Ciguatoxin (CTX) (0.1 pM to 10 nM) added to a suspension of Torpedo synaptosomes incubated in Ca(2+)-free medium caused no detectable acetylcholine (ACh) release. However, subsequent addition of Ca2+ caused a large ACh release that depended on time of exposure, dose of CTX and on [Ca2+]. Tetrodotoxin completely prevented CTX-induced Ca(2+)-dependent ACh release. Simultaneous blockade of Ca2+ channel subtypes by FTX, a toxin extracted from the venom of the spider Agelenopsis aperta, omega-conotoxin and Gd3+ did not prevent ACh release caused by CTX, upon addition of Ca2+. These results suggest that CTX activates the reversed operation of the Na+/Ca2+ exchange system allowing the entry of Ca2+ in exchange for Na+. It is concluded that Torpedo synaptosomes are endowed with Na+ channels sensitive to pico- to nanomolar concentrations of CTX.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0304-3940(93)9000-4 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The regulatory action of acetylcholine and its receptors on B4 and C4 leukotriene formation in the porcine endometrium after experimental inflammogenic infection.
J 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.
Red-shifted GRAB acetylcholine sensors for multiplex imaging .
bioRxiv
December 2024
State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing 100871, China.
The neurotransmitter acetylcholine (ACh) is essential in both the central and peripheral nervous systems. Recent studies highlight the significance of interactions between ACh and various neuromodulators in regulating complex behaviors. The ability to simultaneously image ACh and other neuromodulators can provide valuable information regarding the mechanisms underlying these behaviors.
View Article and Find Full Text PDFAn α7 nicotinic and GABA receptor-mediated pathway controls acetylcholine release in the tripartite neuromuscular junction.
J Physiol
January 2025
Université Paris Cité, CNRS, ENS Paris Saclay, Centre Borelli UMR 9010, Paris, France.
Terminal Schwann cells (TSCs) are capable of regulating acetylcholine (ACh) release at the neuromuscular junction (NMJ). We have identified GABA as a gliotransmitter at mouse NMJs. When ACh activates α7 nicotinic ACh receptor (nAChRs) on TSCs, GABA is released and activates GABA receptors on the nerve terminal that subsequently reduce ACh release.
View Article and Find Full Text PDFStable Convergent Polyneuronal Innervation and Altered Synapse Elimination in Muscles from Patients with Blepharospasm Responding Poorly to Recurrent Botulinum Type-A Neurotoxin Injections.
Toxins (Basel)
November 2024
Institut des Neurosciences Paris-Saclay, UMR 9197, CNRS/Université Paris-Sud, 91198 Gif-sur-Yvette, Cedex, France.
Botulinum neurotoxin type-A (BoNT/A), which blocks quantal acetylcholine (ACh) release at the neuromuscular junction (NMJ), has demonstrated its efficacy in the symptomatic treatment of blepharospasm. In 3.89% of patients treated for blepharospasm at Tenon Hospital, BoNT/A was no longer effective in relieving the patient's symptoms, and a partial upper myectomy of the muscle was performed.
View Article and Find Full Text PDFHaloperidol-Induced Catalepsy and Its Correlations with Acetylcholinesterase Activity in Different Brain Structures of Mice.
Neurol Int
December 2024
Natural and Humanities Sciences Center (CCNH), Experimental Morphophysiology Laboratory, Federal University of ABC (UFABC), São Bernardo do Campo 09606-070, Brazil.
Background/objectives: Antipsychotic medicines are used to treat several psychological disorders and some symptoms caused by dementia and schizophrenia. Haloperidol (Hal) is a typical antipsychotic usually used to treat psychosis; however, its use causes motor or extrapyramidal symptoms (EPS) such as catalepsy. Hal blocks the function of presynaptic D2 receptors on cholinergic interneurons, leading to the release of acetylcholine (ACh), which is hydrolyzed by the enzyme acetylcholinesterase (AChE).
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!