investigation and treatment. Although some studies put the prevalence of TRH as >10%, these levels may be inflated by white-coat hypertension and poor adherence...
September 2016: Journal of Hypertension
Artur Fedorowski, Hongliang Li, Xichun Yu, Kristi A Koelsch, Valerie M Harris, Campbell Liles, Taylor A Murphy, Syed M S Quadri, Robert Hal Scofield, Richard Sutton, Olle Melander, David C Kem
AIMS: Postural tachycardia syndrome (POTS), a common and debilitating cardiovascular disorder, is characterized by an exaggerated heart rate increase during orthostasis and a wide spectrum of adrenergic-related symptoms. To determine the aetiology of POTS, we examined a possible pathophysiological role for autoantibodies against α1-adrenergic (α1AR) and β1/2-adrenergic receptors (β1/2AR). METHODS AND RESULTS: Immunoglobulin G (IgG) derived from 17 POTS patients, 7 with recurrent vasovagal syncope (VVS), and 11 normal controls was analysed for its ability to modulate activity and ligand responsiveness of α1AR and β1/2AR in transfected cells and to alter contractility of isolated rat cremaster arterioles in vitro...
October 4, 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
Shigehiko Ogoh, Henrik Sørensen, Ai Hirasawa, Hiroyuki Sasaki, Takuro Washio, Takeshi Hashimoto, Damian M Bailey, Niels H Secher
What is the central question of this study? Dynamic cerebral autoregulation (CA) is impaired by sympathetic blockade, and the external carotid artery (ECA) vascular bed may prevent adequate internal carotid artery blood flow. We examined whether α1 -receptor blockade-induced attenuation of dynamic CA is related to reduced ECA vasoconstriction. What is the main finding and its importance? α1 -Receptor blockade attenuated dynamic CA, but in contrast to our hypothesis did not affect the ECA blood flow response to acute hypotension...
August 1, 2016: Experimental Physiology
S Y Shin, A Pozzi, S K Boyd, A L Clark
OBJECTIVE: To investigate the role of integrin α1β1 in the progression of post-traumatic osteoarthritis (PTOA), and elucidate the contribution of epidermal growth factor receptor (EGFR) signalling to the mechanism by which integrin α1β1 might control PTOA. We hypothesised that integrin α1β1 plays a protective role in the course of PTOA and that the effect of PTOA (e.g., synovitis, loss of cartilage and growth of osteophytes) would be exacerbated in mice lacking integrin α1β1 at every time point post destabilisation of medial meniscus (DMM)...
October 2016: Osteoarthritis and Cartilage
Suzana Assad Kahn, Silvia Lima Costa, Sharareh Gholamin, Ryan T Nitta, Luiz Gustavo Dubois, Marie Fève, Maria Zeniou, Paulo Lucas Cerqueira Coelho, Elias El-Habr, Josette Cadusseau, Pascale Varlet, Siddhartha S Mitra, Bertrand Devaux, Marie-Claude Kilhoffer, Samuel H Cheshier, Vivaldo Moura-Neto, Jacques Haiech, Marie-Pierre Junier, Hervé Chneiweiss
A variety of drugs targeting monoamine receptors are routinely used in human pharmacology. We assessed the effect of these drugs on the viability of tumor-initiating cells isolated from patients with glioblastoma. Among the drugs targeting monoamine receptors, we identified prazosin, an α1- and α2B-adrenergic receptor antagonist, as the most potent inducer of patient-derived glioblastoma-initiating cell death. Prazosin triggered apoptosis of glioblastoma-initiating cells and of their differentiated progeny, inhibited glioblastoma growth in orthotopic xenografts of patient-derived glioblastoma-initiating cells, and increased survival of glioblastoma-bearing mice...
May 2, 2016: EMBO Molecular Medicine
Christian Schmidt, Judith Leibiger, Markus Fendt
One of the major symptoms of narcolepsy is cataplexy, a sudden loss of muscle tone. Despite the advances in understanding the neuropathology of narcolepsy, cataplexy is still treated symptomatically with antidepressants. Here, we investigate in a murine narcolepsy model the hypothesis that the antidepressants specifically blocking norepinephrine reuptake are more potent in treating narcoleptic episodes than the antidepressants blocking of serotonin reuptake. Furthermore, we tested the effects of α1 receptor stimulation and blockade, respectively, on narcoleptic episodes...
