1
|
Deeney BT, Cao G, Orfanos S, Lee J, Kan M, Himes BE, Parikh V, Koziol-White CJ, An SS, Panettieri RA. Epinephrine evokes shortening of human airway smooth muscle cells following β 2 adrenergic receptor desensitization. Am J Physiol Lung Cell Mol Physiol 2022; 323:L142-L151. [PMID: 35787178 PMCID: PMC9359643 DOI: 10.1152/ajplung.00444.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 06/14/2022] [Accepted: 06/28/2022] [Indexed: 11/22/2022] Open
Abstract
Epinephrine (EPI), an endogenous catecholamine involved in the body's fight-or-flight responses to stress, activates α1-adrenergic receptors (α1ARs) expressed on various organs to evoke a wide range of physiological functions, including vasoconstriction. In the smooth muscle of human bronchi, however, the functional role of EPI on α1ARs remains controversial. Classically, evidence suggests that EPI promotes bronchodilation by stimulating β2-adrenergic receptors (β2ARs). Conventionally, the selective β2AR agonism of EPI was thought to be, in part, due to a predominance of β2ARs and/or a sparse, or lack of α1AR activity in human airway smooth muscle (HASM) cells. Surprisingly, we find that HASM cells express a high abundance of ADRA1B (the α1AR subtype B) and identify a spontaneous "switch-like" activation of α1ARs that evokes intracellular calcium, myosin light chain phosphorylation, and HASM cell shortening. The switch-like responses, and related EPI-induced biochemical and mechanical signals, emerged upon pharmacological inhibition of β2ARs and/or under experimental conditions that induce β2AR tachyphylaxis. EPI-induced procontractile effects were abrogated by an α1AR antagonist, doxazosin mesylate (DM). These data collectively uncover a previously unrecognized feed-forward mechanism driving bronchospasm via two distinct classes of G protein-coupled receptors (GPCRs) and provide a basis for reexamining α1AR inhibition for the management of stress/exercise-induced asthma and/or β2-agonist insensitivity in patients with difficult-to-control, disease subtypes.
Collapse
Affiliation(s)
- Brian T Deeney
- Rutgers Institute for Translational Medicine and Science, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| | - Gaoyuan Cao
- Rutgers Institute for Translational Medicine and Science, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| | - Sarah Orfanos
- Rutgers Institute for Translational Medicine and Science, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| | - Jordan Lee
- The Joint Graduate Program in Toxicology, Department of Pharmacology and Toxicology, Rutgers-Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, New Jersey
| | - Mengyuan Kan
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Blanca E Himes
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Vishal Parikh
- Rutgers Institute for Translational Medicine and Science, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| | - Cynthia J Koziol-White
- Rutgers Institute for Translational Medicine and Science, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| | - Steven S An
- Rutgers Institute for Translational Medicine and Science, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
- The Joint Graduate Program in Toxicology, Department of Pharmacology and Toxicology, Rutgers-Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, New Jersey
- Department of Pharmacology, Rutgers-Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, New Jersey
| | - Reynold A Panettieri
- Rutgers Institute for Translational Medicine and Science, Rutgers, The State University of New Jersey, New Brunswick, New Jersey
| |
Collapse
|
2
|
Islami P, Ilazi A, Jakupi A, Bexheti S, Islami H. Importance of Alpha-adrenergic Receptor Subtypes in Regulating of Airways Tonus at Patients with Bronchial Asthma. Acta Inform Med 2014; 22:174-8. [PMID: 25132710 PMCID: PMC4130673 DOI: 10.5455/aim.2014.22.174-178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 06/14/2014] [Indexed: 11/04/2022] Open
Abstract
Background: In this work, effect of Tamsulosin hydrochloride as antagonist of alpha1A and alpha1B- adrenergic receptor and effect of Salbutamol as agonist of beta2- adrenergic receptor in patients with bronchial asthma and increased bronchial reactibility was studied. Methods: Parameters of the lung function are determined by Body plethysmography. Raw and ITGV were registered and specific resistance (SRaw) was also calculated. Tamsulosin was administered in per os way as a preparation in the form of the capsules with a brand name of “Prolosin”, producer: Niche Generics Limited, Hitchin, Herts. Results: Results gained from this research show that blockage of alpha1A and alpha1B- adrenergic receptor with Tamsulosin hydrochloride (0.4 mg and 0.8 mg in per os way) has not changed significantly (p > 0.1) the bronchomotor tonus of tracheobronchial tree in comparison to the inhalation of Salbutamol as agonist of beta2- adrenergic receptor (2 inh. x 0.2 mg), (p < 0.05). Arterial blood pressure showed no significant decrease following the administration of the dose of 0.8 mg Tamsulosin. Conclusion: This suggests that the activity of alpha1A and alpha1B- adrenergic receptor in the smooth musculature is not a primary mechanism which causes reaction in patients with increased bronchial reactibility, in comparison to agonists of beta2 – adrenergic receptor which emphasizes their significant action in the reduction of specific resistance of airways.
