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Gao AY, Diaz Espinosa AM, Nguyen BBN, Link PA, Meridew J, Jones DL, Gibbard DF, Tschumperlin DJ, Haak AJ. Dopamine Receptor D1 Is Exempt from Transforming Growth Factor β-Mediated Antifibrotic G Protein-Coupled Receptor Landscape Tampering in Lung Fibroblasts. J Pharmacol Exp Ther 2023; 386:277-287. [PMID: 37024146 PMCID: PMC10449101 DOI: 10.1124/jpet.122.001442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 03/13/2023] [Accepted: 03/22/2023] [Indexed: 04/08/2023] Open
Abstract
Pulmonary fibroblasts are the primary producers of extracellular matrix (ECM) in the lungs, and their pathogenic activation drives scarring and loss of lung function in idiopathic pulmonary fibrosis (IPF). This uncontrolled production of ECM is stimulated by mechanosignaling and transforming growth factor beta 1 (TGF-β1) signaling that together promote transcriptional programs including Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ). G protein-coupled receptors (GPCRs) that couple to G α s have emerged as pharmacological targets to inactivate YAP/TAZ signaling and promote lung fibrosis resolution. Previous studies have shown a loss of expression of "antifibrotic GPCRs"-receptors that couple to G α s, in IPF patient-derived fibroblasts compared with non-IPF samples. Of the 14 G α s GPCRs we found to be expressed in lung fibroblasts, the dopamine receptor D1 (DRD1) was one of only two not repressed by TGF-β1 signaling, with the β2-adrenergic receptor being the most repressed. We compared the potency and efficacy of multiple D1 and β2 receptor agonists +/- TGF-β1 treatment in vitro for their ability to elevate cAMP, inhibit nuclear localization of YAP/TAZ, regulate expression of profibrotic and antifibrotic genes, and inhibit cellular proliferation and collagen deposition. Consistently, the activity of β2 receptor agonists was lost, whereas D1 receptor agonists was maintained, after stimulating cultured lung fibroblasts with TGF-β1. These data further support the therapeutic potential of the dopamine receptor D1 and highlight an orchestrated and pervasive loss of antifibrotic GPCRs mediated by TGF-β1 signaling. SIGNIFICANCE STATEMENT: Idiopathic pulmonary fibrosis (IPF) is a deadly lung disease with limited therapies. GPCRs have emerged as a primary target for the development of novel antifibrotic drugs; however, a challenge to this approach is the dramatic changes in GPCR expression in response to profibrotic stimuli. Here, we investigate the impact of TGF-β1 on the expression of antifibrotic GPCRs and show the D1 dopamine receptor expression is uniquely maintained in response to TGF-β1, further implicating it as a compelling target to treat IPF.
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Affiliation(s)
- Ashley Y Gao
- Departments of Physiology and Biomedical Engineering (A.M.D.E., P.A.L., J.M., D.L.J., D.J.T., A.J.H.), Ophthalmology (A.Y.G.), and Molecular Pharmacology and Experimental Therapeutics (B.B.N.N., D.F.G., A.J.H.), Mayo Clinic, Rochester, Minnesota
| | - Ana M Diaz Espinosa
- Departments of Physiology and Biomedical Engineering (A.M.D.E., P.A.L., J.M., D.L.J., D.J.T., A.J.H.), Ophthalmology (A.Y.G.), and Molecular Pharmacology and Experimental Therapeutics (B.B.N.N., D.F.G., A.J.H.), Mayo Clinic, Rochester, Minnesota
| | - Ba Bao N Nguyen
- Departments of Physiology and Biomedical Engineering (A.M.D.E., P.A.L., J.M., D.L.J., D.J.T., A.J.H.), Ophthalmology (A.Y.G.), and Molecular Pharmacology and Experimental Therapeutics (B.B.N.N., D.F.G., A.J.H.), Mayo Clinic, Rochester, Minnesota
| | - Patrick A Link
- Departments of Physiology and Biomedical Engineering (A.M.D.E., P.A.L., J.M., D.L.J., D.J.T., A.J.H.), Ophthalmology (A.Y.G.), and Molecular Pharmacology and Experimental Therapeutics (B.B.N.N., D.F.G., A.J.H.), Mayo Clinic, Rochester, Minnesota
| | - Jeffrey Meridew
- Departments of Physiology and Biomedical Engineering (A.M.D.E., P.A.L., J.M., D.L.J., D.J.T., A.J.H.), Ophthalmology (A.Y.G.), and Molecular Pharmacology and Experimental Therapeutics (B.B.N.N., D.F.G., A.J.H.), Mayo Clinic, Rochester, Minnesota
| | - Dakota L Jones
- Departments of Physiology and Biomedical Engineering (A.M.D.E., P.A.L., J.M., D.L.J., D.J.T., A.J.H.), Ophthalmology (A.Y.G.), and Molecular Pharmacology and Experimental Therapeutics (B.B.N.N., D.F.G., A.J.H.), Mayo Clinic, Rochester, Minnesota
| | - Daniel F Gibbard
- Departments of Physiology and Biomedical Engineering (A.M.D.E., P.A.L., J.M., D.L.J., D.J.T., A.J.H.), Ophthalmology (A.Y.G.), and Molecular Pharmacology and Experimental Therapeutics (B.B.N.N., D.F.G., A.J.H.), Mayo Clinic, Rochester, Minnesota
| | - Daniel J Tschumperlin
- Departments of Physiology and Biomedical Engineering (A.M.D.E., P.A.L., J.M., D.L.J., D.J.T., A.J.H.), Ophthalmology (A.Y.G.), and Molecular Pharmacology and Experimental Therapeutics (B.B.N.N., D.F.G., A.J.H.), Mayo Clinic, Rochester, Minnesota
| | - Andrew J Haak
- Departments of Physiology and Biomedical Engineering (A.M.D.E., P.A.L., J.M., D.L.J., D.J.T., A.J.H.), Ophthalmology (A.Y.G.), and Molecular Pharmacology and Experimental Therapeutics (B.B.N.N., D.F.G., A.J.H.), Mayo Clinic, Rochester, Minnesota