July 15, 2016: Behavioural Brain Research
M Pekař, M Mazur, A Pekařová, J Kozák, A Foltys
INTRODUCTION: Lumbar sympathectomy (LS) irreversibly damages a part of the sympathetic trunk and adjacent ganglia between L1 and L5, typically between L2 and L4. The first LS was performed in 1923. Initially, it used to be performed very often; however, with the progress of vascular and endovascular surgery its importance gradually continues to decline. The aim of the paper is to present literature review focusing on LS over the past 15 years. METHOD: Literature review of 113 academic articles found in academic journal databases...
March 2016: Rozhledy V Chirurgii: Měsíčník Československé Chirurgické Společnosti
Igor A Fernandes, João D Mattos, Monique O Campos, Alessandro C Machado, Marcos P Rocha, Natalia G Rocha, Lauro C Vianna, Antonio C L Nobrega
Handgrip-induced increases in blood flow through the contralateral artery that supplies the cortical representation of the arm have been hypothesized as a consequence of neurovascular coupling and a resultant metabolic attenuation of sympathetic cerebral vasoconstriction. In contrast, sympathetic restraint, in theory, inhibits changes in perfusion of the cerebral ipsilateral blood vessels. To confirm whether sympathetic nerve activity modulates cerebral blood flow distribution during static handgrip (SHG) exercise, beat-to-beat contra- and ipsilateral internal carotid artery blood flow (ICA; Doppler) and mean arterial pressure (MAP; Finometer) were simultaneously assessed in nine healthy men (27 ± 5 yr), both at rest and during a 2-min SHG bout (30% maximal voluntary contraction), under two experimental conditions: 1) control and 2) α1-adrenergic receptor blockade...
June 1, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Fabrice Trovero, Sabrina David, Philippe Bernard, Alain Puech, Jean-Charles Bizot, Jean-Pol Tassin
Alcohol-dependence is a chronic disease with a dramatic and expensive social impact. Previous studies have indicated that the blockade of two monoaminergic receptors, α1b-adrenergic and 5-HT2A, could inhibit the development of behavioral sensitization to drugs of abuse, a hallmark of drug-seeking and drug-taking behaviors in rodents. Here, in order to develop a potential therapeutic treatment of alcohol dependence in humans, we have blocked these two monoaminergic receptors by a combination of antagonists already approved by Health Agencies...
2016: PloS One
Pedro A Fernandes, Eduardo K Tamura, Letícia D'Argenio-Garcia, Sandra M Muxel, Sanseray da Silveira Cruz-Machado, Marina Marçola, Cláudia E Carvalho-Sousa, Erika Cecon, Zulma S Ferreira, Regina P Markus
BACKGROUND/AIM: The nocturnal production of melatonin by the pineal gland is triggered by sympathetic activation of adrenoceptors and may be modulated by immunological signals. The effect of glucocorticoids on nocturnal melatonin synthesis is controversial; both stimulatory and inhibitory effects have been reported. During pathophysiological processes, an increased sympathetic tonus could result in different patterns of adrenoceptor activation in the pineal gland. Therefore, in this investigation, we evaluated whether the pattern of adrenergic stimulation of the pineal gland drives the direction of the glucocorticoid effect on melatonin production...
2017: Neuroendocrinology
Timothy P Just, Darren S DeLorey
Exercise training (ET) increases sympathetic vasoconstrictor responsiveness and enhances contraction-mediated inhibition of sympathetic vasoconstriction (i.e., sympatholysis) through a nitric oxide (NO)-dependent mechanism. Changes in α2-adrenoreceptor vasoconstriction mediate a portion of these training adaptations, however the contribution of other postsynaptic receptors remains to be determined. Therefore, the purpose of this study was to investigate the effect of ET on α1-adrenoreceptor-mediated vasoconstriction in resting and contracting muscle...