Collapse
Affiliation(s)
- Pellumb Islami
- Kosovo Medicines Agency, Hospital st., Prishtina, Kosova
| | - Ali Ilazi
- Kosovo Occupational Health Institute, Clinical Centre N.N. 10000, Gjakova, Kosova
| | - Arianit Jakupi
- Kosovo Medicines Agency, Hospital st., Prishtina, Kosova
| | - Sadi Bexheti
- Department of Anatomy, Faculty of Medicine. University of Prishtina. Clinical Centre, Mother Theresa Str., 10000, Prishtina. Kosova
| | - Hilmi Islami
- Department of Pharmacology, Faculty of Medicine. University of Prishtina. Clinical Centre, Mother Theresa Str., 10000, Prishtina. Kosova
| |
Collapse
|
3
|
Morales DR, Jackson C, Lipworth BJ, Donnan PT, Guthrie B. Adverse respiratory effect of acute β-blocker exposure in asthma: a systematic review and meta-analysis of randomized controlled trials. Chest 2014; 145:779-786. [PMID: 24202435 DOI: 10.1378/chest.13-1235] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND β-Blockers are avoided in asthma over concerns regarding acute bronchoconstriction. Risk is greatest following acute exposure, including the potential for antagonism of β2-agonist rescue therapy. METHODS A systematic review of databases was performed to identify all randomized, blinded, placebo-controlled clinical trials evaluating acute β-blocker exposure in asthma. Effect estimates for changes in respiratory function, symptoms, and β2-agonist response were pooled using random effects meta-analysis with heterogeneity investigated. RESULTS Acute selective β-blockers in the doses given caused a mean change in FEV1 of −6.9% (95% CI, −8.5 to −5.2), a fall in FEV1 of ≥20% in one in eight patients (P=.03), symptoms affecting one in 33 patients (P=.18), and attenuation of concomitant β2-agonist response of −10.2% (95% CI, −14.0 to −6.4). Corresponding values for acute nonselective β-blockers in the doses given were −10.2% (95% CI, −14.7 to −5.6), one in nine patients (P=.02), one in 13 patients (P=.14), and −20.0% (95% CI, −29.4 to −10.7). Following investigation of heterogeneity, clear differences were found for celiprolol and labetalol. A dose-response relationship was demonstrated for selective β-blockers. CONCLUSIONS Selective β-blockers are better tolerated but not completely risk-free. Risk from acute exposure may be mitigated using the smallest dose possible and β-blockers with greater β1-selectivity. β-Blocker-induced bronchospasm responded partially to β2-agonists in the doses given with response blunted more by nonselective β-blockers than selective β-blockers. Use of β-blockers in asthma could possibly be based upon a risk assessment on an individual patient basis.
Collapse
Affiliation(s)
- Daniel R Morales
- Quality, Safety, and Informatics Group, Medical Research Institute, University of Dundee, Dundee.
| | - Cathy Jackson
- Bute Medical School, University of St Andrews, Fife, Scotland
| | - Brian J Lipworth
- Asthma and Allergy Research Group, Medical Research Institute, University of Dundee, Dundee
| | - Peter T Donnan
- Dundee Epidemiology and Biostatistics Unit, Medical Research Institute, University of Dundee, Dundee
| | - Bruce Guthrie
- Quality, Safety, and Informatics Group, Medical Research Institute, University of Dundee, Dundee
| |
Collapse
|
4
|
GADDIE JOHN, SKINNER CRAIG, PALMER K. INTRAVENOUS INDORAMIN AND AEROSOL SALBUTAMOL IN BRONCHIAL ASTHMA. Br J Clin Pharmacol 2012. [DOI: 10.1111/j.1365-2125.1981.tb00300.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
|
5
|
Abstract
The effect of alpha-adrenoceptor blocking drug, thymoxamine alone and in combination with isoprenaline, was studied on the specific airways conductance (SGaw) in ten patients with extrinsic asthma. Thymoxamine when given together with isoprenaline produced significantly greater increase in SGaw as compared to improvement achieved with isoprenaline alone. It is suggested that the potentiation of isoprenaline induced bronchodilatation by thymoxamine is mediated by increased cyclic AMP formation in the bronchial smooth muscle.
Collapse
Affiliation(s)
- K R Patel
- Department of Respiratory Medicine, Western Infirmary, Glasgow
| |
Collapse
|
6
|
Kotlyar E, Keogh AM, Macdonald PS, Arnold RH, McCaffrey DJ, Glanville AR. Tolerability of carvedilol in patients with heart failure and concomitant chronic obstructive pulmonary disease or asthma. J Heart Lung Transplant 2002; 21:1290-5. [PMID: 12490274 DOI: 10.1016/s1053-2498(02)00459-x] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND A substantial proportion of the population with congestive heart failure (CHF) has concomitant airway disease. Little information exists on the tolerability of carvedilol in patients with chronic obstructive pulmonary disease (COPD). In this study, we assessed the tolerability and efficacy of carvedilol in patients with CHF and concomitant COPD or asthma. METHODS Between 1996 and 2000, a total of 487 patients began receiving open-label carvedilol. Forty-three (9%) had COPD (n = 31) or asthma (n = 12). Spirometry supported clinical diagnosis in all, and full pulmonary function testing supported diagnosis in 71%. Sixty percent began carvedilol therapy in the hospital and underwent measurement of peak expiratory flow rates (PEFR) before and after dosing. RESULTS In patients with COPD, mean forced expiratory volume in one second (FEV(1)) was 62% +/- 13% predicted, reversibility was 4% +/- 4% with bronchodilators, and FEV(1)/FVC was 62% +/- 8%. Mean PEFR was 325 +/- 115 liter/min before the dose and increased by 17% 2 hours after the carvedilol dose (p = 0.04). In patients with asthma, mean FEV(1) was 80% +/- 17% predicted, reversibility was 13% +/- 7%, and FEV(1)/FVC was 74% +/- 11%. Mean PEFR was 407 +/- 161 liter/min before the dose with no significant change 2 hours after the dose. Carvedilol was introduced safely in 84% of patients with COPD, with only 1 patient withdrawn from therapy for wheezing. In contrast, only 50% of patients with asthma tolerated carvedilol. Survival at 2.5 years was 72%. In survivors, left ventricular end-diastolic diameter decreased from 76 +/- 11 mm to 72 +/- 14 mm (p = 0.01), left ventricular end-systolic diameter decreased from 65 +/- 13 mm to 60 +/- 15 mm (p = 0.01), and fractional shortening increased from 14% +/- 7% to 17% +/- 7% (p = 0.05) at 12 months. CONCLUSIONS Patients with CHF and COPD tolerated carvedilol well with no significant reversible airflow limitation, but patients with CHF and asthma tolerated carvedilol poorly. The effect of carvedilol on left ventricular dimensions and function in patients with concomitant airway diseases was similar to that seen in our general group of patients. Asthma remains a contraindication to beta-blockade.