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Xing G, Woo AYH, Pan L, Lin B, Cheng MS. Recent Advances in β 2-Agonists for Treatment of Chronic Respiratory Diseases and Heart Failure. J Med Chem 2020; 63:15218-15242. [PMID: 33213146 DOI: 10.1021/acs.jmedchem.0c01195] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
β2-Adrenoceptor (β2-AR) agonists are widely used as bronchodilators. The emerge of ultralong acting β2-agonists is an important breakthrough in pulmonary medicine. In this review, we will provide mechanistic insights into the application of β2-agonists in asthma, chronic obstructive pulmonary disease (COPD), and heart failure (HF). Recent studies in β-AR signal transduction have revealed opposing functions of the β1-AR and the β2-AR on cardiomyocyte survival. Thus, β2-agonists and β-blockers in combination may represent a novel strategy for HF management. Allosteric modulation and biased agonism at the β2-AR also provide a theoretical basis for developing drugs with novel mechanisms of action and pharmacological profiles. Overlap of COPD and HF presents a substantial clinical challenge but also a unique opportunity for evaluation of the cardiovascular safety of β2-agonists. Further basic and clinical research along these lines can help us develop better drugs and innovative strategies for the management of these difficult-to-treat diseases.
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Affiliation(s)
- Gang Xing
- Department of Medicinal Chemistry, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, China.,Key Laboratory of Structure-Based Drug Design and Discovery of Ministry of Education, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Anthony Yiu-Ho Woo
- Department of Pharmacology, School of Life Sciences and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Li Pan
- Department of Medicinal Chemistry, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, China.,Key Laboratory of Structure-Based Drug Design and Discovery of Ministry of Education, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Bin Lin
- Department of Medicinal Chemistry, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, China.,Key Laboratory of Structure-Based Drug Design and Discovery of Ministry of Education, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Mao-Sheng Cheng
- Department of Medicinal Chemistry, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, China.,Key Laboratory of Structure-Based Drug Design and Discovery of Ministry of Education, Shenyang Pharmaceutical University, Shenyang 110016, China
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3
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Atanasovska T, Smith R, Graff C, Tran CT, Melgaard J, Kanters JK, Petersen AC, Tobin A, Kjeldsen KP, McKenna MJ. Protection against severe hypokalemia but impaired cardiac repolarization after intense rowing exercise in healthy humans receiving salbutamol. J Appl Physiol (1985) 2018; 125:624-633. [PMID: 29745804 DOI: 10.1152/japplphysiol.00680.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Intense exercise induces pronounced hyperkalemia, followed by transient hypokalemia in recovery. We investigated whether the β2 agonist salbutamol attenuated the exercise hyperkalemia and exacerbated the postexercise hypokalemia, and whether hypokalemia was associated with impaired cardiac repolarization (QT hysteresis). Eleven healthy adults participated in a randomized, counterbalanced, double-blind trial receiving either 1,000 µg salbutamol (SAL) or placebo (PLAC) by inhalation. Arterial plasma potassium concentration ([K+]a) was measured at rest, during 3 min of intense rowing exercise, and during 60 min of recovery. QT hysteresis was calculated from ECG ( n = 8). [K+]a increased above baseline during exercise (rest, 3.72 ± 0.7 vs. end-exercise, 6.81 ± 1.4 mM, P < 0.001, mean ± SD) and decreased rapidly during early recovery to below baseline; restoration was incomplete at 60 min postexercise ( P < 0.05). [K+]a was less during SAL than PLAC (4.39 ± 0.13 vs. 4.73 ± 0.19 mM, pooled across all times, P = 0.001, treatment main effect). [K+]a was lower after SAL than PLAC, from 2 min preexercise until 2.5 min during exercise, and at 50 and 60 min postexercise ( P < 0.05). The postexercise decline in [K+]a was correlated with QT hysteresis ( r = 0.343, n = 112, pooled data, P = 0.001). Therefore, the decrease in [K+]a from end-exercise by ~4 mM was associated with reduced QT hysteresis by ~75 ms. Although salbutamol lowered [K+]a during exercise, no additive hypokalemic effects occurred in early recovery, suggesting there may be a protective mechanism against severe or prolonged hypokalemia after exercise when treated by salbutamol. This is important because postexercise hypokalemia impaired cardiac repolarization, which could potentially trigger arrhythmias and sudden cardiac death in susceptible individuals with preexisting hypokalemia and/or heart disease. NEW & NOTEWORTHY Intense rowing exercise induced a marked increase in arterial potassium, followed by a pronounced decline to hypokalemic levels. The β2 agonist salbutamol lowered potassium during exercise and late recovery but not during early postexercise, suggesting a protective effect against severe hypokalemia. The decreased potassium in recovery was associated with impaired cardiac QT hysteresis, suggesting a link between postexercise potassium and the heart, with implications for increased risk of cardiac arrhythmias and, potentially, sudden cardiac death.
