... Descriptors : *ACETYLCHOLINE, *NEUROMUSCULAR TRANSMISSION, RATS, CANADA, CHICKENS, ETHANOLS, CURARE ALKALOIDS ...

SYSTEMIC AND INTRA-ACCUMBENS ADMINISTRATION OF AMPHETAMINE DIFFERENTIALLY AFFECTS CORTICAL experiments tested the hypothesis that the amphetamine-induced increase in dopamine release in the nucleus amphetamine to stimulate cortical acetylcholine release. The effects of systemic or intra

1. Histamine secretion from rat mast cells occurs in the presence of nanomolar concentrations of acetylcholine. 2. Intact glycolytic and oxidative metabolism is required for the acetylcholine-induced histamine secretion. Removal of extracellular glucose, hypoxia, cyanide and monoiodoacetate almost completely inhibit the secretion. 3. The secretion of ...

1. The release of acetylcholine by parasympathetic ganglion stimulants from the nerve terminals of the guinea-pig longitudinal muscle strip was studied. The acetylcholine released was collected in the presence of physostigmine sulphate. 2. Nicotine and 1,1-dimethyl-4?-phenylpiperazinium iodide (DMPP) ...

1. beta-Bungarotoxin and crotoxin are phospholipose A2 neurotoxins, which block irreversibly the evoked release of acetylcholine from motor nerve terminals of mouse triangularis sterni preparations. 2. Extracellular recording of nerve terminal action potentials reveal that inhibition of transmitter release is not associated with ...

We investigated the interaction between ambient histamine and acetylcholine by studying ? oscillations in rat hippocampus, induced by bath application of acetylcholine (10 �M combined with 2 �M physostigmine). The power of ? was significantly increased by the H1 antagonist, fexofenadine, and H2 receptor agonist, dimaprit, and ...

Isolated precontracted arteries of various vascular beds relax in response to acetylcholine only if the endothelium is present. One explanation for this is that this drug stimulates the endothelial cells to release a vasodilator substance that in turn relaxes the underlying smooth muscle. To determine whether this mechanism is concerned also in the ...

1. Local endplate depolarization induced by anticholinesterase application to mouse nerve-diaphragm preparations was taken as a measure of non-quantal release of acetylcholine. 2. Non-quantal acetylcholine release occurred within 20-60 s after anticholinesterase application, either ...

Mouse islets were used to test the hypothesis that the B cell membrane must be depolarized for acetylcholine to increase insulin release. The resting membrane potential of B cells (at 3 mM glucose) was slightly decreased (5 mV) by acetylcholine, but no electrical activity appeared. This depolarization was accompanied by a ...

The putative intracellular calcium (Ca) antagonist TMB-8 was shown to reduce postjunctional sensitivity and quantal acetylcholine (ACh) release at low micromolar concentrations. At 10-fold higher concentrations, TMB-8 also blocked caffeine-induced Ca release (as monitored electrophysiologically by changes in ACh ...

In superfusion bioassay systems of rabbit thoracic aorta and femoral artery ring segments as well as canine femoral artery and coronary ring segments the release of endothelium-derived relaxing factor (EDRF) was stimulated by acetylcholine in donor segments with intact endothelium. The transition of EDRF through the vessel wall ("abluminal ...

1. The effects of histamine and agents at histamine receptors on spontaneous and 100 mM K(+)-evoked release of acetylcholine, measured by microdialysis from the cortex of freely moving, rats, and on cognitive tests are described. 2. Local administration of histamine (0.1-100 microM) failed to affect spontaneous but inhibited 100 mM K(+)-stimulated ...

Mediatophore is a protein of approximately 200 kDa able to translocate acetylcholine in response to calcium. It was purified from the presynaptic plasma membranes of the electric organ nerve terminals. Mediatophore is a homooligomer of a 16-kDa subunit, homologous to the proteolipid of V-ATPase. Cells of the N18TG-2 neuronal line are not able to produce quantal ...

... Accession Number : ADP008893. Title : Protein Phosphorylation and Inhibition of Acetylcholine Release by Botulinum Neurotoxin A. ...

