ATP as a cotransmitter in sympathetic and parasympathetic nerves - another Burnstock legacy

2021 ◽  
pp. 102860
Author(s):  
Charles Kennedy
Keyword(s):  
Parasympathetic Nerves

Dysfunction of M2-muscarinic receptors in pulmonary parasympathetic nerves after antigen challenge

1991 ◽  
Vol 71 (6) ◽  
pp. 2255-2261 ◽  
Author(s):  
A. D. Fryer ◽  
M. Wills-Karp
Keyword(s):  
Muscarinic Receptors ◽  
Guinea Pigs ◽  
Antigen Challenge ◽  
Saline Control ◽  
Control Group ◽  
Vagus Nerves ◽  
Parasympathetic Nerves ◽  
Volume Blood ◽  
M2 Muscarinic Receptors ◽  
Stimulation Of

The effect of antigen challenge on the function of neuronal M2-muscarinic autoreceptors in the lungs was studied in anesthetized guinea pigs. Guinea pigs were injected intraperitoneally with saline (control group) or ovalbumin (10 mg/kg) on days 1, 3, and 5. One group of sensitized animals was challenged on days 20–25 with aerosolized ovalbumin for 5 min/day (challenged group), while another group of the sensitized animals was not challenged (sensitized group). On day 26 the animals were anesthetized, paralyzed, tracheostomized, and artificially ventilated. Pulmonary inflation pressure (Ppi), tidal volume, blood pressure, and heart rate were recorded. Both vagus nerves were cut, and electrical stimulation of the distal portions caused bronchoconstriction (measured as an increase in Ppi) and bradycardia. In the control group, pilocarpine (1–100 micrograms/kg iv) attenuated vagally induced bronchoconstriction by stimulating inhibitory M2-muscarinic receptors on parasympathetic nerves in the lungs. Conversely, blockade of these receptors with the antagonist gallamine (0.1–10 mg/kg iv) produced a marked potentiation of vagally induced bronchoconstriction. These results confirm previous findings. In the challenged guinea pigs, pilocarpine did not inhibit vagally induced bronchoconstriction. Furthermore, gallamine did not potentiate vagally induced bronchoconstriction to the same degree as in the controls. In the group of animals that was sensitized but not challenged, the potentiation of vagally induced bronchoconstriction by gallamine was identical to the controls. There was no increase in baseline Ppi in the sensitized or challenged animals compared with the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Adhesion-dependent interactions between eosinophils and cholinergic nerves

2002 ◽  
Vol 282 (6) ◽  
pp. L1229-L1238 ◽  
Author(s):  
Paul J. Kingham ◽  
W. Graham McLean ◽  
Deborah A. Sawatzky ◽  
Marie Therese Walsh ◽  
Richard W. Costello
Keyword(s):  
Adhesion Molecules ◽  
Adhesion Molecule ◽  
Cell Function ◽  
Intercellular Adhesion Molecule ◽  
Cholinergic Nerves ◽  
Intercellular Adhesion Molecule 1 ◽  
Parasympathetic Nerves ◽  
Oxidase Inhibition ◽  
Cell Adhesion Molecule 1 ◽  
Eosinophil Degranulation

Eosinophils adhere to airway cholinergic nerves and influence nerve cell function by releasing granule proteins onto inhibitory neuronal M2 muscarinic receptors. This study investigated the mechanism of eosinophil degranulation by cholinergic nerves. Eosinophils were cocultured with IMR32 cholinergic nerve cells, and eosinophil peroxidase (EPO) or leukotriene C4 (LTC4) release was measured. Coculture of eosinophils with nerves significantly increased EPO and LTC4 release compared with eosinophils alone. IMR32 cells, like parasympathetic nerves, express the adhesion molecules vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 (ICAM-1). Inhibition of these adhesion molecules alone or in combination significantly inhibited eosinophil degranulation. IMR32 cells also significantly augmented the eosinophil degranulation produced by formyl-Met-Leu-Phe. Eosinophil adhesion to IMR32 cells resulted in an ICAM-1-mediated production of reactive oxygen species via a neuronal NADPH oxidase, inhibition of which significantly inhibited eosinophil degranulation. Additionally, eosinophil adhesion increased the release of ACh from IMR32 cells. These neuroinflammatory cell interactions may be relevant in a variety of inflammatory and neurological conditions.

