Blockade of central nicotine acetylcholine receptor signaling attenuate ghrelin-induced food intake in rodents.

Science.gov (United States)

Dickson, S L; Hrabovszky, E; Hansson, C; Jerlhag, E; Alvarez-Crespo, M; Skibicka, K P; Molnar, C S; Liposits, Z; Engel, J A; Egecioglu, E

2010-12-29

Here we sought to determine whether ghrelin's central effects on food intake can be interrupted by nicotine acetylcholine receptor (nAChR) blockade. Ghrelin regulates mesolimbic dopamine neurons projecting from the ventral tegmental area (VTA) to the nucleus accumbens, partly via cholinergic VTA afferents originating in the laterodorsal tegmental area (LDTg). Given that these cholinergic projections to the VTA have been implicated in natural as well as drug-induced reinforcement, we sought to investigate the role of cholinergic signaling in ghrelin-induced food intake as well as fasting-induced food intake, for which endogenous ghrelin has been implicated. We found that i.p. treatment with the non-selective centrally active nAChR antagonist, mecamylamine decreased fasting-induced food intake in both mice and rats. Moreover, central administration of mecamylamine decreased fasting-induced food intake in rats. I.c.v. ghrelin-induced food intake was suppressed by mecamylamine i.p. but not by hexamethonium i.p., a peripheral nAChR antagonist. Furthermore, mecamylamine i.p. blocked food intake following ghrelin injection into the VTA. Expression of the ghrelin receptor, the growth hormone secretagogue receptor 1A, was found to co-localize with choline acetyltransferase, a marker of cholinergic neurons, in the LDTg. Finally, mecamylamine treatment i.p. decreased the ability of palatable food to condition a place preference. These data suggest that ghrelin-induced food intake is partly mediated via nAChRs and that nicotinic blockade decreases the rewarding properties of food. Copyright © 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

[Assessment of anti-tremorogenic drugs--nicotine-induced tail-tremor model].

Science.gov (United States)

Suemaru, K; Kawasaki, H; Gomita, Y

1997-06-01

The repeated administration of nicotine at small doses, which do not produce whole body tremor or convulsion, causes tremor only in the tail (tail-tremor) of rats. The tremor is accompanied by locomotor hyperactivity without rigidity and immobility of the whole body, suggesting that the nicotine-induced tail-tremor model is useful for studying the mechanism underlying tremor associated with movement. The tail-tremor induced by nicotine was suppressed by mecamylamine, a nicotinic antagonist, but not by atropine or scopolamine, muscalinic antagonists. Moreover, the tail-tremor was suppressed by the beta-blockers propranolol and pindolol, as well as the benzodiazepines diazepam and clonazepam. Tremor at rest is observed only in Parkinson's disease, which is improved with anti-muscalinic drugs. Essential tremor is one of the typical tremors connected with movement (postural and kinetic tremor) and is improved with beta-blocker. These findings and results suggest that nicotine-induced tail-tremor is useful for the study of essential tremor in animal models.

Effects of continuous nicotine treatment and subsequent termination on cocaine versus food choice in male rhesus monkeys.

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Schwienteck, Kathryn L; Negus, S Stevens; Poklis, Justin L; Banks, Matthew L

2015-10-01

One complicating factor in cocaine addiction may be concurrent exposure and potential dependence on nicotine. The aim of the present study was to determine the effects of continuous nicotine treatment and subsequent termination on cocaine versus food choice in rhesus monkeys (Macaca mulatta). For comparison, we also determined effects of the nicotinic receptor antagonist mecamylamine on cocaine versus food choice during continuous saline and nicotine treatment. Rhesus monkeys (N = 3) responded under a concurrent schedule of food pellet (1 g) and intravenous cocaine (0-0.1 mg/kg/injection) availability. Saline and ascending nicotine doses (0.1-1.0 mg/kg/hr, intravenous) were continuously infused for 7-day treatment periods and separated by 24-hr saline treatment periods. Acute effects of mecamylamine (0.32-1.8 mg/kg, intramuscular, 15 min pretreatment) were determined during continuous saline and 0.32-mg/kg/hr nicotine treatments. During saline treatment, cocaine maintained a dose-dependent increase in cocaine choice. Nicotine treatment did not alter cocaine versus food choice. In contrast, preference of 0.032 mg/kg/injection cocaine was attenuated 24 hr following termination of 0.32-mg/kg/hr nicotine treatment, despite no somatic abstinence signs being observed. Acute mecamylamine enhanced cocaine choice during saline treatment and mainly suppressed rates of behavior during nicotine treatment. Overall, continuous nicotine exposure, up to 1 mg/kg/hr, does not enhance cocaine choice and does not produce nicotine dependence, as demonstrated by the lack of abstinence signs. (c) 2015 APA, all rights reserved).

Long-term exposure to nicotine markedly reduces kynurenic acid in rat brain - In vitro and ex vivo evidence

International Nuclear Information System (INIS)

Zielinska, Elzbieta; Kuc, Damian; Zgrajka, Wojciech; Turski, Waldemar A.; Dekundy, Andrzej

2009-01-01

Kynurenic acid (KYNA) is a recognized broad-spectrum antagonist of excitatory amino acid receptors with a particularly high affinity for the glycine co-agonist site of the N-methyl-D-aspartate (NMDA) receptor complex. KYNA is also a putative endogenous neuroprotectant. Recent studies show that KYNA strongly blocks α7 subtype of nicotinic acetylcholine receptors (nAChRs). The present studies were aimed at assessing effects of acute and chronic nicotine exposure on KYNA production in rat brain slices in vitro and ex vivo. In brain slices, nicotine significantly increased KYNA formation at 10 mM but not at 1 or 5 mM. Different nAChR antagonists (dihydro-β-erythroidine, methyllycaconitine and mecamylamine) failed to block the influence exerted by nicotine on KYNA synthesis in cortical slices in vitro. Effects of acute (1 mg/kg, i.p.), subchronic (10-day) and chronic (30-day) administration of nicotine in drinking water (100 μg/ml) on KYNA brain content were evaluated ex vivo. Acute treatment with nicotine (1 mg/kg i.p.) did not affect KYNA level in rat brain. The subchronic exposure to nicotine in drinking water significantly increased KYNA by 43%, while chronic exposure to nicotine resulted in a reduction in KYNA by 47%. Co-administration of mecamylamine with nicotine in drinking water for 30 days reversed the effect exerted by nicotine on KYNA concentration in the cerebral cortex. The present results provide evidence for the hypothesis of reciprocal interaction between the nicotinic cholinergic system and the kynurenine pathway in the brain.

Tying up Nicotine: New Selective Competitive Antagonist of the Neuronal Nicotinic Acetylcholine Receptors

DEFF Research Database (Denmark)

Petersen, Ida Nymann; Crestey, François; Jensen, Anders A

2015-01-01

Conformational restriction of the pyrrolidine nitrogen in nicotine by the introduction of an ethylene bridge provided a potent and selective antagonist of the α4β2-subtype of the nicotinic acetylcholine receptors. Resolution by chiral SFC, pharmacological characterization of the two enantiomers...

Global actions of nicotine on the striatal microcircuit.

Science.gov (United States)

Plata, Víctor; Duhne, Mariana; Pérez-Ortega, Jesús; Hernández-Martinez, Ricardo; Rueda-Orozco, Pavel; Galarraga, Elvira; Drucker-Colín, René; Bargas, José

2013-01-01

what is the predominant action induced by the activation of cholinergic-nicotinic receptors (nAChrs) in the striatal network given that nAChrs are expressed by several elements of the circuit: cortical terminals, dopamine terminals, and various striatal GABAergic interneurons. To answer this question some type of multicellular recording has to be used without losing single cell resolution. Here, we used calcium imaging and nicotine. It is known that in the presence of low micromolar N-Methyl-D-aspartate (NMDA), the striatal microcircuit exhibits neuronal activity consisting in the spontaneous synchronization of different neuron pools that interchange their activity following determined sequences. The striatal circuit also exhibits profuse spontaneous activity in pathological states (without NMDA) such as dopamine depletion. However, in this case, most pathological activity is mostly generated by the same neuron pool. Here, we show that both types of activity are inhibited during the application of nicotine. Nicotine actions were blocked by mecamylamine, a non-specific antagonist of nAChrs. Interestingly, inhibitory actions of nicotine were also blocked by the GABAA-receptor antagonist bicuculline, in which case, the actions of nicotine on the circuit became excitatory and facilitated neuronal synchronization. We conclude that the predominant action of nicotine in the striatal microcircuit is indirect, via the activation of networks of inhibitory interneurons. This action inhibits striatal pathological activity in early Parkinsonian animals almost as potently as L-DOPA.

Role of ventrolateral orbital cortex muscarinic and nicotinic receptors in modulation of capsaicin-induced orofacial pain-related behaviors in rats.

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Tamaddonfard, Esmaeal; Erfanparast, Amir; Abbas Farshid, Amir; Delkhosh-Kasmaie, Fatmeh

2017-11-15

Acetylcholine, as a major neurotransmitter, mediates many brain functions such as pain. This study was aimed to investigate the effects of microinjection of muscarinic and nicotinic acetylcholine receptor antagonists and agonists into the ventrolateral orbital cortex (VLOC) on capsaicin-induced orofacial nociception and subsequent hyperalgesia. The right side of VLOC was surgically implanted with a guide cannula in anaesthetized rats. Orofacial pain-related behaviors were induced by subcutaneous injection of a capsaicin solution (1.5µg/20µl) into the left vibrissa pad. The time spent face rubbing with ipsilateral forepaw and general behavior were recorded for 10min, and then mechanical hyperalgesia was determined using von Frey filaments at 15, 30, 45 and 60min post-capsaicin injection. Alone intra-VLOC microinjection of atropine (a muscarinic acetylcholine receptor antagonist) and mecamylamine (a nicotinic acetylcholine receptor antagonist) at a similar dose of 200ng/site did not alter nocifensive behavior and hyperalgesia. Microinjection of oxotremorine (a muscarinic acetylcholine receptor agonist) at doses of 50 and 100ng/site and epibatidine (a nicotinic acetylcholine receptor agonist) at doses of 12.5, 25, 50 and 100ng/site into the VLOC suppressed pain-related behaviors. Prior microinjections of 200ng/site atropine and mecamylamine (200ng/site) prevented oxotremorine (100ng/site)-, and epibatidine (100ng/site)-induced antinociception, respectively. None of the above-mentioned chemicals changed general behavior. These results showed that the VLOC muscarinic and nicotinic acetylcholine receptors might be involved in modulation of orofacial nociception and hypersensitivity. Copyright © 2017 Elsevier B.V. All rights reserved.

Nicotinic and muscarinic cholinergic receptors are recruited by acetylcholine-mediated neurotransmission within the locus coeruleus during the organisation of post-ictal antinociception.

Science.gov (United States)

de Oliveira, Rithiele Cristina; de Oliveira, Ricardo; Biagioni, Audrey Franceschi; Falconi-Sobrinho, Luiz Luciano; Dos Anjos-Garcia, Tayllon; Coimbra, Norberto Cysne

2016-10-01

Post-ictal antinociception is characterised by an increase in the nociceptive threshold that accompanies tonic and tonic-clonic seizures (TCS). The locus coeruleus (LC) receives profuse cholinergic inputs from the pedunculopontine tegmental nucleus. Different concentrations (1μg, 3μg and 5μg/0.2μL) of the muscarinic cholinergic receptor antagonist atropine and the nicotinic cholinergic receptor antagonist mecamylamine were microinjected into the LC of Wistar rats to investigate the role of cholinergic mechanisms in the severity of TCS and the post-ictal antinociceptive response. Five minutes later, TCS were induced by systemic administration of pentylenetetrazole (PTZ) (64mg/kg). Seizures were recorded inside the open field apparatus for an average of 10min. Immediately after seizures, the nociceptive threshold was recorded for 130min using the tail-flick test. Pre-treatment of the LC with 1μg, 3μg and 5μg/0.2μL concentrations of both atropine and mecamylamine did not cause a significant effect on seizure severity. However, the same treatments decreased the post-ictal antinociceptive phenomenon. In addition, mecamylamine caused an earlier decrease in the post-ictal antinociception compared to atropine. These results suggest that muscarinic and mainly nicotinic cholinergic receptors of the LC are recruited to organise tonic-clonic seizure-induced antinociception. Copyright © 2016 Elsevier Inc. All rights reserved.

Global actions of nicotine on the striatal microcircuit

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Victor E Plata

2013-11-01

Full Text Available The question to solve in the present work is: what is the predominant action induced by the activation of cholinergic-nicotinic receptors (nAChrs in the striatal network given that nAChrs are expressed by several elements of the circuit: cortical terminals, dopamine terminals, and various striatal GABAergic interneurons. To answer this question some type of multicellular recording has to be used without losing single cell resolution. Here, we used calcium imaging and nicotine. It is known that in the presence of low micromolar N-Methyl-D-aspartate (NMDA, the striatal microcircuit exhibits neuronal activity consisting in the spontaneous synchronization of different neuron pools that interchange their activity following determined sequences. The striatal circuit also exhibits profuse spontaneous activity in pathological states (without NMDA such as dopamine depletion. However, in this case, most pathological activity is mostly generated by the same neuron pool. Here, we show that both types of activity are inhibited during the application of nicotine. Nicotine actions were blocked by mecamylamine, a non specific antagonist of nAChrs. Interestingly, inhibitory actions of nicotine were also blocked by the GABAA-receptor antagonist bicuculline, in which case, the actions of nicotine on the circuit became excitatory and facilitated neuronal synchronization. We conclude that the predominant action of nicotine in the striatal microcircuit is indirect, via the activation of networks of inhibitory interneurons. This action inhibits striatal pathological activity in early Parkinsonian animals almost as potently as L-DOPA.

Effects of acute administration of nicotinic and muscarinic cholinergic agonists and antagonists on performance in different cost-benefit decision making tasks in rats.

Science.gov (United States)

Mendez, Ian A; Gilbert, Ryan J; Bizon, Jennifer L; Setlow, Barry

2012-12-01

Alterations in cost-benefit decision making accompany numerous neuropsychiatric conditions, including schizophrenia, attention deficit hyperactivity disorder, and addiction. Central cholinergic systems have been linked to the etiology and/or treatment of many of these conditions, but little is known about the role of cholinergic signaling in cost-benefit decision making. The goal of these experiments was to determine how cholinergic signaling is involved in cost-benefit decision making, using a behavioral pharmacological approach. Male Long-Evans rats were trained in either "probability discounting" or "delay discounting" tasks, in which rats made discrete-trial choices between a small food reward and a large food reward associated with either varying probabilities of omission or varying delays to delivery, respectively. The effects of acute administration of different doses of nicotinic and muscarinic acetylcholine receptor agonists and antagonists were assessed in each task. In the probability discounting task, acute nicotine administration (1.0 mg/kg) significantly increased choice of the large risky reward, and control experiments suggested that this was due to robust nicotine-induced impairments in behavioral flexibility. In the delay discounting task, the muscarinic antagonists scopolamine (0.03, 0.1, and 0.3 mg/kg) and atropine (0.3 mg/kg) both significantly increased choice of the small immediate reward. Neither mecamylamine nor oxotremorine produced reliable effects on either of the decision making tasks. These data suggest that cholinergic receptors play multiple roles in decision making contexts which include consideration of reward delay or probability. These roles should be considered when targeting these receptors for therapeutic purposes.

Tracers development for the PET study of nicotinic receptors: [{sup 11}C]-mecamylamine and [{sup 11}C]-SIB 1553A. Tritium and carbon-11 radiolabelling of a serine proteinase inhibitor: the t-PA{sub stop}; Developpement de traceurs pour l'etude des recepteurs nicotiniques par TEP: la [{sup 11}C]-mecamylamine et le [{sup 11}C]SIB 1553A. Radiomarquages par le tritium et le carbone-11 d'un inhibiteur d'une serine protease: le t-PA{sub stop}

Energy Technology Data Exchange (ETDEWEB)

Sobrio, F.

2002-12-15

In order to develop radiotracers for the Positron Emission Tomography (PET), we labelled both the mecamylamine and SIB-1553A with carbon-11 to study the nicotinic cholinergic receptors (nAChRs). The radiosynthesis of [{sup 11}C]-t-PA{sub stop} and the labelling with tritium of one analogue were realized for cerebral ischemia PET studies. The [{sup 11}C]-mecamylamine, a non-competitive and non-selective nAChRs antagonist was synthesized in 45 min via a N-[{sup 11}C]-methylation reaction. In the rat brain, the ex vivo studies showed no radio-metabolite 45 min after the injection of [{sup 11}C]-mecamylamine. The uptake kinetics in the rat brain or in vivo by PET in the anesthetized baboon or in the conscious monkey, reached a plateau around 45-50 min after injection. However, the saturation or displacement experiments did not permit to exhibit nor a significant difference of labelling between the different cerebral regions nor a specific uptake. In consequence, the [{sup 11}C]-mecamylamine was not an appropriate radioligand for nAChRs PET study. The labelling of [{sup 11}C]-SIB 1553A, a selective agonist for the nicotinic {beta}4 subunit, required the synthesis in 5 steps (56% overall yield) of precursor for the incorporation of carbon-11. The radiosynthesis was performed in 36 min by a N-[{sup 11}C]-methylation reaction (yield: 75%). The [{sup 11}C]-t-PA{sub stop} was obtained from [{sup 11}C]-KCN with yields from 80 to 90%. For the first time with carbon-11, the formation of an amidine group was realized from a nitrile group. The labelling by isotopic exchange of hydrogen by tritium of the t-PA{sub stop} did not permit to obtain the [{sup 3}H]-t-PA{sub stop} but a tritiated analogue. This compound will be used to study its vectorization by micro-encapsulation. (author)

Effects of acute administration of nicotinic and muscarinic cholinergic agonists and antagonists on performance in different cost–benefit decision making tasks in rats

Science.gov (United States)

Mendez, Ian A.; Gilbert, Ryan J.; Bizon, Jennifer L.

2012-01-01

Rationale Alterations in cost–benefit decision making accompany numerous neuropsychiatric conditions, including schizophrenia, attention deficit hyperactivity disorder, and addiction. Central cholinergic systems have been linked to the etiology and/or treatment of many of these conditions, but little is known about the role of cholinergic signaling in cost–benefit decision making. Objectives The goal of these experiments was to determine how cholinergic signaling is involved in cost–benefit decision making, using a behavioral pharmacological approach. Methods Male Long-Evans rats were trained in either “probability discounting” or “delay discounting” tasks, in which rats made discrete-trial choices between a small food reward and a large food reward associated with either varying probabilities of omission or varying delays to delivery, respectively. The effects of acute administration of different doses of nicotinic and muscarinic acetylcholine receptor agonists and antagonists were assessed in each task. Results In the probability discounting task, acute nicotine administration (1.0 mg/kg) significantly increased choice of the large risky reward, and control experiments suggested that this was due to robust nicotine-induced impairments in behavioral flexibility. In the delay discounting task, the muscarinic antagonists scopolamine (0.03, 0.1, and 0.3 mg/kg) and atropine (0.3 mg/kg) both significantly increased choice of the small immediate reward. Neither mecamylamine nor oxotremorine produced reliable effects on either of the decision making tasks. Conclusions These data suggest that cholinergic receptors play multiple roles in decision making contexts which include consideration of reward delay or probability. These roles should be considered when targeting these receptors for therapeutic purposes. PMID:22760484

Contribution of adrenal hormones to nicotine-induced inhibition of synovial plasma extravasation in the rat.

Science.gov (United States)

Miao, F J; Benowitz, N L; Heller, P H; Levine, J D

1997-01-01

1. In this study, we examined the mechanism(s) by which s.c. nicotine inhibits synovial plasma extravasation. We found that nicotine dose-dependently inhibited bradykinin (BK)- and platelet activating factor (PAF)-induced plasma extravasation. 2. The effect of nicotine on both BK- and PAF-induced plasma extravasation was attenuated by adrenal medullectomy. ICI-118,551 (a selective beta 2-adrenoceptor blocker) (30 micrograms ml-1, intra-articularly) significantly attenuated the inhibitory action of high-dose (1 mg kg-1) nicotine on BK-induced plasma extravasation without affecting the inhibition by low- (0.01 microgram kg-1) dose nicotine or that on PAF-induced plasma extravasation by nicotine at any dose. This suggested that beta 2-adrenoceptors mediate the inhibitory actions of high-dose, but not low-dose, nicotine. We also found that systemic naloxone (an opioid receptor antagonist) (two hourly injections of 1 mg kg-1, i.p.) attenuated the inhibitory action produced by all doses of nicotine on BK- or PAF-induced plasma extravasation, suggesting the contribution of endogenous opioids. 3. RU-38,486 (a glucocorticoid receptor antagonist) (30 mg kg-1, s.c.), and metyrapone (a glucocorticoid synthesis inhibitor) (two hourly injections of 100 mg kg-1, i.p.) both attenuated the action of high-dose nicotine without affecting that of low-dose nicotine. 4. Spinal mecamylamine (a nicotinic receptor antagonist) (0.025 mg kg-1, intrathecally, i.t.) attenuated the action of high-dose, but not low-dose, nicotine, suggesting that part of the action of high-dose nicotine is mediated by spinal nicotinic receptors. 5. Combined treatment with ICI-118,551, naloxone and RU-38,486 attenuated the action of low-dose nicotine by an amount similar to that produced by naloxone alone but produced significantly greater attenuation of the effect of high-dose nicotine when compared to the action of any of the three antagonists alone.

3-[2,4-Dimethoxybenzylidene]anabaseine (DMXB) selectively activates rat alpha7 receptors and improves memory-related behaviors in a mecamylamine-sensitive manner.

Science.gov (United States)

Meyer, E M; Tay, E T; Papke, R L; Meyers, C; Huang, G L; de Fiebre, C M

1997-09-12

The alpha7 nicotinic receptor agonist 3-[2,4-dimethoxybenzylidene]anabaseine (DMXB; GTS-21) was investigated for its ability to: (1) activate a variety of nicotinic receptor subtypes in Xenopus oocytes; (2) improve passive avoidance and spatial Morris water task performances in mecamylamine-sensitive manners in bilaterally nucleus basalis lesioned rats; and (3) elevate high-affinity [3H]acetylcholine (ACh) and high-affinity alpha-[125I]bungarotoxin binding in rat neocortex following 2 weeks of daily injections. DMXB (100 microM) activated alpha7 homo-oligomeric receptors, without significant activity at alpha2-, alpha3- and alpha4-containing subtypes. Mecamylamine blocked rat alpha7 receptors weakly if co-administered with agonist, but much more potently when pre-applied. Bilateral ibotenic acid lesions of the nucleus basalis interfered with passive avoidance and spatial memory-related behaviors. DMXB (0.5 mg/kg, i.p.) improved passive avoidance behavior in lesioned animals in a mecamylamine-sensitive manner. DMXB (0.5 mg/kg 15 min before each session) also improved performance in the training and probe components of the Morris water task. DMXB-induced improvement in the probe component but not the training phase was mecamylamine-sensitive. [3H]ACh binding was elevated after 14 days of daily i.p. injections with 0.2 mg/kg nicotine but not after 1 mg/kg DMXB. Neither drug elevated high-affinity alpha-[125I]bungarorotoxin binding over this interval.

Nicotine induces mitochondrial fission through mitofusin degradation in human multipotent embryonic carcinoma cells

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Hirata, Naoya; Yamada, Shigeru [Division of Pharmacology, National Institute of Health Sciences (Japan); Asanagi, Miki [Division of Pharmacology, National Institute of Health Sciences (Japan); Faculty of Engineering, Department of Materials Science and Engineering, Yokohama National University (Japan); Sekino, Yuko [Division of Pharmacology, National Institute of Health Sciences (Japan); Kanda, Yasunari, E-mail: kanda@nihs.go.jp [Division of Pharmacology, National Institute of Health Sciences (Japan)

2016-02-05

Nicotine is considered to contribute to the health risks associated with cigarette smoking. Nicotine exerts its cellular functions by acting on nicotinic acetylcholine receptors (nAChRs), and adversely affects normal embryonic development. However, nicotine toxicity has not been elucidated in human embryonic stage. In the present study, we examined the cytotoxic effects of nicotine in human multipotent embryonal carcinoma cell line NT2/D1. We found that exposure to 10 μM nicotine decreased intracellular ATP levels and inhibited proliferation of NT2/D1 cells. Because nicotine suppressed energy production, which is a critical mitochondrial function, we further assessed the effects of nicotine on mitochondrial dynamics. Staining with MitoTracker revealed that 10 μM nicotine induced mitochondrial fragmentation. The levels of the mitochondrial fusion proteins, mitofusins 1 and 2, were also reduced in cells exposed to nicotine. These nicotine effects were blocked by treatment with mecamylamine, a nonselective nAChR antagonist. These data suggest that nicotine degrades mitofusin in NT2/D1 cells and thus induces mitochondrial dysfunction and cell growth inhibition in a nAChR-dependent manner. Thus, mitochondrial function in embryonic cells could be used to assess the developmental toxicity of chemicals.

