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acetylcholine chloride [keywords]
- Antispasmodic and myorelaxant effects of the flavoring agent methyl cinnamate in gut: Potential inhibition of tyrosine kinase. [JOURNAL ARTICLE]
- Eur J Pharmacol 2014 Jul 18.
Methyl cinnamate (MC) is a safe flavoring agent useful to food industry. Although chemically analogue to tyrosine kinase inhibitors, there is little information regarding its biological actions. Here, we aimed at assessing the MC effects on gastrointestinal contractility and the putative involvement of tyrosine kinase in the mediation of these effects. Isometric contractions were recorded in rat isolated strips from stomach, duodenum and colon segments. In gastric strips, MC (3-3000µM) showed antispasmodic effects against carbachol-induced contractions, which remained unchanged by either L-NAME or tetraethylammonium pretreatment and occurred with potency similar to that obtained against contractions evoked by potassium or U-46619. In colon strips, MC was four times more potent than in gastric ones. MC and the positive control genistein inhibited phasic contractions induced by acetylcholine in Ca(2+)-free medium, an effect fully prevented by sodium orthovanadate. Both MC and genistein decreased the time necessary for gastric fundic tissues to reach 50% of maximal relaxation. In freshly isolated colon myocytes, MC decreased the basal levels of cytoplasmic Ca(2+), but not the potassium-elicited cytoplasmic Ca(2+) elevation. Colon strips obtained from rats subjected to intracolonic acetic acid instillation showed reduced contractility to potassium, which was partially recovered in MC-treated rats. Inhibitory effect of nifedipine against cholinergic contractions, blunted in acetic acid-induced colitis, was also recovered in MC-treated rats. In conclusion, MC inhibited the gastrointestinal contractility with a probable involvement of tyrosine kinase pathways. In vivo, it was effective to prevent the deleterious effects of colitis resulting from acetic acid injury.
- Endogenous ACh suppresses LTD induction and nicotine relieves the suppression via different nicotinic ACh receptor subtypes in the mouse hippocampus. [JOURNAL ARTICLE]
- Life Sci 2014 Jul 18.
Studying the normal role of nicotinic cholinergic systems in hippocampal synaptic plasticity is critical for understanding how cholinergic loss in Alzheimer's disease (AD) and tobacco use affect cognitive function. However, it is largely unknown how nicotinic cholinergic systems regulate the induction of long-term depression (LTD).Extracellular field potential recordings were performed in hippocampal slices prepared from wild-type, α2, α7, and β2 knockout (KO) mice. Effects of nicotine and nicotinic antagonists on LTD induction in wild-type, α2, α7, and β2 KO mice were compared.Activation of α7 nicotinic acetylcholine receptors (nAChRs) occurs during LTD-inducing stimulation to suppress LTD induction at CA3-CA1 synapses. Nicotine relieves this suppression, causing larger LTD. This nicotine effect was mediated by the activation of non-α7 nAChR subtypes, which were not activated by ACh released during LTD-inducing stimulation, and requires the presence of endogenous ACh-induced α7 nAChR activation. Furthermore, the effect of nicotine was prevented in the presence of mecamylamine, but not dihydro-β-erythroidine, and was still observed in both α2 KO and β2 KO mice.This is the first report to evaluate the involvement of different nAChR subtypes in LTD induction. Findings indicate the involvement of unique non-α7 nAChR subtypes, which have not been considered in the nicotinic modulation of hippocampal long-term potentiation, in the control of LTD induction. The implication of our results is that the loss of cholinergic projections to the hippocampus, which reduces ACh release as seen in AD patients, and nicotine from tobacco smoking can differentially affect LTD induction.
- Characterization of vascular complications in experimental model of fructose induced metabolic syndrome. [JOURNAL ARTICLE]
- Toxicol Mech Methods 2014 Jul 21.:1-22.