Collapse
Affiliation(s)
- Eugene Kotlyar
- Cardiopulmonary Transplant Unit, St. Vincent's Hospital, Sydney, New South Wales 2010, Australia
| | | | | | | | | | | |
Collapse
|
7
|
Ishiura Y, Fujimura M, Myou S, Amemiya T, Nobata K, Liu Q, Yamamori C. Influence of alpha-adrenoceptor blockade on antigen- and propranolol-induced bronchoconstriction in guinea-pigs in vivo. JOURNAL OF AUTONOMIC PHARMACOLOGY 2000; 20:23-30. [PMID: 11048958 DOI: 10.1046/j.1365-2680.2000.00152.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
1. Beta-adrenoceptor antagonists, such as propranolol, can provoke severe bronchoconstriction only in asthmatic subjects. Recently, we developed a guinea-pig model of propranolol-induced bronchoconstriction (PIB) and the purpose of this study was to investigate the role of alpha-adrenergic nerve pathways in this reaction. 2. Phentolamine administered after an antigen challenge did not inhibit PIB; however, its administration before the antigen challenge significantly inhibited the antigen-induced bronchoconstriction and also bronchoconstriction induced by methacholine inhalation. 3. We conclude that the alpha-adrenergic nerve system is not involved in the development of PIB following allergic reaction in our guinea-pig model.
Collapse
Affiliation(s)
- Y Ishiura
- The Third Department of Internal Medicine, Kanazawa University School of Medicine, Japan
| | | | | | | | | | | | | |
Collapse
|
8
|
Abstract
Ophthalmic administration of phenylephrine caused decreased pulmonary compliance, tidal volume, and peak airflow values in infants with bronchopulmonary dysplasia but not in control infants. The alpha-adrenergic effects of phenylephrine may aggravate the bronchospastic component of bronchopulmonary dysplasia.
Collapse
Affiliation(s)
- S J Mirmanesh
- Section on Newborn Pediatrics, Pennsylvania Hospital
| | | | | |
Collapse
|
9
|
Amirav I, Dowdeswell RJ, Plit M, Panz VR, Joffe BI, Seftel HC. Growth hormone response to exercise in asthmatic and normal children. Eur J Pediatr 1990; 149:443-6. [PMID: 2332018 DOI: 10.1007/bf02009670] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Maximal growth hormone (GH) increments following exercise were compared in asthmatic (n = 14) and normal (n = 8) children. Exercise, which consisted of 6 min ergometer cycling while breathing cold dry (CD) air, induced asthma in all asthmatic patients but not in normal subjects. Baseline plasma GH levels were similar in both groups. Following exercise, however, asthmatic patients had significantly higher mean GH increments than normal subjects (14.8 vs 4.9 ng/ml, P less than 0.025). To evaluate the possible role of bronchoconstriction in the GH response all subjects exercised again, this time while breathing warm humid (WH) air. Despite the absence of exercise-induced asthma (EIA) while breathing WH air, asthmatic patients still had significantly higher mean GH increments than normal subjects (9.2 vs 2.3 ng/ml, P less than 0.05). We conclude that some asthmatic children show excessive GH secretion after exercise regardless of inspired air conditions or the development of EIA.
Collapse
Affiliation(s)
- I Amirav
- Department of Medicine, J. G. Strijdom Hospital, University of the Witwatersrand, Johannesburg, South Africa
| | | | | | | | | | | |
Collapse
|
10
|
Abstract
This review examines the roles and functional significance of alpha and beta-adrenoceptor subtypes in airway smooth muscle, with emphasis on human airway function and the influence of asthma. Specifically, we have examined the distribution of beta-adrenoceptors in lung and the influence of age, the epithelium, respiratory viruses and inflammation associated with asthma on airway smooth muscle beta-adrenoceptor function. Sites of action, beta 2-selectivity, efficacy and tolerance are also examined in relation to the use of beta 2-agonists in man. In addition, alpha-adrenoceptor function in airway smooth muscle has been reviewed, with some emphasis on comparing observations made in airway smooth muscle with those in animal models.