Nicotine induces mitochondrial fission through mitofusin degradation in human multipotent embryonic carcinoma cells

International Nuclear Information System (INIS)

Hirata, Naoya; Yamada, Shigeru; Asanagi, Miki; Sekino, Yuko; Kanda, Yasunari

2016-01-01

Nicotine is considered to contribute to the health risks associated with cigarette smoking. Nicotine exerts its cellular functions by acting on nicotinic acetylcholine receptors (nAChRs), and adversely affects normal embryonic development. However, nicotine toxicity has not been elucidated in human embryonic stage. In the present study, we examined the cytotoxic effects of nicotine in human multipotent embryonal carcinoma cell line NT2/D1. We found that exposure to 10 μM nicotine decreased intracellular ATP levels and inhibited proliferation of NT2/D1 cells. Because nicotine suppressed energy production, which is a critical mitochondrial function, we further assessed the effects of nicotine on mitochondrial dynamics. Staining with MitoTracker revealed that 10 μM nicotine induced mitochondrial fragmentation. The levels of the mitochondrial fusion proteins, mitofusins 1 and 2, were also reduced in cells exposed to nicotine. These nicotine effects were blocked by treatment with mecamylamine, a nonselective nAChR antagonist. These data suggest that nicotine degrades mitofusin in NT2/D1 cells and thus induces mitochondrial dysfunction and cell growth inhibition in a nAChR-dependent manner. Thus, mitochondrial function in embryonic cells could be used to assess the developmental toxicity of chemicals.

The incentive amplifying effects of nicotine are reduced by selective and non-selective dopamine antagonists in rats.

Science.gov (United States)

Palmatier, Matthew I; Kellicut, Marissa R; Brianna Sheppard, A; Brown, Russell W; Robinson, Donita L

2014-11-01

Nicotine is a psychomotor stimulant with 'reinforcement enhancing' effects--the actions of nicotine in the brain increase responding for non-nicotine rewards. We hypothesized that this latter effect of nicotine depends on increased incentive properties of anticipatory cues; consistent with this hypothesis, multiple laboratories have reported that nicotine increases sign tracking, i.e. approach to a conditioned stimulus (CS), in Pavlovian conditioned-approach tasks. Incentive motivation and sign tracking are mediated by mesolimbic dopamine (DA) transmission and nicotine facilitates mesolimbic DA release. Therefore, we hypothesized that the incentive-promoting effects of nicotine would be impaired by DA antagonists. To test this hypothesis, separate groups of rats were injected with nicotine (0.4mg/kg base) or saline prior to Pavlovian conditioning sessions in which a CS (30s illumination of a light or presentation of a lever) was immediately followed by a sweet reward delivered in an adjacent location. Both saline and nicotine pretreated rats exhibited similar levels of conditioned approach to the reward location (goal tracking), but nicotine pretreatment significantly increased approach to the CS (sign tracking), regardless of type (lever or light). The DAD1 antagonist SCH-23390 and the DAD2/3 antagonist eticlopride reduced conditioned approach in all rats, but specifically reduced goal tracking in the saline pretreated rats and sign tracking in the nicotine pretreated rats. The non-selective DA antagonist flupenthixol reduced sign-tracking in nicotine rats at all doses tested; however, only the highest dose of flupenthixol reduced goal tracking in both nicotine and saline groups. The reductions in conditioned approach behavior, especially those by SCH-23390, were dissociated from simple motor suppressant effects of the antagonists. These experiments are the first to investigate the effects of dopaminergic drugs on the facilitation of sign-tracking engendered by

An Anti-Nicotinic Cognitive Challenge Model using Mecamylamine in Comparison with the Anti-Muscarinic Cognitive Challenge using Scopolamine

NARCIS (Netherlands)

Baakman, A. C.; Alvarez-jimenez, R.; Rissmann, R.; Klaassen, E. S.; Stevens, J.; Goulooze, S. C.; Burger, J.; Swart, E. L.; Van Gerven, J. M. A.; Groeneveld, G. J.

Aims The muscarinic acetylcholine receptor antagonist scopolamine is often used for proof-of-pharmacology studies with pro-cognitive compounds. From a pharmacological point of view, it would seem more rational to use a nicotinic rather than a muscarinic anticholinergic challenge to prove

Nicotine Impairs Macrophage Control of Mycobacterium tuberculosis.

Science.gov (United States)

Bai, Xiyuan; Stitzel, Jerry A; Bai, An; Zambrano, Cristian A; Phillips, Matthew; Marrack, Philippa; Chan, Edward D

2017-09-01

Pure nicotine impairs macrophage killing of Mycobacterium tuberculosis (MTB), but it is not known whether the nicotine component in cigarette smoke (CS) plays a role. Moreover, the mechanisms by which nicotine impairs macrophage immunity against MTB have not been explored. To neutralize the effects of nicotine in CS extract, we used a competitive inhibitor to the nicotinic acetylcholine receptor (nAChR)-mecamylamine-as well as macrophages derived from mice with genetic disruption of specific subunits of nAChR. We also determined whether nicotine impaired macrophage autophagy and whether nicotine-exposed T regulatory cells (Tregs) could subvert macrophage anti-MTB immunity. Mecamylamine reduced the CS extract increase in MTB burden by 43%. CS extract increase in MTB was also significantly attenuated in macrophages from mice with genetic disruption of either the α7, β2, or β4 subunit of nAChR. Nicotine inhibited autophagosome formation in MTB-infected THP-1 cells and primary murine alveolar macrophages, as well as increased the intracellular MTB burden. Nicotine increased migration of THP-1 cells, consistent with the increased number of macrophages found in the lungs of smokers. Nicotine induced Tregs to produce transforming growth factor-β. Naive mouse macrophages co-cultured with nicotine-exposed Tregs had significantly greater numbers of viable MTB recovered with increased IL-10 production and urea production, but no difference in secreted nitric oxide as compared with macrophages cocultured with unexposed Tregs. We conclude that nicotine in CS plays an important role in subverting macrophage control of MTB infection.

Nicotinic receptor blockade decreases fos immunoreactivity within orexin/hypocretin-expressing neurons of nicotine-exposed rats.

Science.gov (United States)

Simmons, Steven J; Gentile, Taylor A; Mo, Lili; Tran, Fionya H; Ma, Sisi; Muschamp, John W

2016-11-01

Tobacco smoking is the leading cause of preventable death in the United States. Nicotine is the principal psychoactive ingredient in tobacco that causes addiction. The structures governing nicotine addiction, including those underlying withdrawal, are still being explored. Nicotine withdrawal is characterized by negative affective and cognitive symptoms that enhance relapse susceptibility, and suppressed dopaminergic transmission from ventral tegmental area (VTA) to target structures underlies behavioral symptoms of nicotine withdrawal. Agonist and partial agonist therapies help 1 in 4 treatment-seeking smokers at one-year post-cessation, and new targets are needed to more effectively aid smokers attempting to quit. Hypothalamic orexin/hypocretin neurons send excitatory projections to dopamine (DA)-producing neurons of VTA and modulate mesoaccumbal DA release. The effects of nicotinic receptor blockade, which is commonly used to precipitate withdrawal, on orexin neurons remain poorly investigated and present an attractive target for intervention. The present study sought to investigate the effects of nicotinic receptor blockade on hypothalamic orexin neurons using mecamylamine to precipitate withdrawal in rats. Separate groups of rats were treated with either chronic nicotine or saline for 7-days at which point effects of mecamylamine or saline on somatic signs and anxiety-like behavior were assessed. Finally, tissue from rats was harvested for immunofluorescent analysis of Fos within orexin neurons. Results demonstrate that nicotinic receptor blockade leads to reduced orexin cell activity, as indicated by lowered Fos-immunoreactivity, and suggest that this underlying cellular activity may be associated with symptoms of nicotine withdrawal as effects were most prominently observed in rats given chronic nicotine. We conclude from this study that orexin transmission becomes suppressed in rats upon nicotinic receptor blockade, and that behavioral symptoms associated

Emergence of dormant conditioned incentive approach by conditioned withdrawal in nicotine addiction.

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Scott, Daniel; Hiroi, Noboru

2010-10-15

Nicotine is one of the determinants for the development of persistent smoking, and this maladaptive behavior is characterized by many symptoms, including withdrawal and nicotine seeking. The process by which withdrawal affects nicotine seeking is poorly understood. The impact of a withdrawal-associated cue on nicotine (.2 mg/kg)-conditioned place preference was assessed in male C57BL/6J mice (n = 8-17/group). To establish a cue selectively associated with withdrawal distinct from those associated with nicotine, a tone was paired with withdrawal in their home cages; mice were chronically exposed to nicotine (200 μg/mL for 15 days) from drinking water in their home cages and received the nicotinic acetylcholine receptor antagonist mecamylamine (2.5 mg/kg) to precipitate withdrawal in the presence of a tone. The effect of the withdrawal-associated tone on nicotine-conditioned place preference was then evaluated in the place-conditioning apparatus after a delay, when nicotine-conditioned place preference spontaneously disappeared. A cue associated with precipitated withdrawal reactivated the dormant effect of nicotine-associated cues on conditioned place preference. This effect occurred during continuous exposure to nicotine but not during abstinence. A conditioned withdrawal cue could directly amplify the incentive properties of cues associated with nicotine. This observation extends the contemporary incentive account of the role of withdrawal in addiction to cue-cue interaction. Copyright © 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Hypocretin/orexin signaling in the hypothalamic paraventricular nucleus is essential for the expression of nicotine withdrawal.

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Plaza-Zabala, Ainhoa; Flores, África; Maldonado, Rafael; Berrendero, Fernando

2012-02-01

Hypocretin (orexin) signaling is involved in drug addiction. In this study, we investigated the role of these hypothalamic neuropeptides in nicotine withdrawal by using behavioral and neuroanatomical approaches. Nicotine withdrawal syndrome was precipitated by mecamylamine (2 mg/kg, subcutaneous) in C57BL/6J nicotine-dependent mice (25 mg/kg/day for 14 days) pretreated with the hypocretin receptor 1 (Hcrtr-1) antagonist SB334867 (5 and 10 mg/kg, intraperitoneal), the hypocretin receptor 2 antagonist TCSOX229 (5 and 10 mg/kg, intraperitoneal), and in preprohypocretin knockout mice. c-Fos expression was analyzed in several brain areas related to nicotine dependence by immunofluorescence techniques. Retrograde tracing with rhodamine-labeled fluorescent latex microspheres was used to determine whether the hypocretin neurons project directly to the paraventricular nucleus of the hypothalamus (PVN), and SB334867 was locally administered intra-PVN (10 nmol/side) to test the specific involvement of Hcrtr-1 in this brain area during nicotine withdrawal. Somatic signs of nicotine withdrawal were attenuated in mice pretreated with SB334867 and in preprohypocretin knockout mice. No changes were found in TCSOX229 pretreated animals. Nicotine withdrawal increased the percentage of hypocretin cells expressing c-Fos in the perifornical, dorsomedial, and lateral hypothalamus. In addition, the increased c-Fos expression in the PVN during withdrawal was dependent on hypocretin transmission through Hcrtr-1 activation. Hypocretin neurons directly innervate the PVN and the local infusion of SB334867 into the PVN decreased the expression of nicotine withdrawal. These data demonstrate that hypocretin signaling acting on Hcrtr-1 in the PVN plays a crucial role in the expression of nicotine withdrawal. Copyright © 2012 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Agonist actions of clothianidin on synaptic and extrasynaptic nicotinic acetylcholine receptors expressed on cockroach sixth abdominal ganglion.

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Thany, Steeve H

2009-11-01

Clothianidin is new neonicotinoid insecticide acting selectively on insect nicotinic acetylcholine receptors (nAChRs). Its effects on nAChRs expressed on cercal afferent/giant interneuron synapses and DUM neurons have been studied using mannitol-gap and whole-cell patch-clamp techniques, respectively. Bath-application of clothianidin-induced dose-dependent depolarizations of cockroach cercal afferent/giant interneuron synapses which were not reversed after wash-out suggesting a strong desensitization of postsynaptic interneurons at the 6th abdominal ganglion (A6). Clothinidin activity on the nerve preparation was characterized by an increased firing rate of action potentials which then ceased when the depolarization reached a peak. Clothianidin responses were insensitive to all muscarinic antagonists tested but were blocked by co-application of specific nicotinic antagonists methyllicaconitine, alpha-bungarotoxin and d-tubocurarine. In a second round of experiment, clothianidin actions were tested on DUM neurons isolated from the A6. There was a strong desensitization of nAChRs which was not affected by muscarinic antagonists, pirenzepine and atropine, but was reduced with nicotinic antagonist alpha-bungarotoxin. In addition, clothianidin-induced currents were completely blocked by methyllicaconitine suggesting that (1) clothianidin acted as a specific agonist of nAChR subtypes and (2) a small proportion of receptors blocked by MLA was insensitive to alpha-bungarotoxin. Moreover, because clothianidin currents were blocked by d-tubocurarine and mecamylamine, we provided that clothianidin was an agonist of both nAChRs: imidacloprid-sensitive nAChR1 and -insensitive nAChR2 subtypes.

Cholinergic Modulation during Acquisition of Olfactory Fear Conditioning Alters Learning and Stimulus Generalization in Mice

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Pavesi, Eloisa; Gooch, Allison; Lee, Elizabeth; Fletcher, Max L.

2013-01-01

We investigated the role of cholinergic neurotransmission in olfactory fear learning. Mice receiving pairings of odor and foot shock displayed fear to the trained odor the following day. Pretraining injections of the nicotinic antagonist mecamylamine had no effect on subsequent freezing, while the muscarinic antagonist scopolamine significantly…

Association of nicotinic acetylcholine receptors with central respiratory control in isolated brainstem-spinal cord preparation of neonatal rats

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EIKI HATORI

2006-01-01

Full Text Available Nicotine exposure is a risk factor in several breathing disorders Nicotinic acetylcholine receptors (nAChRs exist in the ventrolateral medulla, an important site for respiratory control. We examined the effects of nicotinic acetylcholine neurotransmission on central respiratory control by addition of a nAChR agonist or one of various antagonists into superfusion medium in the isolated brainstem-spinal cord from neonatal rats. Ventral C4 neuronal activity was monitored as central respiratory output, and activities of respiratory neurons in the ventrolateral medulla were recorded in whole-cell configuration. RJR-2403 (0.1-10mM, alpha4beta2 nAChR agonist induced dose-dependent increases in respiratory frequency. Non-selective nAChR antagonist mecamylamine (0.1-100mM, alpha4beta2 antagonist dihydro-beta-erythroidine (0.1-100mM, alpha7 antagonist methyllycaconitine (0.1-100mM, and a-bungarotoxin (0.01-10mM all induced dose-dependent reductions in C4 respiratory rate. We next examined effects of 20mM dihydro-beta-erythroidine and 20mM methyllycaconitine on respiratory neurons. Dihydro-beta-erythroidine induces hyperpolarization and decreases intraburst firing frequency of inspiratory and preinspiratory neurons. In contrast, methyllycaconitine has no effect on the membrane potential of inspiratory neurons, but does decrease their intraburst firing frequency while inducing hyperpolarization and decreasing intraburst firing frequency in preinspiratory neurons. These findings indicate that alpha4beta2 nAChR is involved in both inspiratory and preinspiratory neurons, whereas alpha7 nAChR functions only in preinspiratory neurons to modulate C4 respiratory rate

Effects of a selective cannabinoid CB2 agonist and antagonist on intravenous nicotine self administration and reinstatement of nicotine seeking.

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Islam Gamaleddin

Full Text Available Over the last decade there have been significant advances in the discovery and understanding of the cannabinoid system along with the development of pharmacologic tools that modulate its function. Characterization of the crosstalk between nicotine addiction and the cannabinoid system may have significant implications on our understanding of the neurobiological mechanisms underlying nicotine dependence. Two types of cannabinoid receptors (CB1 and CB2 have been identified. CB1 receptors are expressed in the brain and modulate drug taking and drug seeking for various drugs of abuse, including nicotine. CB2 receptors have been recently identified in the brain and have been proposed to play a functional role in mental disorders and drug addiction. Our objective was to explore the role of CB2 receptors on intravenous nicotine self administration under two schedules of reinforcement (fixed and progressive ratio and on nicotine seeking induced by nicotine priming or by nicotine associated cues. For this, we evaluated the effects of various doses of the selective CB2 antagonist AM630 (1.25 to 5 mg/kg and CB2 agonist AM1241 (1 to 10 mg/kg on these behavioral responses in rats. Different groups of male Long Evans rats were trained to lever press for nicotine at a unit dose of 30 µg/kg/infusion. Subsequently, animals were randomized using a Latin-square design and injected with either AM1241 or AM630 using a counterbalanced within subject design. Administration of the CB2 ligands did not affect either nicotine-taking nicotine-seeking behavior. Our results do not support the involvement of CB2 receptors in nicotine-taking or nicotine-seeking behavior.

Effect of α7 nicotinic acetylcholine receptor agonists and antagonists on motor function in mice

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Welch, Kevin D.; Pfister, James A.; Lima, Flavia G.; Green, Benedict T.; Gardner, Dale R.

2013-01-01

Nicotinic acetylcholine receptors (nAChRs) are ligand-gated cation channels found throughout the body, and serve to mediate diverse physiological functions. Muscle-type nAChRs located in the motor endplate region of muscle fibers play an integral role in muscle contraction and thus motor function. The toxicity and teratogenicity of many plants (which results in millions of dollars in losses annually to the livestock industry) are due to various toxins that bind to nAChRs including deltaline and methyllycaconitine (MLA) from larkspur (Delphinium) species, and nicotine and anabasine from tobacco (Nicotiana) species. The primary result of the actions of these alkaloids at nAChRs is neuromuscular paralysis and respiratory failure. The objective of this study was to further characterize the motor coordination deficiencies that occur upon exposure to a non-lethal dose of nAChR antagonists MLA and deltaline as well as nAChR agonists nicotine and anabasine. We evaluated the effect of nAChR agonists and antagonists on the motor function and coordination in mice using a balance beam, grip strength meter, rotarod, open field analysis and tremor monitor. These analyses demonstrated that within seconds after treatment the mice had significant loss of motor function and coordination that lasted up to 1 min, followed by a short period of quiescence. Recovery to normal muscle coordination was rapid, typically within approximately 10 min post-dosing. However, mice treated with the nAChR agonist nicotine and anabasine required a slightly longer time to recover some aspects of normal muscle function in comparison to mice treated with the nAChR antagonist MLA or deltaline. -- Highlights: ► Mice treated with nAChR agonists and antagonists have a loss in motor function. ► These deficits are temporary as near normal motor function returns within 10 min. ► There are compound-specific differences in the effects on motor function.

The alpha7 nicotinic acetylcholine receptor-selective antagonist, methyllycaconitine, partially protects against beta-amyloid1-42 toxicity in primary neuron-enriched cultures.

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Martin, Shelley E; de Fiebre, Nancy Ellen C; de Fiebre, Christopher M

2004-10-01

Studies have suggested that the neuroprotective actions of alpha7 nicotinic agonists arise from activation of receptors and not from the extensive desensitization which rapidly follows activation. Here, we report that the alpha7-selective nicotinic antagonist, methyllycaconitine (MLA), protects against beta-amyloid-induced neurotoxicity; whereas the alpha4beta2-selective antagonist, dihydro-beta-erythroidine, does not. These findings suggest that neuroprotective actions of alpha7-acting agents arise from receptor inhibition/desensitization and that alpha7 antagonists may be useful neuroprotective agents.

Cannabinoid CB1 receptor antagonist rimonabant disrupts nicotine reward-associated memory in rats.

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Fang, Qin; Li, Fang-Qiong; Li, Yan-Qin; Xue, Yan-Xue; He, Ying-Ying; Liu, Jian-Feng; Lu, Lin; Wang, Ji-Shi

2011-10-01

Exposure to cues previously associated with drug intake leads to relapse by activating previously acquired memories. Based on previous findings, in which cannabinoid CB(1) receptors were found to be critically involved in specific aspects of learning and memory, we investigated the role of CB(1) receptors in nicotine reward memory using a rat conditioned place preference (CPP) model. In Experiment 1, rats were trained for CPP with alternating injections of nicotine (0.5mg/kg, s.c.) and saline to acquire the nicotine-conditioned memory. To examine the effects of rimonabant on the reconsolidation of nicotine reward memory, rats were administered rimonabant (0, 0.3, and 3.0mg/kg, i.p.) immediately after reexposure to the drug-paired context. In Experiment 2, rats were trained for CPP similarly to Experiment 1. To examine the effects of rimonabant on the reinstatement of nicotine reward memory, rimonabant (0, 0.3, and 3.0mg/kg, i.p.) was administered before the test of nicotine-induced CPP reinstatement. In Experiment 3, to evaluate whether rimonabant itself produces a reward memory, rats were trained for CPP with alternating injections of different doses of rimonabant (0, 0.3, and 3.0mg/kg) and saline. Rimonabant at a dose of 3.0mg/kg significantly disrupted the reconsolidation of nicotine memory and significantly blocked the reinstatement of nicotine-induced CPP. However, rimonabant itself did not produce CPP. These findings provide clear evidence that CB(1) receptors play a role in nicotine reward memory, suggesting that CB(1) receptor antagonists may be a potential target for managing nicotine addiction. Copyright © 2011 Elsevier Inc. All rights reserved.

Effect of α{sub 7} nicotinic acetylcholine receptor agonists and antagonists on motor function in mice

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Welch, Kevin D., E-mail: kevin.welch@ars.usda.gov [USDA/ARS Poisonous Plant Research Laboratory, 1150 E. 1400N., Logan, UT 84341 (United States); Pfister, James A. [USDA/ARS Poisonous Plant Research Laboratory, 1150 E. 1400N., Logan, UT 84341 (United States); Lima, Flavia G. [Federal University of Goías, School of Veterinary Medicine, Goiânia, Goías (Brazil); Green, Benedict T.; Gardner, Dale R. [USDA/ARS Poisonous Plant Research Laboratory, 1150 E. 1400N., Logan, UT 84341 (United States)

2013-02-01

Nicotinic acetylcholine receptors (nAChRs) are ligand-gated cation channels found throughout the body, and serve to mediate diverse physiological functions. Muscle-type nAChRs located in the motor endplate region of muscle fibers play an integral role in muscle contraction and thus motor function. The toxicity and teratogenicity of many plants (which results in millions of dollars in losses annually to the livestock industry) are due to various toxins that bind to nAChRs including deltaline and methyllycaconitine (MLA) from larkspur (Delphinium) species, and nicotine and anabasine from tobacco (Nicotiana) species. The primary result of the actions of these alkaloids at nAChRs is neuromuscular paralysis and respiratory failure. The objective of this study was to further characterize the motor coordination deficiencies that occur upon exposure to a non-lethal dose of nAChR antagonists MLA and deltaline as well as nAChR agonists nicotine and anabasine. We evaluated the effect of nAChR agonists and antagonists on the motor function and coordination in mice using a balance beam, grip strength meter, rotarod, open field analysis and tremor monitor. These analyses demonstrated that within seconds after treatment the mice had significant loss of motor function and coordination that lasted up to 1 min, followed by a short period of quiescence. Recovery to normal muscle coordination was rapid, typically within approximately 10 min post-dosing. However, mice treated with the nAChR agonist nicotine and anabasine required a slightly longer time to recover some aspects of normal muscle function in comparison to mice treated with the nAChR antagonist MLA or deltaline. -- Highlights: ► Mice treated with nAChR agonists and antagonists have a loss in motor function. ► These deficits are temporary as near normal motor function returns within 10 min. ► There are compound-specific differences in the effects on motor function.

Similar precipitated withdrawal effects on intracranial self-stimulation during chronic infusion of an e-cigarette liquid or nicotine alone.

Science.gov (United States)

Harris, A C; Muelken, P; Smethells, J R; Krueger, M; LeSage, M G

2017-10-01

The FDA recently extended their regulatory authority to electronic cigarettes (ECs). Because the abuse liability of ECs is a leading concern of the FDA, animal models are urgently needed to identify factors that influence the relative abuse liability of these products. The ability of tobacco products to induce nicotine dependence, defined by the emergence of anhedonia and other symptoms of nicotine withdrawal following cessation of their use, contributes to tobacco abuse liability. The present study compared the severity of precipitated withdrawal during chronic infusion of nicotine alone or nicotine-dose equivalent concentrations of three different EC refill liquids in rats, as indicated by elevations in intracranial self-stimulation (ICSS) thresholds (anhedonia-like behavior). Because these EC liquids contain constituents that may enhance their abuse liability (e.g., minor alkaloids), we hypothesized that they would be associated with greater withdrawal effects than nicotine alone. Results indicated that the nicotinic acetylcholine receptor antagonist mecamylamine precipitated elevations in ICSS thresholds in rats receiving a chronic infusion of nicotine alone or EC liquids (3.2mg/kg/day, via osmotic pump). Magnitude of this effect did not differ between formulations. Our findings indicate that nicotine alone is the primary CNS determinant of the ability of ECs to engender dependence. Combined with our previous findings that nicotine alone and these EC liquids do not differ in other preclinical addiction models, these data suggest that product standards set by the FDA to reduce EC abuse liability should primarily target nicotine, other constituents with peripheral sensory effects (e.g. flavorants), and factors that influence product appeal (e.g., marketing). Copyright © 2017 Elsevier Inc. All rights reserved.

Synthesis and pharmacological evaluation of DHβE analogs as neuronal nicotinic acetylcholine receptor antagonists

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Jepsen, Tue H.; Jensen, Anders A.; Lund, Mads Henrik

2014-01-01

Dihydro-β-erythroidine (DHβE) is a member of the Erythrina family of alkaloids and a potent competitive antagonist of the α4β2-subtype of the nicotinic acetylcholine receptors (nAChRs). Guided by an X-ray structure of DHβE in complex with an ACh binding protein, we detail the design, synthesis...

A novel nicotinic agonist facilitates induction of long-term potentiation in the rat hippocampus.

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Hunter, B E; de Fiebre, C M; Papke, R L; Kem, W R; Meyer, E M

1994-02-28

Long-term potentiation (LTP) can be modulated by a number of neurotransmitter receptors including muscarinic and GABAergic receptor types. We have found that a novel nicotinic agonist, 2,4-dimethoxybenzylidene anabaseine (DMXB), facilitated the induction of LTP in the hippocampus in a dose-dependent and mecamylamine-sensitive manner. DMXB displaced high affinity nicotinic [125I]alpha-bungarotoxin and [3H]acetylcholine binding in rat brain. Xenopus oocyte studies demonstrated that DMXB has agonist activity at alpha 7 but not alpha 4/beta 2 nicotinic receptor subtypes. These results indicated that DMXB is a novel nicotinic agonist with apparent specificity for the alpha 7/alpha-bungarotoxin nicotinic receptor subtype and indicate that nicotinic receptor activation is capable of modulating the induction of long-term potentiation.