Abstract Vascular dysfunction is an important complications associated with metabolic syndrome (MS). Here we fully characterized vascular complications a rat model of fructose-induced MS. Metabolic syndrome was induced by adding fructose (10%) to drinking water to male Wistar rats 6 weeks age. Blood pressure (BP) and isolated aorta responses phenylephrine (PE), KCl, acetylcholine (ACh), sodium nitroprusside (SNP) were recorded after 6, 9 and 12 weeks of fructose administration. In addition, serum levels of glucose, insulin, uric acid, tumor necrosis factor α (TNFα), lipids, advanced glycation end products (AGEs), and arginase activity were determined. Furthermore, aortic reactive oxygen species (ROS) generation, hemeoxygenase-1 expression and collagen deposition were examined. Fructose administration resulted in a significant hyperinslinemia after 6 weeks which continued for 12 weeks. It was also associated with a significant increase in BP after 6 weeks which was stable for 12 weeks. Aorta isolated from MS animals showed exaggerated contractility to PE and KCl and impaired relaxation to ACh compared to control after 6 weeks which were clearer at 12 weeks of fructose administration. In addition, MS animals showed significant increases in serum levels of lipids, uric acid, AGEs, TNFα and arginase enzyme activity after 12 weeks of fructose administration. Furthermore, aortae isolated from MS animals were characterized by increased ROS generation and collagen deposition. In conclusion, adding fructose (10%) to drinking water produces a model of MS with vascular complications after 12 weeks that are characterized by insulin resistance, hypertension, disturbed vascular reactivity and structure, hyperuricemia, dyslipidaemia and low grade inflammation.
- Progression and reversal of coronary and mesenteric vascular dysfunction associated with obesity. [JOURNAL ARTICLE]
- Obesity (Silver Spring) 2014 Jul 9.
The purpose of this study was to examine progression and reversal of microvascular complications when rats were fed a high fat diet.Sprague-Dawley rats 10 weeks of age were fed a diet containing 45% kcal fat for up to 32 weeks. Blood pressure and heart rate was measured by telemetry. Vascular reactivity of aorta and small coronary and mesenteric vessels was determined after 8, 16, 24, and 32 weeks on diet.There was a modest increase in weight and blood pressure in high fat fed rats. Sodium nitroprusside (SNP)-induced relaxation of coronary arteries was potentiated after 8 weeks on high fat diet, however, this enhanced response was not observed after 16, 24, or 32 weeks of diet. Acetylcholine (Ach) mediated relaxation was attenuated after 16, 24, and 32 weeks of high fat diet in coronary arteries; however, in aorta and mesenteric arteries, Ach-mediated response was not altered until 32 weeks on high fat diet. Reversing the high fat diet for 8 weeks resulted in partial recovery of metabolic parameters; however endothelial function in coronary arteries remained impaired.These studies indicate that high fat diet promotes progressive impairment of coronary vascular function that is difficult to reverse.
- Evaluation of the sensitivity of the novel α4β2* nicotinic acetylcholine receptor PET radioligand (18) F-(-)-NCFHEB to increases in synaptic acetylcholine levels in rhesus monkeys. [JOURNAL ARTICLE]
- Synapse 2014 Jul 17.
Objective: (18) F-(-)-NCFHEB (also known as (18) F-(-)-Flubatine) is a new radioligand to image α4β2* nicotinic acetylcholine receptors in vivo with positron emission tomography (PET), with faster kinetics than previous radioligands such as (18) F-2-F-A85380. The goal of this study was to assess the sensitivity of (18) F-(-)-NCFHEB-PET to increases in synaptic acetylcholine concentration induced by acetylcholinesterase inhibitors. Methods: Two rhesus monkeys were scanned four times each on a Focus 220 scanner: first at baseline, then during two bolus plus infusions of physostigmine (0.06-0.28 mg/kg), and finally following a bolus injection of donepezil (0.25 mg/kg). The arterial input function and the plasma free fraction fP were measured. (18) F-(-)-NCFHEB volume of distribution VT was estimated using the multilinear analysis MA1 and then normalized by plasma free fraction fP . Results: (18) F-(-)-NCFHEB fP was 0.89±0.04. At baseline, (18) F-(-)-NCFHEB VT /fP ranged from 7.9±1.3 mL plasma/cm(3) tissue in the cerebellum to 34.3±8.4 mL plasma/cm(3) tissue in the thalamus. Physostigmine induced a dose-dependent reduction of (18) F-(-)-NCFHEB VT /fP of 34±9% in the putamen, 32±8% in the thalamus, 25±8% in the cortex, and 23±10% in the hippocampus. With donepezil, (18) F-(-)-NCFHEB VT /fP was reduced by 24±2%, 14+3% and 14±5%, 10±6% in the same regions. Conclusion: (18) F-(-)-NCFHEB can be used to detect changes in synaptic acetylcholine concentration and is a promising tracer to study acetylcholine dynamics with shorter scan durations than previous radioligands. Synapse, 2014. © 2014 Wiley Periodicals, Inc.
- Chapter 3: Molecular basis for the therapeutic effectiveness of botulinum neurotoxin type A. [Journal Article]
- Neurourol Urodyn 2014 Jul.:S14-20.