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Affiliation(s)
- Tania Atanasovska
- Institute for Health and Sport, Victoria University , Melbourne, Victoria , Australia
| | - Robert Smith
- Institute for Health and Sport, Victoria University , Melbourne, Victoria , Australia.,Department of Anaesthesia, Western Hospital , Melbourne, Victoria , Australia
| | - Claus Graff
- Department of Health Science and Technology, Faculty of Medicine, Aalborg University , Aalborg , Denmark
| | - Cao T Tran
- Division of Cardiology, John Hopkins University School of Medicine , Baltimore, Maryland
| | - Jacob Melgaard
- Department of Health Science and Technology, Faculty of Medicine, Aalborg University , Aalborg , Denmark
| | - Jørgen K Kanters
- Laboratory of Experimental Cardiology, Department of Biomedical Sciences, Copenhagen University , Copenhagen , Denmark
| | - Aaron C Petersen
- Institute for Health and Sport, Victoria University , Melbourne, Victoria , Australia
| | - Antony Tobin
- Intensive Care Unit, St. Vincent Hospital , Melbourne, Victoria , Australia
| | - Keld P Kjeldsen
- Department of Health Science and Technology, Faculty of Medicine, Aalborg University , Aalborg , Denmark.,Medical Department, Copenhagen University Hospital (Holbæk Hospital), Holbæk, Denmark.,Institute of Clinical Medicine, Faculty of Medicine, Copenhagen University , Copenhagen , Denmark
| | - Michael J McKenna
- Institute for Health and Sport, Victoria University , Melbourne, Victoria , Australia
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4
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Altarawneh MM, Petersen A, Smith R, Rouffet DM, Billaut F, Perry BD, Wyckelsma VL, Tobin A, McKenna MJ. Salbutamol effects on systemic potassium dynamics during and following intense continuous and intermittent exercise. Eur J Appl Physiol 2016; 116:2389-2399. [PMID: 27771799 DOI: 10.1007/s00421-016-3481-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 09/22/2016] [Indexed: 11/27/2022]
Abstract
PURPOSE Salbutamol inhalation is permissible by WADA in athletic competition for asthma management and affects potassium regulation, which is vital for muscle function. Salbutamol effects on arterial potassium concentration ([K+]a) during and after high-intensity continuous exercise (HIcont) and intermittent exercise comprising repeated, brief sprints (HIint), and on performance during HIint are unknown and were investigated. METHODS Seven recreationally active men participated in a double-blind, randomised, cross-over design, inhaling 1000 µg salbutamol or placebo. Participants cycled continuously for 5 min at 40 % [Formula: see text]O2peak and 60 % [Formula: see text]O2peak, then HIcont (90 s at 130 % [Formula: see text]O2peak), 20 min recovery, and then HIint (3 sets, 5 × 4 s sprints), with 30 min recovery. RESULTS Plasma [K+]a increased throughout exercise and subsequently declined below baseline (P < 0.001). Plasma [K+]a was greater during HIcont than HIint (P < 0.001, HIcont 5.94 ± 0.65 vs HIint set 1, 4.71 ± 0.40 mM); the change in [K+]a from baseline (Δ[K+]a) was 2.6-fold greater during HIcont than HIint (P < 0.001). The Δ[K+] throughout the trial was less with salbutamol than placebo (P < 0.001, treatment main effect, 0.03 ± 0.67 vs 0.22 ± 0.69 mM, respectively); and remained less after correction for fluid shifts (P < 0.001). The Δ[K+] during HIcont was less after salbutamol (P < 0.05), but not during HIint. Blood lactate, plasma pH, and the work output during HIint did not differ between trials. CONCLUSIONS Inhaled salbutamol modulated the [K+]a rise across the trial, comprising intense continuous and intermittent exercise and recovery, lowering Δ[K+] during HIcont. The limited [K+]a changes during HIint suggest that salbutamol is unlikely to influence systemic [K+] during periods of intense effort in intermittent sports.