Effects of the nicotinic agonist varenicline, nicotinic antagonist r-bPiDI, and DAT inhibitor (R)-modafinil on co-use of ethanol and nicotine in female P rats.

Science.gov (United States)

Maggio, Sarah E; Saunders, Meredith A; Baxter, Thomas A; Nixon, Kimberly; Prendergast, Mark A; Zheng, Guangrong; Crooks, Peter; Dwoskin, Linda P; Slack, Rachel D; Newman, Amy H; Bell, Richard L; Bardo, Michael T

2018-05-01

Co-users of alcohol and nicotine are the largest group of polysubstance users worldwide. Commonalities in mechanisms of action for ethanol (EtOH) and nicotine proposes the possibility of developing a single pharmacotherapeutic to treat co-use. Toward developing a preclinical model of co-use, female alcohol-preferring (P) rats were trained for voluntary EtOH drinking and i.v. nicotine self-administration in three phases: (1) EtOH alone (0 vs. 15%, two-bottle choice), (2) nicotine alone (0.03 mg/kg/infusion, active vs. inactive lever), and (3) concurrent access to both EtOH and nicotine. Using this model, we examined the effects of (1) varenicline, a nicotinic acetylcholine receptor (nAChR) partial agonist with high affinity for the α4β2* subtype; (2) r-bPiDI, a subtype-selective antagonist at α6β2* nAChRs; and (3) (R)-modafinil, an atypical inhibitor of the dopamine transporter (DAT). In phases 1 and 2, pharmacologically relevant intake of EtOH and nicotine was achieved. In the concurrent access phase (phase 3), EtOH consumption decreased while nicotine intake increased relative to phases 1 and 2. For drug pretreatments, in the EtOH access phase (phase 1), (R)-modafinil (100 mg/kg) decreased EtOH consumption, with no effect on water consumption. In the concurrent access phase, varenicline (3 mg/kg), r-bPiDI (20 mg/kg), and (R)-modafinil (100 mg/kg) decreased nicotine self-administration but did not alter EtOH consumption, water consumption, or inactive lever pressing. These results indicate that therapeutics which may be useful for smoking cessation via selective inhibition of α4β2* or α6β2* nAChRs, or DAT inhibition, may not be sufficient to treat EtOH and nicotine co-use.

Overexpression of CRF in the BNST diminishes dysphoria but not anxiety-like behavior in nicotine withdrawing rats.

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Qi, Xiaoli; Guzhva, Lidia; Yang, Zhihui; Febo, Marcelo; Shan, Zhiying; Wang, Kevin K W; Bruijnzeel, Adriaan W

2016-09-01

Smoking cessation leads to dysphoria and anxiety, which both increase the risk for relapse. This negative affective state is partly mediated by an increase in activity in brain stress systems. Recent studies indicate that prolonged viral vector-mediated overexpression of stress peptides diminishes stress sensitivity. Here we investigated whether the overexpression of corticotropin-releasing factor (CRF) in the bed nucleus of the stria terminalis (BNST) diminishes nicotine withdrawal symptoms in rats. The effect of nicotine withdrawal on brain reward function was investigated with an intracranial self-stimulation (ICSS) procedure. Anxiety-like behavior was investigated in the elevated plus maze test and a large open field. An adeno-associated virus (AAV) pseudotype 2/5 vector was used to overexpress CRF in the lateral BNST and nicotine dependence was induced using minipumps. Administration of the nicotinic receptor antagonist mecamylamine and cessation of nicotine administration led to a dysphoria-like state, which was prevented by the overexpression of CRF in the BNST. Nicotine withdrawal also increased anxiety-like behavior in the elevated plus maze test and large open field test and slightly decreased locomotor activity in the open field. The overexpression of CRF in the BNST did not prevent the increase in anxiety-like behavior or decrease in locomotor activity. The overexpression of CRF increased CRF1 and CRF2 receptor gene expression and increased the CRF2/CRF1 receptor ratio. In conclusion, the overexpression of CRF in the BNST prevents the dysphoria-like state associated with nicotine withdrawal and increases the CRF2/CRF1 receptor ratio, which may diminish the negative effects of CRF on mood. Published by Elsevier B.V.

The role of nicotinic acetylcholine and opioid systems of the ventral orbital cortex in modulation of formalin-induced orofacial pain in rats.

Science.gov (United States)

Yousofizadeh, Shahnaz; Tamaddonfard, Esmaeal; Farshid, Amir Abbas

2015-07-05

Nicotinic acetylcholine and opioid receptors are involved in modulation of pain. In the present study, we investigated the effects of microinjection of nicotinic acetylcholine and opioid compounds into the ventral orbital cortex (VOC) on the formalin-induced orofacial pain in rats. For this purpose, two guide cannulas were placed into the left and right sides of the VOC of the brain. Orofacial pain was induced by subcutaneous injection of a diluted formalin solution (50μl, 1.5%) into the right vibrissa pad and face rubbing durations were recorded at 3-min blocks for 45min. Formalin produced a marked biphasic pain response (first phase: 0-3min and second phase: 15-33min). Epibatidine (a nicotinic receptor agonist) at doses of 0.05, 0.1 and 0.2μg/site, morphine (an opioid receptor agonist) at doses of 0.5, 1 and 2μg/site and their sub-analgesic doses (0.025μg/site epibatidine with 0.25μg/site morphine) combination treatment suppressed the second phase of pain. The antinociceptive effect induced by 0.2μg/site of epibatidine, but not morphine (2μg/site), was prevented by 2μg/site of mecamylamine (a nicotinic receptor antagonist). Naloxone (an opioid receptor antagonist) at a dose of 2μg/site prevented the antinociceptive effects induced by 2μg/site of morphine and 0.2μg/site of epibatidine. No above-mentioned chemical compounds affected locomotor activity. These results showed that at the VOC level, epibatidine and morphine produced antinociception. In addition, opioid receptor might be involved in epibatidine-induced antinociception, but the antinociception induced by morphine was not mediated through nicotinic acetylcholine receptor. Copyright © 2015 Elsevier B.V. All rights reserved.

Nicotine anxiogenic and rewarding effects are decreased in mice lacking beta-endorphin.

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Trigo, José M; Zimmer, Andreas; Maldonado, Rafael

2009-06-01

The endogenous opioid system plays an important role in the behavioral effects of nicotine. Thus, micro-opioid receptor and the endogenous opioids derived from proenkephalin are involved in the central effects of nicotine. However, the role played by the different endogenous opioid peptides in the acute and chronic effects of nicotine remains to be fully established. Mice lacking beta-endorphin were acutely injected with nicotine at different doses to evaluate locomotor, anxiogenic and antinociceptive responses. The rewarding properties of nicotine were evaluated by using the conditioned place-preference paradigm. Mice chronically treated with nicotine were acutely injected with mecamylamine to study the behavioral expression of nicotine withdrawal. Mice lacking beta-endorphin exhibited a spontaneous hypoalgesia and hyperlocomotion and a reduction on the anxiogenic and rewarding effects induced by nicotine. Nicotine induced similar antinociception and hypolocomotion in both genotypes and no differences were found in the development of physical dependence. The dissociation between nicotine rewarding properties and physical dependence suggests a differential implication of beta-endorphin in these addictive related responses.

Nicotine anxiogenic and rewarding effects are decreased in mice lacking β-endorphin

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Trigo, José M.; Zimmer, Andreas; Maldonado, Rafael

2009-01-01

The endogenous opioid system plays an important role in the behavioral effects of nicotine. Thus, μ-opioid receptor and the endogenous opioids derived from proenkephalin are involved in the central effects of nicotine. However, the role played by the different endogenous opioid peptides in the acute and chronic effects of nicotine remains to be fully established. Mice lacking β-endorphin were acutely injected with nicotine at different doses to evaluate locomotor, anxiogenic and antinociceptive responses. The rewarding properties of nicotine were evaluated by using the conditioned place-preference paradigm. Mice chronically treated with nicotine were acutely injected with mecamylamine to study the behavioral expression of nicotine withdrawal. Mice lacking β-endorphin exhibited a spontaneous hypoalgesia and hyperlocomotion and a reduction on the anxiogenic and rewarding effects induced by nicotine. Nicotine induced similar antinociception and hypolocomotion in both genotypes and no differences were found in the development of physical dependence. The dissociation between nicotine rewarding properties and physical dependence suggests a differential implication of β-endorphin in these addictive related responses. PMID:19376143

Scopolamine and amphetamine produce similar decision-making deficits on a rat gambling task via independent pathways.

Science.gov (United States)

Silveira, Mason M; Malcolm, Emma; Shoaib, Mohammed; Winstanley, Catharine A

2015-03-15

Disorders characterized by disturbed cholinergic signaling, such as schizophrenia, exhibit impaired performance on measures of real-world cost/benefit decision-making. Whether the cholinergic system contributes to the choice deficits observed is currently unknown. We therefore determined the effects of broad-acting agonists and antagonists at the nicotinic and muscarinic receptor on decision making, as measured by the rodent gambling task (rGT). Given the anatomical and functional connectivity of the cholinergic and dopaminergic systems, we also sought to modulate amphetamine's previously reported effect on rGT performance via the cholinergic system. Male rats were trained on the rGT, during which animals chose from four different options. The optimal strategy on the rGT is to favor options associated with smaller immediate rewards and less punishment/loss. Impulsive action was also measured by recording the number of premature responses made. Performance on the rGT was assessed following acute treatment with the muscarinic receptor agonist oxotremorine, the muscarinic receptor antagonist scopolamine, nicotine, and the nicotinic receptor antagonist mecamylamine. Similar to the effect produced by amphetamine, muscarinic receptor antagonism with scopolamine (0.1mg/kg) impaired decision making, albeit to a lesser degree. Prior muscarinic agonism with oxotremorine was unable to attenuate amphetamine's effects on rGT performance. Oxotremorine, nicotine, and mecamylamine did not affect the choice profile. We therefore conclude that modulation of the muscarinic, but not nicotinic, receptor system can affect decision making under conditions of risk and uncertainty. Such findings contribute to a broader understanding of the cognitive deficits observed in disorders in which cholinergic signaling is compromised. Copyright © 2014 Elsevier B.V. All rights reserved.

Antidepressant-like effects of nicotinic acetylcholine receptor antagonists, but not agonists, in the mouse forced swim and mouse tail suspension tests

DEFF Research Database (Denmark)

Andreasen T., Jesper; Olsen, G M; Wiborg, O

2009-01-01

Current literature suggests involvement of nicotinic acetylcholine receptors (nAChRs) in major depression. However, it is controversial whether the antidepressant-like effect of nAChR modulation is induced by activation, desensitization or inhibition of central nAChRs. In addition, the specific n......AChR subtype/s involved remains unknown. In this study, we systematically compared the effects of non-selective and selective nicotinic agonists and antagonists in two different tests for antidepressant effects in mice: the tail suspension test and the forced swim test. Compounds: nicotine, RJR-2403 (alpha4...

Prenatal nicotinic exposure upregulates pulmonary C-fiber NK1R expression to prolong pulmonary C-fiber-mediated apneic response

International Nuclear Information System (INIS)

Zhao, Lei; Zhuang, Jianguo; Zang, Na; Lin, Yong; Lee, Lu-Yuan; Xu, Fadi

2016-01-01

Prenatal nicotinic exposure (PNE) prolongs bronchopulmonary C-fiber (PCF)-mediated apneic response to intra-atrial bolus injection of capsaicin in rat pups. The relevant mechanisms remain unclear. Pulmonary substance P and adenosine and their receptors (neurokinin-A receptor, NK1R and ADA 1 receptor, ADA 1 R) and transient receptor potential cation channel subfamily V member 1 (TRPV1) expressed on PCFs are critical for PCF sensitization and/or activation. Here, we compared substance P and adenosine in BALF and NK1R, ADA 1 R, and TRPV1 expression in the nodose/jugular (N/J) ganglia (vagal pulmonary C-neurons retrogradely labeled) between Ctrl and PNE pups. We found that PNE failed to change BALF substance P and adenosine content, but significantly upregulated both mRNA and protein TRPV1 and NK1R in the N/J ganglia and only NK1R mRNA in pulmonary C-neurons. To define the role of NK1R in the PNE-induced PCF sensitization, the apneic response to capsaicin (i.v.) without or with pretreatment of SR140333 (a peripheral and selective NK1R antagonist) was compared and the prolonged apnea by PNE significantly shortened by SR140333. To clarify if the PNE-evoked responses depended on action of nicotinic acetylcholine receptors (nAChRs), particularly α7nAChR, mecamylamine or methyllycaconitine (a general nAChR or a selective α7nAChR antagonist) was administrated via another mini-pump over the PNE period. Mecamylamine or methyllycaconitine eliminated the PNE-evoked mRNA and protein responses. Our data suggest that PNE is able to elevate PCF NK1R expression via activation of nAChRs, especially α7nAChR, which likely contributes to sensitize PCFs and prolong the PCF-mediated apneic response to capsaicin. - Highlights: • PNE upregulated NK1R and TRPV1 gene and protein expression in the N/J ganglia. • PNE only elevated NK1R mRNA in vagal pulmonary C-neurons. • Blockage of peripheral NK1R reduced the PNE-induced PCF sensitization. • PNE induced gene and protein changes in

Serotonergic modulation of nicotine-induced kinetic tremor in mice

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Naofumi Kunisawa

2017-06-01

Full Text Available We previously demonstrated that nicotine elicited kinetic tremor by elevating the neural activity of the inferior olive via α7 nicotinic acetylcholine (nACh receptors. Since α7 nACh receptors reportedly facilitate synaptic monoamine release, we explored the role of 5-HT receptors in induction and/or modulation of nicotine tremor. Treatment of mice with nicotine induced kinetic tremor that normally appeared during movement. The 5-HT1A agonist, 8-hydroxydipropylaminotetraline (8-OH-DPAT, significantly enhanced nicotine-induced tremor and the action of 8-OH-DPAT was antagonized by WAY-100135 (5-HT1A antagonist. In addition, the cerebral 5-HT depletion by repeated treatment with p-chlorophenylalanine did not reduce, but rather potentiated the facilitatory effects of 8-OH-DPAT. In contrast, the 5-HT2 agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI, significantly attenuated nicotine tremor, which was antagonized by ritanserin (5-HT2 antagonist. The 5-HT3 agonist SR-57227 did not affect nicotine-induced tremor. Furthermore, when testing the direct actions of 5-HT antagonists, nicotine tremor was inhibited by WAY-100135, but was unaffected by ritanserin, ondansetron (5-HT3 antagonist or SB-258585 (5-HT6 antagonist. These results suggest that postsynaptic 5-HT1A receptors are involved in induction of nicotine tremor mediated by α7 nACh receptors. In addition, 5-HT2 receptors have an inhibitory modulatory role in induction of nicotine tremor.

Attenuated nicotine‐like effects of varenicline but not other nicotinic ACh receptor agonists in monkeys receiving nicotine daily

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Cunningham, Colin S; Moerke, Megan J; Javors, Martin A; Carroll, F Ivy

2016-01-01

Background and Purpose Chronic treatment can differentially impact the effects of pharmacologically related drugs that differ in receptor selectivity and efficacy. Experimental Approach The impact of daily nicotine treatment on the effects of nicotinic ACh receptor (nAChR) agonists was examined in two groups of rhesus monkeys discriminating nicotine (1.78 mg·kg−1 base weight) from saline. One group received additional nicotine treatment post‐session (1.78 mg·kg−1 administered five times daily, each dose 2 h apart; i.e. Daily group), and the second group did not (Intermittent group). Key Results Daily repeated nicotine treatment produced a time‐related increase in saliva cotinine. There was no significant difference in the ED50 values of the nicotine discriminative stimulus between the Daily and Intermittent group. Mecamylamine antagonized the effects of nicotine, whereas dihydro‐β‐erythroidine did not. Midazolam produced 0% nicotine‐lever responding. The nAChR agonists epibatidine, RTI‐36, cytisine and varenicline produced >96% nicotine‐lever responding in the Intermittent group. The respective maximum effects in the Daily group were 100, 72, 59 and 28%, which shows that the ability of varenicline to produce nicotine‐like responding was selectively decreased in the Daily as compared with the Intermittent group. When combined with nicotine, both varenicline and cytisine increased the potency of nicotine to produce discriminative stimulus effects. Conclusion and Implications Nicotine treatment has a greater impact on the sensitivity to the effects of varenicline as compared with some other nAChR agonists. Collectively, these results strongly suggest that varenicline differs from nicotine in its selectivity for multiple nAChR subtypes. PMID:27667659

Melatonin modulation of presynaptic nicotinic acetylcholine receptors located on short noradrenergic neurons of the rat vas deferens: a pharmacological characterization

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Zago W.M.

1999-01-01

Full Text Available Melatonin, the pineal hormone produced during the dark phase of the light-dark cycle, modulates neuronal acetylcholine receptors located presynaptically on nerve terminals of the rat vas deferens. Recently we showed the presence of high affinity nicotine-binding sites during the light phase, and low and high affinity binding sites during the dark phase. The appearance of the low affinity binding sites was due to the nocturnal melatonin surge and could be mimicked by exposure to melatonin in vitro. The aim of the present research was to identify the receptor subtypes responsible for the functional response during the light and the dark phase. The rank order of potency of agonists was dimethylphenylpiperazinium (DMPP = cytisine > nicotine > carbachol and DMPP = nicotine = cytisine > carbachol, during the light and dark phase, respectively, due to an increase in apparent affinity for nicotine. Mecamylamine similarly blocked the DMPP response during the light and the dark phase, while the response to nicotine was more efficiently blocked during the light phase. In contrast, methyllycaconitine inhibited the nicotine-induced response only at 21:00 h. Since a7 nicotinic acetylcholine receptors (nAChRs have low affinity for nicotine in binding assays, we suggest that a mixed population composed of a3ß4 - plus a7-bearing nAChR subtypes is present at night. This plasticity in receptor subtypes is probably driven by melatonin since nicotine-induced contraction in organs from animals sacrificed at 15:00 h and incubated with melatonin (100 pg/ml, 4 h is not totally blocked by mecamylamine. Thus melatonin, by acting directly on the short adrenergic neurons that innervate the rat vas deferens, induces the appearance of the low affinity binding site, probably an a7 nAChR subtype.

Serotonergic modulation of nicotine-induced kinetic tremor in mice.

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Kunisawa, Naofumi; Iha, Higor A; Nomura, Yuji; Onishi, Misaki; Matsubara, Nami; Shimizu, Saki; Ohno, Yukihiro

2017-06-01

We previously demonstrated that nicotine elicited kinetic tremor by elevating the neural activity of the inferior olive via α7 nicotinic acetylcholine (nACh) receptors. Since α7 nACh receptors reportedly facilitate synaptic monoamine release, we explored the role of 5-HT receptors in induction and/or modulation of nicotine tremor. Treatment of mice with nicotine induced kinetic tremor that normally appeared during movement. The 5-HT 1A agonist, 8-hydroxydipropylaminotetraline (8-OH-DPAT), significantly enhanced nicotine-induced tremor and the action of 8-OH-DPAT was antagonized by WAY-100135 (5-HT 1A antagonist). In addition, the cerebral 5-HT depletion by repeated treatment with p-chlorophenylalanine did not reduce, but rather potentiated the facilitatory effects of 8-OH-DPAT. In contrast, the 5-HT 2 agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI), significantly attenuated nicotine tremor, which was antagonized by ritanserin (5-HT 2 antagonist). The 5-HT 3 agonist SR-57227 did not affect nicotine-induced tremor. Furthermore, when testing the direct actions of 5-HT antagonists, nicotine tremor was inhibited by WAY-100135, but was unaffected by ritanserin, ondansetron (5-HT 3 antagonist) or SB-258585 (5-HT 6 antagonist). These results suggest that postsynaptic 5-HT 1A receptors are involved in induction of nicotine tremor mediated by α7 nACh receptors. In addition, 5-HT 2 receptors have an inhibitory modulatory role in induction of nicotine tremor. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Effects of the histamine H₃ receptor antagonist ABT-239 on cognition and nicotine-induced memory enhancement in mice.

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Kruk, Marta; Miszkiel, Joanna; McCreary, Andrew C; Przegaliński, Edmund; Filip, Małgorzata; Biała, Grażyna

2012-01-01

The strong correlation between central histaminergic and cholinergic pathways on cognitive processes has been reported extensively. However, the role of histamine H(3) receptor mechanisms interacting with nicotinic mechanisms has not previously been extensively investigated. The current study was conducted to determine the interactions of nicotinic and histamine H(3) receptor systems with regard to learning and memory function using a modified elevated plus-maze test in mice. In this test, the latency for mice to move from the open arm to the enclosed arm (i.e., transfer latency) was used as an index of memory. We tested whether ABT-239 (4-(2-{2-[(2R)-2-methylpyrrolidinyl]ethyl}-benzofuran-5-yl), an H(3) receptor antagonist/inverse agonist, had influence on two different stages of memory, i.e., memory acquisition and consolidation (administered prior to or immediately after the first trial, respectively) and whether ABT-239 influenced nicotine-induced memory enhancement. Our results revealed that the acute administration of nicotine (0.035 and 0.175 mg/kg), but not of ABT-239 (0.1-3 mg/kg) reduced transfer latency in the acquisition and consolidation phases. In combination studies, concomitant administration of either ABT-239 (1 and 3 mg/kg) and nicotine (0.035 mg/kg), or ABT-239 (0.1 mg/kg) and nicotine (0.0175 mg/kg) further increased nicotine-induced improvement in both memory acquisition and consolidation. The present data confirm an important role for H(3) receptors in regulating nicotine-induced mnemonic effects since inhibition of H(3) receptors augmented nicotine-induced memory enhancement in mice.

Nicotine-like effects of the neonicotinoid insecticides acetamiprid and imidacloprid on cerebellar neurons from neonatal rats.

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Junko Kimura-Kuroda

Full Text Available Acetamiprid (ACE and imidacloprid (IMI belong to a new, widely used class of pesticide, the neonicotinoids. With similar chemical structures to nicotine, neonicotinoids also share agonist activity at nicotinic acetylcholine receptors (nAChRs. Although their toxicities against insects are well established, their precise effects on mammalian nAChRs remain to be elucidated. Because of the importance of nAChRs for mammalian brain function, especially brain development, detailed investigation of the neonicotinoids is needed to protect the health of human children. We aimed to determine the effects of neonicotinoids on the nAChRs of developing mammalian neurons and compare their effects with nicotine, a neurotoxin of brain development.Primary cultures of cerebellar neurons from neonatal rats allow for examinations of the developmental neurotoxicity of chemicals because the various stages of neurodevelopment-including proliferation, migration, differentiation, and morphological and functional maturation-can be observed in vitro. Using these cultures, an excitatory Ca(2+-influx assay was employed as an indicator of neural physiological activity. Significant excitatory Ca(2+ influxes were evoked by ACE, IMI, and nicotine at concentrations greater than 1 µM in small neurons in cerebellar cultures that expressed the mRNA of the α3, α4, and α7 nAChR subunits. The firing patterns, proportion of excited neurons, and peak excitatory Ca(2+ influxes induced by ACE and IMI showed differences from those induced by nicotine. However, ACE and IMI had greater effects on mammalian neurons than those previously reported in binding assay studies. Furthermore, the effects of the neonicotinoids were significantly inhibited by the nAChR antagonists mecamylamine, α-bungarotoxin, and dihydro-β-erythroidine.This study is the first to show that ACE, IMI, and nicotine exert similar excitatory effects on mammalian nAChRs at concentrations greater than 1 µM. Therefore, the

Solid-phase synthesis and pharmacological evaluation of analogues of PhTX-12-A potent and selective nicotinic acetylcholine receptor antagonist

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Strømgaard, Kristian; Mellor, Ian R; Andersen, Kim

2002-01-01

Philanthotoxin-12 (PhTX-12) is a novel potent and selective, noncompetitive antagonist of nicotinic acetylcholine receptors (nAChRs). Homologues of PhTX-12 with 7-11 methylene groups between the primary amino group and the aromatic head-group were synthesized using solid-phase methodology. In vitro...

