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Pharmacological Research Aug 2019Sympathetic activity plays an important role in modulation of cardiac rhythm. Indeed, while exerting positive tropic effects in response to physiologic and pathologic... (Review)
Review
Sympathetic activity plays an important role in modulation of cardiac rhythm. Indeed, while exerting positive tropic effects in response to physiologic and pathologic stressors, β-adrenergic stimulation influences cardiac electrophysiology and can lead to disturbances of the heart rhythm and potentially lethal arrhythmias, particularly in pathological settings. For this reason, β-blockers are widely utilized clinically as antiarrhythmics. In this review, the molecular mechanisms of β-adrenergic action in the heart, the cellular and tissue level cardiac responses to β-adrenergic stimulation, and the clinical use of β-blockers as antiarrhythmic agents are reviewed. We emphasize the complex interaction between cardiomyocyte signaling, contraction, and electrophysiology occurring over multiple time- and spatial-scales during pathophysiological responses to β-adrenergic stimulation. An integrated understanding of this complex system is essential for optimizing therapies aimed at preventing arrhythmias.
Topics: Adrenergic beta-Antagonists; Animals; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Humans; Myocardium
PubMed: 31100336
DOI: 10.1016/j.phrs.2019.104274 -
Annals of Medicine Dec 2022Phytochemicals have garnered much attention because they are useful in managing several human diseases. Yohimbine is one such phytochemical with significant... (Review)
Review
Phytochemicals have garnered much attention because they are useful in managing several human diseases. Yohimbine is one such phytochemical with significant pharmacological potential and could be exploited for research by medicinal chemists. It is an indole alkaloid obtained from various natural/synthetic sources. The research on yohimbine started early, and its use as a stimulant and aphrodisiac by humans has been reported for a long time. The pharmacological activity of yohimbine is mediated by the combined action of the central and peripheral nervous systems. It selectively blocks the pre and postsynaptic α-adrenergic receptors and has a moderate affinity for 1 and 2 subtypes. Yohimbine also binds to other behaviourally relevant monoaminergic receptors in the following order: α-2 NE > 5HT-1A>, 5HT-1B > 1-D > D3 > D2 receptors. The current review highlights some significant findings that contribute to developing yohimbine-based drugs. It also highlights the therapeutic potential of yohimbine against selected human diseases. However, further research is recommended on the pharmacokinetics, molecular mechanisms, and drug safety requirements using well-designed randomized clinical trials to produce yohimbine as a pharmaceutical agent for human use.Key MessagesYohimbine is a natural indole alkaloid with significant pharmacological potential.Humans have used it as a stimulant and aphrodisiac from a relatively early time.It blocks the pre- and postsynaptic α2-adrenergic receptors that could be exploited for managing erectile dysfunction, myocardial dysfunction, inflammatory disorders, and cancer.
Topics: Male; Humans; Yohimbine; Adrenergic alpha-Antagonists; Aphrodisiacs; Receptors, Adrenergic, alpha-2; Pharmaceutical Preparations
PubMed: 36263866
DOI: 10.1080/07853890.2022.2131330 -
Cancer Cell Jan 2018Catecholamines stimulate epithelial proliferation, but the role of sympathetic nerve signaling in pancreatic ductal adenocarcinoma (PDAC) is poorly understood....
Catecholamines stimulate epithelial proliferation, but the role of sympathetic nerve signaling in pancreatic ductal adenocarcinoma (PDAC) is poorly understood. Catecholamines promoted ADRB2-dependent PDAC development, nerve growth factor (NGF) secretion, and pancreatic nerve density. Pancreatic Ngf overexpression accelerated tumor development in LSL-Kras;Pdx1-Cre (KC) mice. ADRB2 blockade together with gemcitabine reduced NGF expression and nerve density, and increased survival of LSL-Kras;LSL-Trp53;Pdx1-Cre (KPC) mice. Therapy with a Trk inhibitor together with gemcitabine also increased survival of KPC mice. Analysis of PDAC patient cohorts revealed a correlation between brain-derived neurotrophic factor (BDNF) expression, nerve density, and increased survival of patients on nonselective β-blockers. These findings suggest that catecholamines drive a feedforward loop, whereby upregulation of neurotrophins increases sympathetic innervation and local norepinephrine accumulation.