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Affiliation(s)
- Muath M Altarawneh
- Institute of Sport, Exercise and Active Living (ISEAL), Clinical Exercise Science Research Program, Victoria University, PO Box 14428, Melbourne, VIC, 8001, Australia
| | - Aaron Petersen
- Institute of Sport, Exercise and Active Living (ISEAL), Clinical Exercise Science Research Program, Victoria University, PO Box 14428, Melbourne, VIC, 8001, Australia
| | - Robert Smith
- Institute of Sport, Exercise and Active Living (ISEAL), Clinical Exercise Science Research Program, Victoria University, PO Box 14428, Melbourne, VIC, 8001, Australia
- Department of Anaesthesia, Western Hospital, Melbourne, Australia
| | - David M Rouffet
- Institute of Sport, Exercise and Active Living (ISEAL), Clinical Exercise Science Research Program, Victoria University, PO Box 14428, Melbourne, VIC, 8001, Australia
| | - Francois Billaut
- Institute of Sport, Exercise and Active Living (ISEAL), Clinical Exercise Science Research Program, Victoria University, PO Box 14428, Melbourne, VIC, 8001, Australia
- Département de Kinésiologie, Université Laval, Québec, Canada
| | - Ben D Perry
- Institute of Sport, Exercise and Active Living (ISEAL), Clinical Exercise Science Research Program, Victoria University, PO Box 14428, Melbourne, VIC, 8001, Australia
| | - Victoria L Wyckelsma
- Institute of Sport, Exercise and Active Living (ISEAL), Clinical Exercise Science Research Program, Victoria University, PO Box 14428, Melbourne, VIC, 8001, Australia
| | - Antony Tobin
- Intensive Care Unit, St Vincent's Hospital, Melbourne, Australia
| | - Michael J McKenna
- Institute of Sport, Exercise and Active Living (ISEAL), Clinical Exercise Science Research Program, Victoria University, PO Box 14428, Melbourne, VIC, 8001, Australia.
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Tamm M, Richards DH, Beghé B, Fabbri L. Inhaled corticosteroid and long-acting β2-agonist pharmacological profiles: effective asthma therapy in practice. Respir Med 2013; 106 Suppl 1:S9-19. [PMID: 23273165 DOI: 10.1016/s0954-6111(12)70005-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Fixed-dose combinations of inhaled corticosteroids (ICSs) and long-acting β2-agonists (LABAs) have been used to manage asthma for several years. They are the preferred therapy option for patients who do not achieve optimal control of their asthma with low-dose ICS monotherapy. In Europe, four ICS/LABA products are commercially available for asthma maintenance therapy (fluticasone propionate/formoterol fumarate, fluticasone propionate/salmeterol xinafoate, budesonide/formoterol fumarate and beclometasone dipropionate/formoterol fumarate), and other combinations are likely to be developed over the next few years (e.g. mometasone/formoterol fumarate, fluticasone furoate/vilanterol, mometasone/indacaterol). Data from randomized, controlled, clinical trials do not demonstrate a clear overall efficacy difference among ICS/LABA combinations approved for asthma therapy. Conversely, pharmacological data indicate that there may be certain advantages to using one ICS or LABA over another because of the specific pharmacodynamic and pharmacokinetic profiles associated with particular treatments. This review article summarizes the pharmacological characteristics oft he various ICSs and LABAs available for the treatment of asthma, including the potential for ICS and LABA synergy, and gives an insight into the rationale for the development of the latest ICS/LABA combination approved for asthma maintenance therapy.
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Affiliation(s)
- Michael Tamm
- University Hospital Basel, Clinic of Pneumology, Petersgraben 4, Basel 4031, Switzerland.
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Henz S, Maeder MT, Huber S, Schmid M, Loher M, Fehr T. Influence of drugs and comorbidity on serum potassium in 15 000 consecutive hospital admissions. Nephrol Dial Transplant 2008; 23:3939-45. [PMID: 18614817 DOI: 10.1093/ndt/gfn380] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Drug trials often exclude subjects with relevant comorbidity or comedication. Nevertheless, after approval, these drugs will be prescribed to a much broader collective. Our goal was to quantify the impact of drugs and comorbidity on serum potassium in unselected patients admitted to the hospital. METHODS This was a retrospective pharmacoepidemiologic study in 15 000 consecutive patients admitted to the medical department of the Kantonsspital St. Gallen, a 700-bed tertiary hospital in eastern Switzerland. Patients with 'haemolytic' plasma and patients on dialysis or with an estimated glomerular filtration rate (GFR) <10 mL/min/1.73 m(2) were excluded. For the remaining 14 146 patients, drug history on admission, age, sex, body weight, physical findings, comorbidity (ICD-10 diagnoses) and laboratory information (potassium and creatinine) were extracted from electronic sources. RESULTS Estimated GFR was the strongest predictor of serum potassium (P < 0.0001). Angiotensin-converting enzyme inhibitors, cyclosporine, loop diuretics and potassium-sparing diuretics all showed a significant effect modification with decreasing GFR (P < 0.001). Similarly, in patients with liver cirrhosis a significantly stronger effect on potassium was found for angiotensin receptor blockers, betablockers and loop diuretics (P < 0.01). Several significant drug-drug interactions were identified. Diabetes, male sex, older age, lower blood pressure and higher body weight were all independently associated with higher serum potassium levels (P < 0.001). The model explained 14% of the variation of serum potassium. CONCLUSIONS The effects of various drugs on serum potassium are highly influenced by comorbidity and comedication. Although the presented model cannot be used to predict potassium in individual patients, we demonstrate that clinical databases could evolve as a powerful tool for industry-independent analysis of postmarketing drug safety.
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Affiliation(s)
- Samuel Henz
- Department of Internal Medicine, Kantonsspital, CH-9007 St. Gallen, Switzerland.