Collapse
Affiliation(s)
- R G Goldie
- Department of Pharmacology, University of Western Australia, Perth, Nedlands
| | | | | |
Collapse
|
11
|
Spina D, Rigby PJ, Paterson JW, Goldie RG. Alpha 1-adrenoceptor function and autoradiographic distribution in human asthmatic lung. Br J Pharmacol 1989; 97:701-8. [PMID: 2547482 PMCID: PMC1854554 DOI: 10.1111/j.1476-5381.1989.tb12006.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
1. The autoradiographic distribution of alpha 1-adrenoceptors was investigated in non-diseased and asthmatic human lung by use of [3H]-prazosin (H-PZ). To validate binding and autoradiographic methods, H-PZ binding was also measured in rat heart. 2. Significant levels of specific H-PZ binding were detected in sections of rat heart. This binding was associated with a single class of non-interacting sites of high affinity (dissociation constant, Kd = 1.17 +/- 0.26 nM). The maximum binding capacity (Bmax) was 59.5 +/- 4.5 fmol mg-1 protein. 3. In sharp contrast, very low levels of specific H-PZ binding were found in both human nondiseased and asthmatic bronchus, although a high level of binding of [125I]-iodocyanopindolol (I-CYP, 50 pM) to beta-adrenoceptors was detected in these airways. Furthermore, very low levels of autoradiographic grains representing specific H-PZ binding were found in all airway structures in human non-diseased or asthmatic lung parenchyma. 4. Consistent with these data, the alpha-adrenoceptor agonist phenylephrine failed to induce significant increases in tone in bronchi isolated from either non-diseased or asthmatic human lung. Results indicate that asthma does not involve significant increases in airway alpha 1-adrenoceptor function.
Collapse
Affiliation(s)
- D Spina
- Department of Pharmacology, University of Western Australia, Perth
| | | | | | | |
Collapse
|
12
|
Cabanes LR, Weber SN, Matran R, Regnard J, Richard MO, Degeorges ME, Lockhart A. Bronchial hyperresponsiveness to methacholine in patients with impaired left ventricular function. N Engl J Med 1989; 320:1317-22. [PMID: 2541334 DOI: 10.1056/nejm198905183202005] [Citation(s) in RCA: 189] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
To elucidate the pathogenesis of bronchospasm in congestive heart failure, we studied 23 patients with chronic impairment of left ventricular function due to coronary artery disease or dilated cardiomyopathy. In 21 of them we found marked bronchial hyperresponsiveness to methacholine. The mean dose (+/- SD) of methacholine that elicited a 20 percent decrease in the forced expiratory volume in one second (FEV1) was 421 +/- 298 micrograms, nearly the same as in patients with symptomatic asthma. In contrast, there was no bronchial response to methacholine in 9 of 10 patients who had coronary artery disease but normal left ventricular function. Administration of the bronchodilator albuterol led to a partial (43 percent) reversal of the methacholine-induced bronchial obstruction. In 12 patients, pretreatment with the alpha-adrenergic agonist methoxamine (10 mg by inhalation), a potent vasoconstrictor, fully prevented the methacholine-induced decrease in FEV1. The protective effect of methoxamine was blocked by the alpha-adrenergic antagonist phentolamine in all six patients who received this agent. We conclude that bronchial hyperresponsiveness to cholinergic agonists is frequent in patients with impaired left ventricular function and may contribute to the wheezy dyspnea commonly observed in such patients. The bronchoconstriction may be mediated at least in part by dilatation of the bronchial vessels.
Collapse
Affiliation(s)
- L R Cabanes
- Department of Physiology, Université René Descartes, Hôpital Cochin, Paris, France
| | | | | | | | | | | | | |
Collapse
|
13
|
Sandström T, Henriksson R, Hörnkvist R, Bäck O, Rosenhall L. Increased peripheral alpha-adrenoceptor response in allergic asthmatics. Allergy 1988; 43:49-52. [PMID: 2830803 DOI: 10.1111/j.1398-9995.1988.tb02043.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The peripheral alpha-adrenoceptor reactivity, measured as dermal blanching response to iontophoretically administered phenylephrine, was studied in 28 allergic asthmatics, 13 patients with allergic rhinoconjunctivitis and 21 healthy controls. The blanching response, which has previously been demonstrated to be mediated via alpha 1-adrenoceptors, was found to be significantly increased in allergic asthmatics compared with controls. It is suggested that there is an increased peripheral alpha-adrenoceptor reactivity in allergic asthma.
Collapse
Affiliation(s)
- T Sandström
- Dept. of Lung Medicine, University Hospital of Umeå, Sweden
| | | | | | | | | |
Collapse
|
14
|
|
15
|
|
16
|
Abstract
Although primary neural control of airway function is through parasympathetic pathways, more recent evidence indicates that there are important adrenergic and non-adrenergic, non-cholinergic neural mechanisms that may also influence respiratory function. The parasympathetic nervous system component includes neural receptors in the airways as well as afferent and efferent pathways that travel in the vagus nerves. Afferent vagal sensory receptors mediate the response to irritant or rapidly adapting receptor activation, Hering-Breuer, and the unmyelinated "C" fibers or "J" receptor pathways. The motor component of the parasympathetic nervous system has several important functions that regulate tone in normal system has several important functions that regulate tone in normal and obstructed airways. These pathways affect the following respiratory structures: bronchial smooth muscle; the mucociliary system; the larynx; and the nose. Finally, the parasympathetic nervous system may play a role in some species in the control of breathing and in the hyperpneic responses associated with airflow obstruction. In addition to cholinergic neural mechanisms, bronchomotor tone may also be influenced by adrenergic mechanisms and non-adrenergic, non-cholinergic neural pathways. Although there is minimal innervation of the airways by the sympathetic nervous system, there is ample evidence that beta-adrenoreceptors are present on bronchial smooth muscle. Beta-receptor stimulation not only relaxes airway smooth muscle, but also inhibits mediator release from mast cells in the airways and may alter vascular permeability. Alpha-adrenoreceptors are found in human airways and stimulation of these receptors causes bronchoconstriction. Although the importance of alpha-adrenoreceptors has been questioned, recent evidence suggests that alpha stimulation may play a role in cold air- and exercise-induced asthma. Finally, non-adrenergic, non-cholinergic nerves have been shown to cause relaxation of human airways in in vivo studies. There is increasing evidence that vasoactive intestinal peptide and peptide histidine methanol are the mediators of these responses. More recently, other neuropeptides (substance P, neurokinin A, and calcitonin gene-related peptide) have been localized in nerves in airways. These cause bronchoconstriction in vitro and may be released from afferent nerve terminals by an axon reflex. Although the precise role of these substances in controlling airway tone and bronchial secretions in humans is not fully understood, they may have important modulatory effects on the neural control of airway function.