The utility of botulinum neurotoxin type A (BoNT/A) for treating overactive muscles and endocrine glands is attributable to a unique conflation of properties honed to exploit and inactivate synaptic transmission. Specific, high-affinity coincident binding to gangliosides plus an intraluminal loop of synaptic vesicle protein 2 (SV2) by the heavy chain (HC) of BoNT/A confers selectivity for presynaptic nerve terminals and subsequent uptake by endocytosis. Upon vesicle acidification, the HC forms a channel for transmembrane transfer of the light chain to the cytosol, as observed by single channel recordings. The light chain is a Zn(2+) -dependent endoprotease that cleaves and inactivates SNAP-25, thereby blocking exocytotic release of transmitters, a discovery that revealed the pivotal role of the latter in synaptic vesicle fusion. A di-leucine motif in BoNT/A light chain stabilizes this protease, contributing to its longevity inside nerves. The ubiquity of SV2 and SNAP-25 has prompted re-evaluation of the nerve types susceptible to BoNT/A. In urology, there is emerging evidence that BoNT/A blocks neuropeptide release from afferent nerves, exocytosis of acetylcholine and purines from efferent nerves, and possibly ATP release from the urothelium. Suppression by BoNT/A of the surface expression of nociceptor channels on bladder afferents might also contribute to its improvement of urological sensory symptoms. Neurourol. Urodynam. 33:S14-S20, 2014. © 2014 Wiley Periodicals, Inc.
- Nicotinic acetylcholine receptors control acetylcholine and noradrenaline release in the rodent habenulo-interpeduncular complex. [JOURNAL ARTICLE]
- Br J Pharmacol 2014 Jul 9.
Nicotinic acetylcholine receptors (nAChRs) play a central role in the habenulo-interpeduncular system. We studied nicotine-induced release of noradrenaline (NA) and ACh in the habenula and interpeduncular nucleus (IPN).The habenula and IPN were loaded with [3H]-choline or [3H]-NA and placed in superfusion chambers. [3H]-ACh release was also stimulated using nicotinic agonists, electrical pulses, and elevated [KCl]o in hippocampal and cortical slices from rats, wild-type mice, and mice lacking α5, α7, β2, or β4 nAChR subunits. Finally, we analysed nAChR subtypes in the IPN using immunoprecipitation.Nicotine induced the release of [3H]-ACh in the IPN of both rats and mice. This release was calcium-dependent but was not blocked by tetrodotoxin (TTX); moreover, [3H]-ACh release was abolished in β4-knockout mice but was unaffected in β2- and α5-knockout mice. In contrast, nicotine-induced-release of [3H]-NA in the IPN and habenula was blocked by TTX and largely reduced in both β2-knockout and β4-knockout mice; finally, the dose-response curves were right-shifted in α5-knockout mice. Although electrical stimuli triggered the release of both transmitters, [3H]-ACh release required more pulses delivered at a higher frequency.Our results confirm a previous report that β4-containing nAChRs are critical for [3H]-ACh release in the mouse IPN. Experiments using α5-knockout mice also revealed that unlike in the hippocampus, nicotine-induced [3H]-NA release in the habenulo-interpeduncular system is altered in this knockout model. As α5-containing nAChRs play a key role in nicotine intake, our results add NA to the list of transmitters involved in this mechanism.
- Alpha-7 nicotinic acetylcholine receptor agonist treatment reduces neuroinflammation, oxidative stress and brain injury in mice with ischemic stroke and bone fracture. [JOURNAL ARTICLE]
- J Neurochem 2014 Jul 10.
Bone fracture at the acute stage of stroke exacerbates stroke injury by increasing neuroinflammation. We hypothesize that activation of α-7 nicotinic acetylcholine (α-7 nAchR) agonist attenuates neuroinflammation and oxidative stress, and reduces brain injury in mice with bone fracture and stroke. Permanent middle cerebral artery occlusion (pMCAO) was performed in C57BL/6J mice followed by tibia fracture 1 day later. Mice were treated with 0.8 mg/kg PHA568487 (PHA, α-7 nAchR-specific agonist), 6 mg/kg Methyllycaconitine (MLA, α-7 nAchR antagonist), or saline 1 and 2 days after pMCAO. Behavior was tested 3 days after pMCAO. Neuronal injury, CD68(+) , M1 (pro-inflammatory) and M2 (anti-inflammatory) microglia/macrophages, phosphorylated p65 component of NF-kb in microglia/macrophages, oxidative and anti-oxidant gene expression were quantified. Compared to saline-treated mice, PHA-treated mice performed better in behavioral tests, had fewer apoptotic neurons (NeuN(+) TUNEL(+) ), fewer CD68(+) and M1 macrophages, and more M2 macrophages. PHA increased anti-oxidant gene expression and decreased oxidative stress and phosphorylation of NF-κb p65. MLA had the opposite effects. Our data indicate that α-7 nAchR agonist treatment reduces neuroinflammation and oxidative stress, which are associated with reduced brain injury in mice with ischemic stroke plus tibia fracture. This article is protected by copyright. All rights reserved.