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Waring WS, Leigh RB. Haemodynamic responses to salbutamol and isometric exercise are altered in young adults with mild asthma. Eur J Clin Pharmacol 2005; 61:9-14. [PMID: 15785958 DOI: 10.1007/s00228-004-0880-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Accepted: 11/22/2004] [Indexed: 10/25/2022]
Abstract
OBJECTIVES Tolerance to the haemodynamic effects of regularly inhaled beta(2) agonists has been reported in a research setting. It is unclear whether cardiovascular responses in adults with asthma are influenced by their use in routine clinical practice. This study aimed to characterise the effects of acute salbutamol administration on systemic haemodynamics in adults with mild asthma who were receiving intermittent beta(2) agonist treatment. METHODS Ten patients with mild asthma and ten healthy age and sex-matched controls were recruited to a randomised placebo-controlled double-blind two-way crossover study. Each received salbutamol 200 mug or placebo, then performed sustained isometric handgrip exercise as an adrenergic cardiovascular stimulus. Heart rate and blood pressure responses were observed during rest and exercise, and cardiac index and systemic vascular resistance index were measured using non-invasive impedance cardiography. RESULTS Isometric exercise caused a greater increase in heart rate (12+/-3 vs. 8+/-3 bpm, P<0.01) and diastolic blood pressure (19+/-3 vs. 12+/-3 mmHg, P<0.01) in patients with asthma compared with healthy controls. Salbutamol administration significantly increased heart rate, blood pressure and cardiac index in healthy controls, but these responses were attenuated in patients with asthma. CONCLUSION These findings indicate that adults with asthma, who are receiving intermittent beta(2) agonist treatment, have a greater cardiovascular responses to sympathetic stimulation, and haemodynamic tolerance to acute salbutamol administration.
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Affiliation(s)
- W Stephen Waring
- Clinical Pharmacology Unit and Research Centre, The University of Edinburgh, Edinburgh, UK.
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van Baak MA, Mayer LH, Kempinski RE, Hartgens F. Effect of salbutamol on muscle strength and endurance performance in nonasthmatic men. Med Sci Sports Exerc 2000; 32:1300-6. [PMID: 10912897 DOI: 10.1097/00005768-200007000-00018] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The ergogenic effect of acute beta2-adrenergic agonist administration in nonasthmatic individuals has not been clearly demonstrated. Therefore, the acute effects of oral administration of the beta2-adrenergic agonist salbutamol (4 mg) on muscle strength and endurance performance were studied in 16 nonasthmatic men in a double-blind randomized cross-over study. METHODS Peak expiratory flow (Mini Wright Peakflowmeter), isokinetic strength of the knee extensors and knee flexors at four angular velocities (Cybex II dynamometer), and endurance performance in a cycle ergometer test until exhaustion at 70% of maximal workload were measured. RESULTS Peak expiratory flow increased from 601 +/- 67 L x min(-1) to 629 +/- 64 L x min(-1) after salbutamol (P < 0.05). Peak torque was higher after salbutamol than after placebo (4.4% for the knee extensors, 4.9% for the knee flexors) (P < 0.05). Mean endurance time increased from 3,039 +/- 1,031 s after placebo to 3,439 +/- 1,287 s after salbutamol (P = 0.19). When four subjects complaining about adverse side effects were excluded from the analysis, the increase in endurance time (729 +/- 1,007 s or 29%) was statistically significant (P <-0.05). Salbutamol did not affect VO2, respiratory exchange ratio, heart rate, and plasma free fatty acid and glycerol concentration during exercise; plasma lactate and potassium concentrations were increased (P < 0.05). CONCLUSIONS Under the conditions of this study, oral salbutamol appears to be an effective ergogenic aid in nonasthmatic individuals not experiencing adverse side effects.
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Affiliation(s)
- M A van Baak
- Department of Human Biology, Maastricht University, The Netherlands.
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9
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Silke B, Hanratty CG, Riddell JG. Heart-rate variability effects of beta-adrenoceptor agonists (xamoterol, prenalterol, and salbutamol) assessed nonlinearly with scatterplots and sequence methods. J Cardiovasc Pharmacol 1999; 33:859-67. [PMID: 10367588 DOI: 10.1097/00005344-199906000-00005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Full antagonists of the cardiac beta-adrenoceptor improve heart-rate variability (HRV) in humans; however, partial agonism at the beta2-adrenoceptor has been suggested to decrease HRV. We therefore studied the HRV effects of some partial agonists of the beta1- and beta2-adrenoceptors in normal volunteers. Under double-blind and randomised conditions (Latin square design), eight healthy volunteers received placebo; xamoterol, 200 mg (beta1-adrenoceptor partial agonist); prenalterol, 50 mg (beta1- and beta2-adrenoceptor partial agonist); salbutamol, 8 mg (beta2-adrenoceptor partial agonist); ICI 118,551, 25 mg (selective beta2-adrenoceptor antagonist); and combinations of each partial agonist with ICI 118,551. Single oral doses of medication (at