Topics: Adrenergic Agents; Animals; Carcinoma in Situ; Catecholamines; Cell Line, Tumor; Deoxycytidine; Mice, Transgenic; Nerve Growth Factors; Pancreatic Neoplasms; Gemcitabine
PubMed: 29249692
DOI: 10.1016/j.ccell.2017.11.007 -
American Family Physician Mar 2020More than 70% of adults treated for primary hypertension will eventually require at least two antihypertensive agents, either initially as combination therapy or as... (Review)
Review
More than 70% of adults treated for primary hypertension will eventually require at least two antihypertensive agents, either initially as combination therapy or as add-on therapy if monotherapy and lifestyle modifications do not achieve adequate blood pressure control. Four main classes of medications are used in combination therapy for the treatment of hypertension: thiazide diuretics, calcium channel blockers, angiotensin-converting enzyme inhibitors (ACEIs), and angiotensin receptor blockers (ARBs). ACEIs and ARBs should not be used simultaneously. In black patients, at least one agent should be a thiazide diuretic or a calcium channel blocker. Patients with heart failure with reduced ejection fraction should be treated initially with a beta blocker and an ACEI or ARB (or an angiotensin receptor-neprilysin inhibitor), followed by add-on therapy with a mineralocorticoid receptor antagonist and a diuretic based on volume status. Treatment for patients with chronic kidney disease and proteinuria should include an ACEI or ARB plus a thiazide diuretic or a calcium channel blocker. Patients with diabetes mellitus should be treated similarly to those without diabetes unless proteinuria is present, in which case combination therapy should include an ACEI or ARB.
Topics: Adrenergic beta-Antagonists; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Blood Pressure; Calcium Channel Blockers; Drug Therapy, Combination; Humans; Hypertension
PubMed: 32163253
DOI: No ID Found -
Critical Care (London, England) Feb 2018Vasoplegia is a ubiquitous phenomenon in all advanced shock states, including septic, cardiogenic, hemorrhagic, and anaphylactic shock. Its pathophysiology is complex,... (Review)
Review
Vasoplegia is a ubiquitous phenomenon in all advanced shock states, including septic, cardiogenic, hemorrhagic, and anaphylactic shock. Its pathophysiology is complex, involving various mechanisms in vascular smooth muscle cells such as G protein-coupled receptor desensitization (adrenoceptors, vasopressin 1 receptors, angiotensin type 1 receptors), alteration of second messenger pathways, critical illness-related corticosteroid insufficiency, and increased production of nitric oxide. This review, based on a critical appraisal of the literature, discusses the main current treatments and future approaches. Our improved understanding of these mechanisms is progressively changing our therapeutic approach to vasoplegia from a standardized to a personalized multimodal treatment with the prescription of several vasopressors. While norepinephrine is confirmed as first line therapy for the treatment of vasoplegia, the latest Surviving Sepsis Campaign guidelines also consider that the best therapeutic management of vascular hyporesponsiveness to vasopressors could be a combination of multiple vasopressors, including norepinephrine and early prescription of vasopressin. This new approach is seemingly justified by the need to limit adrenoceptor desensitization as well as sympathetic overactivation given its subsequent deleterious impacts on hemodynamics and inflammation. Finally, based on new pathophysiological data, two potential drugs, selepressin and angiotensin II, are currently being evaluated.
Topics: Adrenal Cortex Hormones; Adrenergic alpha-Agonists; Humans; Norepinephrine; Shock; Vasoconstrictor Agents; Vasoplegia
PubMed: 29486781
DOI: 10.1186/s13054-018-1967-3 -
Nature Nov 2022G-protein-coupled receptors (GPCRs), the largest family of signalling receptors, as well as important drug targets, are known to activate extracellular-signal-regulated...