Collapse
|
17
|
Jenkins C, Breslin AB, Marlin GE. The role of alpha and beta adrenoceptors in airway hyperresponsiveness to histamine. J Allergy Clin Immunol 1985; 75:364-72. [PMID: 2857739 DOI: 10.1016/0091-6749(85)90073-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effect of a specific alpha 1-adrenoceptor antagonist, prazosin, on histamine-induced bronchoconstriction was compared to a beta 2-adrenoceptor agonist, salbutamol, in 16 subjects with nonspecific bronchial hyperresponsiveness whose PC20H ranged from 0.10 to 5.12 mg/ml. PC20H was calculated from a histamine inhalation test performed before and after 0.5 mg of prazosin by dry powder inhalation and 200 mcg of salbutamol by pressurized aerosol. PC20H was also measured in six subjects before and after placebo (20 mg lactose) by dry powder inhalation in a randomized double-blind study with prazosin. Mean (+/- SE) PC20H before and after placebo was 1.77 (0.32) and 1.57 (0.38) mg/ml, respectively, an 0.89-fold change. Mean (+/- SE) PC20H before and after prazosin for the 16 subjects was 1.92 (0.34) and 3.10 (0.72) mg/ml, a 1.51-fold change (p less than 0.001), and PC20H before and after salbutamol was 2.08 (0.33) and 9.54 (2.51) mg/ml, a 4.08-fold change (p less than 0.001). There was a positive correlation between the prazosin and salbutamol responses (r = 0.55, p less than 0.05). A dose response for salbutamol was performed in eight subjects, and PC20H was determined by use of increasing doses of salbutamol until PC20H was more than 16 mg/ml. The dose of salbutamol required varied widely between subjects and did not relate to baseline PC20H. The results suggest a role for alpha-adrenoceptors in addition to beta-adrenoceptors in histamine-induced bronchoconstriction.
Collapse
|
18
|
|
19
|
|
20
|
Advenier C, Floch-Saint-Aubin A. Bronchopulmonary effects of phenylephrine and methoxamine in the guinea-pig. Interaction with bronchoconstrictor drugs. Eur J Pharmacol 1984; 100:59-69. [PMID: 6144552 DOI: 10.1016/0014-2999(84)90315-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The bronchopulmonary effects of phenylephrine (Phe) and methoxamine (Met) were investigated in vitro on isolated guinea-pig tracheas and lung strips and in vivo on pulmonary airway resistance (Raw) in conscious guinea-pigs. Phe, but not Met, relaxed the isolated trachea precontracted with acetylcholine (ACh); this effect was inhibited by propranolol and ascribed to beta-adrenergic stimulation. In the presence of propranolol, both Phe and Met contracted the isolated trachea (-log EC50 were 3.80 +/- 0.37 and 3.04 +/- 0.25 respectively (n = 5] and this effect was competitively antagonized by phentolamine. Phe and Met contracted the isolated lung strips more strongly than the trachea (-log EC50 were 5.14 +/- 0.23 and 4.30 +/- 0.14 respectively (n = 5]. In contrast with the latter, the maximum response was equivalent to that induced by ACh; this effect was also antagonized by phentolamine. In the conscious guinea-pig, Phe (100 and 300 micrograms/kg) and Met (1 and 3 mg/kg) had no effect on Raw but significantly reduced the bronchoconstriction induced by ACh (25 micrograms/kg), histamine (20 micrograms/kg) and serotonin (15 micrograms/kg); this protective effect was unmodified by propranolol (2 mg/kg), yohimbine (1 mg/kg) or piperoxan (0.3 mg/kg) but was significantly inhibited by prazosin (30 micrograms/kg) or AR- C239 (50 micrograms/kg). These results suggest that alpha-adrenergic vasoconstriction with subsequent shrinkage of the bronchial mucosa is responsible for the protective effect of Phe and Met against ACh-induced bronchoconstriction. In isolated lung strips, vasoconstriction would increase tension.