February 2016: Physiological Reports
Marek Bednarski, Monika Otto, Magdalena Dudek, Marcin Kołaczkowski, Adam Bucki, Agata Siwek, Grażyna Groszek, Elżbieta Maziarz, Piotr Wilk, Jacek Sapa
β-Adrenergic receptor antagonists are important therapeutics for the treatment of cardiovascular disorders. In the group of β-blockers, much attention is being paid to the third-generation drugs that possess important ancillary properties besides inhibiting β-adrenoceptors. Vasodilating activity of these drugs is produced through different mechanisms, such as nitric oxide (NO) release, β2 -agonistic action, α1 -blockade, antioxidant action, and Ca(2+) entry blockade. Here, a study on evaluation of the cardiovascular activity of five new compounds is presented...
March 2016: Archiv der Pharmazie
L Lladó-Pelfort, E Troyano-Rodriguez, H E van den Munkhof, A Cervera-Ferri, N Jurado, M Núñez-Calvet, F Artigas, P Celada
The non-competitive NMDA receptor (NMDA-R) antagonist phencyclidine (PCP) markedly disrupts thalamocortical activity, increasing excitatory neuron discharge and reducing low frequency oscillations (LFO, <4Hz) that temporarily group neuronal discharge. These actions are mainly driven by PCP interaction with NMDA-R in GABAergic neurons of the thalamic reticular nucleus and likely underlie PCP psychotomimetic activity. Here we report that classical (haloperidol, chlorpromazine, perphenazine) and atypical (clozapine, olanzapine, quetiapine, risperidone, ziprasidone, aripripazole) antipsychotic drugs--but not the antidepressant citalopram--countered PCP-evoked fall of LFO in the medial prefrontal cortex (mPFC) of anesthetized rats...
March 2016: European Neuropsychopharmacology: the Journal of the European College of Neuropsychopharmacology
Carolin Pügge, Jai Mediratta, Noah J Marcus, Harold D Schultz, Alicia M Schiller, Irving H Zucker
Recent data suggest that exercise training (ExT) is beneficial in chronic heart failure (CHF) because it improves autonomic and peripheral vascular function. In this study, we hypothesized that ExT in the CHF state ameliorates the renal vasoconstrictor responses to hypoxia and that this beneficial effect is mediated by changes in α1-adrenergic receptor activation. CHF was induced in rabbits. Renal blood flow (RBF) and renal vascular conductance (RVC) responses to 6 min of 5% isocapnic hypoxia were assessed in the conscious state in sedentary (SED) and ExT rabbits with CHF with and without α1-adrenergic blockade...
February 1, 2016: Journal of Applied Physiology
Bradford D Fischer, Donna M Platt, Sundari K Rallapalli, Ojas A Namjoshi, James M Cook, James K Rowlett
BACKGROUND: Conventional benzodiazepines bind non-selectively to GABAA receptors containing α1, α2, α3, and α5 subunits (α1GABAA, α2GABAA, α3GABAA, and α5GABAA receptors, respectively), and the role of these different GABAA receptor subtypes in the reinforcing effects of benzodiazepines has not been characterized fully. We used a pharmacological antagonist approach with available subtype-selective ligands to evaluate the role of GABAA receptor subtypes in the reinforcing effects of the non-selective conventional benzodiazepine, triazolam...
January 1, 2016: Drug and Alcohol Dependence
Magdalena Dudek, Joanna Knutelska, Marek Bednarski, Leszek Nowiński, Małgorzata Zygmunt, Barbara Mordyl, Monika Głuch-Lutwin, Grzegorz Kazek, Jacek Sapa, Karolina Pytka
The search for drugs with anorectic activity, acting within the adrenergic system has attracted the interest of researchers. Partial α2-adrenoceptor agonists might offer the potential for effective and safe treatment of obesity. We compared the effectiveness and safety of α2-adrenoceptor ligands in reducing body mass. We also analyzed if antagonist and partial agonists of α2-adrenoceptor--yohimbine and guanfacine--act similarly, and determined which course of action is connected with anorectic activity. We tested intrinsic activity and effect on the lipolysis of these compounds in cell cultures, evaluated their effect on meal size, body weight in Wistar rats with high-fat diet-induced obesity, and determined their effect on blood pressure, heart rate, lipid profile, spontaneous locomotor activity, core temperature and glucose, as well as glycerol and cortisol levels...
2015: PloS One
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