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Ion Channels and The Control of Uterine Contractility
Published in Robert E. Garfield, Thomas N. Tabb, Control of Uterine Contractility, 2019
In the myometrium, an increase in the concentration of free calcium in the cytoplasm is essential for the initiation of contraction. Calcium can enter the cell through plasma membrane channels of two different classes. Voltage-sensitive ion channels mediate rapid, voltage-gated changes in ion conductance during the action potential. The calcium entering during action potentials serves as the primary intracellular second messenger for initiating excitation-contraction coupling and multiple calcium-activated biochemical processes. In addition, these channels can be regulated by receptor-dependent processes, including protein phosphorylation and interaction with GTP-binding proteins. In contrast, ligand-gated ion channels are opened in response to activation of an associated receptor. Typical channels of this class include the nonspecific channels that are opened by activation of membrane receptors. Generally, activation of ligand-gated ion channels mediates local increases in ion conductance, producing depolarization or hyperpolarization of the membrane.
Protein Function As Cell Surface And Nuclear Receptor In Human Diseases
Published in Debarshi Kar Mahapatra, Sanjay Kumar Bharti, Medicinal Chemistry with Pharmaceutical Product Development, 2019
Urmila Jarouliya, Raj K. Keservani
It is ligand-gated ion channels that are widely distributed in the human brain where they have a modulatory function associated with numerous transmitter systems. The receptor channel opens in response to the neurotransmitter acetylcholine (and to nicotine). This receptor is found in the postsynaptic membrane of neurons at certain synapses and in the muscle fibers (myocytes) at neuromuscular junctions. Acetylcholine released by an excited neuron diffuses a few micrometers across the synaptic cleft or the neuromuscular junction to the postsynaptic neuron or myocyte, where it interacts with the acetylcholine receptor and triggers electrical excitation (depolarization) of the receiving cell. Reductions in nAChR density have been identified in a number of neurodegenerative disorders, including Alzheimer’s disease (AD), dementia with Lewy bodies (DLB), and Parkinson’s disease (PD) [28–30].
Answers
Published in Calver Pang, Ibraz Hussain, John Mayberry, Pre-Clinical Medicine, 2017
Calver Pang, Ibraz Hussain, John Mayberry
There are three main groups of ion channels which are voltage gated channels, extracellular ligand activated channels and intracellular ligand gated ion channels. Examples of voltage gated channels include sodium, potassium and calcium. Examples of extracellular ligand gated ion channels include nicotinic acetylcholine receptors, GABA and ROMK channel. Example of intracellular ligated ion channels includes CFTR.
Is chronic pain as an autoimmune disease?
Published in Canadian Journal of Pain, 2022
In a normal physiological state, microglia are “resting” yet dynamic, continuously scanning their environment for any changes that could alter homeostasis. Upon exposure to certain signals, microglia are activated to perform innate immune functions.34 In this later state, microglia drive synaptic alterations within the dorsal horn of the spinal cord, representing a key pronociceptive event.35 It is thought that microglia that fail to return to a resting state contribute to persistent neuropathic pain.36,37 The finding that the purinergic receptor 4, a highly sensitive ligand-gated ion channel, is expressed by microglia highlighted their importance in mediating peripherally induced nociceptive hypersensitivity in rodent models of pain.38
Treatment Options for Anti-N-methyl-D-aspartate Receptor Encephalitis
Published in The Neurodiagnostic Journal, 2018
N-methyl-d-aspartate (NMDA) is an excitotoxin; it destroys nerve cells by overexciting them (Watkins 2015). This water-soluble artificial element is described as not typically found in organic issue (Masuko et al. 2008). NMDA receptors are a precise type of ionotropic glutamate receptor that controls synaptic plasticity and memory function and are ubiquitous throughout the body, primarily localized in the brain and spinal cord (Kadewaga et al. 2007; Watkins 2015). These receptors are indispensable for human interaction, judgment, and memory. Ionotropic receptors are also referred to as ligand-gated ion channels (Thompson et al. 2013). The receptors are a group of transmembrane ion channel proteins that permit ions such as Ca2+ and Na+ to cross through the membrane (Thompson et al. 2013).
Cell signal transduction: hormones, neurotransmitters and therapeutic drugs relate to purine nucleotide structure
Published in Journal of Receptors and Signal Transduction, 2018
Major GPCR receptor classes aligned to Gs, Gi and Gq alpha subunits, ligand- and voltage-gated ion channels are identified within the IUPHAR/BPS Guide to Pharmacology [5]. GPCR receptors: 5-hydroxytryptamine (5-HT), acetylcholine (muscarinic), adenosine, α- and β-adrenoceptors, dopamine, GABAB, histamine, glutamate (metabotropic), opioid, prostanoid. Voltage-gated ion channels: cyclic nucleotide-regulated (CNG), potassium (KV, BKCa, KATP), calcium (VGCC), sodium. Ligand-gated ion channels (LGIC): 5-HT3, epithelial sodium channel (ENaC), GABAA, glycine, glutamate (ionotropic), acetylcholine (nicotinic). Molecular structures representative of receptor and ion channel classes are taken from the IUPHAR database (www.guidetopharmacology.org), Pubchem (http://pubchem.ncbi.nlm.nih.gov) and company websites marketing potent and selective agonist and antagonist compounds.