Prenatal nicotinic exposure upregulates pulmonary C-fiber NK1R expression to prolong pulmonary C-fiber-mediated apneic response

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Zhao, Lei; Zhuang, Jianguo; Zang, Na; Lin, Yong [Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, NM (United States); Lee, Lu-Yuan [Department of Physiology, University of Kentucky, Lexington, KY (United States); Xu, Fadi, E-mail: fxu@lrri.org [Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, NM (United States); Department of Physiology, University of Kentucky, Lexington, KY (United States)

2016-01-01

Prenatal nicotinic exposure (PNE) prolongs bronchopulmonary C-fiber (PCF)-mediated apneic response to intra-atrial bolus injection of capsaicin in rat pups. The relevant mechanisms remain unclear. Pulmonary substance P and adenosine and their receptors (neurokinin-A receptor, NK1R and ADA{sub 1} receptor, ADA{sub 1}R) and transient receptor potential cation channel subfamily V member 1 (TRPV1) expressed on PCFs are critical for PCF sensitization and/or activation. Here, we compared substance P and adenosine in BALF and NK1R, ADA{sub 1}R, and TRPV1 expression in the nodose/jugular (N/J) ganglia (vagal pulmonary C-neurons retrogradely labeled) between Ctrl and PNE pups. We found that PNE failed to change BALF substance P and adenosine content, but significantly upregulated both mRNA and protein TRPV1 and NK1R in the N/J ganglia and only NK1R mRNA in pulmonary C-neurons. To define the role of NK1R in the PNE-induced PCF sensitization, the apneic response to capsaicin (i.v.) without or with pretreatment of SR140333 (a peripheral and selective NK1R antagonist) was compared and the prolonged apnea by PNE significantly shortened by SR140333. To clarify if the PNE-evoked responses depended on action of nicotinic acetylcholine receptors (nAChRs), particularly α7nAChR, mecamylamine or methyllycaconitine (a general nAChR or a selective α7nAChR antagonist) was administrated via another mini-pump over the PNE period. Mecamylamine or methyllycaconitine eliminated the PNE-evoked mRNA and protein responses. Our data suggest that PNE is able to elevate PCF NK1R expression via activation of nAChRs, especially α7nAChR, which likely contributes to sensitize PCFs and prolong the PCF-mediated apneic response to capsaicin. - Highlights: • PNE upregulated NK1R and TRPV1 gene and protein expression in the N/J ganglia. • PNE only elevated NK1R mRNA in vagal pulmonary C-neurons. • Blockage of peripheral NK1R reduced the PNE-induced PCF sensitization. • PNE induced gene and protein

T-type calcium channel antagonism decreases motivation for nicotine and blocks nicotine- and cue-induced reinstatement for a response previously reinforced with nicotine.

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Uslaner, Jason M; Vardigan, Joshua D; Drott, Jason M; Uebele, Victor N; Renger, John J; Lee, Ariel; Li, Zhaoxia; Lê, A D; Hutson, Pete H

2010-10-15

Recent evidence suggests an involvement of T-type calcium channels in the effects of drugs of abuse. We examined the influence of the novel, potent, and selective T-type calcium channel antagonist [2-(4-cyclopropylphenyl)-N-((1R)-1-{5-[2,2,2-trifluoroethyl]oxo}pyridine-2-yl)ethyl]acetamide] (TTA-A2) (.3, 1, or 3 mg/kg) on motivation for nicotine, as measured by nicotine self-administration on a progressive ratio (PR) schedule, and nicotine- and cue-induced reinstatement for a response previously reinforced with nicotine delivery (n = 11 or 12 Long Evans rats/group). Furthermore, we examined the specificity of the TTA-A2 effects by characterizing its influence on PR responding for food (in the absence or presence of nicotine-potentiated responding), food- versus nicotine-induced cue-potentiated reinstatement for a response previously reinforced by food administration (n = 11 or 12 Wistar Hannover rats/group), and its ability to induce a conditioned place aversion. TTA-A2 dose-dependently decreased self-administration of nicotine on a PR schedule and the ability of both nicotine and a cue paired with nicotine to reinstate responding. The effects were specific for nicotine's incentive motivational properties, as TTA-A2 did not influence responding for food on a PR schedule but did attenuate the ability of nicotine to potentiate responding for food. Likewise, TTA-A2 did not alter food-induced cue-potentiated reinstatement for a response previously reinforced by food but did decrease nicotine-induced cue-potentiated reinstatement. Finally, TTA-A2 did not produce an aversive state, as indicated by a lack of ability to induce conditioned place aversion. These data suggest that T-type calcium channel antagonists have potential for alleviating nicotine addiction by selectively decreasing the incentive motivational properties of nicotine. Copyright © 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

The effects of nicotine in the neonatal quinpirole rodent model of psychosis: Neural plasticity mechanisms and nicotinic receptor changes.

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Peterson, Daniel J; Gill, W Drew; Dose, John M; Hoover, Donald B; Pauly, James R; Cummins, Elizabeth D; Burgess, Katherine C; Brown, Russell W

2017-05-15

Neonatal quinpirole (NQ) treatment to rats increases dopamine D2 receptor sensitivity persistent throughout the animal's lifetime. In Experiment 1, we analyzed the role of α7 and α4β2 nicotinic receptors (nAChRs) in nicotine behavioral sensitization and on the brain-derived neurotrophic factor (BDNF) response to nicotine in NQ- and neonatally saline (NS)-treated rats. In Experiment 2, we analyzed changes in α7 and α4β2 nAChR density in the nucleus accumbens (NAcc) and dorsal striatum in NQ and NS animals sensitized to nicotine. Male and female Sprague-Dawley rats were neonatally treated with quinpirole (1mg/kg) or saline from postnatal days (P)1-21. Animals were given ip injections of either saline or nicotine (0.5mg/kg free base) every second day from P33 to P49 and tested on behavioral sensitization. Before each injection, animals were ip administered the α7 nAChR antagonist methyllycaconitine (MLA; 2 or 4mg/kg) or the α4β2 nAChR antagonist dihydro beta erythroidine (DhβE; 1 or 3mg/kg). Results revealed NQ enhanced nicotine sensitization that was blocked by DhβE. MLA blocked the enhanced nicotine sensitization in NQ animals, but did not block nicotine sensitization. NQ enhanced the NAcc BDNF response to nicotine which was blocked by both antagonists. In Experiment 2, NQ enhanced nicotine sensitization and enhanced α4β2, but not α7, nAChR upregulation in the NAcc. These results suggest a relationship between accumbal BDNF and α4β2 nAChRs and their role in the behavioral response to nicotine in the NQ model which has relevance to schizophrenia, a behavioral disorder with high rates of tobacco smoking. Copyright © 2017. Published by Elsevier B.V.

Dual Nicotinic Acetylcholine Receptor α4β2 Antagonists/α7 Agonists: Synthesis, Docking Studies, and Pharmacological Evaluation of Tetrahydroisoquinolines and Tetrahydroisoquinolinium Salts

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Crestey, François; Jensen, Anders A; Soerensen, Christian

2018-01-01

We describe the synthesis of tetrahydroisoquinolines and tetrahydroisoquinolinium salts together with their pharmacological properties at various nicotinic acetylcholine receptors. In general, the compounds were α4β2 nAChR antagonists, with the tetrahydroisoquinolinium salts being more potent than...

Monepantel is a non-competitive antagonist of nicotinic acetylcholine receptors from Ascaris suum and Oesophagostomum dentatum

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Melanie Abongwa

2018-04-01

Full Text Available Zolvix® is a recently introduced anthelmintic drench containing monepantel as the active ingredient. Monepantel is a positive allosteric modulator of DEG-3/DES-2 type nicotinic acetylcholine receptors (nAChRs in several nematode species. The drug has been reported to produce hypercontraction of Caenorhabditis elegans and Haemonchus contortus somatic muscle. We investigated the effects of monepantel on nAChRs from Ascaris suum and Oesophagostomum dentatum heterologously expressed in Xenopus laevis oocytes. Using two-electrode voltage-clamp electrophysiology, we studied the effects of monepantel on a nicotine preferring homomeric nAChR subtype from A. suum comprising of ACR-16; a pyrantel/tribendimidine preferring heteromeric subtype from O. dentatum comprising UNC-29, UNC-38 and UNC-63 subunits; and a levamisole preferring subtype (O. dentatum comprising UNC-29, UNC-38, UNC-63 and ACR-8 subunits. For each subtype tested, monepantel applied in isolation produced no measurable currents thereby ruling out an agonist action. When monepantel was continuously applied, it reduced the amplitude of acetylcholine induced currents in a concentration-dependent manner. In all three subtypes, monepantel acted as a non-competitive antagonist on the expressed receptors. ACR-16 from A. suum was particularly sensitive to monepantel inhibition (IC50 values: 1.6 ± 3.1 nM and 0.2 ± 2.3 μM. We also investigated the effects of monepantel on muscle flaps isolated from adult A. suum. The drug did not significantly increase baseline tension when applied on its own. As with acetylcholine induced currents in the heterologously expressed receptors, contractions induced by acetylcholine were antagonized by monepantel. Further investigation revealed that the inhibition was a mixture of competitive and non-competitive antagonism. Our findings suggest that monepantel is active on multiple nAChR subtypes. Keywords: Monepantel, Zolvix®, Nicotinic acetylcholine

Delivery of nicotine aerosol to mice via a modified electronic cigarette device.

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Lefever, Timothy W; Lee, Youn O K; Kovach, Alexander L; Silinski, Melanie A R; Marusich, Julie A; Thomas, Brian F; Wiley, Jenny L

2017-03-01

Although both men and women use e-cigarettes, most preclinical nicotine research has focused on its effects in male rodents following injection. The goals of the present study were to develop an effective e-cigarette nicotine delivery system, to compare results to those obtained after subcutaneous (s.c.) injection, and to examine sex differences in the model. Hypothermia and locomotor suppression were assessed following aerosol exposure or s.c. injection with nicotine in female and male mice. Subsequently, plasma and brain concentrations of nicotine and cotinine were measured. Passive exposure to nicotine aerosol produced concentration-dependent and mecamylamine reversible hypothermic and locomotor suppressant effects in female and male mice, as did s.c. nicotine injection. In plasma and brain, nicotine and cotinine concentrations showed dose/concentration-dependent increases in both sexes following each route of administration. Sex differences in nicotine-induced hypothermia were dependent upon route of administration, with females showing greater hypothermia following aerosol exposure and males showing greater hypothermia following injection. In contrast, when they occurred, sex differences in nicotine and cotinine levels in brain and plasma consistently showed greater concentrations in females than males, regardless of route of administration. In summary, the e-cigarette exposure device described herein was used successfully to deliver pharmacologically active doses of nicotine to female and male mice. Further, plasma nicotine concentrations following exposure were similar to those after s.c. injection with nicotine and within the range observed in human smokers. Future research on vaped products can be strengthened by inclusion of translationally relevant routes of administration. Copyright © 2017 Elsevier B.V. All rights reserved.

Exploring the binding energy profiles of full agonists, partial agonists, and antagonists of the α7 nicotinic acetylcholine receptor.

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Tabassum, Nargis; Ma, Qianyun; Wu, Guanzhao; Jiang, Tao; Yu, Rilei

2017-09-01

Nicotinic acetylcholine receptors (nAChRs) belong to the Cys-loop receptor family and are important drug targets for the treatment of neurological diseases. However, the precise determinants of the binding efficacies of ligands for these receptors are unclear. Therefore, in this study, the binding energy profiles of various ligands (full agonists, partial agonists, and antagonists) were quantified by docking those ligands with structural ensembles of the α7 nAChR exhibiting different degrees of C-loop closure. This approximate treatment of interactions suggested that full agonists, partial agonists, and antagonists of the α7 nAChR possess distinctive binding energy profiles. Results from docking revealed that ligand binding efficacy may be related to the capacity of the ligand to stabilize conformational states with a closed C loop.

Effects of chronic mild stress on the development of drug dependence in rats.

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Papp, Mariusz; Gruca, Piotr; Lason-Tyburkiewicz, Magdalena; Litwa, Ewa; Willner, Paul

2014-09-01

There is high comorbidity between depression and addiction. Features of addiction relevant to depression have been studied extensively, but less is known about features of depression relevant to addiction. Here, we have studied the effects of chronic mild stress (CMS), a valid animal model of depression, on measures of physical and psychological dependence resulting from subchronic treatment of rats with three drugs of abuse that act through disparate neurobiological mechanisms: morphine, nicotine and diazepam. In animals not treated subchronically with drugs of abuse, CMS increased the withdrawal-like effects of the opiate antagonist naloxone, but not those of the nicotinic antagonist mecamylamine or the benzodiazepine antagonist flumazenil. In animals treated subchronically with drugs of abuse, CMS exacerbated, precipitated and conditioned withdrawal effects associated with all three antagonists. CMS also potentiated withdrawal-induced and cue-induced place aversions associated with all three antagonists. All of the effects of CMS were reversed by chronic treatment with the specific serotonin reuptake inhibitor citalopram. These results suggest that treatment of comorbid depression, although not a primary treatment for addiction, may facilitate other treatments for addiction, by decreasing the severity of withdrawal symptoms and the likelihood of relapse.

Nicotine Prevents and Reverses Paclitaxel-Induced Mechanical Allodynia in a Mouse Model of CIPN.

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Kyte, S Lauren; Toma, Wisam; Bagdas, Deniz; Meade, Julie A; Schurman, Lesley D; Lichtman, Aron H; Chen, Zhi-Jian; Del Fabbro, Egidio; Fang, Xianjun; Bigbee, John W; Damaj, M Imad; Gewirtz, David A

2018-01-01

Chemotherapy-induced peripheral neuropathy (CIPN), a consequence of peripheral nerve fiber dysfunction or degeneration, continues to be a dose-limiting and debilitating side effect during and/or after cancer chemotherapy. Paclitaxel, a taxane commonly used to treat breast, lung, and ovarian cancers, causes CIPN in 59-78% of cancer patients. Novel interventions are needed due to the current lack of effective CIPN treatments. Our studies were designed to investigate whether nicotine can prevent and/or reverse paclitaxel-induced peripheral neuropathy in a mouse model of CIPN, while ensuring that nicotine will not stimulate lung tumor cell proliferation or interfere with the antitumor properties of paclitaxel. Male C57BL/6J mice received paclitaxel every other day for a total of four injections (8 mg/kg, i.p.). Acute (0.3-0.9 mg/kg, i.p.) and chronic (24 mg/kg per day, s.c.) administration of nicotine respectively reversed and prevented paclitaxel-induced mechanical allodynia. Blockade of the antinociceptive effect of nicotine with mecamylamine and methyllycaconitine suggests that the reversal of paclitaxel-induced mechanical allodynia is primarily mediated by the α 7 nicotinic acetylcholine receptor subtype. Chronic nicotine treatment also prevented paclitaxel-induced intraepidermal nerve fiber loss. Notably, nicotine neither promoted proliferation of A549 and H460 non-small cell lung cancer cells nor interfered with paclitaxel-induced antitumor effects, including apoptosis. Most importantly, chronic nicotine administration did not enhance Lewis lung carcinoma tumor growth in C57BL/6J mice. These data suggest that the nicotinic acetylcholine receptor-mediated pathways may be promising drug targets for the prevention and treatment of CIPN. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Cholinergic pairing with visual activation results in long-term enhancement of visual evoked potentials.

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Jun Il Kang

Full Text Available Acetylcholine (ACh contributes to learning processes by modulating cortical plasticity in terms of intensity of neuronal activity and selectivity properties of cortical neurons. However, it is not known if ACh induces long term effects within the primary visual cortex (V1 that could sustain visual learning mechanisms. In the present study we analyzed visual evoked potentials (VEPs in V1 of rats during a 4-8 h period after coupling visual stimulation to an intracortical injection of ACh analog carbachol or stimulation of basal forebrain. To clarify the action of ACh on VEP activity in V1, we individually pre-injected muscarinic (scopolamine, nicotinic (mecamylamine, alpha7 (methyllycaconitine, and NMDA (CPP receptor antagonists before carbachol infusion. Stimulation of the cholinergic system paired with visual stimulation significantly increased VEP amplitude (56% during a 6 h period. Pre-treatment with scopolamine, mecamylamine and CPP completely abolished this long-term enhancement, while alpha7 inhibition induced an instant increase of VEP amplitude. This suggests a role of ACh in facilitating visual stimuli responsiveness through mechanisms comparable to LTP which involve nicotinic and muscarinic receptors with an interaction of NMDA transmission in the visual cortex.

Nicotine promotes cell proliferation via α7-nicotinic acetylcholine receptor and catecholamine-synthesizing enzymes-mediated pathway in human colon adenocarcinoma HT-29 cells

International Nuclear Information System (INIS)

Wong, Helen Pui Shan; Yu Le; Lam, Emily Kai Yee; Tai, Emily Kin Ki; Wu, William Ka Kei; Cho, Chi Hin

2007-01-01

Cigarette smoking has been implicated in colon cancer. Nicotine is a major alkaloid in cigarette smoke. In the present study, we showed that nicotine stimulated HT-29 cell proliferation and adrenaline production in a dose-dependent manner. The stimulatory action of nicotine was reversed by atenolol and ICI 118,551, a β 1 - and β 2 -selective antagonist, respectively, suggesting the role of β-adrenoceptors in mediating the action. Nicotine also significantly upregulated the expression of the catecholamine-synthesizing enzymes [tyrosine hydroxylase (TH), dopamine-β-hydroxylase (DβH) and phenylethanolamine N-methyltransferase]. Inhibitor of TH, a rate-limiting enzyme in the catecholamine-biosynthesis pathway, reduced the actions of nicotine on cell proliferation and adrenaline production. Expression of α7-nicotinic acetylcholine receptor (α7-nAChR) was demonstrated in HT-29 cells. Methyllycaconitine, an α7-nAChR antagonist, reversed the stimulatory actions of nicotine on cell proliferation, TH and DβH expression as well as adrenaline production. Taken together, through the action on α7-nAChR nicotine stimulates HT-29 cell proliferation via the upregulation of the catecholamine-synthesis pathway and ultimately adrenaline production and β-adrenergic activation. These data reveal the contributory role α7-nAChR and β-adrenoceptors in the tumorigenesis of colon cancer cells and partly elucidate the carcinogenic action of cigarette smoke on colon cancer

NMDA receptors regulate nicotine-enhanced brain reward function and intravenous nicotine self-administration: role of the ventral tegmental area and central nucleus of the amygdala.

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Kenny, Paul J; Chartoff, Elena; Roberto, Marisa; Carlezon, William A; Markou, Athina

2009-01-01

Nicotine is considered an important component of tobacco responsible for the smoking habit in humans. Nicotine increases glutamate-mediated transmission throughout brain reward circuitries. This action of nicotine could potentially contribute to its intrinsic rewarding and reward-enhancing properties, which motivate consumption of the drug. Here we show that the competitive N-methyl-D-aspartate (NMDA) receptor antagonist LY235959 (0.5-2.5 mg per kg) abolished nicotine-enhanced brain reward function, reflected in blockade of the lowering of intracranial self-stimulation (ICSS) thresholds usually observed after experimenter-administered (0.25 mg per kg) or intravenously self-administered (0.03 mg per kg per infusion) nicotine injections. The highest LY235959 dose (5 mg per kg) tested reversed the hedonic valence of nicotine from positive to negative, reflected in nicotine-induced elevations of ICSS thresholds. LY235959 doses that reversed nicotine-induced lowering of ICSS thresholds also markedly decreased nicotine self-administration without altering responding for food reinforcement, whereas the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor antagonist NBQX had no effects on nicotine intake. In addition, nicotine self-administration upregulated NMDA receptor subunit expression in the central nucleus of the amygdala (CeA) and ventral tegmental area (VTA), suggesting important interactions between nicotine and the NMDA receptor. Furthermore, nicotine (1 microM) increased NMDA receptor-mediated excitatory postsynaptic currents in rat CeA slices, similar to its previously described effects in the VTA. Finally, infusion of LY235959 (0.1-10 ng per side) into the CeA or VTA decreased nicotine self-administration. Taken together, these data suggest that NMDA receptors, including those in the CeA and VTA, gate the magnitude and valence of the effects of nicotine on brain reward systems, thereby regulating motivation to consume the drug.

Electrophysiological characterization of harmane-induced activation of mesolimbic dopamine neurons.

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Arib, Ouafa; Rat, Pascal; Molimard, Robert; Chait, Abderrahman; Faure, Philippe; de Beaurepaire, Renaud

2010-03-10

It has been suggested that the beta-carbolines harmane and norharmane may be involved in the pathophysiology of Parkinson's disease, psychosis and addiction, but the mechanisms of these possible effects remain to be elucidated. In the present study, the effects of the two compounds were examined by using in vivo extracellular recordings of ventral tegmental dopamine neurons. The effects of harmane (2mg/kg) and norharmane (2mg/kg), were compared to those of nicotine (11microg/kg), of cotinine (0.5mg/kg), of the monoamine-oxidase-A inhibitor befloxatone (0.12mg/kg), and of the monoamine-oxidase-B inhibitor selegiline (0.5mg/kg). The effects of harmane were also tested after pre-treatment with the nicotine receptor antagonist mecamylamine. The results show that all substances, except befloxatone, activate the firing and/or burst activity of dopamine neurons. The increase in firing rate produced by harmane was approximately 18 times greater than that produced by nicotine. Such powerful excitation of dopamine neurons by harmane may in part explain its involvement in neurotoxicity, psychosis and addiction. The absence of effect of befloxatone supports the hypothesis that the effect of harmane is not related to its monoamine-oxidase-A inhibitory properties. Mecamylamine inhibited by approximately 80% the activity of harmane, indicating that the activating effect of harmane on dopamine neurons involves several mechanisms, among which activation of nicotinic receptors likely has a prominent importance. The results of the present study support the hypothesis that harmane could be a tobacco (or smoke) component other than nicotine involved in tobacco dependence. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Role of adenosine A2A receptor signaling in the nicotine-evoked attenuation of reflex cardiac sympathetic control

International Nuclear Information System (INIS)

El-Mas, Mahmoud M.; El-gowilly, Sahar M.; Fouda, Mohamed A.; Saad, Evan I.

2011-01-01

Baroreflex dysfunction contributes to increased cardiovascular risk in cigarette smokers. Given the importance of adenosinergic pathways in baroreflex control, the hypothesis was tested that defective central adenosinergic modulation of cardiac autonomic activity mediates the nicotine-baroreflex interaction. Baroreflex curves relating changes in heart rate (HR) to increases or decreases in blood pressure (BP) evoked by i.v. doses (1-16 μg/kg) of phenylephrine (PE) and sodium nitroprusside (SNP), respectively, were constructed in conscious rats; slopes of the curves were taken as measures of baroreflex sensitivity (BRS). Nicotine (25 and 100 μg/kg i.v.) dose-dependently reduced BRS SNP in contrast to no effect on BRS PE . BRS SNP was also attenuated after intracisternal (i.c.) administration of nicotine. Similar reductions in BRS SNP were observed in rats pretreated with atropine or propranolol. The combined treatment with nicotine and atropine produced additive inhibitory effects on BRS, an effect that was not demonstrated upon concurrent exposure to nicotine and propranolol. BRS SNP was reduced in preparations treated with i.c. 8-phenyltheophylline (8-PT, nonselective adenosine receptor antagonist), 8-(3-Chlorostyryl) caffeine (CSC, A 2A antagonist), or VUF5574 (A 3 antagonist). In contrast, BRS SNP was preserved after blockade of A 1 (DPCPX) or A 2B (alloxazine) receptors or inhibition of adenosine uptake by dipyridamole. CSC or 8-PT abrogated the BRS SNP depressant effect of nicotine whereas other adenosinergic antagonists were without effect. Together, nicotine preferentially impairs reflex tachycardia via disruption of adenosine A 2A receptor-mediated facilitation of reflex cardiac sympathoexcitation. Clinically, the attenuation by nicotine of compensatory sympathoexcitation may be detrimental in conditions such as hypothalamic defense response, posture changes, and ventricular rhythms. - Research highlights: → The role of central adenosinergic sites in

Nicotine Receptor Subtype-Specific Effects on Auditory Evoked Oscillations and Potentials

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Featherstone, Robert E.; Phillips, Jennifer M.; Thieu, Tony; Ehrlichman, Richard S.; Halene, Tobias B.; Leiser, Steven C.; Christian, Edward; Johnson, Edwin; Lerman, Caryn; Siegel, Steven J.

2012-01-01

Background Individuals with schizophrenia show increased smoking rates which may be due to a beneficial effect of nicotine on cognition and information processing. Decreased amplitude of the P50 and N100 auditory event-related potentials (ERPs) is observed in patients. Both measures show normalization following administration of nicotine. Recent studies identified an association between deficits in auditory evoked gamma oscillations and impaired information processing in schizophrenia, and there is evidence that nicotine normalizes gamma oscillations. Although the role of nicotine receptor subtypes in augmentation of ERPs has received some attention, less is known about how these receptor subtypes regulate the effect of nicotine on evoked gamma activity. Methodology/Principal Findings We examined the effects of nicotine, the α7 nicotine receptor antagonist methyllycaconitine (MLA) the α4β4/α4β2 nicotine receptor antagonist dihydro-beta-erythroidine (DHβE), and the α4β2 agonist AZD3480 on P20 and N40 amplitude as well as baseline and event-related gamma oscillations in mice, using electrodes in hippocampal CA3. Nicotine increased P20 amplitude, while DHβE blocked nicotine-induced enhancements in P20 amplitude. Conversely, MLA did not alter P20 amplitude either when presented alone or with nicotine. Administration of the α4β2 specific agonist AZD3480 did not alter any aspect of P20 response, suggesting that DHβE blocks the effects of nicotine through a non-α4β2 receptor specific mechanism. Nicotine and AZD3480 reduced N40 amplitude, which was blocked by both DHβE and MLA. Finally, nicotine significantly increased event-related gamma, as did AZD3480, while DHβE but not MLA blocked the effect of nicotine on event-related gamma. Conclusions/Significance These results support findings showing that nicotine-induced augmentation of P20 amplitude occurs via a DHβE sensitive mechanism, but suggests that this does not occur through activation of α4β2

Differential Effects of Systemic Cholinergic Receptor Blockade on Pavlovian Incentive Motivation and Goal-Directed Action Selection

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Ostlund, Sean B; Kosheleff, Alisa R; Maidment, Nigel T

2014-01-01

Reward-seeking actions can be guided by external cues that signal reward availability. For instance, when confronted with a stimulus that signals sugar, rats will prefer an action that produces sugar over a second action that produces grain pellets. Action selection is also sensitive to changes in the incentive value of potential rewards. Thus, rats that have been prefed a large meal of sucrose will prefer a grain-seeking action to a sucrose-seeking action. The current study investigated the dependence of these different aspects of action selection on cholinergic transmission. Hungry rats were given differential training with two unique stimulus-outcome (S1-O1 and S2-O2) and action-outcome (A1-O1 and A2-O2) contingencies during separate training phases. Rats were then given a series of Pavlovian-to-instrumental transfer tests, an assay of cue-triggered responding. Before each test, rats were injected with scopolamine (0, 0.03, or 0.1 mg/kg, intraperitoneally), a muscarinic receptor antagonist, or mecamylamine (0, 0.75, or 2.25 mg/kg, intraperitoneally), a nicotinic receptor antagonist. Although the reward-paired cues were capable of biasing action selection when rats were tested off-drug, both anticholinergic treatments were effective in disrupting this effect. During a subsequent round of outcome devaluation testing—used to assess the sensitivity of action selection to a change in reward value—we found no effect of either scopolamine or mecamylamine. These results reveal that cholinergic signaling at both muscarinic and nicotinic receptors mediates action selection based on Pavlovian reward expectations, but is not critical for flexibly selecting actions using current reward values. PMID:24370780

Effects of pharmacological manipulation of the kappa opioid receptors on the aversive effects of nicotine.