weekly intervals) were administered at 22:30 h with HRV assessed from the overnight sleeping heart rates. HRV was determined by using standard time-domain summary statistics and two nonlinear methods, the Poincaré plot (scatterplot) and cardiac sequence analysis. On placebo, the sleeping heart rate decreased significantly, between 2 and 8 h after dosing. The heart rate with ICI 118,551 was unaltered. Xamoterol, prenalterol, and salbutamol increased the sleeping heart rate. ICI 118,551 blocked the heart-rate effects of salbutamol, attenuated those of prenalterol, but did not influence the xamoterol heart rate. The scatterplot (Poincaré) area was reduced by beta1-adrenoceptor (xamoterol), beta2-adrenoceptor (salbutamol), and combined beta1- and beta2-adrenoceptor (prenalterol) agonism. A reduction in scatterplot length followed salbutamol, prenalterol alone, and prenalterol in combination with ICI 118,551. The geometric analysis of the scatterplots allowed width assessment (i.e., dispersion) at fixed RR intervals. At higher heart rates (i.e., 25 and 50% of RR scatterplot length), dispersion was decreased after xamoterol, prenalterol, and prenalterol/ICI 118,551. Cardiac sequence analysis (differences between three adjacent beats; deltaRR vs. deltaRRn+1) assessed the short-term patterns of cardiac acceleration and deceleration; four patterns were identified: +/+ (a lengthening sequencing), +/- or -/+ (balanced sequences), and finally -/- (a shortening sequence). Cardiac acceleration or deceleration episodes (i.e., number of times deltaRR and deltaRRn+1 were altered in the same direction) were increased after salbutamol and prenalterol. In conclusion, partial agonism at either the cardiac beta1-adrenoceptor (xamoterol), beta2-adrenoceptor (salbutamol), and beta1- plus beta2-adrenoceptors (prenalterol) altered the autonomic balance toward sympathetic dominance in healthy volunteers; blockade of the beta2-adrenoceptor with the highly selective beta2-antagonist ICI 118,551 prevented the effects of salbutamol on HRV, attenuated the HRV effects of prenalterol, but had no effect on the actions of xamoterol. Agonism at both the beta1- and beta2-adrenoceptor reduced HRV in healthy subjects; the implications for the preventive use of the beta-adrenoceptor compounds in cardiovascular disease warrant further investigation.
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Affiliation(s)
- B Silke
- Therapeutics and Pharmacology, The Whitla Division of Medicine, The Queen's University of Belfast, Ireland
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10
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Hanratty CG, Silke B, Riddell JG. Evaluation of the effect on heart rate variability of a beta2-adrenoceptor agonist and antagonist using non-linear scatterplot and sequence methods. Br J Clin Pharmacol 1999; 47:157-66. [PMID: 10190650 PMCID: PMC2014165 DOI: 10.1046/j.1365-2125.1999.00862.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
AIMS To examine the impact on heart rate variability (HRV), of agonism or antagonism at the cardiac beta2-adrenoceptor in healthy volunteers, using standard time-domain summary statistics and non-linear methods (scatterplot and quadrant analysis). METHODS Under double-blind and randomised conditions (Latin square design), 17 normal volunteers received placebo, salbutamol (beta2-adrenoceptor partial agonist), ICI 118,551 (specific beta2-adrenoceptor antagonist), or salbutamol plus ICI 118,551. Single oral doses of medication (at weekly intervals) were administered at 22.30 h, with HRV assessed from the sleeping heart rates. RESULTS Salbutamol reduced the long-term (SDNN: 135 ms [120, 156], SDANN: 107 ms [89, 124]) time-domain indicators of HRV compared with placebo (SDNN: 39 [24, 55], SDANN 42 [29, 56], [mean difference [95% confidence intervals of difference]]). Alone, ICI 118,551 did not effect HRV, but in combination blocked the actions of salbutamol. Scatterplot length (944 ms [869, 1019]) and area (222*10(3) ms2 [191, 253]) were reduced by salbutamol compared with placebo; (length difference (164 [98, 230]) and area difference 59 [36, 83]). Scatterplot width (dispersion) was lower at both low (width RR-1 25% salbutamol 277 ms [261, 293]: salbutamol minus placebo 14 ms [0, 28]) and high (width 75% salbutamol 417 [391, 443]: salbutamol minus placebo 41 [20, 62]) heart rates. ICI 118,551 alone did not alter scatterplot parameters but in combination blocked the effect of salbutamol. Cardiac acceleration episodes (i.e. consecutive deltaRR and deltaRRn+1 shorten) were increased following salbutamol 7288 [6089, 8486] compared with placebo -1890 [-2600, -1179]; the beat-to beat difference (deltaRRn+1) was reduced after salbutamol compared with the other treatments. ICI 118,551 did not effect acceleration episodes but reduced the effect of salbutamol when used in combination. CONCLUSIONS Agonism at the cardiac beta2-adrenoceptor in healthy volunteers with salbutamol altered autonomic balance towards sympathetic dominance; this re-balancing was blocked by ICI 118,551 given in combination with salbutamol. However antagonism at the beta2-adrenoceptor with ICI 118,551 alone did not significantly alter the HRV. The beta2-adrenoceptor modulates HRV in healthy volunteers; the implications of agonism and antagonism at the beta2-adrenoceptor in cardiovascular disease states warrants further investigation.