A soluble toxic extract derived from spine tissue of the lionfish (Pterois volitans) decreased heart rate and force of contraction in isolated clam and frog hearts. These actions were due to the presence of micromolar concentrations of acetylcholine in the extract. Toxicity was retained after hydrolysis of acetylcholine by exogenous acetylcholinesterase, ...

Pure gastrin I of Gregory and Tracy stimulated secretion not only of gastric acid but also of pancreatic fluid and protein material. Similarly, endogenous release of gastrin from a transplanted pouch of the pyloric gland area of the stomach, initiated by irrigation with solutions of acetylcholine, stimulated gastric acid secretion and pancreatic flow and ...

Brain Research 894 (2001) 74�87 www.elsevier.com/locate/bres Research report Amphetamine administration of amphetamine results in increases in the release of acetylcholine in the cortex. Basal forebrain for amphetamine-induced increase in cortical acetylcholine by examining whether intra-basalis perfusion

. The factors included: Condition (sham, lesion); Age (young, old); Dose (vehicle, 1.0 mg/kg ZK 93 426, 5.0 mg in young shams, aged shams and young lesioned rats, but not in aged lesioned rats. Administration stimulated cortical acetylcholine efflux in young and aged sham rats. FG 7142-induced increases

... Title : THE EFFECTS OF P-2-AM ON THE RELEASE OF ACETYLCHOLINE FROM THE ISOLATED DIAPHRAGM OF THE RAT,. ...

We evaluated the possible role of NO in modulating tissue plasminogen activator (t-PA) release in the forearm microcirculation of normotensive subjects and hypertensive patients. Essential hypertensive patients are characterized by endothelial dysfunction because of a reduced NO availability and also show an impaired t-PA release. In healthy volunteers and ...

Ghrelin is a powerful orexigenic peptide predominantly secreted by the stomach. Blood concentration of ghrelin increases before meals and fall postprandial. Its regulation appears to be influenced by the type of macronutrient ingested, the vagus nerve stimulation and by other post-meal stimulated hormonal factors. However, the direct role of nutrients (amino acids or lipids), neuronal (vagal ...

This study evaluates the biochemical and genetic aspects of the acetylcholine receptor proteins and cholinergic ligands in Drosophila melanogaster and Torpedo californica. Included are (1) a comparative study of nicotinic ligand-induced cation release from acetylcholine receptors isolated from Torpedo californica ...

Background and purpose:The present study investigated whether calcium-activated K⁺ channels are involved in acetylcholine-evoked nitric oxide (NO) release and relaxation.Experimental approach:Simultaneous measurements of NO concentration and relaxation were performed in rat superior mesenteric artery and endothelial cell membrane ...

Recent research has demonstrated that a variety of sensory stimuli can increase acetylcholine release in the frontal cortex of rats. The aim of the present experiments was to investigate the pharmacological regulation of sensory stimulation-induced increases in the activity of basal forebrain cholinergic neurons. To this end, the ...

Guinea-pig isolated atria were incubated and loaded with [3H]-noradrenaline. The release of 3H and of [3H]-noradrenaline was induced by field stimulation (6-9 trains of 150 pulses at 5 Hz). The stimulation-evoked overflows of 3H and of [3H]-noradrenaline were determined. In the absence of an inhibitor of acetylcholinesterase, ...

The possible role of acetylcholine receptors on the HgCl(2)-induced dopamine (DA) release from rat striatum was investigated by using in vivo brain microdialysis technique after administration of selective nicotinic and muscarinic receptor antagonists, mecamylamine and atropine, respectively. Intrastriatal infusion of 1mM HgCl(2) ...

The intravenous administration of synthetic cannabinoid agonists was recently shown to dose dependently increase acetylcholine release from the rat prefrontal cortex and hippocampus (Eur. J. Pharmacol. 401 (2000) 179]. We report here that the active ingredient of cannabis preparations, delta9-tetrahydrocannabinol, administered at 10, 37.5, 75 and 150 ...