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Ward, Melissa; Norman, Haval; D'Souza, Manoranjan S

2018-02-15

Nicotine, an addictive component of tobacco smoke, produces both rewarding and aversive effects. Increasing the aversive effects of nicotine may help in promoting smoking cessation. However, neural targets mediating the aversive effects of nicotine have not been fully identified. In this study, we evaluated the role of kappa opioid receptors (KORs) in the aversive effects of nicotine (0.4 mg/kg, base; s.c.) using the nicotine-induced conditioned taste aversion (CTA) model in Wistar rats. The KORs were activated using the selective KOR agonist (±)U-50,488H (0, 0.03, 0.15 & 0.3mg/kg; s.c.) and inhibited using the KOR antagonist nor-binaltorphimine (nor-BNI; 0, 15 & 30mg/kg; s.c.) in separate groups of rats using a between-subjects design. Pretreatment with the KOR agonist (±)U-50,488H (0.3mg/kg) significantly increased aversion for the nicotine-associated solution. Additionally, (±)U-50,488H (0.3mg/kg) on its own induced aversion to the flavored solution associated with it even in the absence of nicotine, suggesting that the KOR agonist induced increase in nicotine-induced aversion was an additive effect. Interestingly, administration of the KOR antagonist nor-BNI (30mg/kg) prior to conditioning with nicotine/saline, but not after conditioning with nicotine/saline, attenuated nicotine-induced aversive effects compared to saline controls. Taken together, these data suggest a role for KORs in the aversive effects of nicotine. Copyright © 2017 Elsevier B.V. All rights reserved.

Intraportal nicotine infusion in rats decreases hepatic blood flow through endothelin-1 and both endothelin A and endothelin B receptors

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Hashimoto, Takashi; Yoneda, Masashi; Shimada, Tadahito; Kurosawa, Mieko; Terano, Akira

2004-01-01

Smoking has been demonstrated to aggravate liver injury. Nicotine, a major pharmacological component of tobacco smoke, affects a multitude of functions. Smoking and nicotine induce synthesis of endothelin (ET)-1. The effect of intraportal infusion of nicotine on hepatic circulation and an involvement of ET-1 and ET receptor in the action of nicotine were investigated in rats. Nicotine (0-100 μg/kg/h) was infused into the portal vein of urethane-anesthetized rats, and changes of hepatic blood flow were evaluated. Intraportal infusion of nicotine dose-dependently decreased hepatic blood flow and increased portal pressure without any alteration of heart rate or arterial blood pressure. This action of intraportal nicotine was completely abolished by pretreatment of ET-1 antibody. Either BQ485 (ET A receptor antagonist) or BQ788 (ET B receptor antagonist) partially reversed the effect of nicotine, and combination of BQ788 and BQ485 completely abolished it. These findings suggest that nicotine inhibits hepatic circulation through ET-1, and ET A and ET B receptor

The Nicotinic Acetylcholine Receptor as a Target for Antidepressant Drug Development

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Noah S. Philip

2012-01-01

Full Text Available An important new area of antidepressant drug development involves targeting the nicotinic acetylcholine receptor (nAChR. This receptor, which is distributed widely in regions of the brain associated with depression, is also implicated in other important processes that are relevant to depression, such as stress and inflammation. The two classes of drugs that target nAChRs can be broadly divided into mecamylamine- and cytisine-based compounds. These drugs probably exert their effects via antagonism at α4β2 nAChRs, and strong preclinical data support the antidepressant efficacy of both classes when used in conjunction with other primary antidepressants (e.g., monoamine reuptake inhibitors. Although clinical data remain limited, preliminary results in this area constitute a compelling argument for further evaluation of the nAChR as a target for future antidepressant drug development.

[3H]cytisine binding to nicotinic cholinergic receptors in brain

International Nuclear Information System (INIS)

Pabreza, L.A.; Dhawan, S.; Kellar, K.J.

1991-01-01

Cytisine, a ganglionic agonist, competes with high affinity for brain nicotinic cholinergic receptors labeled by any of several nicotinic 3 H-agonist ligands. Here we have examined the binding of [ 3 H]cytisine in rat brain homogenates. [ 3 H]Cytisine binds with high affinity (Kd less than 1 nM), and specific binding represented 60-90% of total binding at all concentrations examined up to 15 nM. The nicotinic cholinergic agonists nicotine, acetylcholine, and carbachol compete with high affinity for [ 3 H]cytisine binding sites, whereas among nicotinic receptor antagonists only dihydro-beta-erythroidine competes with high affinity (in the nanomolar range). Comparison of binding in several brain regions showed that [ 3 H]cytisine binding is higher in the thalamus, striatum, and cortex than in the hippocampus, cerebellum, or hypothalamus. The pharmacology and brain regional distribution of [ 3 H]cytisine binding sites are those predicted for neuronal nicotinic receptor agonist recognition sites. The high affinity and low nonspecific binding of [ 3 H]cytisine should make it a very useful ligand for studying neuronal nicotinic receptors

Nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone induce cyclooxygenase-2 activity in human gastric cancer cells: Involvement of nicotinic acetylcholine receptor (nAChR) and β-adrenergic receptor signaling pathways

International Nuclear Information System (INIS)

Shin, Vivian Yvonne; Jin, H.C.; Ng, Enders K.O.; Yu Jun; Leung, W.K.; Cho, C.H.; Sung, J.J.Y.

2008-01-01

Induction of cyclooxygenase-2 (COX-2) associates with cigarette smoke exposure in many malignancies. Nicotine and its derivative, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), are the two important components in cigarette smoke that contributes to cancer development. However, the molecular mechanism(s) by which nicotine or NNK promotes gastric carcinogenesis remains largely unknown. We found that nicotine and NNK significantly enhanced cell proliferation in AGS cells that expressed both alpha7 nicotinic acetylcholine receptor (α7 nAChR) and β-adrenergic receptors. Treatment of cells with α-bungarotoxin (α-BTX, α7nAChR antagonist) or propranolol (β-adrenergic receptor antagonist) blocked NNK-induced COX-2/PGE 2 and cell proliferation, while nicotine-mediated cell growth and COX-2/PGE 2 induction can only be suppressed by propranolol, but not α-BTX. Moreover, in contrast to the dependence of growth promoting effect of nicotine on Erk activation, inhibitor of p38 mitogen-activated protein kinase (MAPK) repressed NNK-induced COX-2 upregulation and resulted in suppression of cell growth. In addition, nicotine and NNK mediated COX-2 induction via different receptors to modulate several G1/S transition regulatory proteins and promote gastric cancer cell growth. Selective COX-2 inhibitor (SC-236) caused G1 arrest and abrogated nicotine/NNK-induced cell proliferation. Aberrant expression of cyclin D1 and other G1 regulatory proteins are reversed by blockade of COX-2. These results pointed to the importance of adrenergic and nicotinic receptors in gastric tumor growth through MAPK/COX-2 activation, which may perhaps provide a chemoprevention strategy for cigarette smoke-related gastric carcinogenesis

Glucose attenuates impairments in memory and CREB activation produced by an α4β2 but not an α7 nicotinic receptor antagonist.

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Morris, Ken A; Li, Sisi; Bui, Duat D; Gold, Paul E

2013-04-01

Glucose improves memory for a variety of tasks when administered to rats and mice near the time of training. Prior work indicates glucose may enhance memory by increasing the synthesis and release of the neurotransmitter acetylcholine in the brain. To investigate if specific acetylcholine receptor subtypes may mediate some of the memory-enhancing actions of glucose, we examined the effects of subtype-specific nicotinic acetylcholine receptor antagonists on memory in Fischer-344 rats and also examined the ability of glucose to reverse drug-induced impairments. Pre-training peripheral injections of methyllycaconitine (MLA) or dihydro-beta-erythroidine (DHβE), which are specific α7 and α4β2 nicotinic receptor antagonists, respectively, dose-dependently impaired retention latencies in an inhibitory avoidance task when tested 7-days but not 1 h after training. Immediate post-training glucose injections attenuated the impairments, but were more effective in attenuating the DHβE-induced impairments. Likewise, peripheral or direct intrahippocampal injections of MLA or DHβE dose-dependently impaired spatial working memory scores on a spontaneous alternation task. Concurrent administration of glucose reversed DHβE- but not MLA-induced impairments. CREB phosphorylation downstream of cholinergic signaling was assessed 30 min after spontaneous alternation testing and intrahippocampal drug infusions. Both MLA and DHβE impaired hippocampal CREB phosphorylation; glucose reversed DHβE- but not MLA-induced deficits. The effectiveness of glucose in reversing DHβE- but not MLA-induced impairments in behavioral performance and CREB phosphorylation suggests that activation of α7 receptors may play an important role in memory enhancement by glucose. Copyright © 2012 Elsevier Ltd. All rights reserved.

In vivo interactions between α7 nicotinic acetylcholine receptor and nuclear peroxisome proliferator-activated receptor-α: Implication for nicotine dependence.

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Jackson, Asti; Bagdas, Deniz; Muldoon, Pretal P; Lichtman, Aron H; Carroll, F Ivy; Greenwald, Mark; Miles, Michael F; Damaj, M Imad

2017-05-15

Chronic tobacco use dramatically increases health burdens and financial costs. Limitations of current smoking cessation therapies indicate the need for improved molecular targets. The main addictive component of tobacco, nicotine, exerts its dependency effects via nicotinic acetylcholine receptors (nAChRs). Activation of the homomeric α7 nAChR reduces nicotine's rewarding properties in conditioned place preference (CPP) test and i.v. self-administration models, but the mechanism underlying these effects is unknown. Recently, the nuclear receptor peroxisome proliferator-activated receptor type-α (PPARα) has been implicated as a downstream signaling target of the α7 nAChR in ventral tegmental area dopamine cells. The present study investigated PPARα as a possible mediator of the effect of α7 nAChR activation in nicotine dependence. Our results demonstrate the PPARα antagonist GW6471 blocks actions of the α7 nAChR agonist PNU282987 on nicotine reward in an unbiased CPP test in male ICR adult mice. These findings suggests that α7 nAChR activation attenuates nicotine CPP in a PPARα-dependent manner. To evaluate PPARα activation in nicotine dependence we used the selective and potent PPARα agonist, WY-14643 and the clinically used PPARα activator, fenofibrate, in nicotine CPP and we observed attenuation of nicotine preference, but fenofibrate was less potent. We also studied PPARα in nicotine dependence by evaluating its activation in nicotine withdrawal. WY-14643 reversed nicotine withdrawal signs whereas fenofibrate had modest efficacy. This suggests that PPARα plays a role in nicotine reward and withdrawal and that further studies are warranted to elucidate its function in mediating the effects of α7 nAChRs in nicotine dependence. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of nicotinic receptor binding and biotransformation of coniine in the rat and chick.

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Forsyth, C S; Speth, R C; Wecker, L; Galey, F D; Frank, A A

1996-12-31

Coniine, an alkaloid from Conium maculatum (poison hemlock), is a known teratogen in many domestic species with maternal ingestion resulting in arthrogryposis of the offspring. We have previously shown that rats are not susceptible and rabbits only weakly susceptible to coniine-induced arthrogryposis. However, the chick embryo does provide a reproducible laboratory animal model of coniine-induced teratogenesis. The reason for this cross-species variation is unknown. The purpose of this study was to evaluate coniine binding to nicotinic receptors and to measure coniine metabolism in vitro between susceptible and non-susceptible species. Using the chick model, neither the peripheral nicotinic receptor antagonist d-tubocurarine chloride nor the central nicotinic receptor antagonist trimethaphan camsylate blocked the teratogenesis or lethality of 1.5% coniine (50 microliters/egg). Trimethaphan camsylate enhanced coniine-induced lethality in a dose-dependent manner. Neither nicotinic receptor blocker prevented nicotine sulfate-induced malformations but d-tubocurarine chloride did block lethality in a dose-dependent manner. Competition by coniine for [125I]-alpha-bungarotoxin to nicotinic receptors isolated from adult rat diaphragm and chick thigh muscle and competition by coniine for [3H]-cytisine to receptors from rat and chick brain were used to assess coniine binding to nicotinic receptors. The IC50 for coniine in rat diaphragm was 314 microM while that for chick leg muscle was 70 microM. For neuronal nicotinic receptors, the IC50s of coniine for maternal rat brain, fetal rat brain, and chick brain were 1100 microM, 820 microM, and 270 microM, respectively. There were no differences in coniine biotransformation in vitro by microsomes from rat or chick livers. Differences in apparent affinity of coniine for nicotinic receptors or differences in the quantity of the nicotinic receptor between the rat and chick may explain, in part, the differences in susceptibility of

Cholinergic innervation of the zebrafish olfactory bulb.

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Edwards, Jeffrey G; Greig, Ann; Sakata, Yoko; Elkin, Dimitry; Michel, William C

2007-10-20

A number of fish species receive forebrain cholinergic input but two recent reports failed to find evidence of cholinergic cell bodies or fibers in the olfactory bulbs (OBs) of zebrafish. In the current study we sought to confirm these findings by examining the OBs of adult zebrafish for choline acetyltransferase (ChAT) immunoreactivity. We observed a diffuse network of varicose ChAT-positive fibers associated with the nervus terminalis ganglion innervating the mitral cell/glomerular layer (MC/GL). The highest density of these fibers occurred in the anterior region of the bulb. The cellular targets of this cholinergic input were identified by exposing isolated OBs to acetylcholine receptor (AChR) agonists in the presence of agmatine (AGB), a cationic probe that permeates some active ion channels. Nicotine (50 microM) significantly increased the activity-dependent labeling of mitral cells and juxtaglomerular cells but not of tyrosine hydroxlase-positive dopaminergic neurons (TH(+) cells) compared to control preparations. The nAChR antagonist mecamylamine, an alpha7-nAChR subunit-specific antagonist, calcium-free artificial cerebrospinal fluid, or a cocktail of ionotropic glutamate receptor (iGluR) antagonists each blocked nicotine-stimulated labeling, suggesting that AGB does not enter the labeled neurons through activated nAChRs but rather through activated iGluRs following ACh-stimulated glutamate release. Deafferentation of OBs did not eliminate nicotine-stimulated labeling, suggesting that cholinergic input is primarily acting on bulbar neurons. These findings confirm the presence of a functioning cholinergic system in the zebrafish OB.

Nicotinic binding in rat brain: autoradiographic comparison of [3H]acetylcholine, [3H]nicotine, and [125I]-alpha-bungarotoxin

International Nuclear Information System (INIS)

Clarke, P.B.; Schwartz, R.D.; Paul, S.M.; Pert, C.B.; Pert, A.

1985-01-01

Three radioligands have been commonly used to label putative nicotinic cholinoceptors in the mammalian central nervous system: the agonists [ 3 H]nicotine and [ 3 H]acetylcholine ([ 3 H]ACh--in the presence of atropine to block muscarinic receptors), and the snake venom extract, [ 125 I]-alpha-bungarotoxin([ 125 I]BTX), which acts as a nicotinic antagonist at the neuromuscular junction. Binding studies employing brain homogenates indicate that the regional distributions of both [ 3 H]nicotine and [ 3 H]ACh differ from that of [ 125 I]BTX. The possible relationship between brain sites bound by [ 3 H]nicotine and [ 3 H]ACh has not been examined directly. The authors have used the technique of autoradiography to produce detailed maps of [ 3 H]nicotine, [ 3 H]ACh, and [ 125 I]BTX labeling; near-adjacent tissue sections were compared at many levels of the rat brain. The maps of high affinity agonist labeling are strikingly concordant, with highest densities in the interpeduncular nucleus, most thalamic nuclei, superior colliculus, medial habenula, presubiculum, cerebral cortex (layers I and III/IV), and the substantia nigra pars compacta/ventral tegmental area. The pattern of [ 125 I]BTX binding is strikingly different, the only notable overlap with agonist binding being the cerebral cortex (layer I) and superior colliculus. [ 125 I]BTX binding is also dense in the inferior colliculus, cerebral cortex (layer VI), hypothalamus, and hippocampus, but is virtually absent in thalamus. Various lines of evidence suggest that the high affinity agonist-binding sites in brain correspond to nicotinic cholinergic receptors similar to those found at autonomic ganglia; BTX-binding sites may also serve as receptors for nicotine and are possibly related to neuromuscular nicotinic cholinoceptors

The μ-opioid receptor gene and smoking initiation and nicotine dependence

Directory of Open Access Journals (Sweden)

Kendler Kenneth S

2006-08-01

Full Text Available Abstract The gene encoding the mu-opioid receptor (OPRM1 is reported to be associated with a range of substance dependence. Experiments in knockout mice indicate that the mu-opioid receptor may mediate reinforcing effects of nicotine. In humans, opioid antagonist naltrexone may reduce the reinforcing effects of tobacco smoking. Additionally, the OPRM1 gene is located in a region showing linkage to nicotine dependence. The OPRM1 is thus a plausible candidate gene for smoking behavior. To investigate whether OPRM1 contributes to the susceptibility of smoking initiation and nicotine dependence, we genotyped 11 SNPs in the gene for 688 Caucasian subjects of lifetime smokers and nonsmokers. Three SNPs showed nominal significance for smoking initiation and one reached significance for nicotine dependence. The global test for three-marker (rs9479757-rs2075572-rs10485057 haplotypes was significant for smoking initiation (p = 0.0022. The same three-marker haplotype test was marginal (p = 0.0514 for nicotine dependence. These results suggest that OPRM1 may be involved in smoking initiation and nicotine dependence.

Acetylcholine induces GABA release onto rod bipolar cells through heteromeric nicotinic receptors expressed in A17 amacrine cells.

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Elgueta, Claudio; Vielma, Alex H; Palacios, Adrian G; Schmachtenberg, Oliver

2015-01-01

Acetylcholine (ACh) is a major retinal neurotransmitter that modulates visual processing through a large repertoire of cholinergic receptors expressed on different retinal cell types. ACh is released from starburst amacrine cells (SACs) under scotopic conditions, but its effects on cells of the rod pathway have not been investigated. Using whole-cell patch clamp recordings in slices of rat retina, we found that ACh application triggers GABA release onto rod bipolar (RB) cells. GABA was released from A17 amacrine cells and activated postsynaptic GABAA and GABAC receptors in RB cells. The sensitivity of ACh-induced currents to nicotinic ACh receptor (nAChR) antagonists (TMPH ~ mecamylamine > erysodine > DhβE > MLA) together with the differential potency of specific agonists to mimic ACh responses (cytisine > RJR2403 ~ choline), suggest that A17 cells express heteromeric nAChRs containing the β4 subunit. Activation of nAChRs induced GABA release after Ca(2+) accumulation in A17 cell dendrites and varicosities mediated by L-type voltage-gated calcium channels (VGCCs) and intracellular Ca(2+) stores. Inhibition of acetylcholinesterase depolarized A17 cells and increased spontaneous inhibitory postsynaptic currents in RB cells, indicating that endogenous ACh enhances GABAergic inhibition of RB cells. Moreover, injection of neostigmine or cytisine reduced the b-wave of the scotopic flash electroretinogram (ERG), suggesting that cholinergic modulation of GABA release controls RB cell activity in vivo. These results describe a novel regulatory mechanism of RB cell inhibition and complement our understanding of the neuromodulatory control of retinal signal processing.

Neurobiological mechanisms involved in nicotine dependence and reward: participation of the endogenous opioid system

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Berrendero, Fernando; Robledo, Patricia; Trigo, José Manuel; Martín-García, Elena; Maldonado, Rafael

2010-01-01

Nicotine is the primary component of tobacco that maintains the smoking habit and develops addiction. The adaptive changes of nicotinic acetylcholine receptors produced by repeated exposure to nicotine play a crucial role in the establishment of dependence. However, other neurochemical systems also participate in the addictive effects of nicotine including glutamate, cannabinoids, GABA and opioids. This review will cover the involvement of these neurotransmitters in nicotine addictive properties, with a special emphasis on the endogenous opioid system. Thus, endogenous enkephalins and beta-endorphins acting on mu-opioid receptors are involved in nicotine rewarding effects, whereas opioid peptides derived from prodynorphin participate in nicotine aversive responses. An upregulation of mu-opioid receptors has been reported after chronic nicotine treatment that could counteract the development of nicotine tolerance, whereas the downregulation induced on kappa-opioid receptors seems to facilitate nicotine tolerance. Endogenous enkephalins acting on mu-opioid receptors also play a role in the development of physical dependence to nicotine. In agreement with these actions of the endogenous opioid system, the opioid antagonist naltrexone has shown to be effective for smoking cessation in certain subpopulations of smokers. PMID:20170672

New trends in the treatment of nicotine addiction.

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Sliwińska-Mossoń, Mariola; Zieleń, Iwona; Milnerowicz, Halina

2014-01-01

The aim of this study was to discuss the therapeutic substances used to treat nicotine addiction, not registered in Poland. This paper presents the results of the latest clinical trials and the possibility of their use in the treatment of nicotine addiction. The first two discussed drugs clonidine and nortriptyline are recommended by clinical practice guidelines AHRQ (Agency for Healthcare Research and Quality) as the substance of the second line in the fight against addiction. Nortriptyline belongs to tricyclic antidepressants. Its mechanism of action is the inhibition of the reuptake of norepinephrine. It is suggested as the antagonist of activity of nicotinic receptors. The results confirm its efficacy in the treatment of nicotine addiction, but many side effects limit its use. Clonidine acts presumably by inhibition of sympathetic hyperactivity characteristic of symptoms associated with nicotine rehab. The remaining compounds under discussion, such as: venlafaxine, fluoxetine, moclobemide and rimonabant, are not registered in any country with an indication to use in the treatment of nicotine addiction, however, due to the mechanism in which they act, the possibility of their use in the treatment of this disease is considered. The possibility of using anxiolytics such as: buspirone, diazepam, meprobamate and beta-blockers: metoprolol and oxprenolol is also considered in order to treat the anxiety appearing as one of the symptoms of abstinence. An interesting proposal to combat nicotine addiction are vaccines--NicVAX, CYT002-NicQb and TA-NIC. Currently, they are in clinical phase I and II of their development. Their operation would be based on the induction of specific antibodies that bind nicotine in the plasma, thus prevent it reaching the nicotinic receptors. Preliminary results confirm the possible positive effects in the prevention and treatment of nicotine addiction.

Nicotine inhibits potassium currents in Aplysia bag cell neurons

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White, Sean H.; Sturgeon, Raymond M.

2016-01-01

Acetylcholine and the archetypal cholinergic agonist, nicotine, are typically associated with the opening of ionotropic receptors. In the bag cell neurons, which govern the reproductive behavior of the marine snail, Aplysia californica, there are two cholinergic responses: a relatively large acetylcholine-induced current and a relatively small nicotine-induced current. Both currents are readily apparent at resting membrane potential and result from the opening of distinct ionotropic receptors. We now report a separate current response elicited by applying nicotine to cultured bag cell neurons under whole cell voltage-clamp. This current was ostensibly inward, best resolved at depolarized voltages, presented a noncooperative dose-response with a half-maximal concentration near 1.5 mM, and associated with a decrease in membrane conductance. The unique nicotine-evoked response was not altered by intracellular perfusion with the G protein blocker GDPβS or exposure to classical nicotinic antagonists but was occluded by replacing intracellular K+ with Cs+. Consistent with an underlying mechanism of direct inhibition of one or more K+ channels, nicotine was found to rapidly reduce the fast-inactivating A-type K+ current as well as both components of the delayed-rectifier K+ current. Finally, nicotine increased bag cell neuron excitability, which manifested as reduction in spike threshold, greater action potential height and width, and markedly more spiking to continuous depolarizing current injection. In contrast to conventional transient activation of nicotinic ionotropic receptors, block of K+ channels could represent a nonstandard means for nicotine to profoundly alter the electrical properties of neurons over prolonged periods of time. PMID:26864763

Alpha7 nicotinic receptor mediated protection against ethanol-induced cytotoxicity in PC12 cells.

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Li, Y; King, M A; Grimes, J; Smith, N; de Fiebre, C M; Meyer, E M

1999-01-16

Ethanol caused a concentration-dependent loss of PC12 cells over a 24 h interval, accompanied by an increase in intracellular calcium. The specific alpha7 nicotinic receptor partial agonist DMXB attenuated both of these ethanol-induced actions at a concentration (3 microM) found previously to protect against apoptotic and necrotic cell loss. The alpha7 nicotinic receptor antagonist methylylaconitine blocked the neuroprotective action of DMXB when applied with but not 30 min after the agonist. These results indicate that activation of alpha7 nicotinic receptors may be therapeutically useful in preventing ethanol-neurotoxicity. Copyright 1999 Elsevier Science B.V.

Nicotine facilitates nicotinic acetylcholine receptor targeting to mitochondria but makes them less susceptible to selective ligands.