Collapse
|
21
|
Brenner BE. Bronchial asthma in adults: presentation to the emergency department. Part I: Pathogenesis, clinical manifestations, diagnostic evaluation, and differential diagnosis. Am J Emerg Med 1983; 1:50-70. [PMID: 6097275 PMCID: PMC7134914 DOI: 10.1016/0735-6757(83)90038-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/02/1982] [Indexed: 01/18/2023] Open
|
22
|
Smith SR. Alpha-adrenergic blocking agents in the treatment of asthma. JOURNAL OF CLINICAL AND HOSPITAL PHARMACY 1983; 8:201-8. [PMID: 6135718 DOI: 10.1111/j.1365-2710.1983.tb01051.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
23
|
Advenier C, Floch A, Mallard B. Bronchopulmonary effects of clonidine on the bronchomotor responses of the guinea-pig. Eur J Pharmacol 1983; 89:85-94. [PMID: 6861893 DOI: 10.1016/0014-2999(83)90611-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In conscious guinea pigs, clonidine (10 and 100 micrograms/kg i.v.) lowered diastolic (-7.9 +/- 3.5 and -12.4 +/- 5.2%) and systolic (-8.6 +/- 3.0 and -11.9 +/- 4.2%) arterial pressure and reduced heart rate (-14.5 +/- 3.9 and -27.7 +/- 3.8%), but did not significantly modify pulmonary airway resistance. Hypotension was suppressed by yohimbine and bradycardia was partially suppressed by atropine and yohimbine, which demonstrates in this animal an alpha 2-adrenergic effect for hypotension and a mixed cholinergic and alpha 2-adrenergic effect for bradycardia. Clonidine (10 and 100 micrograms/kg i.v.) enhanced the bronchoconstrictor effects of histamine 20 micrograms/kg (+80.0 +/- 22.5 and 89.1 +/- 26.5%), acetylcholine 25 micrograms/kg (+66.4 +/- 19.8 and +95.4 +/- 25.4%) and serotonin 15 micrograms/kg (+68.5 +/- 23.2 and +81.4 +/- 34.1%). The duration of this effect was comparable to that of the hypotensive and cardiac effects of clonidine. The effects of clonidine were suppressed after pretreatment with propranolol, reserpine or pentobarbitone, all drugs which enhance the bronchoconstrictor effect of ACh. Yohimbine (1 mg/kg), piperoxan (0.3 mg/kg) or prazosin in high dosage (0.3 mg/kg) inhibited the potentiation by clonidine of ACh-induced bronchoconstriction, whereas prazosin in lower doses (0.03 mg/kg) or AR-C 239 (0.05 mg/kg) had no action. A specific involvement of alpha 2-adrenoceptors stimulated by clonidine with subsequent reduction of the adrenergic activity associated with bronchospasm could therefore be demonstrated in the conscious guinea-pig during bronchomotor reactions.
Collapse
|
24
|
Davis PB, Kaliner M. Autonomic nervous system abnormalities in cystic fibrosis. JOURNAL OF CHRONIC DISEASES 1983; 36:269-78. [PMID: 6298269 DOI: 10.1016/0021-9681(83)90062-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The basic defect in cystic fibrosis, the most common lethal genetic diseases of white Americans, is unknown, but the character of the generalized exocrinopathy suggests some disorder of the regulation and control of the process of glandular secretion. Definite abnormalities in all branches of the autonomic nervous system have been demonstrated in patients with cystic fibrosis, including increased sensitivity to alpha-adrenergically stimulated pupillary dilation; increased responsiveness to cholinergic stimulation of pupillary constriction, parotid saliva secretion, and eccrine sweat secretion; and decreased responsiveness to beta-adrenergic stimulation of the cardiovascular system as well as circulating lymphocytes and granulocytes. Since these abnormalities also occur in asymptomatic heterozygotes for cystic fibrosis (parents of patients), they are likely to be inherited characteristics and not secondarily acquired. This constellation of inherited autonomic abnormalities--alpha-adrenergic and cholinergic hyperresponsiveness and beta-adrenergic resistance--may contribute to the pathophysiology of cystic fibrosis and may also be an important clue to the nature of the basic defect.
Collapse
|
25
|
|
26
|
Barnes PJ, Wilson NM, Vickers H. Prazosin, an alpha 1-adrenoceptor antagonist, partially inhibits exercise-induced asthma. J Allergy Clin Immunol 1981; 68:411-5. [PMID: 6118384 DOI: 10.1016/0091-6749(81)90193-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The effect of prazosin, a potent and specific alpha 1-adrenoceptor antagonist given by inhalation (total nebulized 2 mg) was compared with placebo in a double-blind randomized study of 10 atopic asthmatic children. Prazosin significantly (p less than 0.01) reduced the severity of post-exercise bronchoconstriction (maximum fall in peak expiratory flow after exercise 21.4% +/- SEM 6.3% after prazosin compared with 42.5% +/- 7.3% after placebo). This protective action of prazosin suggests that activation of alpha 1-adrenoceptor may be involved in the pathogenesis of exercise-induced asthma either by facilitation of mast-cell mediator release or by direct contraction of bronchial smooth muscle. Prazosin did not significantly change resting bronchomotor tone or histamine-induced bronchoconstriction, suggesting no effect on bronchial smooth muscle contractility.
Collapse
|
27
|
Abstract
Since Szentivanyi proposed the idea that asthma and other atopic diseases are due to a beta adrenergic defect there has been much interest in the role of the adrenergic receptors in allergy. The radioactive ligand binding techniques developed within the last few years have greatly increased our knowledge concerning the molecular nature of the adrenoceptors and the events following receptor stimulation. The adrenoceptors have shown to be very dynamic structures. Their number and affinity may be altered due to various physiological and pharmacological stimuli. Their role in the pathogenesis of atopic diseases has not been definitely settled, but there seem to be a true beta adrenergic hyporesponsiveness and alpha hyperresponsiveness in asthma. This article briefly describes the radioligand binding technique and summarizes our present knowledge of the nature of the alpha and beta adrenoceptors and their possible role in atopic diseases.