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Affiliation(s)
- C G Hanratty
- Therapeutics and Pharmacology, The Whitla Division of Medicine, The Queen's University of Belfast, Medical Biology Centre
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Affiliation(s)
- B J Lipworth
- Department of Clinical Pharmacology, Ninewells Hospital and Medical School, University of Dundee, UK
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Lipworth BJ, Grove A. Evaluation of partial β-adrenoceptor agonist activity. Br J Clin Pharmacol 1997. [DOI: 10.1111/j.1365-2125.1997.tb00130.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Abstract
The demographic characteristics of patients used in clinical trials (such as the severity of airway obstruction) can significantly influence the results of dose-response studies, emphasising the need to evaluate effects on the steep part of the dose-response curve. Differences in inhaler devices can also influence study outcomes, as for inhaled drugs both airway efficacy and adverse effect profiles are primarily determined by lung deposition and hence bioavailability. Dose-response studies with short- and long-acting beta 2-agonists show an excellent therapeutic ratio at conventional doses used in everyday clinical practice (i.e. 2 to 4 puffs). Dose-related systemic effects of beta 2-agonist occur at higher doses, for salbutamol (albuterol) > 500 micrograms. Fenoterol is a beta 2-agonists with higher intrinsic activity than salbutamol and produces greater systemic effects at higher than conventional doses on a microgram equivalent basis, although even at 4000 micrograms such differences are unlikely to be clinically relevant. No differences between fenoterol and salbutamol have been shown in terms of bronchodilator potency on a microgram equivalent basis. The long-acting beta 2-agonist salmeterol, as a partial agonist, has the potential to attenuate the acute bronchodilator response to a higher activity beta 2-agonist such as salbutamol or fenoterol, although there is no evidence to date on whether this is relevant in the setting of acute asthma. When comparing inhaled corticosteroids, attention should be focused on their respective risk-benefit ratios for antiasthmatic versus systemic activity. In terms of detecting systemic activity, it is important to use sensitive measures, such as urinary cortisol excretion, rather than insensitive parameters, such as a single morning plasma cortisol measurement between 0800h and 1000h. For fluticasone, a greater in vitro potency results in only marginal differences in antiasthmatic efficacy, particularly on the flatter part of the dose-response curve above 1000 micrograms/day in adults and 400 micrograms/day in children. However, the same enhanced potency translates directly into commensurate differences in systemic adverse effects on the steep part of the systemic dose-response curve above 1000 micrograms/day in adults and 400 micrograms/day in children, respectively. Furthermore, with repeated twice-daily administration, a longer elimination half-life and prolonged systemic tissue retention due to enhanced lipophilicity will result in greater systemic activity observed at steady-state in long term administration studies. This dissociation of airway and systemic dose-response curves results in a J-shaped curve for benefit: risk ratio, with a watershed area above 1000 microgram/day in adults. This fall in the benefit: risk ratio is likely to be greater for fluticasone than for budesonide or beclomethasone. Further studies are needed to clearly define the dose-response relationships of higher potency steroids such as fluticasone, particularly on the steep part of the curve (for clinical efficacy), using the appropriate back-titration design along with sensitive measures of antiasthmatic and systemic activity.
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Affiliation(s)
- D J Clark
- Department of Clinical Pharmacology, Ninewells Hospital and Medical School, University of Dundee, Scotland.
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Abstract
A partial beta-adrenoceptor (beta-AR) agonist will exhibit opposite agonist and antagonist activity depending on the prevailing degree of adrenergic tone or the presence of a beta-AR agonist with higher intrinsic activity. In vivo partial beta-AR agonist activity will be evident at rest with low endogenous adrenergic tone, as for example with chronotropicity (beta 1/beta 2), inotropicity (beta 1) or peripheral vasodilatation and finger tremor (beta 2). beta-AR blocking drugs which have partial agonist activity may exhibit a better therapeutic profile when used for hypertension because of maintained cardiac output without increased systemic vascular resistance, along with an improved lipid profile. In the presence of raised endogenous adrenergic tone such as exercise or an exogenous full agonist, beta-AR subtype antagonist activity will become evident in terms of effects on exercise induced heart rate (beta 1) and potassium (beta 2) responses. Reduction of exercise heart rate will occur to a lesser degree in the case of a beta-adrenoceptor blocker with partial beta 1-AR agonist activity compared with a beta-adrenoceptor blocker devoid of partial agonist activity. This may result in reduced therapeutic efficacy in the treatment of angina on effort when using beta-AR blocking drugs with partial beta 1-AR agonist activity. Effects on exercise hyperkalaemia are determined by the balance between beta 2-AR partial agonist activity and endogenous adrenergic activity. For predominantly beta 2-AR agonist such as salmeterol and salbutamol, potentiation of exercise hyperkalaemia occurs. For predominantly beta 2-AR antagonists such as carteolol, either potentiation or attenuation of exercise hyperkalaemia occurs at low and high doses respectively. beta 2-AR partial agonist activity may also be expressed as antagonism in the presence of an exogenous full agonist, as for example attenuation of fenoterol induced responses by salmeterol. Studies are required to investigate whether this phenomenon is relevant in the setting of acute severe asthma.