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Uspenska, Kateryna; Lykhmus, Olena; Gergalova, Galyna; Chernyshov, Volodymyr; Arias, Hugo R; Komisarenko, Sergiy; Skok, Maryna

2017-08-24

Several nicotinic acetylcholine receptor (nAChR) subtypes are expressed in mitochondria to regulate the internal pathway of apoptosis in ion channel-independent manner. However, the mechanisms of nAChR activation in mitochondria and targeting to mitochondria are still unknown. Nicotine has been shown to favor nAChR pentamer assembly, folding, and maturation on the way of biosynthesis. The idea of the present work was to determine whether nicotine affects the content, glycosylation, and function of mitochondrial nAChRs. Experiments were performed in isolated liver mitochondria from mice, that either consumed or not nicotine with the drinking water (200μL/L) for 7days. Mitochondria detergent lysates were studied by sandwich or lectin ELISA for the presence and carbohydrate composition of different nAChR subunits. Intact mitochondria were examined by flow cytometry for the binding of fluorescently labeled α-cobratoxin and were tested in functional assay of cytochrome c release under the effect of either Ca 2+ or wortmannin in the presence or absence of nAChR-selective ligands, including PNU-282987 (1nM), dihydro-β-erythroidine (DhβE, 1μM), PNU-120596 (0.3, 3, or 10μM) and desformylflustrabromine hydrochloride (dFBr, 0.001, 0.3, or 1μM). It was found that nicotine consumption increased the ratio of mitochondrial vs non-mitochondrial nAChRs in the liver, enhanced fucosylation of mitochondrial nAChRs, but prevented the binding of α-cobratoxin and the cytochrome c release-attenuating effects of nAChR-specific agonists, antagonists, or positive allosteric modulators. It is concluded that nicotine consumption in vivo favors nAChR glycosylation and trafficking to mitochondria but makes them less susceptible to the effects of specific ligands. Copyright © 2017 Elsevier B.V. All rights reserved.

Cardiovascular effects of the intracerebroventricular injection of adrenomedullin: roles of the peripheral vasopressin and central cholinergic systems

International Nuclear Information System (INIS)

Cam-Etoz, B.; Isbil-Buyukcoskun, N.; Ozluk, K.

2012-01-01

Our objective was to investigate in conscious Sprague-Dawley (6-8 weeks, 250-300 g) female rats (N = 7 in each group) the effects of intracerebroventricularly (icv) injected adrenomedullin (ADM) on blood pressure and heart rate (HR), and to determine if ADM and calcitonin gene-related peptide (CGRP) receptors, peripheral V 1 receptors or the central cholinergic system play roles in these cardiovascular effects. Blood pressure and HR were observed before and for 30 min following drug injections. The following results were obtained: 1) icv ADM (750 ng/10 µL) caused an increase in both blood pressure and HR (ΔMAP = 11.8 ± 2.3 mmHg and ΔHR = 39.7 ± 4.8 bpm). 2) Pretreatment with a CGRP receptor antagonist (CGRP 8-37 ) and ADM receptor antagonist (ADM 22-52 ) blocked the effect of central ADM on blood pressure and HR. 3) The nicotinic receptor antagonist mecamylamine (25 µg/10 µL, icv) and the muscarinic receptor antagonist atropine (5 µg/10 µL, icv) prevented the stimulating effect of ADM on blood pressure. The effect of ADM on HR was blocked only by atropine (5 µg/10 µL, icv). 4) The V 1 receptor antagonist [β-mercapto-β-β-cyclopentamethylenepropionyl 1 , O-me-Tyr 2 ,Arg 8 ]-vasopressin (V2255; 10 µg/kg), that was applied intravenously, prevented the effect of ADM on blood pressure and HR. This is the first study reporting the role of specific ADM and CGRP receptors, especially the role of nicotinic and muscarinic central cholinergic receptors and the role of peripheral V 1 receptors in the increasing effects of icv ADM on blood pressure and HR

Stimulation of Na+ -K+ -pump currents by epithelial nicotinic receptors in rat colon.

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Bader, Sandra; Lottig, Lena; Diener, Martin

2017-05-01

Acetylcholine-induced epithelial Cl - secretion is generally thought to be mediated by epithelial muscarinic receptors and nicotinic receptors on secretomotor neurons. However, recent data have shown expression of nicotinic receptors by intestinal epithelium and the stimulation of Cl - secretion by nicotine, in the presence of the neurotoxin, tetrodotoxin. Here, we aimed to identify the transporters activated by epithelial nicotinic receptors and to clarify their role in cholinergic regulation of intestinal ion transport. Ussing chamber experiments were performed, using rat distal colon with intact epithelia. Epithelia were basolaterally depolarized to measure currents across the apical membrane. Apically permeabilized tissue was also used to measure currents across the basolateral membrane in the presence of tetrodotoxin. Nicotine had no effect on currents through Cl - channels in the apical membrane or on currents through K + channels in the apical or the basolateral membrane. Instead, nicotine stimulated the Na + -K + -pump as indicated by Na + -dependency and sensitivity of the nicotine-induced current across the basolateral membrane to cardiac steroids. Effects of nicotine were inhibited by nicotinic receptor antagonists such as hexamethonium and mimicked by dimethyl-4-phenylpiperazinium, a chemically different nicotinic agonist. Simultaneous stimulation of epithelial muscarinic and nicotinic receptors led to a strong potentiation of transepithelial Cl - secretion. These results suggest a novel concept for the cholinergic regulation of transepithelial ion transport by costimulation of muscarinic and nicotinic epithelial receptors and a unique role of nicotinic receptors controlling the activity of the Na + -K + -ATPase. © 2017 The British Pharmacological Society.

Agmatine attenuates nicotine induced conditioned place preference in mice through modulation of neuropeptide Y system.

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Kotagale, Nandkishor R; Walke, Sonali; Shelkar, Gajanan P; Kokare, Dadasaheb M; Umekar, Milind J; Taksande, Brijesh G

2014-04-01

The purpose of the present study was to examine the effect of agmatine on nicotine induced conditioned place preference (CPP) in male albino mice. Intra-peritoneal (ip) administration of nicotine (1mg/kg) significantly increased time spent in drug-paired compartment. Agmatine (20 and 40 mg/kg, ip) co-administered with nicotine during the 6 days conditioning sessions completely abolished the acquisition of nicotine-induced CPP in mice. Concomitant administration of neuropeptide Y (NPY) (1 pg/mouse, icv) or [Leu(31), Pro(34)]-NPY (0.1 pg/mouse, icv), selective NPY Y1 receptor agonist potentiated the inhibitory effect of agmatine (10 mg/kg, ip) on nicotine CPP. Conversely, pretreatment with NPY Y1 receptor antagonist, BIBP3226 (0.01 ng/mouse, icv) blocked the effect of agmatine (20 mg/kg, ip) on nicotine induced CPP. In immunohistochemical study, nicotine decreased NPY-immunoreactivity in nucleus accumbens shell (AcbSh), bed nucleus of stria terminalis, lateral part (BNSTl), arcuate nucleus (ARC) and paraventricular nucleus (PVN). Conversely, administration of agmatine prior to the nicotine significantly reversed the effect of nicotine on NPY-immunoreactivity in the above brain nuclei. This data indicate that agmatine attenuate nicotine induced CPP via modulation of NPYergic neurotransmission in brain. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of MK-801 on the development of nicotine sensitization of nucleus accumbens dopamine release

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Hong, Soo Kyung; Choung, In Soon; Kim, Sang Eun [Seoul National University College of Medicine, Seoul (Korea, Republic of)

2005-07-01

We have previously found that MK-801, a noncompetitive NMDA receptor antagonist, prevents behavioral sensitization to nicotine. This study aimed to investigate the effect of MK-801 on a neurochemical component of nicotine sensitization by evaluating the effect of the drug on nicotine sensitization of nucleus accumbens dopamine (DA) release. Sprague-Dawley rats were pretreated with MK-801 (0.3 mg/kg, i.p.) or saline 30 min before injection of nicotine (0.4 mg/kg, s.c., once daily) for 7 consecutive days. Twenty-four hours after the last drug injection, animals were challenged with local perfusion of 5 mM nicotine into the shell of nucleus accumbens and DA release was monitored using in vivo microdialysis. In rats pretreated with chronic nicotine, local nicotine challenge induced a greater increase of accumbal DA release than in saline-treated animals (maximal DA response 969 {+-} 235% (mean {+-} SEM) of basal level vs. 520 {+-} 93%, P < 0.05). Co-administration of MK-801 with nicotine attenuated an increase of DA release elicited by local nicotine challenge, compared with nicotine alone (maximal DA response 427 {+-} 83% of basal level vs. 969 {+-} 235%, P < 0.01). These results suggest that MK-801 blocks the development of nicotine sensitization of nucleus accumbens DA release, further supporting the involvement of NMDA receptors in the development of behavioral sensitization to nicotine.

Effect of MK-801 on the development of nicotine sensitization of nucleus accumbens dopamine release

International Nuclear Information System (INIS)

Hong, Soo Kyung; Choung, In Soon; Kim, Sang Eun

2005-01-01

We have previously found that MK-801, a noncompetitive NMDA receptor antagonist, prevents behavioral sensitization to nicotine. This study aimed to investigate the effect of MK-801 on a neurochemical component of nicotine sensitization by evaluating the effect of the drug on nicotine sensitization of nucleus accumbens dopamine (DA) release. Sprague-Dawley rats were pretreated with MK-801 (0.3 mg/kg, i.p.) or saline 30 min before injection of nicotine (0.4 mg/kg, s.c., once daily) for 7 consecutive days. Twenty-four hours after the last drug injection, animals were challenged with local perfusion of 5 mM nicotine into the shell of nucleus accumbens and DA release was monitored using in vivo microdialysis. In rats pretreated with chronic nicotine, local nicotine challenge induced a greater increase of accumbal DA release than in saline-treated animals (maximal DA response 969 ± 235% (mean ± SEM) of basal level vs. 520 ± 93%, P < 0.05). Co-administration of MK-801 with nicotine attenuated an increase of DA release elicited by local nicotine challenge, compared with nicotine alone (maximal DA response 427 ± 83% of basal level vs. 969 ± 235%, P < 0.01). These results suggest that MK-801 blocks the development of nicotine sensitization of nucleus accumbens DA release, further supporting the involvement of NMDA receptors in the development of behavioral sensitization to nicotine

Nicotine induces resistance to chemotherapy by modulating mitochondrial signaling in lung cancer.

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Zhang, Jingmei; Kamdar, Opal; Le, Wei; Rosen, Glenn D; Upadhyay, Daya

2009-02-01

Continued smoking causes tumor progression and resistance to therapy in lung cancer. Carcinogens possess the ability to block apoptosis, and thus may induce development of cancers and resistance to therapy. Tobacco carcinogens have been studied widely; however, little is known about the agents that inhibit apoptosis, such as nicotine. We determine whether mitochondrial signaling mediates antiapoptotic effects of nicotine in lung cancer. A549 cells were exposed to nicotine (1 muM) followed by cisplatin (35 muM) plus etoposide (20 muM) for 24 hours. We found that nicotine prevented chemotherapy-induced apoptosis, improved cell survival, and caused modest increases in DNA synthesis. Inhibition of mitogen-activated protein kinase (MAPK) and Akt prevented the antiapoptotic effects of nicotine and decreased chemotherapy-induced apoptosis. Small interfering RNA MAPK kinase-1 blocked antiapoptotic effects of nicotine, whereas small interfering RNA MAPK kinase-2 blocked chemotherapy-induced apoptosis. Nicotine prevented chemotherapy-induced reduction in mitochondrial membrane potential and caspase-9 activation. Antiapoptotic effects of nicotine were blocked by mitochondrial anion channel inhibitor, 4,4'diisothiocyanatostilbene-2,2'disulfonic acid. Chemotherapy enhanced translocation of proapoptotic Bax to the mitochondria, whereas nicotine blocked these effects. Nicotine up-regulated Akt-mediated antiapoptotic X-linked inhibitor of apoptosis protein and phosphorylated proapoptotic Bcl2-antagonist of cell death. The A549-rho0 cells, which lack mitochondrial DNA, demonstrated partial resistance to chemotherapy-induced apoptosis, but blocked the antiapoptotic effects of nicotine. Accordingly, we provide evidence that nicotine modulates mitochondrial signaling and inhibits chemotherapy-induced apoptosis in lung cancer. The mitochondrial regulation of nicotine imposes an important mechanism that can critically impair the treatment of lung cancer, because many cancer

Agonist and antagonist effects of tobacco-related nitrosamines on human α4β2 nicotinic acetylcholine receptors.

Directory of Open Access Journals (Sweden)

Simone eBrusco

2015-09-01

Full Text Available Regulation of the ‘neuronal’ nicotinic acetylcholine receptors (nAChRs is implicated in both tobacco addiction and smoking-dependent tumor promotion. Some of these effects are caused by the tobacco-derived N-nitrosamines, which are carcinogenic compounds that avidly bind to nAChRs. However, the functional effects of these drugs on specific nAChR subtypes are largely unknown. By using patch-clamp methods, we tested 4-(methylnitrosamine-1-(3-pyridyl-1-butanone (NNK and N’-nitrosonornicotine (NNN on human α4β2 nAChRs. These latter are widely distributed in the mammalian brain and are also frequently expressed outside the nervous system. NNK behaved as a partial agonist, with an apparent EC50 of 16.7 μM. At 100 μM, it activated 16 % of the maximal current activated by nicotine. When NNK was co-applied with nicotine, it potentiated the currents elicited by nicotine concentrations ≤ 100 nM. At higher concentrations of nicotine, NNK always inhibited the α4β2 nAChR. In contrast, NNN was a pure inhibitor of this nAChR subtype, with IC50 of approximately 1 nM in the presence of 10 μM nicotine. The effects of both NNK and NNN were mainly competitive and largely independent of Vm. The different actions of NNN and NNK must be taken into account when interpreting their biological effects in vitro and in vivo.

Dextromethorphan interactions with histaminergic and serotonergic treatments to reduce nicotine self-administration in rats.

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Briggs, Scott A; Hall, Brandon J; Wells, Corinne; Slade, Susan; Jaskowski, Paul; Morrison, Margaret; Rezvani, Amir H; Rose, Jed E; Levin, Edward D

2016-03-01

Combining effective treatments with diverse mechanisms of action for smoking cessation may provide better therapy by targeting multiple points of control in the neural circuits underlying addiction. Previous research in a rat model has shown that dextromethorphan, which has α3β4 nicotinic and NMDA glutamatergic antagonist actions, significantly decreases nicotine self-administration. We have found in the rat model that the H1 histamine antagonist pyrilamine and the serotonin 5HT2C agonist lorcaserin also significantly reduce nicotine self-administration. The current studies were conducted to determine the interactive effects of dextromethorphan with pyrilamine and lorcaserin on nicotine self-administration in rats. Young adult female rats were fitted with jugular IV catheters and trained to self-administer a nicotine infusion dose of 0.03-mg/kg/infusion. In an initial dose-effect function study of dextromethorphan, we found a monotonic decrease in nicotine self-administration over a dose range of 1 to 30-mg/kg with the lowest effective dose of 3-mg/kg. Then, with two separate cohorts of rats, dextromethorphan (0, 3.3, and 10-mg/kg) interactions with pyrilamine (0, 4.43, and 13.3-mg/kg) were investigated as well as interactions with lorcaserin (0, 0.3125 and 0.625-mg/kg). In the pyrilamine-dextromethorphan interaction study, an acute dose of pyrilamine (13.3-mg/kg) as well as an acute dose of dextromethorphan caused a significant decrease in nicotine self-administration. There were mutually augmenting effects of these two drugs. The combination of dextromethorphan (10-mg/kg) and pyrilamine (13.3-mg/kg) significantly lowered nicotine self-administration relative to either 10-mg/kg of dextromethorphan alone (pdextromethorphan study, an acute dose of lorcaserin (0.312-mg/kg) as well as an acute dose of dextromethorphan (10-mg/kg) caused a significant decrease in nicotine self-administration replicating previous findings. Augmenting interactions were observed with

Variable effects of nicotine, anabasine, and their interactions on parasitized bumble bees

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Thorburn, Lukas P.; Adler, Lynn S.; Irwin, Rebecca E.; Palmer-Young, Evan C.

2015-01-01

Secondary metabolites in floral nectar have been shown to reduce parasite load in two common bumble bee species. Previous studies on the effects of nectar secondary metabolites on parasitized bees have focused on single compounds in isolation; however, in nature, bees are simultaneously exposed to multiple compounds. We tested for interactions between the effects of two alkaloids found in the nectar of Nicotiana spp. plants, nicotine and anabasine, on parasite load and mortality in bumble bees ( Bombus impatiens) infected with the intestinal parasite Crithidia bombi. Adult worker bees inoculated with C. bombi were fed nicotine and anabasine diet treatments in a factorial design, resulting in four nectar treatment combinations:  2 ppm nicotine, 5 ppm anabasine, 2ppm nicotine and 5 ppm anabasine together, or a control alkaloid-free solution. We conducted the experiment twice: first, with bees incubated under variable environmental conditions (‘Variable’; temperatures varied from 10-35°C with ambient lighting); and second, under carefully controlled environmental conditions (‘Stable’; 27°C incubator, constant darkness). In ‘Variable’, each alkaloid alone significantly decreased parasite loads, but this effect was not realized with the alkaloids in combination, suggesting an antagonistic interaction. Nicotine but not anabasine significantly increased mortality, and the two compounds had no interactive effects on mortality. In ‘Stable’, nicotine significantly increased parasite loads, the opposite of its effect in ‘Variable’. While not significant, the relationship between anabasine and parasite loads was also positive. Interactive effects between the two alkaloids on parasite load were non-significant, but the pattern of antagonistic interaction was similar to that in the variable experiment. Neither alkaloid, nor their interaction, significantly affected mortality under controlled conditions. Our results do not indicate synergy between Nicotiana

Nicotine increases impulsivity and decreases willingness to exert cognitive effort despite improving attention in "slacker" rats: insights into cholinergic regulation of cost/benefit decision making.

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Hosking, Jay G; Lam, Fred C W; Winstanley, Catharine A

2014-01-01

Successful decision making in our daily lives requires weighing an option's costs against its associated benefits. The neuromodulator acetylcholine underlies both the etiology and treatment of a number of illnesses in which decision making is perturbed, including Alzheimer's disease, attention-deficit/hyperactivity disorder, and schizophrenia. Nicotine acts on the cholinergic system and has been touted as a cognitive enhancer by both smokers and some researchers for its attention-boosting effects; however, it is unclear whether treatments that have a beneficial effect on attention would also have a beneficial effect on decision making. Here we utilize the rodent Cognitive Effort Task (rCET), wherein animals can choose to allocate greater visuospatial attention for a greater reward, to examine cholinergic contributions to both attentional performance and choice based on attentional demand. Following the establishment of baseline behavior, four drug challenges were administered: nicotine, mecamylamine, scopolamine, and oxotremorine (saline plus three doses for each). As per previous rCET studies, animals were divided by their baseline preferences, with "worker" rats choosing high-effort/high-reward options more than their "slacker" counterparts. Nicotine caused slackers to choose even fewer high-effort trials than at baseline, but had no effect on workers' choice. Despite slackers' decreased willingness to expend effort, nicotine improved their attentional performance on the task. Nicotine also increased measures of motor impulsivity in all animals. In contrast, scopolamine decreased animals' choice of high-effort trials, especially for workers, while oxotremorine decreased motor impulsivity for all animals. In sum, the cholinergic system appears to contribute to decision making, and in part these contributions can be understood as a function of individual differences. While nicotine has been considered as a cognitive enhancer, these data suggest that its modest

Evidence for the involvement of NMDA receptors in the antidepressant-like effect of nicotine in mouse forced swimming and tail suspension tests.

Science.gov (United States)

Haj-Mirzaian, Arya; Kordjazy, Nastaran; Haj-Mirzaian, Arvin; Ostadhadi, Sattar; Ghasemi, Mehdi; Amiri, Shayan; Faizi, Mehrdad; Dehpour, AhmadReza

2015-10-01

The antidepressant action of acute nicotine administration in clinical and animal studies is well recognized. But the underlying mechanism for this effect has not been carefully discovered. We attempted to evaluate the possible role of N-Methyl-D-aspartate (NMDA) receptors in the antidepressant-like effect of nicotine. After the assessment of locomotor activity in the open-field test, forced swimming test (FST) and tail suspension test (TST) were used to evaluate the antidepressant-like effect of nicotine in mice. We performed intraperitoneal administration of nicotine at different doses and periods before the tests. To assess the possible involvement of NMDA receptors, non-effective doses of NMDA antagonists and an NMDA agonist were obtained and were administered simultaneously with the non-effective and effective doses of nicotine, respectively. Nicotine (0.2 mg/kg, 30 min before FST/TST) significantly reduced the immobility time of mice similar to fluoxetine (20 mg/kg). Nicotine did not affect the locomotor behavior of mice in open-field test. Co-administration of non-effective doses of NMDA receptor antagonists, ketamine (1 or 0.3 mg/kg), MK-801 (0.05 or 0.005 mg/kg), and magnesium sulfate (10 or 5 mg/kg) with nicotine (0.1 or 0.03 mg/kg) had remarkable synergistic antidepressant effect in both FST and TST. Also, non-effective NMDA (75 or 30 mg/kg) reversed the anti-immobility effect of nicotine (0.2 mg/kg) on mouse FST and TST. Our study has for the first time confirmed that the antidepressant-like effect of nicotine on mice is NMDA-mediated, and nicotine presumably exerts this effect by antagonizing the glutamatergic NMDA receptors.

Waterpipe tobacco products: nicotine labelling versus nicotine delivery.

Science.gov (United States)

Vansickel, Andrea R; Shihadeh, Alan; Eissenberg, Thomas

2012-05-01

Waterpipe tobacco package labelling typically indicates "0.0% tar" and "0.05% or 0.5% nicotine". To determine the extent to which nicotine labeling is related to nicotine delivery. 110 waterpipe smokers engaged in a 45-minute waterpipe smoking session. Puff topography and plasma nicotine were measured. Three waterpipe tobacco brands were used: Nakhla (0.5% nicotine), Starbuzz (0.05% nicotine), and Al Fakher (0.05% nicotine). Data were analyzed by one-way ANOVA. Topography did not differ across brands. Peak plasma nicotine varied significantly across brands. Al Fakher had the highest nicotine delivery (11.4 ng/ml) followed by Nakhla (9.8 ng/ml) and Starbuzz (5.8 ng/ml). Nicotine labelling on waterpipe tobacco products does not reflect delivery; smoking a brand with a "0.05% nicotine" label led to greater plasma nicotine levels than smoking a brand with a "0.5% nicotine" label. Waterpipe tobacco products should be labelled in a manner that does not mislead consumers.

Inhibition of allergen-induced basophil activation by ASM-024, a nicotinic receptor ligand.

Science.gov (United States)

Watson, Brittany M; Oliveria, John Paul; Nusca, Graeme M; Smith, Steven G; Beaudin, Sue; Dua, Benny; Watson, Rick M; Assayag, Evelynne Israël; Cormier, Yvon F; Sehmi, Roma; Gauvreau, Gail M

2014-01-01

Nicotinic acetylcholine receptors (nAChRs) were identified on eosinophils and shown to regulate inflammatory responses, but nAChR expression on basophils has not been explored yet. We investigated surface receptor expression of nAChR α4, α7 and α1/α3/α5 subunits on basophils. Furthermore, we examined the effects of ASM-024, a synthetic nicotinic ligand, on in vitro anti-IgE and in vivo allergen-induced basophil activation. Basophils were enriched from the peripheral blood of allergic donors and the expression of nAChR subunits and muscarinic receptors was determined. Purified basophils were stimulated with anti-IgE in the presence of ASM-024 with or without muscarinic or nicotinic antagonists for the measurement of CD203c expression and histamine release. The effect of 9 days of treatment with 50 and 200 mg ASM-024 on basophil CD203c expression was examined in the blood of mild allergic asthmatics before and after allergen inhalation challenge. nAChR α4, α7 and α1/α3/α5 receptor subunit expression was detected on basophils. Stimulation of basophils with anti-IgE increased CD203c expression and histamine release, which was inhibited by ASM-024 (10(-5) to 10(-)(3) M, p ASM-024 was reversed in the presence of muscarinic and nicotinic antagonists. In subjects with mild asthma, ASM-024 inhalation significantly inhibited basophil CD203c expression measured 24 h after allergen challenge (p = 0.03). This study shows that ASM-024 inhibits IgE- and allergen-induced basophil activation through both nicotinic and muscarinic receptors, and suggests that ASM-024 may be an efficacious agent for modulating allergic asthma responses. © 2015 S. Karger AG, Basel.

Cardiovascular effects of the intracerebroventricular injection of adrenomedullin: roles of the peripheral vasopressin and central cholinergic systems

Directory of Open Access Journals (Sweden)

B. Cam-Etoz

2012-03-01

Full Text Available Our objective was to investigate in conscious Sprague-Dawley (6-8 weeks, 250-300 g female rats (N = 7 in each group the effects of intracerebroventricularly (icv injected adrenomedullin (ADM on blood pressure and heart rate (HR, and to determine if ADM and calcitonin gene-related peptide (CGRP receptors, peripheral V1 receptors or the central cholinergic system play roles in these cardiovascular effects. Blood pressure and HR were observed before and for 30 min following drug injections. The following results were obtained: 1 icv ADM (750 ng/10 µL caused an increase in both blood pressure and HR (DMAP = 11.8 ± 2.3 mmHg and ΔHR = 39.7 ± 4.8 bpm. 2 Pretreatment with a CGRP receptor antagonist (CGRP8-37 and ADM receptor antagonist (ADM22-52 blocked the effect of central ADM on blood pressure and HR. 3 The nicotinic receptor antagonist mecamylamine (25 µg/10 µL, icv and the muscarinic receptor antagonist atropine (5 µg/10 µL, icv prevented the stimulating effect of ADM on blood pressure. The effect of ADM on HR was blocked only by atropine (5 µg/10 µL, icv. 4 The V1 receptor antagonist [β-mercapto-β-β-cyclopentamethylenepropionyl¹, O-me-Tyr²,Arg8]-vasopressin (V2255; 10 µg/kg, that was applied intravenously, prevented the effect of ADM on blood pressure and HR. This is the first study reporting the role of specific ADM and CGRP receptors, especially the role of nicotinic and muscarinic central cholinergic receptors and the role of peripheral V1 receptors in the increasing effects of icv ADM on blood pressure and HR.