- Presence and content of kynurenic acid in animal feed. [JOURNAL ARTICLE]
- J Anim Physiol Anim Nutr (Berl) 2014 Jul 12.
Kynurenic acid (KYNA) was found to be an antagonist of iontropic glutamate receptors and alpha7 nicotinic acetylcholine receptors. Furthermore, it was documented that KYNA is an agonist of G-protein coupled GPR35 receptors which are mainly present in the gastrointestinal tract. It was also found that KYNA is present in the gastrointestinal tract and that its concentration gradually increases along it. The origin of KYNA in the gastrointestinal tract is not known. Both might be synthesized from tryptophan in it or absorbed from food and other dietary products. Therefore, the aim of the study was to investigate the concentration of KYNA in animal feed. The results indicate that the highest concentration of KYNA was found in animal feeds intended for livestock. The lower amount of KYNA was detected in animal feeds for fish. Interestingly, the lowest amount of KYNA was found in dog and cat feeds. Furthermore, an analysis of KYNA content in animal food ingredients was conducted. The concentration of KYNA found in one of the ingredients - rapeseed meal - was several times higher in comparison to animal feeds studied. The content of KYNA in the remaining feed ingredients tested was significantly lower. This is the first report on the concentration of KYNA in animal feeds. There is a need for further detailed analysis leading to establishing a set of guidelines for animal feeding.
- [Preliminary research on multi-neurotransmitters' change regulation in 120 depression patients' brains]. [English Abstract, Journal Article]
- Zhongguo Zhong Yao Za Zhi 2014 Apr; 39(8):1516-24.
In view of the effective traditional Chinese medicine (TCM) in the treatment of clinical depression, the mechanism is not clear, this study attempts to research the cause of depression in a complex situation to lay the foundation for the next step of TCM curative effect evaluation. Based on the brain wave of 120 depression patients and 40 ordinary person, the change regulation of acetylcholine, dopamine, norepinephrine, depression neurotransmitters and excited neurotransmitters in the whole and various encephalic regions' multi-neurotransmitters of depression patients-serotonin are analysed by search of encephalo-telex (SET) system, which lays the foundation for the diagnosis of depression. The result showed that: contrased with the normal person group, the mean value of the six neurotransmitters in depression patients group are: (1) in the whole encephalic region of depression patients group the dopamine fall (P < 0.05), and in the double centralregions, right temporal region and right parietal region distinct fall (P < 0.01); (2) in the right temporal region of depression patients group the serotonin rise (P < 0.05); (3) in the right central region, left parietal region of depression patients group the acetylcholine fall (P < 0.05), left rear temporal region fall obviously (P < 0.01). The correlation research between antagonizing pairs of neurotransmitters and neurotransmitters: (1) the three antagonizing pairs of neurotransmitters-serotonin and dopamine, acetylcholine and norepinephrine, depression neurotransmitters and excited neurotransmitters, in ordinary person group and depression patients group are characterizeed by middle or strong negative correlation. Serotonin and dopamine, which are characterized by weak negative correlation in the right rear temporal region of ordinary person group, are characterized by strong negative correlation in the other encephalic regions and the whole encephalic (ordinary person group except the right rear temporal region: the range of [r] is [0.82, 0.92], P < 0.01)/(depression patients group:the range of [r] is [0.88, 0.94], P < 0.01); acetylcholine and norepinephrine, in the whole and various encephalic region are characterized by middle negative correlation(ordinary person group:the range of [r] is [0.39, 0.76], P < 0.01 or P < 0.05)/(depression patients group: the range of [Ir] is [0.56, 0.64], P < 0.01); depression neurotransmitters and excited neurotransmitters are characterized by middle strong negative correlation (ordinary person group: the range of [r] is [0.57, 0.80], P < 0.01)/(depression patients group: the range of [r] is [0.68, 0.78], P < 0.01). (2) The two neurotransmitters which are not antagonizing pairs of neurotransmitters, serotonin and excited neurotransmitters, or acetylcholine and depression neurotra-nsmitters, or dopamine and depression neurotransmitters in the various encephalic regions are characterized by weak negative correlation. Serotonin and excited neurotransmitters are characterizeed by weak negative correlation (ordinary person group: in the right central region, left parietal region, double front temporal regions, right rear temporal region, the range of [r] is [0.25, 0.50], P < 0.01 or P < 0.05)/(depression patients group: in the whole encephalic regions, double parietal regions, double occipital regions, right front temporal