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Affiliation(s)
- B J Lipworth
- University Department of Clinical Pharmacology, Ninewells Hospital & Medical School, Dundee, UK
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Grove A, Lipworth BJ. Effects of prior treatment with salmeterol and formoterol on airway and systemic beta 2 responses to fenoterol. Thorax 1996; 51:585-9. [PMID: 8693438 PMCID: PMC1090487 DOI: 10.1136/thx.51.6.585] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Previous studies have shown that both salmeterol and formoterol act as partial beta 2 receptor agonists in terms of antagonising the extrapulmonary responses to fenoterol in normal subjects. The aim of the present study was to extend previous observations in evaluating the effect of prior treatment with salmeterol and formoterol on bronchodilator responses to fenoterol, a full beta 2 receptor agonist, in patients with asthma. METHODS Ten stable asthmatic patients of mean (SE) age 37 (3.7) years and forced expiratory volume in one second (FEV1) 59.5 (4.1)% of predicted completed the study. One hour after inhaling single doses of placebo, salmeterol 25 micrograms, or formoterol 12 micrograms, dose-response curves to repeated doses of inhaled fenoterol were constructed (cumulative doses of 100-3200 micrograms). Measurements of airway and systemic beta 2 receptor mediated responses were made at baseline, after inhalation of placebo, salmeterol, or formoterol, and after each dose of fenoterol. RESULTS Salmeterol and formoterol produced significant bronchodilation compared with placebo (mean difference and 95% CI compared with placebo): FEV1, salmeterol 0.41 (95% CI 0.13 to 0.69) 1, formoterol 0.47 (95% CI 0.19 to 0.75) 1. Salmeterol and formoterol had no significant effect on systemic responses compared with placebo. There were no significant differences in peak airway responses to fenoterol after treatment with salmeterol or formoterol compared with placebo (mean (pooled SE)): FEV1, placebo 2.84 (0.03) 1, salmeterol 2.87 (0.03) 1, and formoterol 2.88 (0.03) 1. There were no significant differences in the area under the dose-response curve for any of the parameters during the dose-response curve following treatment with salmeterol or formoterol compared with placebo. There was no difference in the slope of the dose-response curves to fenoterol for FEV1 or forced expiratory flow (FEF25-75) after treatment with salmeterol or formoterol compared with placebo, although there was a significant (p < 0.05) attenuation of the slope in the dose-response curve for the peak expiratory flow rate (PEFR). CONCLUSIONS Prior treatment with low doses of salmeterol or formoterol does not significantly alter bronchodilator dose-response curves to repeated doses of fenoterol in stable asthmatic patients.
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Affiliation(s)
- A Grove
- Department of Clinical Pharmacology, University of Dundee, UK
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Grove A, Lipworth BJ. Evaluation of the beta 2 adrenoceptor agonist/antagonist activity of formoterol and salmeterol. Thorax 1996; 51:54-8. [PMID: 8658370 PMCID: PMC472800 DOI: 10.1136/thx.51.1.54] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Salmeterol and formoterol have a lower intrinsic activity at beta 2 receptors than isoprenaline in human bronchus in vitro. The aim of the present study was to evaluate in vivo the beta 2 agonist/antagonist activity of salmeterol and formoterol at rest with low endogenous adrenergic tone, on exercise with raised endogenous adrenergic tone, and in the presence of fenoterol, an exogenous full beta 2 receptor agonist. METHODS Eight normal subjects were randomised to receive single doses of placebo, salmeterol 300 micrograms, formoterol 72 micrograms, or propranolol 80 mg at weekly intervals. beta 2 adrenoceptor responses were evaluated at rest, at peak exercise, and after treatment with fenoterol 2.4 mg. RESULTS At rest salmeterol and formoterol exhibited equivalent beta 2 agonist activity with regard to decrease in serum potassium levels and increase in finger tremor, with propranolol having no effect. Salmeterol and formoterol, like propranolol, potentiated the hyperkalaemic delta response to exercise compared with placebo, consistent with beta 2 antagonism: (mean difference and 95% confidence interval (CI) compared with placebo) salmeterol 0.20 (0.02 to 0.38) mmol/l, formoterol 0.17 (0.00 to 0.34) mmol/l, propranolol 0.45 (0.08 to 0.82) mmol/l. Propranolol blunted the heart rate delta response to exercise, consistent with beta 1 blockade, whilst salmeterol and formoterol had no effect. Salmeterol and formoterol, like propranolol, attenuated the hypokalaemic, tremor, and heart rate delta responses to fenoterol compared with placebo, in keeping with beta 2 blockade: potassium, salmeterol 0.18 (0.0 to 0.36) mmol/l, formoterol 0.17 (-0.03 to 0.37) mmol/l, propranolol 0.80 (0.54 to 1.06) mmol/l; tremor, salmeterol -0.69 (-1.26 to -0.12) log units, formoterol -0.71 (-1.53 to 0.11) log units, propranolol -0.85 (-1.66 to -0.04) log units; heart rate, salmeterol -6 (-13 to 1) beats/min, formoterol -10 (-19 to -1) beats/min, propranolol -18 (-29 to -7) beats/min. CONCLUSIONS At rest with low endogenous adrenergic tone salmeterol and formoterol showed equivalent beta 2 mediated agonist activity in terms of serum potassium and finger tremor responses. In the presence of raised endogenous adrenergic tone at peak exercise and in the presence of fenoterol (an exogenous full beta 2 receptor agonist), salmeterol and formoterol, like propranolol, exhibited beta 2 receptor antagonism as evidenced by their attenuation of beta 2 receptor mediated responses. The degree of beta 2 blockade with formoterol and salmeterol was comparable but less than with propranolol. The relevance of these findings at extrapulmonary beta 2 receptors with regard to airway beta 2 responses remains unclear and warrants further investigation.
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Affiliation(s)
- A Grove
- Department of Clinical Pharmacology, Ninewells Hospital and Medical School, University of Dundee, UK
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