G-protein-coupled receptors (GPCRs), the largest family of signalling receptors, as well as important drug targets, are known to activate extracellular-signal-regulated kinase (ERK)-a master regulator of cell proliferation and survival. However, the precise mechanisms that underlie GPCR-mediated ERK activation are not clearly understood. Here we investigated how spatially organized β-adrenergic receptor (βAR) signalling controls ERK. Using subcellularly targeted ERK activity biosensors, we show that βAR signalling induces ERK activity at endosomes, but not at the plasma membrane. This pool of ERK activity depends on active, endosome-localized Gα and requires ligand-stimulated βAR endocytosis. We further identify an endosomally localized non-canonical signalling axis comprising Gα, RAF and mitogen-activated protein kinase kinase, resulting in endosomal ERK activity that propagates into the nucleus. Selective inhibition of endosomal βAR and Gα signalling blunted nuclear ERK activity, MYC gene expression and cell proliferation. These results reveal a non-canonical mechanism for the spatial regulation of ERK through GPCR signalling and identify a functionally important endosomal signalling axis.
Topics: Adrenergic Agents; Cell Proliferation; Endosomes; Extracellular Signal-Regulated MAP Kinases; Genes, myc; GTP-Binding Protein alpha Subunits, Gs; Mitogen-Activated Protein Kinase Kinases; Phosphorylation; Receptors, Adrenergic, beta-2; Signal Transduction
PubMed: 36289326
DOI: 10.1038/s41586-022-05343-3 -
Journal of the American College of... Dec 2021The use of β-adrenergic receptor blocking agents in symptomatic patients with obstructive hypertrophic cardiomyopathy (HCM) rests on clinical experience and... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
The use of β-adrenergic receptor blocking agents in symptomatic patients with obstructive hypertrophic cardiomyopathy (HCM) rests on clinical experience and observational cohort studies.
OBJECTIVES
This study aimed to investigate the effects of metoprolol on left ventricular outflow tract (LVOT) obstruction, symptoms, and exercise capacity in patients with obstructive HCM.
METHODS
This double-blind, placebo-controlled, randomized crossover trial enrolled 29 patients with obstructive HCM and New York Heart Association (NYHA) functional class II or higher symptoms from May 2018 to September 2020. Patients received metoprolol or placebo for 2 consecutive 2-week periods in random order. The effect parameters were LVOT gradients, NYHA functional class, Canadian Cardiovascular Society (CCS) angina class, Kansas City Cardiomyopathy Questionnaire Overall Summary Score (KCCQ-OSS), and cardiopulmonary exercise testing.
RESULTS
Compared with placebo, the LVOT gradient during metoprolol was lower at rest (25 mm Hg [interquartile range (IQR): 15-58 mm Hg] vs 72 mm Hg [IQR: 28-87 mm Hg]; P = 0.007), at peak exercise (28 mm Hg [IQR: 18-40 mm Hg] vs 62 mm Hg [IQR: 31-113 mm Hg]; P < 0.001), and postexercise (45 mm Hg [IQR: 24-100 mm Hg] vs 115 mm Hg [IQR: 55-171 mm Hg]; P < 0.0001). During metoprolol treatment, 14% of patients were in NYHA functional class III or higher compared with 38% of patients receiving placebo (P < 0.01). Similarly, no patients were in CCS class III or higher during metoprolol treatment compared with 10% during placebo treatment (P < 0.01). These findings were confirmed by higher KCCQ-OSS during metoprolol treatment (76.2 ± 16.2 vs 73.8 ± 19.5; P = 0.039). Measures of exercise capacity, peak oxygen consumption, and N-terminal pro-B-type natriuretic peptide did not differ between the study arms.
CONCLUSIONS
Compared with placebo, metoprolol reduced LVOT obstruction at rest and during exercise, provided symptom relief, and improved quality of life in patients with obstructive HCM. Maximum exercise capacity remained unchanged. (The Effect of Metoprolol in Patients with Hypertrophic Obstructive Cardiomyopathy [TEMPO]; NCT03532802).