Cardiovascular effects of the intracerebroventricular injection of adrenomedullin: roles of the peripheral vasopressin and central cholinergic systems

Energy Technology Data Exchange (ETDEWEB)

Cam-Etoz, B.; Isbil-Buyukcoskun, N.; Ozluk, K. [Department of Physiology, Uludag University Medical Faculty, Gorukle/Bursa (Turkey)

2012-03-02

Our objective was to investigate in conscious Sprague-Dawley (6-8 weeks, 250-300 g) female rats (N = 7 in each group) the effects of intracerebroventricularly (icv) injected adrenomedullin (ADM) on blood pressure and heart rate (HR), and to determine if ADM and calcitonin gene-related peptide (CGRP) receptors, peripheral V{sub 1} receptors or the central cholinergic system play roles in these cardiovascular effects. Blood pressure and HR were observed before and for 30 min following drug injections. The following results were obtained: 1) icv ADM (750 ng/10 µL) caused an increase in both blood pressure and HR (ΔMAP = 11.8 ± 2.3 mmHg and ΔHR = 39.7 ± 4.8 bpm). 2) Pretreatment with a CGRP receptor antagonist (CGRP{sub 8-37}) and ADM receptor antagonist (ADM{sub 22-52}) blocked the effect of central ADM on blood pressure and HR. 3) The nicotinic receptor antagonist mecamylamine (25 µg/10 µL, icv) and the muscarinic receptor antagonist atropine (5 µg/10 µL, icv) prevented the stimulating effect of ADM on blood pressure. The effect of ADM on HR was blocked only by atropine (5 µg/10 µL, icv). 4) The V{sub 1} receptor antagonist [β-mercapto-β-β-cyclopentamethylenepropionyl{sup 1}, O-me-Tyr{sup 2},Arg{sup 8}]-vasopressin (V2255; 10 µg/kg), that was applied intravenously, prevented the effect of ADM on blood pressure and HR. This is the first study reporting the role of specific ADM and CGRP receptors, especially the role of nicotinic and muscarinic central cholinergic receptors and the role of peripheral V{sub 1} receptors in the increasing effects of icv ADM on blood pressure and HR.

Extended nicotine self-administration increases sensitivity to nicotine, motivation to seek nicotine and the reinforcing properties of nicotine-paired cues.

Science.gov (United States)

Clemens, Kelly J; Lay, Belinda P P; Holmes, Nathan M

2017-03-01

An array of pharmacological and environmental factors influence the development and maintenance of tobacco addiction. The nature of these influences likely changes across the course of an extended smoking history, during which time drug seeking can become involuntary and uncontrolled. The present study used an animal model to examine the factors that drive nicotine-seeking behavior after either brief (10 days) or extended (40 days) self-administration training. In Experiment 1, extended training increased rats' sensitivity to nicotine, indicated by a leftward shift in the dose-response curve, and their motivation to work for nicotine, indicated by an increase in the break point achieved under a progressive ratio schedule. In Experiment 2, extended training imbued the nicotine-paired cue with the capacity to maintain responding to the same high level as nicotine itself. However, Experiment 3 showed that the mechanisms involved in responding for nicotine or a nicotine-paired cue are dissociable, as treatment with the partial nicotine receptor agonist, varenicline, suppressed responding for nicotine but potentiated responding for the nicotine-paired cue. Hence, across extended nicotine self-administration, pharmacological and environmental influences over nicotine seeking increase such that nicotine seeking is controlled by multiple sources, and therefore highly resistant to change. © 2015 Society for the Study of Addiction.

Design, synthesis, and biological activity of 5'-phenyl-1,2,5,6-tetrahydro-3,3'-bipyridine analogues as potential antagonists of nicotinic acetylcholine receptors.

Science.gov (United States)

Jin, Yafei; Huang, Xiaoqin; Papke, Roger L; Jutkiewicz, Emily M; Showalter, Hollis D; Zhan, Chang-Guo

2017-09-15

Starting from a known non-specific agonist (1) of nicotinic acetylcholine receptors (nAChRs), rationally guided structural-based design resulted in the discovery of a small series of 5'-phenyl-1,2,5,6-tetrahydro-3,3'-bipyridines (3a-3e) incorporating a phenyl ring off the pyridine core of 1. The compounds were synthesized via successive Suzuki couplings on a suitably functionalized pyridine starting monomer 4 to append phenyl and pyridyl substituents off the 3- and 5-positions, respectively, and then subsequent modifications were made on the flanking pyridyl ring to provide target compounds. Compound 3a is a novel antagonist, which is highly selective for α3β4 nAChR (K i =123nM) over the α4β2 and α7 receptors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Covalent attachment of antagonists to the a7 nicotinic acetylcholine receptor: synthesis and reactivity of substituted maleimides

DEFF Research Database (Denmark)

Ambrus, Joseph I; Halliday, Jill I; Kanizaj, Nicholas

2012-01-01

The 3-methylmaleimide congeners of the natural product methyllycaconitine (MLA) and an analogue covalently attach to functional cysteine mutants of the a7 nicotinic acetylcholine receptor (nAChR).......The 3-methylmaleimide congeners of the natural product methyllycaconitine (MLA) and an analogue covalently attach to functional cysteine mutants of the a7 nicotinic acetylcholine receptor (nAChR)....

Blockade of rat alpha3beta4 nicotinic receptor function by methadone, its metabolites, and structural analogs.

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Xiao, Y; Smith, R D; Caruso, F S; Kellar, K J

2001-10-01

The opioid agonist properties of (+/-)-methadone are ascribed almost entirely to the (-)-methadone enantiomer. To extend our knowledge of the pharmacological actions of methadone at ligand-gated ion channels, we investigated the effects of the two enantiomers of methadone and its metabolites R-(+)-2-ethyl-1,5-dimethyl-3,3-diphenylpyrrolinium perchlorate (EDDP) and R-(+)-2-ethyl-5-methyl-3,3-diphenyl-1-pyrroline hydrochloride (EMDP), as well as structural analogs of methadone, including (-)-alpha-acetylmethadol hydrochloride (LAAM) and (+)-alpha-propoxyphene, on rat alpha3beta4 neuronal nicotinic acetylcholine receptors (nAChRs) stably expressed in a human embryonic kidney 293 cell line, designated KXalpha3beta4R2. (+/-)-methadone inhibited nicotine-stimulated 86Rb+ efflux from the cells in a concentration-dependent manner with an IC50 value of 1.9 +/- 0.2 microM, indicating that it is a potent nAChR antagonist. The (-)- and (+)-enantiomers of methadone have similar inhibitory potencies on nicotine-stimulated 86Rb+ efflux, with IC50 values of approximately 2 microM. EDDP, the major metabolite of methadone, is even more potent, with an IC50 value of approximately 0.5 microM, making it one of the most potent nicotinic receptor blockers reported. In the presence of (+/-)-methadone, EDDP, or LAAM, the maximum nicotine-stimulated 86Rb+ efflux was markedly decreased, but the EC50 value for nicotine stimulation was altered only slightly, if at all, indicating that these compounds block alpha3beta4 nicotinic receptor function by a noncompetitive mechanism. Consistent with a noncompetitive mechanism, (+/-)-methadone, its metabolites, and structural analogs have very low affinity for nicotinic receptor agonist binding sites in membrane homogenates from KXalpha3beta4R2 cells. We conclude that both enantiomers of methadone and its metabolites as well as LAAM and (+)-alpha-propoxyphene are potent noncompetitive antagonists of alpha3beta4 nAChRs.

Cartap hydrolysis relative to its action at the insect nicotinic channel.

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Lee, Seog-Jong; Caboni, Pierluigi; Tomizawa, Motohiro; Casida, John E

2004-01-14

The insecticide cartap is the bis(thiocarbamate) derivative of 2-(dimethylamino)propane-1,3-dithiol, which on oxidation forms the natural toxicant nereistoxin (NTX) [4-(dimethylamino)-1,2-dithiolane]. Both cartap and NTX are ion channel blockers of the nicotinic acetylcholine receptor (nAChR). Cartap was originally proposed to act only after metabolic conversion to NTX and later suggested to block directly without activation. The present study uses a new approach to differentiate these hypotheses, that is, pH effects on channel-blocking activity and hydrolysis rates. As controls, mecamylamine (the classic channel blocker) and NTX are stable and similar in channel-blocking potency ([(3)H]thienylcyclohexylpiperidine binding assay, honeybee nAChR) at pH 6.1-8.4. In contrast, cartap is >200-fold more effective at pH 7.4 than at pH 6.1, indicating that it undergoes hydrolytic activation. Cartap slowly hydrolyzes to cartap monothiol at pH 6.1 but quickly forms the dithiol and some NTX at pH 7.4. The relationship between potency and hydrolysis products at various pH ranges suggests that cartap dithiol is the most plausible blocking agent.

Isotopic rubidium ion efflux assay for the functional characterization of nicotinic acetylcholine receptors on clonal cell lines

International Nuclear Information System (INIS)

Lukas, R.J.; Cullen, M.J.

1988-01-01

An isotopic rubidium ion efflux assay has been developed for the functional characterization of nicotinic acetylcholine receptors on cultured neurons. This assay first involves the intracellular sequestration of isotopic potassium ion analog by the ouabain-sensitive action of a sodium-potassium ATPase. Subsequently, the release of isotopic rubidium ion through nicotinic acetylcholine receptor-coupled monovalent cation channels is activated by application of nicotinic agonists. Specificity of receptor-mediated efflux is demonstrated by its sensitivity to blockade by nicotinic, but not muscarinic, antagonists. The time course of agonist-mediated efflux, within the temporal limitations of the assay, indicates a slow inactivation of receptor function on prolonged exposure to agonist. Dose-response profiles (i) have characteristic shapes for different nicotinic agonists, (ii) are described by three operationally defined parameters, and (iii) reflect different affinities of agonists for binding sites that control receptor activation and functional inhibition. The rubidium ion efflux assay provides fewer hazards but greater sensitivity and resolution than isotopic sodium or rubidium ion influx assays for functional nicotinic receptors

Different physiological and behavioural effects of e-cigarette vapour and cigarette smoke in mice.

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Ponzoni, L; Moretti, M; Sala, M; Fasoli, F; Mucchietto, V; Lucini, V; Cannazza, G; Gallesi, G; Castellana, C N; Clementi, F; Zoli, M; Gotti, C; Braida, D

2015-10-01

Nicotine is the primary addictive substance in tobacco smoke and electronic cigarette (e-cig) vapour. Methodological limitations have made it difficult to compare the role of the nicotine and non-nicotine constituents of tobacco smoke. The aim of this study was to compare the effects of traditional cigarette smoke and e-cig vapour containing the same amount of nicotine in male BALB/c mice exposed to the smoke of 21 cigarettes or e-cig vapour containing 16.8 mg of nicotine delivered by means of a mechanical ventilator for three 30-min sessions/day for seven weeks. One hour after the last session, half of the animals were sacrificed for neurochemical analysis, and the others underwent mecamylamine-precipitated or spontaneous withdrawal for the purposes of behavioural analysis. Chronic intermittent non-contingent, second-hand exposure to cigarette smoke or e-cig vapour led to similar brain cotinine and nicotine levels, similar urine cotinine levels and the similar up-regulation of α4β2 nicotinic acetylcholine receptors in different brain areas, but had different effects on body weight, food intake, and the signs of mecamylamine-precipitated and spontaneous withdrawal episodic memory and emotional responses. The findings of this study demonstrate for the first time that e-cig vapour induces addiction-related neurochemical, physiological and behavioural alterations. The fact that inhaled cigarette smoke and e-cig vapour have partially different dependence-related effects indicates that compounds other than nicotine contribute to tobacco dependence. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

Nicotinic receptor activation contrasts pathophysiological bursting and neurodegeneration evoked by glutamate uptake block on rat hypoglossal motoneurons.

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Corsini, Silvia; Tortora, Maria; Nistri, Andrea

2016-11-15

Impaired uptake of glutamate builds up the extracellular level of this excitatory transmitter to trigger rhythmic neuronal bursting and delayed cell death in the brainstem motor nucleus hypoglossus. This process is the expression of the excitotoxicity that underlies motoneuron degeneration in diseases such as amyotrophic lateral sclerosis affecting bulbar motoneurons. In a model of motoneuron excitotoxicity produced by pharmacological block of glutamate uptake in vitro, rhythmic bursting is suppressed by activation of neuronal nicotinic receptors with their conventional agonist nicotine. Emergence of bursting is facilitated by nicotinic receptor antagonists. Following excitotoxicity, nicotinic receptor activity decreases mitochondrial energy dysfunction, endoplasmic reticulum stress and production of toxic radicals. Globally, these phenomena synergize to provide motoneuron protection. Nicotinic receptors may represent a novel target to contrast pathological overactivity of brainstem motoneurons and therefore to prevent their metabolic distress and death. Excitotoxicity is thought to be one of the early processes in the onset of amyotrophic lateral sclerosis (ALS) because high levels of glutamate have been detected in the cerebrospinal fluid of such patients due to dysfunctional uptake of this transmitter that gradually damages brainstem and spinal motoneurons. To explore potential mechanisms to arrest ALS onset, we used an established in vitro model of rat brainstem slice preparation in which excitotoxicity is induced by the glutamate uptake blocker dl-threo-β-benzyloxyaspartate (TBOA). Because certain brain neurons may be neuroprotected via activation of nicotinic acetylcholine receptors (nAChRs) by nicotine, we investigated if nicotine could arrest excitotoxic damage to highly ALS-vulnerable hypoglossal motoneurons (HMs). On 50% of patch-clamped HMs, TBOA induced intense network bursts that were inhibited by 1-10 μm nicotine, whereas nAChR antagonists

Effects of Nicotine on the Neurophysiological and Behavioral Effects of Ketamine in Humans

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Daniel H Mathalon

2014-01-01

Full Text Available Background: N-methyl-D-aspartate (NMDA receptor hypofunction has been implicated in the pathophysiology of schizophrenia and its associated neurocognitive impairments. The high rate of cigarette smoking in schizophrenia raises questions about how nicotine modulates putative NMDA receptor hypofunction in the illness. Accordingly, we examined the modulatory effects of brain nicotinic acetylcholine receptor (nAChR stimulation on NMDA receptor hypofunction by examining the interactive effects of nicotine, a nAChR agonist, and ketamine, a noncompetitive NMDA receptor antagonist, on behavioral and neurophysiological measures in healthy human volunteers.Methods: From an initial sample of 17 subjects (age range 18 - 55 years, 8 subjects successfully completed 4 test sessions, each separated by at least 3 days, during which they received ketamine or placebo and two injections of nicotine or placebo in a double-blind, counterbalanced manner. Schizophrenia-like effects (PANSS, perceptual alterations (CADSS, subjective effects (VAS and auditory event-related brain potentials (mismatch negativity, P300 were assessed during each test session.Results: Consistent with existing studies, ketamine induced transient schizophrenia-like behavioral effects. P300 was reduced and delayed by ketamine regardless of whether it was elicited by a target or novel stimulus, while nicotine only reduced the amplitude of P3a. Nicotine did not rescue P300 from the effects of ketamine; the interactions of ketamine and nicotine were not significant. While nicotine significantly reduced MMN amplitude, ketamine did not. Conclusion: Nicotine failed to modulate ketamine-induced schizophrenia-like effects in this preliminary study. Interestingly, ketamine reduced P3b amplitude and nicotine reduced P3a amplitude, suggesting independent roles of NMDA receptor and nAChR in the generation of P3b and P3a, respectively.

Reduced-Nicotine Cigarettes in Young Smokers: Impact of Nicotine Metabolism on Nicotine Dose Effects.

Science.gov (United States)

Faulkner, Paul; Ghahremani, Dara G; Tyndale, Rachel F; Cox, Chelsea M; Kazanjian, Ari S; Paterson, Neil; Lotfipour, Shahrdad; Hellemann, Gerhard S; Petersen, Nicole; Vigil, Celia; London, Edythe D

2017-07-01

The use of cigarettes delivering different nicotine doses allows evaluation of the contribution of nicotine to the smoking experience. We compared responses of 46 young adult smokers to research cigarettes, delivering 0.027, 0.110, 0.231, or 0.763 mg nicotine, and conventional cigarettes. On five separate days, craving, withdrawal, affect, and sustained attention were measured after overnight abstinence and again after smoking. Participants also rated each cigarette, and the nicotine metabolite ratio (NMR) was used to identify participants as normal or slow metabolizers. All cigarettes equally alleviated craving, withdrawal, and negative affect in the whole sample, but normal metabolizers reported greater reductions of craving and withdrawal than slow metabolizers, with dose-dependent effects. Only conventional cigarettes and, to a lesser degree, 0.763-mg nicotine research cigarettes increased sustained attention. Finally, there were no differences between ratings of lower-dose cigarettes, but the 0.763-mg cigarettes and (even more so) conventional cigarettes were rated more favorably than lower-dose cigarettes. The findings indicate that smoking-induced relief of craving and withdrawal reflects primarily non-nicotine effects in slow metabolizers, but depends on nicotine dose in normal metabolizers. By contrast, relief of withdrawal-related attentional deficits and cigarette ratings depend on nicotine dose regardless of metabolizer status. These findings have bearing on the use of reduced-nicotine cigarettes to facilitate smoking cessation and on policy regarding regulation of nicotine content in cigarettes. They suggest that normal and slow nicotine metabolizers would respond differently to nicotine reduction in cigarettes, but that irrespective of metabolizer status, reductions to <0.763 mg/cigarette may contribute to temporary attentional deficits.

Nicotine poisoning

Science.gov (United States)

Nicotine is found in: Chewing tobacco Cigarettes E-cigarettes Liquid nicotine Nicotine gum (Nicorette) Nicotine patches (Habitrol, Nicoderm) Pipe tobacco Some insecticides Tobacco leaves Note: This list may not be all-inclusive.

Concomitant release of ventral tegmental acetylcholine and accumbal dopamine by ghrelin in rats.

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Elisabet Jerlhag

Full Text Available Ghrelin, an orexigenic peptide, regulates energy balance specifically via hypothalamic circuits. Growing evidence suggest that ghrelin increases the incentive value of motivated behaviours via activation of the cholinergic-dopaminergic reward link. It encompasses the cholinergic afferent projection from the laterodorsal tegmental area (LDTg to the dopaminergic cells of the ventral tegmental area (VTA and the mesolimbic dopamine system projecting from the VTA to nucleus accumbens (N.Acc.. Ghrelin receptors (GHS-R1A are expressed in these reward nodes and ghrelin administration into the LDTg increases accumbal dopamine, an effect involving nicotinic acetylcholine receptors in the VTA. The present series of experiments were undertaken directly to test this hypothesis. Here we show that ghrelin, administered peripherally or locally into the LDTg concomitantly increases ventral tegmental acetylcholine as well as accumbal dopamine release. A GHS-R1A antagonist blocks this synchronous neurotransmitter release induced by peripheral ghrelin. In addition, local perfusion of the unselective nicotinic antagonist mecamylamine into the VTA blocks the ability of ghrelin (administered into the LDTg to increase N.Acc.-dopamine, but not VTA-acetylcholine. Collectively our data indicate that ghrelin activates the LDTg causing a release of acetylcholine in the VTA, which in turn activates local nicotinic acetylcholine receptors causing a release of accumbal dopamine. Given that a dysfunction in the cholinergic-dopaminergic reward system is involved in addictive behaviours, including compulsive overeating and alcohol use disorder, and that hyperghrelinemia is associated with such addictive behaviours, ghrelin-responsive circuits may serve as a novel pharmacological target for treatment of alcohol use disorder as well as binge eating.

Nicotine increases impulsivity and decreases willingness to exert cognitive effort despite improving attention in "slacker" rats: insights into cholinergic regulation of cost/benefit decision making.

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Jay G Hosking

Full Text Available Successful decision making in our daily lives requires weighing an option's costs against its associated benefits. The neuromodulator acetylcholine underlies both the etiology and treatment of a number of illnesses in which decision making is perturbed, including Alzheimer's disease, attention-deficit/hyperactivity disorder, and schizophrenia. Nicotine acts on the cholinergic system and has been touted as a cognitive enhancer by both smokers and some researchers for its attention-boosting effects; however, it is unclear whether treatments that have a beneficial effect on attention would also have a beneficial effect on decision making. Here we utilize the rodent Cognitive Effort Task (rCET, wherein animals can choose to allocate greater visuospatial attention for a greater reward, to examine cholinergic contributions to both attentional performance and choice based on attentional demand. Following the establishment of baseline behavior, four drug challenges were administered: nicotine, mecamylamine, scopolamine, and oxotremorine (saline plus three doses for each. As per previous rCET studies, animals were divided by their baseline preferences, with "worker" rats choosing high-effort/high-reward options more than their "slacker" counterparts. Nicotine caused slackers to choose even fewer high-effort trials than at baseline, but had no effect on workers' choice. Despite slackers' decreased willingness to expend effort, nicotine improved their attentional performance on the task. Nicotine also increased measures of motor impulsivity in all animals. In contrast, scopolamine decreased animals' choice of high-effort trials, especially for workers, while oxotremorine decreased motor impulsivity for all animals. In sum, the cholinergic system appears to contribute to decision making, and in part these contributions can be understood as a function of individual differences. While nicotine has been considered as a cognitive enhancer, these data suggest

Design and synthesis of labeled analogs of PhTX-56, a potent and selective AMPA receptor antagonist

DEFF Research Database (Denmark)

Andersen, Trine F; Vogensen, Stine B; Jensen, Lars S

2005-01-01

Polyamines and polyamine toxins are biologically important molecules, having modulatory effects on nucleotides and proteins. The wasp toxin, philanthotoxin-433 (PhTX-433), is a non-selective and uncompetitive antagonist of ionotropic receptors, such as ionotropic glutamate receptors and nicotinic...

Nicotine Vapor Method to Induce Nicotine Dependence in Rodents.

Science.gov (United States)

Kallupi, Marsida; George, Olivier

2017-07-05

Nicotine, the main addictive component of tobacco, induces potentiation of brain stimulation reward, increases locomotor activity, and induces conditioned place preference. Nicotine cessation produces a withdrawal syndrome that can be relieved by nicotine replacement therapy. In the last decade, the market for electronic cigarettes has flourished, especially among adolescents. The nicotine vaporizer or electronic nicotine delivery system is a battery-operated device that allows the user to simulate the experience of tobacco smoking without inhaling smoke. The device is designed to be an alternative to conventional cigarettes that emits vaporized nicotine inhaled by the user. This report describes a procedure to vaporize nicotine in the air to produce blood nicotine levels in rodents that are clinically relevant to those that are observed in humans and produce dependence. We also describe how to construct the apparatus to deliver nicotine vapor in a stable, reliable, and consistent manner, as well as how to analyze air for nicotine content. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

Hippocampal long term memory: effect of the cholinergic system on local protein synthesis.

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Lana, Daniele; Cerbai, Francesca; Di Russo, Jacopo; Boscaro, Francesca; Giannetti, Ambra; Petkova-Kirova, Polina; Pugliese, Anna Maria; Giovannini, Maria Grazia

2013-11-01

The present study was aimed at establishing a link between the cholinergic system and the pathway of mTOR and its downstream effector p70S6K, likely actors in long term memory encoding. We performed in vivo behavioral experiments using the step down inhibitory avoidance test (IA) in adult Wistar rats to evaluate memory formation under different conditions, and immunohistochemistry on hippocampal slices to evaluate the level and the time-course of mTOR and p70S6K activation. We also examined the effect of RAPA, inhibitor of mTORC1 formation, and of the acetylcholine (ACh) muscarinic receptor antagonist scopolamine (SCOP) or ACh nicotinic receptor antagonist mecamylamine (MECA) on short and long term memory formation and on the functionality of the mTOR pathway. Acquisition test was performed 30 min after i.c.v. injection of RAPA, a time sufficient for the drug to diffuse to CA1 pyramidal neurons, as demonstrated by MALDI-TOF-TOF imaging. Recall test was performed 1 h, 4 h or 24 h after acquisition. To confirm our results we performed in vitro experiments on live hippocampal slices: we evaluated whether stimulation of the cholinergic system with the cholinergic receptor agonist carbachol (CCh) activated the mTOR pathway and whether the administration of the above-mentioned antagonists together with CCh could revert this activation. We found that (1) mTOR and p70S6K activation in the hippocampus were involved in long term memory formation; (2) RAPA administration caused inhibition of mTOR activation at 1 h and 4 h and of p70S6K activation at 4 h, and long term memory impairment at 24 h after acquisition; (3) scopolamine treatment caused short but not long term memory impairment with an early increase of mTOR/p70S6K activation at 1 h followed by stabilization at longer times; (4) mecamylamine plus scopolamine treatment caused short term memory impairment at 1 h and 4 h and reduced the scopolamine-induced increase of mTOR/p70S6K activation at 1 h and 4 h; (5

Interaction between anti-Alzheimer and antipsychotic drugs in modulating extrapyramidal motor disorders in mice

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Saki Shimizu

2015-04-01

Full Text Available Antipsychotics are often used in conjunction with anti-Alzheimer drugs to treat the behavioral and psychological symptoms of dementia (BPSD. Here, we examined the effects of cholinesterase inhibitors (ChEIs, donepezil and galantamine, on antipsychotic-induced extrapyramidal side effects (EPS in mice. The effects of serotonergic agents on the EPS drug interaction were also evaluated. Donepezil (0.3–3 mg/kg did not induce EPS signs by itself; however, it significantly potentiated bradykinesia induction with a low dose of haloperidol (0.5 mg/kg in dose-dependent and synergistic manners. Galantamine (0.3–3 mg/kg elicited mild bradykinesia at a high dose and dose-dependently augmented haloperidol-induced bradykinesia. The EPS potentiation by galantamine was blocked by trihexyphenidyl (a muscarinic antagonist, but not by mecamylamine (a nicotinic antagonist. In addition, the bradykinesia potentiation by galantamine was significantly reduced by (±-8-hydroxy-2-(di-n-propylamino-tetralin (a 5-HT1A agonist, ritanserin (a 5-HT2 antagonist, and SB-258585 (a 5-HT6 antagonist. The present results give us a caution for the antipsychotics and ChEIs interaction in inducing EPS in the treatment of BPSD. In addition, second generation antipsychotics, which can stimulate 5-HT1A receptors or antagonize 5-HT2 and 5-HT6 receptors, seem to be favorable as an adjunctive therapy for BPSD.