Sepsis has been reported to impair endothelium-dependent vasodilations mediated by nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF). Although some studies demonstrate that statins can improve NO-mediated response in septic animals, little is known about its effect on the EDHF response. The present study examined the effects of atorvastatin pretreatment on ...

To elucidate innervation in the upper esophageal sphincter (UES) muscle of the eel, a key muscle in swallowing, repetitive electrical field stimulation (EFS; 30 mA, 40 V, 300 micros, 10 Hz, 10 trains) was employed. Anatomically, the eel UES muscle consists of striated fibers. The EFS-induced contraction of the UES was completely blocked by tetrodotoxin and curare, and ...

The contribution of pre and postsynaptic activation on the release of {sup 3}H-purines was studied in the isolated sympathetic paravertebral ganglion of the frog. Preganglionic stimulation induced an overall release of {sup 3}H-purines. This release is blocked by atropine and curare and can be ...

There is increasing evidence that the cholinergic habenulo-interpeduncular pathway and the dopaminergic mesolimbic pathway may jointly mediate the reinforcing properties of addictive drugs. However, the effects of addictive drug on the functioning of the habenulo-interpeduncular pathway have not been well-characterized. Thus, several drugs of abuse (i.e., nicotine, cocaine, amphetamine) have been ...

Somatostatin has been shown to inhibit antral motility in vivo. To examine the effect of somatostatin on cholinergic neurotransmission in the canine antrum, we studied the mechanical response of and the release of ({sup 3}H)acetylcholine from canine longitudinal antral muscle in response to substance P, gastrin 17, and electrical stimulation. In ...

1. Acetylcholine (ACh) evoked secretion by the calcium ionophore, ionomycin, was studied at frog motor nerve endings. 2. Bath application of ionomycin stimulated an irreversible increase in the rate of spontaneous, quantal ACh release in the presence of extracellular Ca2+. In contrast, local application of ionomycin stimulated a rapid, reversible ...

1. Acetylcholine (ACh) evoked secretion by the calcium ionophore, ionomycin, was studied at frog motor nerve endings. 2. Bath application of ionomycin stimulated an irreversible increase in the rate of spontaneous, quantal ACh release in the presence of extracellular Ca2+. In contrast, local application of ionomycin stimulated a rapid, reversible ...

1. Human galanin (0.32 nmol per rat, i.c.v.), an endogenous neuropeptide, administered 30 min before acquisition or retention trials, significantly impaired the acquisition of learning and recall of memory in a step-through type passive avoidance performance. 2. The role of dynorphin A (1-13) in learning and memory is controversial. Dynorphin A (1-13) (0.5 nmol per rat, i.c.v.) administered 5 min ...

Ecstasy is a dangerous drug that causes the release of serotonin, dopamine, norepinephrine, and acetylcholine. These molecules are neurotransmitters.

Stimulation-induced increases in the efflux of radioactivity (S-I efflux) were measured in the bathing medium following labelling of the noradrenergic transmitter pools of rat atria and rabbit artery preparations with [3H]-noradrenaline. In atria stimulated with trains of 16 or 60 pulses at 2 Hz, phentolamine enhanced, whereas acetylcholine inhibited S-I ...

The relationship between nitric oxide (NO) concentration measured with an NO-specific microelectrode and endothelium-dependent relaxation was investigated in isolated rat superior mesenteric artery contracted with 1 ?M noradrenaline.Acetylcholine (10 ?M) induced endothelium-dependent simultaneous increases in luminal NO concentration of 21 � 6 nM, and ...

Effects of vasoactive intestinal polypeptide (VIP) on the release of acetylcholine (ACh) from longitudinal muscle strips with myenteric plexus (LM) preparations were examined in the guinea pig small intestine. VIP (10 to 10 W M) induced a concentration-dependent contraction of LM preparation. The VIP-induced ...

Acetylcholine rapidly lowered the intracellular levels of cyclic AMP in stage 5 and 6 Xenopus laevis oocytes. Acetylcholine alone did not induce oocyte maturation, though it did accelerate maturation induced by progesterone. The effect of acetylcholine on oocyte maturation was independent of ...