Topics: Adrenergic beta-1 Receptor Antagonists; Aged; Cardiomyopathy, Hypertrophic; Cross-Over Studies; Double-Blind Method; Exercise Tolerance; Female; Humans; Male; Metoprolol; Middle Aged; Ventricular Outflow Obstruction
PubMed: 34915981
DOI: 10.1016/j.jacc.2021.07.065 -
Signal Transduction and Targeted Therapy Jul 2023Traumatic brain injury (TBI) accelerates fracture healing, but the underlying mechanism remains largely unknown. Accumulating evidence indicates that the central nervous...
Traumatic brain injury (TBI) accelerates fracture healing, but the underlying mechanism remains largely unknown. Accumulating evidence indicates that the central nervous system (CNS) plays a pivotal role in regulating immune system and skeletal homeostasis. However, the impact of CNS injury on hematopoiesis commitment was overlooked. Here, we found that the dramatically elevated sympathetic tone accompanied with TBI-accelerated fracture healing; chemical sympathectomy blocks TBI-induced fracture healing. TBI-induced hypersensitivity of adrenergic signaling promotes the proliferation of bone marrow hematopoietic stem cells (HSCs) and swiftly skews HSCs toward anti-inflammation myeloid cells within 14 days, which favor fracture healing. Knockout of β3- or β2-adrenergic receptor (AR) eliminate TBI-mediated anti-inflammation macrophage expansion and TBI-accelerated fracture healing. RNA sequencing of bone marrow cells revealed that Adrb2 and Adrb3 maintain proliferation and commitment of immune cells. Importantly, flow cytometry confirmed that deletion of β2-AR inhibits M2 polarization of macrophages at 7th day and 14th day; and TBI-induced HSCs proliferation was impaired in β3-AR knockout mice. Moreover, β3- and β2-AR agonists synergistically promote infiltration of M2 macrophages in callus and accelerate bone healing process. Thus, we conclude that TBI accelerates bone formation during early stage of fracture healing process by shaping the anti-inflammation environment in the bone marrow. These results implicate that the adrenergic signals could serve as potential targets for fracture management.
Topics: Mice; Animals; Fracture Healing; Bone Marrow; Myelopoiesis; Mice, Knockout; Brain Injuries, Traumatic; Adrenergic Agents
PubMed: 37402714
DOI: 10.1038/s41392-023-01457-w -
Handbook of Experimental Pharmacology 2017History suggests β agonists, the cognate ligand of the β adrenoceptor, have been used as bronchodilators for around 5,000 years, and β agonists remain today the... (Review)
Review
History suggests β agonists, the cognate ligand of the β adrenoceptor, have been used as bronchodilators for around 5,000 years, and β agonists remain today the frontline treatment for asthma and chronic obstructive pulmonary disease (COPD). The β agonists used clinically today are the products of significant expenditure and over 100 year's intensive research aimed at minimizing side effects and enhancing therapeutic usefulness. The respiratory physician now has a therapeutic toolbox of long acting β agonists to prophylactically manage bronchoconstriction, and short acting β agonists to relieve acute exacerbations. Despite constituting the cornerstone of asthma and COPD therapy, these drugs are not perfect; significant safety issues have led to a black box warning advising that long acting β agonists should not be used alone in patients with asthma. In addition there are a significant proportion of patients whose asthma remains uncontrolled. In this chapter we discuss the evolution of β agonist use and how the understanding of β agonist actions on their principal target tissue, airway smooth muscle, has led to greater understanding of how these drugs can be further modified and improved in the future. Research into the genetics of the β adrenoceptor will also be discussed, as will the implications of individual DNA profiles on the clinical outcomes of β agonist use (pharmacogenetics). Finally we comment on what the future may hold for the use of β agonists in respiratory disease.
Topics: Adrenergic beta-2 Receptor Agonists; Animals; Asthma; Bronchodilator Agents; Humans; Pharmacogenetics; Polymorphism, Single Nucleotide; Pulmonary Disease, Chronic Obstructive
PubMed: 27878470
DOI: 10.1007/164_2016_64 -
Function (Oxford, England) 2022
Topics: Adrenergic Agents; Myocytes, Cardiac; A Kinase Anchor Proteins; Cyclic AMP-Dependent Protein Kinases; Biochemical Phenomena
PubMed: 36156892
DOI: 10.1093/function/zqac024