Collapse
MESH Headings
- Adrenergic alpha-Antagonists/therapeutic use
- Animals
- Asthma/drug therapy
- Asthma/immunology
- Cyclic AMP/metabolism
- Guinea Pigs
- Humans
- Hypersensitivity, Immediate/immunology
- Protein Conformation
- Radioligand Assay
- Receptors, Adrenergic
- Receptors, Adrenergic, alpha/classification
- Receptors, Adrenergic, alpha/metabolism
- Receptors, Adrenergic, beta/classification
- Receptors, Adrenergic, beta/metabolism
Collapse
|
28
|
Abstract
Prazosin, a potent and selective alpha-adrenergic antagonist, was given by inhalation to nine asthmatic subjects aged 25-48 years (six with positive skin tests). Prazosin 0.5 mg, salbutamol 1 mg, or placebo were given by nebuliser in randomised double-blind fashion on separate days. Although all subjects showed a significant increase in FEV1, vital capacity, and maximum expiratory flow at 70% of total lung capacity after salbutamol, there was no significant difference between prazosin and placebo. This suggests that alpha-adrenergic receptors are not important in the control of bronchial tone in asthma. The weak bronchodilatation ascribed to alpha-antagonists in previous studies could be explained by other pharmacological actions of the drugs used.
Collapse
|
29
|
Schofield NM, Green M, Davies RJ. Response of the lung airway to exercise testing in asthma and rhinitis. BRITISH JOURNAL OF DISEASES OF THE CHEST 1980; 74:155-63. [PMID: 7426354 DOI: 10.1016/0007-0971(80)90027-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The reactivity of the large and small airways of the lung in a group of ten atopic subjects with rhinitis was compared with that in ten non-atopic control subjects and in 17 with atopic asthma. Atopic state was assessed by skin prick testing with 22 common allergens and by measurement of total serum immunoglobulin E (IgE) antibody. The atopic state of the rhinitis and asthma patients was similar. Exercise provocation tests were performed on each subject and changes in airway function were measured by peak expiratory flow rate, forced expiratory volume in one second, vital capacity, maximal expiratory flow volume curves and closing volume. There were no statistically significant differences between the changes in lung function after exercise in the rhinitis patients compared with the controls. There were, however, statistically significant changes in all the measurements of respiratory function in those with asthma compared with the other two groups. The falls in forced expiratory flow rates in the asthmatic subjects were greater at lower lung volumes than near the total lung capacity, perhaps indicating that narrowing of small, as well as large, airways was occurring. No correlation was found between the magnitude of the airway response to exercise and either the total serum IgE antibody or the mean weal diameter of positive skin tests in each subject. Atopic subjects with rhinitis but not asthma showed no evidence of bronchial hyper-reactivity on exercise testing. It is therefore suggested that single exercise provocation test can discriminate subjects with atopic asthma from those with other atopic disorders.
Collapse
|
30
|
Henderson WR, Shelhamer JH, Reingold DB, Smith LJ, Evans R, Kaliner M. Alpha-adrenergic hyper-responsiveness in asthma. N Engl J Med 1979; 300:642-7. [PMID: 216913 DOI: 10.1056/nejm197903223001203] [Citation(s) in RCA: 116] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Because alpha-adrenergic stimulation causes bronchoconstriction, the alpha-adrenergic responsiveness of 21 subjects with allergic asthma was compared with that of 16 subjects with allergic rhinitis and 38 normal control subjects. None of the patients had taken medications for at least 30 days before study. Alpha-adrenergic responsiveness was measured by the capacity of phenylephrine to constrict the cutaneous vascular bed and to dilate the pupillary sphincter muscle. Asthmatic subjects required 4.0 +/- 0.6 ng to reduce their cutaneous blood flow by 50 per cent, whereas normal controls required 32.0 +/- 7.5 ng (P less than 0.005) and subjects with allergic rhinitis required 23.7 +/- 9.4 ng (P less than 0.02). The pupils of asthmatic subjects dilated by greater than 0.5 mm in response to 1.8 +/- 0.14 per cent phenylephrine, patients with allergic rhinitis required 2.4 +/- 0.16 (P less than 0.01), and normal controls needed 2.7 +/- 0.07 (P less than 0.00001). Therefore, the patients with allergic asthma had significantly enhanced alpha-adrenergic responses when compared both to normal subjects and patients with allergic rhinitis; the possibility that increased alpha-adrenergic activity contributes to the asthmatic diathesis warrants further exploration.
Collapse
|
31
|
Thomson NC, Patel KR. Effect of dopamine on airways conductance in normals and extrinsic asthmatics. Br J Clin Pharmacol 1978; 5:421-4. [PMID: 148897 PMCID: PMC1429342 DOI: 10.1111/j.1365-2125.1978.tb01648.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
1 Specific conductance was measured before and after infused and/or inhaled dopamine in nine normal subjects and twelve patients with extrinsic bronchial asthma. 2 There was no significant change in conductance in either group. 3 The alpha-adrenergic receptor antagonist thymoxamine infused in combination with dopamine had no significant effect on conductance in three asthmatics. 4 It is concluded that dopamine has no acute effect on airways resistance and that specific dopamine receptors are unlikely to exist in human airways.
Collapse
|
32
|
Svedmyr N, Simonsson BG. Drugs in the treatment of asthma. PHARMACOLOGY & THERAPEUTICS. PART B: GENERAL & SYSTEMATIC PHARMACOLOGY 1978; 3:397-440. [PMID: 32558 DOI: 10.1016/s0306-039x(78)90005-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
33
|
Chyrssanthopoulos C, Barboriak JJ, Fink JN, Stekiel WJ, Maksud MG. Adrenergic responses of asthmatic and normal subjects to submaximal and maximal work levels. J Allergy Clin Immunol 1978; 61:17-22. [PMID: 618943 DOI: 10.1016/0091-6749(78)90468-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The response of the adrenergic system of asthmatic subjects to exercise and the role of plasma catecholamines in exercise-induced asthma were investigated. Plasma levels of norepinephrine and epinephrine were measured at rest, during and after exercise in 7 asthmatic and 9 matched normal subjects. Exercise-induced bronchospasm occurred in all asthmatic subjects following exercise, while no significant change was observed in the normal subjects. The results showed that plasma levels of norepinephrine and epinephrine at rest and changes that occcurred during and after exercise were similar in both normal and asthmatic subjects. These data suggest that the adrenergic response of asthmatics to the same relative exercise stress as reflected in plasma catecholamine levels does not differ from that of normal subjects. It appears that changes in the circulating catecholamines do not play a significant role in the pathogenesis of exercised-induced asthma.