We investigated acetylcholine esterase (AChE) activity, acetylcholine and muscarinic M1, M3 receptors kinetics in the cerebral cortex of young and old streptozotocin induced and insulin treated diabetic rats. The role of muscarinic receptors in intracellular calcium release from pancreatic islets was studied in ...

The origin of motor nerve antidromic activity (backfiring) induced by anticholinesterase treatment was examined in the mouse phrenic nerve-hemidiaphragm preparation. Botulinum toxin was used to determine whether backfiring is due to (a) a direct effect of the cholinesterase inhibitor on the nerve terminal, or (b) an indirect effect via the prolongation of the action of ...

Both acetylcholine (ACh) and theta oscillations are important for learning and memory, but the dynamic interaction between these two processes remains unclear. Recent advances in amperometry techniques have revealed phasic ACh releases in vivo. However, it is unknown whether phasic ACh release co-occurs with theta oscillations. We ...

The muscarinic receptors that modulate acetylcholine release from rat cortical synaptosomes were characterized with respect to sensitivity to drugs that act selectively at M1 or M2 receptor subtypes, as well as to changes in ionic strength and membrane potential. The modulatory receptors appear to be of the M2 type, since they are activated by carbachol, ...

Stimulation with acetylcholine, serotonin, and noradrenalin of the hypothalamic, preoptic, and septal areas induced emotional-affective reactions with negative staining (acetylcholine), activation of the behavior (acetylcholine and serotonin). Sleep has b...

1. The release of catecholamines (CA) from rat adrenal incubated in vivo in Locke solution was studied. 2. Acetylcholine-induced release of CA and CA release by 56 mM KCl were inhibited by verapamil and lanthanum chloride which block calcium permeability. 3. CA secretion induced by salbutamol ...

GABA, THIP and muscimol enhance spontaneous and inhibit electrically induced release of tritium labelled compounds from rat striatal slices which have been pre-labelled with /sup 3/H-choline. Baclofen is inactive in this model. Muscimol can inhibit electrically induced release of tritiated material by approximately ...

The aim was to study the mechanism of the previously established decrease in acetylcholine (ACh) concentration in the rat hippocampus under cold stress. Male rats were exposed for 14 days to cold (5/degree/C) or kept (controls) at room temperature (24/degree/C). Acetylcholine content, release and muscarinic receptor binding were ...

In the present experiments the release and synthesis of acetylcholine (ACh) were measured in rat diaphragms incubated in the absence or presence of AH5183, a compound known to block the uptake of ACh by cholinergic synaptic vesicles. The testing release w...

The release of acetylcholine from rat and guinea-pig isolated diaphragm preparations stimulated through the phrenic nerve was optimal at 37� in Krebs solution with 5�10^-6 neostigmine methylsulphate. The amount of acetylcholine released by a 20 min. tetanus was reduced by cooling. At ...

Our previous observation that low concentrations of stonefish (Synanceia trachynis) venom elicit spontaneous quantal acetylcholine release from vertebrate motor nerve terminals prompted our present study to purify the quantal transmitter-releasing toxin present in the venom and to characterize the toxin's ability to alter the ...

Reliable neuronal communication depends on accurate temporal correlation between the action potential and neurotransmitter release. Although a requirement for Ca²⁺ in neurotransmitter release is amply documented, recent studies have shown that voltage-sensitive G protein�coupled receptors (GPCRs) are also involved in this process. ...

The current study examined the hypothesis that acetylcholine-induced N(omega)-Nitro-L-arginine methyl ester (L-NAME)-resistant endothelium-dependent relaxations in the chicken carotid artery are mediated by nitric oxide and carbon monoxide. Acetylcholine (1 nM-3 microM) caused a concentration-dependent relaxation (pD(2) 6.81+/-0.05, R(max) 115+/-3%) of the ...

It is controversial whether the endothelial cell release of nitric oxide (NO) or a different factor(s) accounts for endothelium-dependent hyperpolarization, because in many arteries endothelium-dependent relaxation and hyperpolarization resists inhibitors of NO synthase. The contribution of NO to acetylcholine-induced endothelium-dependent ...