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Cholinergic Antagonists
Published in Sahab Uddin, Rashid Mamunur, Advances in Neuropharmacology, 2020
Vishal S. Gulecha, Manoj S. Mahajan, Aman Upaganlawar, Abdulla Sherikar, Chandrashekhar Upasani
Ganglionic blockers are the drugs those competitively antagonize nicotinic (NN) receptors of parasympathetic and sympathetic autonomic ganglia thereby inhibiting the action of ACh and other agonists. Some drugs belonging to the class are nonselective at both the autonomic ganglia therefore ineffective as neuromuscular blocker. Thus, these agents block the entire outflow of the ANS at the NN receptors (Sharma and Sharma, 2017; Barar, 2004).
Neurotransmitters and pharmacology
Published in Mark J. Ashley, David A. Hovda, Traumatic Brain Injury, 2017
Ronald A. Browning, Richard W. Clough
The neuromuscular blocking agents are also classified into two types: 1) depolarizing blockers and 2) nondepolarizing blockers. Succinylcholine (Anectine®) is the only clinically useful and best-known depolarizing blocker available. It binds to the nicotinic receptor at the neuromuscular junction and produces a depolarization of the membrane, which remains in persistent depolarization for a long time, rendering the synapse nonfunctional. After a period of time, the neuromuscular block actually converts to a competitive-type block, which is called Phase II. Giving a cholinesterase inhibitor will not antagonize the action of a depolarizing blocker and, in fact, may make the block worse. On the other hand, nondepolarizing blockers such as d-tubocurarine, atracurium, vecuronium (Norcuron®), and pancuronium (Pavulon®) are competitive neuromuscular blockers that compete with ACh for the receptor. Thus, administering a cholinesterase inhibitor (e.g., physostigmine or neostigmine) can reverse the block produced by competitive antagonists, such as d-tubocurarine. All neuromuscular blockers and most ganglionic blockers have a charged nitrogen atom and, therefore, do not get into the brain when injected systemically. In fact, if they are injected into the cerebrospinal fluid, they typically cause seizures. Mecamylamine, on the other hand, is a ganglionic blocking agent and a secondary amine that can enter the brain. Ganglionic blockers are used to lower blood pressure during removal of tumors of the adrenal gland, and neuromuscular blockers are used to relax (or paralyze) muscles during endoscopic examinations, surgery, and electroconvulsive shock therapy.
Pharmacotherapeutic strategies for treating hypertension in patients with obesity
Published in Expert Opinion on Pharmacotherapy, 2018
Revathy Carnagarin, Vance Matthews, Cynthia Gregory, Markus P. Schlaich
Pharmacological studies, isotope dilution methodologies to assess organ-specific noradrenaline spillover, and direct recording from post-ganglionic sympathetic nerves with microneurograpy clearly demonstrate exaggerated sympathetic nerve activity contributing substantially to arterial hypertension in obesity [18,19]. Combined adrenergic (α + β) blockade with doxazosin and atenolol showed a greater BP reduction in patients with OHT compared with their lean counterparts [20]. A similar approach with the ganglionic blocker trimethaphan, inducing complete but transient autonomic withdrawal showed that much of the BP increase observed in subjects with obesity was mediated by the sympathetic nervous system [21]. The resting energy expenditure was higher in subjects with obesity and remained significantly elevated after autonomic blockade resulting from increased muscle mass (a 30-kg increase in fat mass was accompanied by a 12-kg increase in lean muscle mass) in obesity which explained 83% of the resting energy expenditure variability [21]. OHT has evolved as a major variant of neurogenic hypertension often accompanied by volume overload, inadequate RAS stimulation, hormonal resistance (insulin and leptin), a scenario further complicated by obstructive sleep apnea syndrome in obesity all of which contribute to the common clinical presentation with resistant hypertension.
Mechanisms involved in the cardiovascular effects caused by acute osmotic stimulation in conscious rats
Published in Stress, 2020
Eduardo Albino Trindade Fortaleza, Cristiane Busnardo, Aline Fassini, Ivaldo Jesus Almeida Belém-Filho, Gislaine Almeida-Pereira, José Antunes-Rodrigues, Fernando Morgan Aguiar Corrêa
First, we tested the involvement of the sympathetic nervous system in these responses by pretreating animals with the ganglion blocker pentolinium that affects transmission in both sympathetic and parasympathetic nervous systems. Treatment with pentolinium significantly reduced baseline blood pressure values, confirming ganglion blockade effectiveness. Pentolinium abolished the initial phasic component of the pressor response to the OS, but did not affect the subsequent OS-evoked sustained blood pressure increase.
The effect of hyoscine-N-butylbromide on pain perception during and after hysterosalpingography in infertile women: a systematic review and meta-analysis of randomised controlled trials
Published in Human Fertility, 2022
Rehab Abdelhamid Aboshama, Mohammad Abrar Shareef, Abdulhadi A. AlAmodi, Wesam Kurdi, Mohammed M. Al-Tuhaifi, Marwah Ghazi Bintalib, Sileem Ahmed Sileem, Osama Abdelazem, Ahmed Mohamed Abdelhakim, Ahmed M. A. Sobh, Sahar M. Y. Elbaradie
HBB acts mainly by binding to the muscarinic receptors on smooth muscle cells in different organs and is considered to belong to the family of the anticholinergic drugs (Tytgat, 2007). Thus, spasmolytic and relaxing influences on smooth muscle cells can be achieved by HBB. HBB is used to treat abdominal pain resulting from cramping by muscarinic receptors blockage and HBB can attach to nicotinic receptors and act as a ganglionic blocker (Tytgat, 2007).