region, left central region, left frontal region, the range of [r] is [0.18, 0.37], P < 0.01 or P < 0.05); acetylcholine and depression, neurotransmitters are characterized by weak negative correlation (ordinary person group: in the double frontal regions, left parietal region, left front temporal region, right rear temporal region, the range of [r] is [0.31, 0.46], P < 0.01 or P < 0.05)/(depression patients group: in double rear temporal regions, right front temporal region, double occipital regions, left central region, the range of [r] is [0.20, 0.32] , P < 0.01 or P < 0.05); do-pamine and depression neurotransmitters are characterized by weak middle negative correlation (ordinary person group: in left parietal region, right central region, left frontal region, left occipital region, double front temporal regions, the range of [r] is [0.33, 0.68], P < 0.01 or P < 0.05)/(depression patients group: in the whole region and other various regions except the left frontal region, right central region, the range of Irl is [0.21, 0.34], P < 0.01 or P < 0.05). Dopamine and acetylcholine or norepinephrine and serotonin are characterized by weak positive correlation in all encephalic regions. Dopamine and acetylcholine are characterized by weak positive correlation (ordinary person group: in left frontal region, right parietal region, left front temporal region and left rear temporal region, the range of [r] is [0.37, 0.46], P < 0.01)/(depression patients group: in the whole region and the orther various regions except the double central regions, the range of [r] is [0.23, 0.5], P < 0.01 or P < 0.05); norepinephrine and serotonin are characterized by weak positive correlation (ordinary person group: in double front temporal regions, double rear temporal regions, right frontal region and left parietal region, the range of [r] is [0.34, 0.48], P < 0.01 or P < 0.05)/(depression patients group: in the whole and various regions, the range of [r] is [0.18, 0.42], P < 0.01). The main differences between the depression patients group and ordinary person group are: (1) In the whole regin, left frontal region and right central region of depression patients group, the six neurotransmitters all fall normally (P < 0.05). (2) The percent of dopamine falling or including dopamine falling, or including dopamine falling and serotonin rising in depression patients group increases. The percent of dopamine falling or including dopamine falling in the whole region, right frontal region, right central region increases (P < 0.01), such as dopamine decreasing, serotonin increasing dopamine decreasing, serotonin increasing acetylcholine decreasing dopamine decreasing, dopamine decreasing norepinephrine increasing depression neurotransmitters decreasing, serotonin increasing acetylcholine decreasing dopamine decreasing neurotransmitters increasing and so on. (3) The percent of acetylcholine falling, or including acetylcholine falling, or including acetylcholine falling and neurotransmitters (beta)-receptor)rising in depression patients group increases. The percent of acetylcholine falling, or including acetylcholine falling in the right temporal region, double central regions increases (P < 0.05 or P < 0.01), such as acetylcholine decreasing, acetylcholine decreasing neurotransmitters increaseng, acetylcholine decreasing neurotransmitters increasing depression neurotransmitters decreasing, serotonin increasing acetylcholine decreasing dopamine decreasing neurotransmitters increasing and so on. It's showed in research that depression patients' brain are characterized by multi-neurotransmitters abnormal, the synchronous change of multi-neurotransmitters has some certain regularities, which are not the simple linear relation. It's conformed that the three antagonizing pairs, neurotransmitters-serotonin and dopamine, acetylcholine and norepinephrine, depression eurotransmitters and excited neurotransmitters of ordinary person group and depression patients group, are both characterized by strong antagonizing relation, that the two neurotransmitters which are not antagonizing pairs of neurotransmitters are characterized by weak positive correlation or negative correlation, prompt maybe has the indirect causal relationship. And the change of six neurotransmitters in depression patients' various encephalic regions is rather complex. It's conformed preliminarily that the right frontal region and right central region are characterized by dopamine decreasing, acetylcholine decreasing, serotonin increasing dopamine decreasing, serotonin increasing acetylcholine decreasing dopamine decreasing, dopamine decreasing norepinephrine increasing excited neurotransmitters decreasing, serotonin increasing acetylcholine decreasing dopamine decreasing neurotransmitters increasing, acetylchoine decreasing neurotransmitters increasing, acetylcholine decreasing neurotransmitters increasing excited neurotransmitters decreasing and so on. Contrasted with the ordinary person group, the depression patients group have the notable difference.