Collapse
|
34
|
Beil M, Brecht HM, Rasche B. Plasma catecholamines in exercise induced bronchoconstriction. KLINISCHE WOCHENSCHRIFT 1977; 55:577-81. [PMID: 18638 DOI: 10.1007/bf01490511] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Plasma nor-epinephrine (NE) and epinephrine (E) levels at rest and immediately after exercise were estimated in 8 patients with asymptomatic extrinsic allergic bronchial asthma. The patients had a normal airway resistance at rest and developed a marked bronchoconstriction (EIB) during exercise, which could be prevented by previous alpha-adrenergic blockade with phentolamine. In 7 control persons NE and E levels were measured also after beta-adrenergic blockade with propranolol. The following results were obtained: 1. At rest NE levels showed no significant differences between the groups. After exercise an increase of NE was observed in all groups, but in patients, even after phentolamine, and in normals after propranolol the increase was significantly higher than in the normal group within the control test. 2. No significant differences between the groups were found in E levels at rest and after exercise. Exercise caused no significant increase of E levels, except in the normals after propranolol application. 3. No significant correlation existed between NE levels and the increase of airway resistance after exercise. It is concluded that during exercise in asthmatics the sympathetic activity is enhanced, but the provocation of an EIB does not seem to be mediated by enhanced plasma NE levels.
Collapse
|
35
|
Spector SL, Hudson L, Petty TL. Effect of bronkosol and its components on cardiopulmonary parameters in asthmatic patients. J Allergy Clin Immunol 1977; 59:371-6. [PMID: 323326 DOI: 10.1016/0091-6749(77)90021-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Bronkosol and its components, isoetharine hydrochloride and phenylephrine hydrochloride, were compared in a double-blind randomized fashion for their effect on pulmonary and cardiovascular parameters in patients with reversible bronchospasm. Bronkosol and isoetharine produced significant bronchodilatation as measured by forced expiratory volume in one second (FEV), forced vital capacity (FVC), and mean forced expiratory flow during the middle half of the FVC (isovolume FEF 25% to 75%), and phenylephrine did not. There was no difference between Bronkosol and isoetharine in the degree or duration of bronchodilatation. Significantly more patients had to "discontinue" after 15 min on the day of testing with phenylephrine than with Bronkosol or isoetharine. Heart rate was not increased after Bronkosol or isoetharine, confirming its selective beta-2 action. The addition of phenylephrine to isoetharine had no beneficial effect on oxygen saturation. There was no significant difference between these drugs in systolic and diastolic blood pressure, pulse, or respiration. The results of this study cast doubt on the useful contribution of phenylephrine in Bronkosol.
Collapse
|
36
|
Patel KR, Kerr JW, MacDonald EB, MacKenzie AM. The effect of thymoxamine and cromolyn sodium on postexercise bronchoconstriction in asthma. J Allergy Clin Immunol 1976; 57:285-92. [PMID: 131139 DOI: 10.1016/0091-6749(76)90084-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Of the 22 patients with extrinsic bronchial asthma, 13 patients developed post-exercise bronchoconstriction after treadmill exercise, whereas in 9 patients treadmill exercise had no effect on the ventilatory capacity. No statistical difference in the resting lung volumes and CO transfer factor was found between the two groups. A significant inhibition of postexercise bronchoconstriction was observed in 12 of 13 patients following thymoxamine or cromolyn sodium inhalation. Inhibition of postexercise bronchoconstriction by alpha blockade with thymoxamine suggests that increased alpha adrenergic activity in the presence of diminished beta receptor responsiveness to catecholamines, norepinephrine released during exercise could have a marked alpha agonistic effect giving rise to bronchoconstriction. It has been suggested that cromolyn sodium has a cyclic phosphodiesterase inhibiting action. This might increase levels of AMP and restore the beta receptor responsiveness to catecholamines.
Collapse
|
37
|
Patel KR, Kerr JW. Effect of alpha receptor blocking drug, thymoxamine, on allergen induced bronchoconstriction in extrinsic asthma. Clin Exp Allergy 1975; 5:311-6. [PMID: 126824 DOI: 10.1111/j.1365-2222.1975.tb01868.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In ten patients with extrinsic bronchial asthma, allergen provoked bronchospasm was significantly inhibited by the alpha receptor blocking drug thymoxamine given intravenously. In two of these patients thymoxamine by inhalation also effectively inhibited allergen induced bronchoconstriction. It is suggested that thymoxamine may be acting either by increasing intracellular levels of cyclic AMP and thus inhibiting mediator release following allergen challenge or by modifying the airways response to these mediators by altering the bronchomotor tone. The variable responses recorded after allergen challenge in presence of alpha blockade with thymoxamine suggests that the dominant effect is on the bronchomotor tone rather than the mediator release.
Collapse
|
38
|
|
39
|
|
40
|
|
41
|
Pegelow KO. Bronchial reactivity to inhaled histamine in asthmatic patients, before and after administration of atropine, phentolamine or disodium cromoglycate. ACTA ALLERGOLOGICA 1974; 29:365-84. [PMID: 4215272 DOI: 10.1111/j.1398-9995.1974.tb01472.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|