Search results for "Adrenergic"

Age-related regulation of bone formation by the sympathetic cannabinoid CB1 receptor.

2017

The endocannabinoid (eCB) system, including its receptors, ligands, and their metabolizing enzymes, plays an important role in bone physiology. Skeletal cannabinoid type 1 (CB1) receptor signaling transmits retrograde signals that restrain norepinephrine (NE) release, thus transiently stimulating bone formation following an acute challenge, suggesting a feedback circuit between sympathetic nerve terminals and osteoblasts. To assess the effect of chronic in vivo occurrence of this circuit, we characterized the skeletal phenotype of mice with a conditional deletion of the CB1 receptor in adrenergic/noradrenergic cells, including sympathetic nerves. Whereas the deletion of the CB1 receptor did…

Protein misfolding, amyotrophic lateral sclerosis and guanabenz: Protocol for a phase II RCT with futility design (ProMISe trial)

2017

IntroductionRecent studies suggest that endoplasmic reticulum stress may play a critical role in the pathogenesis of amyotrophic lateral sclerosis (ALS) through an altered regulation of the proteostasis, the cellular pathway-balancing protein synthesis and degradation. A key mechanism is thought to be the dephosphorylation of eIF2α, a factor involved in the initiation of protein translation. Guanabenz is an alpha-2-adrenergic receptor agonist safely used in past to treat mild hypertension and is now an orphan drug. A pharmacological action recently discovered is its ability to modulate the synthesis of proteins by the activation of translational factors preventing misfolded protein accumula…

A Stat6/Pten Axis Links Regulatory T Cells with Adipose Tissue Function

2017

Obesity and type 2 diabetes are associated with metabolic defects and adipose tissue inflammation. Foxp3(+) regulatory T cells (Tregs) control tissue homeostasis by counteracting local inflammation. However, if and how T cells interlink environmental influences with adipocyte function remains unknown. Here, we report that enhancing sympathetic tone by cold exposure, beta3-adrenergic receptor (ADRB3) stimulation or a short-term high-calorie diet enhances Treg induction in vitro and in vivo. CD4(+) T cell proteomes revealed higher expression of Foxp3 regulatory networks in response to cold or ADRB3 stimulation in vivo reflecting Treg induction. Specifically, Ragulator-interacting protein C17o…

Adrenoceptors—New roles for old players

2019

LINKED ARTICLES This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.

Agonist‐induced desensitisation of β 3 ‐adrenoceptors: Where, when, and how?

2019

β3 -Adrenoceptor agonists have proven useful in the treatment of overactive bladder syndrome, but it is not known whether their efficacy during chronic administration may be limited by receptor-induced desensitisation. Whereas the β2 -adrenoceptor has phosphorylation sites that are important for desensitisation, the β3 -adrenoceptor lacks these; therefore, it had been assumed that β3 -adrenoceptors are largely resistant to agonist-induced desensitisation. While all direct comparative studies demonstrate that β3 -adrenoceptors are less susceptible to desensitisation than β2 -adrenoceptors, desensitisation of β3 -adrenoceptors has been observed in many models and treatment settings. Chimeric …

The β3 -adrenoceptor agonist mirabegron increases human atrial force through β1 -adrenoceptors: an indirect mechanism?

2017

Background and Purpose Mirabegron has been classified as a β3-adrenoceptor agonist approved for overactive bladder syndrome. We investigated possible cardiac effects of mirabegron in the absence or presence of β-adrenoceptor subtype antagonists. In view of its phenylethanolamine structure, we investigated whether mirabegron has indirect sympathomimetic activity by using neuronal uptake blockers. Experimental Approach Right atrial trabeculae, from non-failing hearts, were paced and contractile force measured at 37°C. Single concentrations of mirabegron were added in the absence or presence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX), β3 (L-748,337), β1 (CGP 20712A),…

Cardiac β3‐adrenoceptors—A role in human pathophysiology?

2019

As β3 -adrenoceptors were first demonstrated to be expressed in adipose tissue they have received much attention for their metabolic effects in obesity and diabetes. After the existence of this subtype had been suggested to be present in the heart, studies focused on its role in cardiac function. While the presence and functional role of β3 -adrenoceptors in the heart has not uniformly been detected, there is a broad consensus that they become up-regulated in pathological conditions associated with increased sympathetic activity such as heart failure and diabetes. When detected, the β3 -adrenceptor has been demonstrated to mediate negative inotropic effects in an inhibitory G protein-depend…

α1-adrenoceptor activity of β-adrenoceptor ligands – An expected drug property with limited clinical relevance

2020

Many β-adrenoceptor agonists and antagonists including several clinically used drugs have been reported to also exhibit binding to α1-adrenoceptors. Such promiscuity within the adrenoceptor family appears to occur more often than off-target effects of drugs in general. It should not be considered surprising based on the amino acid homology among the nine adrenoceptor subtypes including the counter-ions for binding the endogenous catecholamines. When β-adrenoceptor ligands also bind to α1-adrenoceptors, they almost always act as antagonists, regardless of being agonists or antagonists at the β-adrenoceptor. The α1-adrenoceptor affinity of β-adrenoceptor ligands in most cases is at least one,…

How β3 -adrenoceptor-selective is mirabegron?

2016

Activation of α1A-adrenoceptors desensitizes the rat aorta response to phenylephrine through a neuronal NOS pathway, a mechanism lost with ageing

2017

Background and purpose A NO-mediated desensitization of vasoconstrictor responses evoked by stimulation of α1 -adrenoceptors has been reported in different vessels. We investigated the involvement of each α1 -adrenoceptor subtype and constitutive NOS isoforms and the influence of ageing and hypertension on this process. Experimental approach Wistar and spontaneously hypertensive rats (SHR), 16, 32, 52 and 72 weeks-old, were used to evaluate the desensitization process. Expression of α1 -adrenoceptor subtypes, endothelial NOS (eNOS) and neuronal NOS (nNOS) were determined in rat aorta and left ventricle (LV). Expression levels were also evaluated in LV of a group of heart failure patients wi…