Neuromuscular Relaxants as Antagonists for M2and M3Muscarinic Receptors 

1998 ◽  
Vol 88 (3) ◽  
pp. 744-750 ◽  
Author(s):  
Vivian Y. Hou ◽  
Carol A. Hirshman ◽  
Charles W. Emala
Keyword(s):  
Muscarinic Receptor ◽  
Muscarinic Receptors ◽  
Radioligand Binding ◽  
Chinese Hamster ◽  
Neuromuscular Relaxants ◽  
Ovary Cell ◽  
Relative Order ◽  
Parasympathetic Nerves ◽  
M2 Muscarinic Receptor ◽  
M3 Muscarinic Receptor

Background Neuromuscular relaxants such as pancuronium bind to M2 and M3 muscarinic receptors as antagonists. Blockade of muscarinic receptors in atria of the M2 subtype mediates tachycardia. In the lung, blockade of M2 receptors on parasympathetic nerves potentiates vagally induced bronchospasm, whereas blockade of M3 receptors on bronchial smooth muscle inhibits bronchospasm. The current study was designed to quantify the affinity of a series of neuromuscular relaxants for the M2 and M3 muscarinic receptors, which were individually stably transfected in Chinese hamster ovary cell lines. Methods Competitive radioligand binding assays determined the relative binding affinities of the neuromuscular relaxants pancuronium, succinylcholine, mivacurium, doxacurium, atracurium, rocuronium, gallamine, and pipecuronium for the muscarinic receptor in the presence of a muscarinic receptor antagonist (3H-QNB) in membranes prepared from cells individually expressing either the M2 or M3 muscarinic receptor. Results All muscle relaxants evaluated displaced 3H-QNB from muscarinic receptors. The relative order of potency for the M2 muscarinic receptor (highest to lowest) was pancuronium, gallamine, rocuronium, atracurium, pipecuronium, doxacurium, mivacurium, and succinylcholine. The relative order of potency for the M3 muscarinic receptor (highest to lowest) was pancuronium, atracurium, pipecuronium, rocuronium, mivacurium, gallamine, succinylcholine, and doxacurium. Conclusions All neuromuscular relaxants studied had affinities for the M2 and M3 muscarinic receptor, but only pancuronium and gallamine had affinities within the range of concentrations achieved with clinical use. The high affinities of gallamine and pancuronium for the M2 muscarinic receptor are consistent with a mechanism of M2 receptor blockade in relaxant-induced tachycardia.

scholarly journals Ocular Autonomic Nervous System: An Update from Anatomy to Physiological Functions

Vision ◽  
2022 ◽  
Vol 6 (1) ◽  
pp. 6
Author(s):  
Feipeng Wu ◽  
Yin Zhao ◽  
Hong Zhang
Keyword(s):  
Nervous System ◽  
Autonomic Nervous System ◽  
Neural Control ◽  
Entire Body ◽  
Physiological Functions ◽  
Autonomic Nervous ◽  
Parasympathetic Nerves ◽  
Physiological Processes ◽  
New Research ◽  
Almost All

The autonomic nervous system (ANS) confers neural control of the entire body, mainly through the sympathetic and parasympathetic nerves. Several studies have observed that the physiological functions of the eye (pupil size, lens accommodation, ocular circulation, and intraocular pressure regulation) are precisely regulated by the ANS. Almost all parts of the eye have autonomic innervation for the regulation of local homeostasis through synergy and antagonism. With the advent of new research methods, novel anatomical characteristics and numerous physiological processes have been elucidated. Herein, we summarize the anatomical and physiological functions of the ANS in the eye within the context of its intrinsic connections. This review provides novel insights into ocular studies.

Localization of eosinophils to airway nerves and effect on neuronal M2 muscarinic receptor function

1997 ◽  
Vol 273 (1) ◽  
pp. L93-L103 ◽  
Author(s):  
R. W. Costello ◽  
B. H. Schofield ◽  
G. M. Kephart ◽  
G. J. Gleich ◽  
D. B. Jacoby ◽  
...  
Keyword(s):  
Guinea Pigs ◽  
Acetylcholine Release ◽  
Basic Protein ◽  
Receptor Function ◽  
Major Basic Protein ◽  
Parasympathetic Nerves ◽  
M2 Muscarinic Receptor ◽  
Fatal Asthma ◽  
Eosinophil Major Basic Protein ◽  
M2 Muscarinic Receptors

Neuronal M2 muscarinic receptors inhibit acetylcholine release from pulmonary parasympathetic nerves but are dysfunctional in antigen-challenged animals and asthmatics. Deletion of pulmonary eosinophils protects M2 receptor function in antigen-challenged guinea pigs. Therefore, the association of eosinophils with airway nerves was investigated. Nerve-associated eosinophils were significantly increased in challenged animals compared with controls (0.75 +/- 0.05 vs. 0.28 +/- 0.05 eosinophils/nerve). In antigen-challenged animals, eosinophil density was greatest around airway nerves, suggesting recruitment to the nerves. M2 receptor function was inversely correlated with the number of eosinophils per nerve, thus eosinophils are associated with airway nerves in antigen-challenged guinea pigs, where they impair M2 receptor function. In airways from three patients with fatal asthma, 196 of 637 eosinophils (30%) were associated with nerves, and release of eosinophil major basic protein was evident; conversely, in three control patients 1 of 11 (9%) eosinophils were in contact with nerves. Thus eosinophils and their granule proteins are also seen in association with airway nerves in patients with asthma.

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