Acetylcholine is the predominant neurotransmitter in the neuromuscular junction, and a role in bone has been postulated. The expression of nicotinic receptors has been reported in osteoblasts, but the expression and function of muscarinic receptor in bone remain obscure. In this study, we investigated the expression and functional activities of muscarinic receptor subtypes in human osteoblast cell lines and animal and human bone tissue. The mRNA levels of muscarinic receptor subtypes were detected by reverse-transcription polymerase chain reaction. We found that muscarinic subtypes m1, m2, m3, m4, and m5 were expressed at different levels in human osteosarcoma HOS cells, rat femur, and human rib bone tissue; m1, m4, m5 were in cultured mouse femur bone cells and cultured mouse calvarial bone cells; m2, m3, m4 were in bovine bone. The mRNA of neuronal markers, light-, medium- and heavy-neurofilament, was not found in human bone tissues to exclude the possible contamination from neuronal tissue. Methacholine induced an elevation in cytosolic calcium concentration and proliferation in HOS cells. Both effects were blocked by atropine. We conclude that muscarinic receptor is present in bone tissue to evoke calcium signaling and modulate cell proliferation. Different muscarinic receptor subtypes are distributed in various parts of the animal skeletal system including the different species and bone portions. Bone remodeling involving osteoblast proliferation leads the possibilities that muscarinic receptor may play roles in bone remodeling.
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http://dx.doi.org/10.1016/j.ejphar.2010.09.031 | DOI Listing |
Unlabelled: Multiple sclerosis (MS) is an immune-mediated demyelinating disease of the central nervous system (CNS). Clemastine fumarate, the over-the-counter antihistamine and muscarinic receptor blocker, has remyelinating potential in MS. A clemastine arm was added to an ongoing platform clinical trial TRAP-MS ( NCT03109288 ) to identify a cerebrospinal fluid (CSF) remyelination signature and to collect safety data on clemastine in patients progressing independently of relapse activity (PIRA).
View Article and Find Full Text PDFCNS Drugs
January 2025
New York State Psychiatric Institute, 1051 Riverside Drive, New York, NY, 10032, USA.
J Family Med Prim Care
December 2024
Medicines Evaluation Unit, Manchester University National Health Service Foundation Trust, University of Manchester, Manchester, United Kingdom.
Context: An inhaled corticosteroid (ICS) in combination with a long-acting β2-agonist (LABA) is a common treatment approach for asthma patients not controlled on ICS alone, but a significant proportion of patients remain uncontrolled on this combination and treatment adherence can also be a challenge. One of the options for adults whose asthma is uncontrolled in an ICS/LABA is the addition of a long-acting muscarinic receptor antagonist (LAMA), an approach commonly referred to as 'triple therapy'. The use of medium-strength ICS/LABA/LAMA is established in treating chronic obstructive pulmonary disease but is less well-established in asthma.
View Article and Find Full Text PDFJ Vet Res
December 2024
Division of Reproductive Biology, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, 10-748 Olsztyn, Poland.
Introduction: Endometritis is a very common pathology in animals which changes endometrial leukotriene (LT) formation and muscarinic 2 and 3 receptor subtypes (M2R/M3R) and α-7 nicotinic acetylcholine (ACh) receptor (α-7 nAChR) expression patterns. With the relationship between ACh, its receptors and LT production remaining unclear, the role of M2R, M3R and α-7 nAChR in action of ACh on the 5-lipoxygenase (5-LO), LTA4 hydrolase (LTAH) and LTC4 synthase (LTCS) protein abundances in the inflamed porcine endometrium and on the tissue secretion of LTB4 and LTC4 were studied.
Material And Methods: On day three of the oestrous cycle in gilts aged 7-8 months, 50 mL of either saline solution (control group, n = 5) or an suspension at 10 colony-forming units/mL ( group, n = 5), was injected into each uterine horn.
Am J Physiol Lung Cell Mol Physiol
January 2025
Smooth Muscle Research Centre, Dundalk Institute of Technology, Dublin Road, Dundalk, Co. Louth, Ireland.
Cholinergic tone is elevated in obstructive lung conditions such as COPD and asthma, but the cellular mechanisms underlying cholinergic contractions of airway smooth muscle (ASM) are still unclear. Some studies report an important role for L-type Ca channels (LTCC) and Ano1 Ca-activated Cl™ channels (CACC) in these responses, but others dispute their importance. Cholinergic contractions of ASM involve activation of M3Rs, however stimulation of M2Rs exerts a profound hypersensitisation of these responses.
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