Use of Nicotine in Electronic Nicotine and Non-Nicotine Delivery Systems by US Adults, 2015.

Science.gov (United States)

Weaver, Scott R; Kemp, Catherine B; Heath, J Wesley; Pechacek, Terry F; Eriksen, Michael P

Nicotine in electronic nicotine and non-nicotine delivery systems (ENDS/ENNDS) may present a risk of harm to those with cardiovascular disease and the fetuses of pregnant women. We assessed the extent to which adult users of ENDS/ENNDS used these products with nicotine. We obtained data for this study from a national probability survey of 6051 US adults that was conducted in August and September 2015. Of 399 adult ENDS/ENNDS users who were current smokers, 337 (80.7%) used ENDS/ENNDS containing nicotine, whereas only 29 of 71 (36.9%) ENDS/ENNDS users who were never smokers used ENDS/ENNDS containing nicotine. Assessments of the population health impact of ENDS/ENNDS use among never smokers should take into account the extent to which use involves nicotine.

Acquisition and reinstatement of ethanol-induced conditioned place preference in rats: Effects of the cholinesterase inhibitors donepezil and rivastigmine.

Science.gov (United States)

Gawel, Kinga; Labuz, Krzysztof; Gibula-Bruzda, Ewa; Jenda, Malgorzata; Marszalek-Grabska, Marta; Silberring, Jerzy; Kotlinska, Jolanta H

2016-07-01

The present study examined the influence of the cholinesterase inhibitors donepezil (a selective inhibitor of acetylcholinesterase) and rivastigmine (also an inhibitor of butyrylcholinesterase) on the acquisition and reinstatement of ethanol-induced conditioned place preference (CPP) in rats. Before the CPP procedure, animals received a single injection of ethanol (0.5 g/kg, 10% w/v, intraperitoneally [i.p.]) for 15 days. The ethanol-induced CPP (biased method) was developed by four injections of ethanol (0.5 g/kg, 10% w/v, i.p.) every second day. Control rats received saline instead of ethanol. Donepezil (0.5, 1 or 3 mg/kg, i.p.) or rivastigmine (0.03, 0.5 or 1 mg/kg, i.p.) were administered before ethanol during conditioning or before the reinstatement of ethanol-induced CPP. The cholinesterase inhibitors were equally effective in increasing (dose dependently) the acquisition of ethanol-induced CPP. Furthermore, priming injections of both inhibitors reinstated (cross-reinstatement) the ethanol-induced CPP with similar efficacy. These effects of both cholinesterase inhibitors were reversed by mecamylamine (3 mg/kg, i.p.), a nicotinic acetylcholine receptor antagonist, but not by scopolamine (0.5 mg/kg, i.p.), a muscarinic acetylcholine receptor antagonist. Thus, our results show that the cholinergic system is involved in the reinforcing properties of ethanol, and nicotinic acetylcholine receptors play an important role in the relapse to ethanol-seeking behaviour. © The Author(s) 2016.

A synthetic combinatorial strategy for developing a-conotoxin analogs as potent a7 nicotinic acetylcholine receptor antagonists

DEFF Research Database (Denmark)

Armishaw, Christopher J; Singh, Narender; Medina-Franco, Jose L

2010-01-01

alpha-Conotoxins are peptide neurotoxins isolated from venomous cone snails that display exquisite selectivity for different subtypes of nicotinic acetylcholine receptors (nAChR). They are valuable research tools that have profound implications in the discovery of new drugs for a myriad of neurop......alpha-Conotoxins are peptide neurotoxins isolated from venomous cone snails that display exquisite selectivity for different subtypes of nicotinic acetylcholine receptors (nAChR). They are valuable research tools that have profound implications in the discovery of new drugs for a myriad...

Effects of Nicotine Metabolites on Nicotine Withdrawal Behaviors in Mice.

Science.gov (United States)

Elhassan, Sagi; Bagdas, Deniz; Damaj, M Imad

2017-06-01

Rodent studies suggest that nicotine metabolites and minor tobacco alkaloids such as nornicotine and cotinine may promote cigarette smoking by enhancing nicotine rewarding and reinforcing effects. However, there is little information on the effects of these minor tobacco alkaloids on nicotine withdrawal. The present studies were conducted to determine whether the minor tobacco alkaloids nornicotine and cotinine exhibit nicotine-like behavioral effects in a mouse model of spontaneous nicotine withdrawal. Mice were infused with nicotine or saline for 14 days. Experiments were conducted on day 15, 18-24 hours after minipump removal. Ten minutes prior to testing, nicotine-dependent ICR male mice received an acute injection of nicotine (0.05 and 0.5 mg/kg), nornicotine (2.5 and 25 mg/kg), or cotinine (5 and 50 mg/kg) to determine effects on somatic signs, anxiety-like behaviors, and hyperalgesia spontaneous signs of withdrawal. Nicotine and the minor tobacco alkaloid nornicotine, but not cotinine, produced dose-dependent reversal of nicotine withdrawal signs in the mouse. The minor tobacco alkaloid and nicotine metabolite nornicotine at high doses have nicotinic like effects that may contribute to tobacco consumption and dependence. © The Author 2017. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effects of chronic sazetidine-A, a selective α4β2 neuronal nicotinic acetylcholine receptors desensitizing agent on pharmacologically-induced impaired attention in rats.

Science.gov (United States)

Rezvani, Amir H; Cauley, Marty; Xiao, Yingxian; Kellar, Kenneth J; Levin, Edward D

2013-03-01

Nicotine and nicotinic agonists have been shown to improve attentional function. Nicotinic receptors are easily desensitized, and all nicotinic agonists are also desensitizing agents. Although both receptor activation and desensitization are components of the mechanism that mediates the overall effects of nicotinic agonists, it is not clear how each of the two opposed actions contributes to attentional improvements. Sazetidine-A has high binding affinity at α4β2 nicotinic receptors and causes a relatively brief activation followed by a long-lasting desensitization of the receptors. Acute administration of sazetidine-A has been shown to significantly improve attention by reversing impairments caused by the muscarinic cholinergic antagonist scopolamine and the NMDA glutamate antagonist dizocilpine. In the current study, we tested the effects of chronic subcutaneous infusion of sazetidine-A (0, 2, or 6 mg/kg/day) on attention in Sprague-Dawley rats. Furthermore, we investigated the effects of chronic sazetidine-A treatment on attentional impairment induced by an acute administration of 0.02 mg/kg scopolamine. During the first week period, the 6-mg/kg/day sazetidine-A dose significantly reversed the attentional impairment induced by scopolamine. During weeks 3 and 4, the scopolamine-induced impairment was no longer seen, but sazetidine-A (6 mg/kg/day) significantly improved attentional performance on its own. Chronic sazetidine-A also reduced response latency and response omissions. This study demonstrated that similar to its acute effects, chronic infusions of sazetidine-A improve attentional performance. The results indicate that the desensitization of α4β2 nicotinic receptors with some activation of these receptors may play an important role in improving effects of sazetidine-A on attention.

Variable effects of nicotine, anabasine, and their interactions on parasitized bumble bees [version 2; referees: 2 approved

Directory of Open Access Journals (Sweden)

Lukas P. Thorburn

2015-12-01

Full Text Available Secondary metabolites in floral nectar have been shown to reduce parasite load in two common bumble bee species. Previous studies on the effects of nectar secondary metabolites on parasitized bees have focused on single compounds in isolation; however, in nature, bees are simultaneously exposed to multiple compounds. We tested for interactions between the effects of two alkaloids found in the nectar of Nicotiana spp. plants, nicotine and anabasine, on parasite load and mortality in bumble bees (Bombus impatiens infected with the intestinal parasite Crithidia bombi. Adult worker bees inoculated with C. bombi were fed nicotine and anabasine diet treatments in a factorial design, resulting in four nectar treatment combinations:  2 ppm nicotine, 5 ppm anabasine, 2ppm nicotine and 5 ppm anabasine together, or a control alkaloid-free solution. We conducted the experiment twice: first, with bees incubated under variable environmental conditions (‘Variable’; temperatures varied from 10-35°C with ambient lighting; and second, under carefully controlled environmental conditions (‘Stable’; 27°C incubator, constant darkness. In ‘Variable’, each alkaloid alone significantly decreased parasite loads, but this effect was not realized with the alkaloids in combination, suggesting an antagonistic interaction. Nicotine but not anabasine significantly increased mortality, and the two compounds had no interactive effects on mortality. In ‘Stable’, nicotine significantly increased parasite loads, the opposite of its effect in ‘Variable’. While not significant, the relationship between anabasine and parasite loads was also positive. Interactive effects between the two alkaloids on parasite load were non-significant, but the pattern of antagonistic interaction was similar to that in the variable experiment. Neither alkaloid, nor their interaction, significantly affected mortality under controlled conditions. Our results do not indicate synergy

Design, synthesis and biological evaluation of Erythrina alkaloid analogues as neuronal nicotinic acetylcholine receptor antagonists

DEFF Research Database (Denmark)

Crestey, François; Jensen, Anders A.; Borch, Morten

2013-01-01

The synthesis of a new series of Erythrina alkaloid analogues and their pharmacological characterization at various nicotine acetylcholine receptor (nAChR) subtypes are described. The compounds were designed to be simplified analogues of aromatic erythrinanes with the aim of obtaining subtype...

Cigarette nicotine yields and nicotine intake among Japanese male workers

OpenAIRE

Ueda, K; Kawachi, I; Nakamura, M; Nogami, H; Shirokawa, N; Masui, S; Okayama, A; Oshima, A

2002-01-01

Objectives: To analyse brand nicotine yield including "ultra low" brands (that is, cigarettes yielding ≤ 0.1 mg of nicotine by Federal Trade Commission (FTC) methods) in relation to nicotine intake (urinary nicotine, cotinine and trans-3'-hydroxycotinine) among 246 Japanese male smokers.

Nicotine Lozenges

Science.gov (United States)

Nicotine lozenges are used to help people stop smoking. Nicotine lozenges are in a class of medications called smoking cessation aids. They work by providing nicotine to your body to decrease the withdrawal symptoms ...

Fluoxetine induces vasodilatation of cerebral arterioles by co-modulating NO/muscarinic signalling

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Ofek, Keren; Schoknecht, Karl; Melamed-Book, Naomi; Heinemann, Uwe; Friedman, Alon; Soreq, Hermona

2012-01-01

Ischaemic stroke patients treated with Selective Serotonin Reuptake Inhibitors (SSRI) show improved motor, cognitive and executive functions, but the underlying mechanism(s) are incompletely understood. Here, we report that cerebral arterioles in the rat brain superfused with therapeutically effective doses of the SSRI fluoxetine showed consistent, dose-dependent vasodilatation (by 1.2 to 1.6-fold), suppressible by muscarinic and nitric oxide synthase (NOS) antagonists [atropine, NG-nitro-l-arginine methyl ester (l-NAME)] but resistant to nicotinic and serotoninergic antagonists (mecamylamine, methylsergide). Fluoxetine administered 10–30 min. following experimental vascular photo-thrombosis increased arterial diameter (1.3–1.6), inducing partial, but lasting reperfusion of the ischaemic brain. In brain endothelial b.End.3 cells, fluoxetine induced rapid muscarinic receptor-dependent increases in intracellular [Ca2+] and promoted albumin- and eNOS-dependent nitric oxide (NO) production and HSP90 interaction. In vitro, fluoxetine suppressed recombinant human acetylcholinesterase (rhAChE) activity only in the presence of albumin. That fluoxetine induces vasodilatation of cerebral arterioles suggests co-promotion of endothelial muscarinic and nitric oxide signalling, facilitated by albumin-dependent inhibition of serum AChE. PMID:22697296

ANTAGONISM OF PROGESTERONE RECEPTOR SUPPRESSES CAROTID BODY RESPONSES TO HYPOXIA AND NICOTINE IN RAT PUPS

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JOSEPH, V.; NIANE, L. M.; BAIRAM, A.

2013-01-01

We tested the hypothesis that antagonism of progesterone receptor (PR) in newborn rats alters carotid body and respiratory responses to hypoxia and nicotinic receptor agonists. Rats were treated with the PR antagonist mifepristone (daily oral gavage 40 μg/g/d) or vehicle between post-natal days 3 and 15. In 11–14-day-old rats, we used in vitro carotid body/carotid sinus nerve preparation and whole body plethysmography to assess the carotid body and ventilatory responses to hypoxia (65 mmHg in vitro, 10% O2 in vivo) and to nicotinic receptor agonists (as an excitatory modulator of carotid body activity—nicotine 100 μM for in vitro studies, and epibatidine 5 μg/kg, i.p., which mainly acts on peripheral nicotinic receptors, for in vivo studies). The carotid body responses to hypoxia and nicotine were drastically reduced by mifepristone. Compared with vehicle, mifepristone-treated rats had a reduced body weight. The ventilatory response to epibatidine was attenuated; however, the hypoxic ventilatory response was similar between vehicle and mifepristone-treated pups. Immunohistochemical staining revealed that mifepristone treatment did not change carotid body morphology. We conclude that PR activity is a critical factor ensuring proper carotid body function in newborn rats. PMID:22326965

Nicotine self-administration and reinstatement of nicotine-seeking in male and female rats.

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Feltenstein, Matthew W; Ghee, Shannon M; See, Ronald E

2012-03-01

Tobacco addiction is a relapsing disorder that constitutes a substantial worldwide health problem, with evidence suggesting that nicotine and nicotine-associated stimuli play divergent roles in maintaining smoking behavior in men and women. While animal models of tobacco addiction that utilize nicotine self-administration have become more widely established, systematic examination of the multiple factors that instigate relapse to nicotine-seeking have been limited. Here, we examined nicotine self-administration and subsequent nicotine-seeking in male and female Sprague-Dawley rats using an animal model of self-administration and relapse. Rats lever pressed for nicotine (0.03 and 0.05 mg/kg/infusion, IV) during 15 daily 2-h sessions, followed by extinction of lever responding. Once responding was extinguished, we examined the ability of previously nicotine-paired cues (tone+light), the anxiogenic drug yohimbine (2.5mg/kg, IP), a priming injection of nicotine (0.3mg/kg, SC), or combinations of drug+cues to reinstate nicotine-seeking. Both males and females readily acquired nicotine self-administration and displayed comparable levels of responding and intake at both nicotine doses. Following extinction, exposure to the previously nicotine-paired cues or yohimbine, but not the nicotine-prime alone, reinstated nicotine-seeking in males and females. Moreover, when combined with nicotine-paired cues, both yohimbine and nicotine enhanced reinstatement. No significant sex differences or estrous cycle dependent changes were noted across reinstatement tests. These results demonstrate the ability to reinstate nicotine-seeking with multiple modalities and that exposure to nicotine-associated cues during periods of a stressful state or nicotine can increase nicotine-seeking. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Autoradiographic localization of putative nicotinic receptors in the rat brain using 125I-neuronal bungarotoxin

International Nuclear Information System (INIS)

Schulz, D.W.; Loring, R.H.; Aizenman, E.; Zigmond, R.E.

1991-01-01

Neuronal bungarotoxin (NBT), a snake venom neurotoxin, selectively blocks nicotinic receptors in many peripheral and central neuronal preparations. alpha-Bungarotoxin (alpha BT), on the other hand, a second toxin isolated from the venom of the same snake, is an ineffective nicotinic antagonist in most vertebrate neuronal preparations studied thus far. To examine central nicotinic receptors recognized by NBT, we have characterized the binding of 125I-labeled NBT (125I-NBT) to rat brain membranes and have mapped the distribution of 125I-NBT binding in brain sections using quantitative light microscopic autoradiography. The binding of 125I-NBT was found to be saturable, of high affinity, and heterogeneously distributed in the brain. Pharmacological studies suggested that more than one population of sites is labeled by 125I-NBT. For example, one component of 125I-NBT binding was also recognized by alpha BT, while a second component, not recognized by alpha BT, was recognized by the nicotinic agonist nicotine. The highest densities of these alpha BT-insensitive, nicotine-sensitive sites were found in the fasciculus retroflexus, the lateral geniculate nucleus, the medial terminal nucleus of the accessory optic tract, and the olivary pretectal nucleus. alpha BT-sensitive NBT binding sites were found in highest density in the lateral geniculate nucleus, the subthalamic nucleus, the dorsal tegmental nucleus, and the medial mammillary nucleus (lateral part). The number of brain regions with a high density of 125I-NBT binding sites, blocked either by alpha BT or by nicotine, is low when compared with results obtained using other approaches to studying the central distribution of nicotinic receptors, such as labeling with 3H-nicotine or labeling with cDNA probes to mRNAs coding for putative receptor subunits

Evaluation of nicotine in tobacco-free-nicotine commercial products.

Science.gov (United States)

Hellinghausen, Garrett; Lee, Jauh T; Weatherly, Choyce A; Lopez, Diego A; Armstrong, Daniel W

2017-06-01

Recently, a variety of new tobacco-free-nicotine, TFN, products have been commercialized as e-liquids. Tobacco-derived nicotine contains predominantly (S)-(-)-nicotine, whereas TFN products may not. The TFN products are said to be cleaner, purer substances, devoid of toxic components that come from the tobacco extraction process. A variety of commercial tobacco and TFN products were analyzed to identify the presence and composition of each nicotine enantiomer. A rapid and effective enantiomeric separation of nicotine has been developed using a modified macrocyclic glycopeptide bonded to superficially porous particles. The enantiomeric assay can be completed in nicotine, which is present in much greater quantities in commercial TFN products compared to commercial tobacco-derived products. Such studies are required by the FDA for new enantiomeric pharmacological products. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Alpha-conotoxin analogs with additional positive charge show increased selectivity towards Torpedo californica and some neuronal subtypes of nicotinic acetylcholine receptors

NARCIS (Netherlands)

Kasheverov, I.E.; Zhmak, M.N.; Vulfius, C.A.; Corbacheva, E.V.; Mordvintsev, D.Y.; Utkin, Y.N.; van Elk, R.; Smit, A.B.; Tsetlin, V.I.

2006-01-01

α-Conotoxins from Conus snails are indispensable tools for distinguishing various subtypes of nicotinic acetylcholine receptors (nAChRs), and synthesis of α-conotoxin analogs may yield novel antagonists of higher potency and selectivity. We incorporated additional positive charges into α-conotoxins

Effect of urinary pH and nicotine excretion rate on plasma nicotine during cigarette smoking and chewing nicotine gum

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Feyerabend, C.; Russell, M. A. H.

1978-01-01

1 Plasma nicotine levels produced by chewing nicotine gum were compared with those obtained by cigarette smoking under conditions of controlled urinary pH. 2 Although absorption was slower, plasma levels comparable to cigarette smoking were built up on 4 mg (but not 2 mg) nicotine gum. 3 Urinary excretion of nicotine was influenced markedly by pH and the rate of urine flow. 4 Plasma nicotine was higher under alkaline compared to acidic conditions (P < 0.001) but the rate of urinary nicotine excretion appeared to have little effect on the plasma level.

Calcium pathways such as cAMP modulate clothianidin action through activation of α-bungarotoxin-sensitive and -insensitive nicotinic acetylcholine receptors.

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Calas-List, Delphine; List, Olivier; Quinchard, Sophie; Thany, Steeve H

2013-07-01

Clothianidin is a neonicotinoid insecticide developed in the early 2000s. We have recently demonstrated that it was a full agonist of α-bungarotoxin-sensitive and -insensitive nicotinic acetylcholine receptors expressed in the cockroach dorsal unpaired median neurons. Clothianidin was able to act as an agonist of imidacloprid-insensitive nAChR2 receptor and internal regulation of cAMP concentration modulated nAChR2 sensitivity to clothianidin. In the present study, we demonstrated that cAMP modulated the agonist action of clothianidin via α-bungarotoxin-sensitive and insensitive receptors. Clothianidin-induced current-voltage curves were dependent to clothianidin concentrations. At 10 μM clothianidin, increasing cAMP concentration induced a linear current-voltage curve. Clothianidin effects were blocked by 0.5 μM α-bungarotoxin suggesting that cAMP modulation occurred through α-bungarotoxin-sensitive receptors. At 1 mM clothianidin, cAMP effects were associated to α-bungarotoxin-insensitive receptors because clothianidin-induced currents were blocked by 5 μM mecamylamine and 20 μM d-tubocurarine. In addition, we found that application of 1mM clothianidin induced a strong increase of intracellular calcium concentration. These data reinforced the finding that calcium pathways including cAMP modulated clothianidin action on insect nicotinic acetylcholine receptors. We proposed that intracellular calcium pathways such as cAMP could be a target to modulate the mode of action of neonicotinoid insecticides. Copyright © 2013 Elsevier Inc. All rights reserved.

Nicotine response and nicotinic receptors in long-sleep and short-sleep mice.

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De Fiebre, C M; Medhurst, L J; Collins, A C

1987-01-01

Nicotine response and nicotinic receptor binding were characterized in long-sleep (LS) and short-sleep (SS) mice which have been selectively bred for differential "sleep-time" following ethanol administration. LS mice are more sensitive than SS mice to nicotine as measured by a battery of behavioral and physiological tests and as measured by sensitivity to nicotine-induced seizures. The greater sensitivity of the LS mice is not due to differences in binding of [3H]nicotine. Unlike inbred mouse strains which differ in sensitivity to nicotine-induced seizures, these selected mouse lines do not differ in levels of binding of [125I]alpha-bungarotoxin (BTX) in the hippocampus. Significant differences in BTX binding were found in the cerebellum and striatum. Although these two mouse lines do not differ in blood levels of nicotine following nicotine administration, they differ slightly in brain levels of nicotine indicating differential distribution of the drug. Since this distribution difference is much smaller than the observed behavioral differences, these mice probably differ in CNS sensitivity to nicotine; however, follow-up studies are necessary to test whether the differential response of these mice is due to subtle differences in distribution of nicotine to the brain.

Promoted neuronal differentiation after activation of alpha4/beta2 nicotinic acetylcholine receptors in undifferentiated neural progenitors.

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Takeshi Takarada

Full Text Available BACKGROUND: Neural progenitor is a generic term used for undifferentiated cell populations of neural stem, neuronal progenitor and glial progenitor cells with abilities for proliferation and differentiation. We have shown functional expression of ionotropic N-methyl-D-aspartate (NMDA and gamma-aminobutyrate type-A receptors endowed to positively and negatively regulate subsequent neuronal differentiation in undifferentiated neural progenitors, respectively. In this study, we attempted to evaluate the possible functional expression of nicotinic acetylcholine receptor (nAChR by undifferentiated neural progenitors prepared from neocortex of embryonic rodent brains. METHODOLOGY/PRINCIPAL FINDINGS: Reverse transcription polymerase chain reaction analysis revealed mRNA expression of particular nAChR subunits in undifferentiated rat and mouse progenitors prepared before and after the culture with epidermal growth factor under floating conditions. Sustained exposure to nicotine significantly inhibited the formation of neurospheres composed of clustered proliferating cells and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide reduction activity at a concentration range of 1 µM to 1 mM without affecting cell survival. In these rodent progenitors previously exposed to nicotine, marked promotion was invariably seen for subsequent differentiation into cells immunoreactive for a neuronal marker protein following the culture of dispersed cells under adherent conditions. Both effects of nicotine were significantly prevented by the heteromeric α4β2 nAChR subtype antagonists dihydro-β-erythroidine and 4-(5-ethoxy-3-pyridinyl-N-methyl-(3E-3-buten-1-amine, but not by the homomeric α7 nAChR subtype antagonist methyllycaconitine, in murine progenitors. Sustained exposure to nicotine preferentially increased the expression of Math1 among different basic helix-loop-helix proneural genes examined. In undifferentiated progenitors from embryonic mice

Acute effects of nicotine amplify accumbal neural responses during nicotine-taking behavior and nicotine-paired environmental cues.

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Karine Guillem

Full Text Available Nicotine self-administration (SA is maintained by several variables, including the reinforcing properties of nicotine-paired cues and the nicotine-induced amplification of those cue properties. The nucleus accumbens (NAc is implicated in mediating the influence of these variables, though the underlying neurophysiological mechanisms are not yet understood. In the present study, Long-Evans rats were trained to self-administer nicotine. During SA sessions each press of a lever was followed by an intravenous infusion of nicotine (30 µg/kg paired with a combined light-tone cue. Extracellular recordings of single-neuron activity showed that 20% of neurons exhibited a phasic change in firing during the nicotine-directed operant, the light-tone cue, or both. The phasic change in firing for 98% of neurons was an increase. Sixty-two percent of NAc neurons additionally or alternatively showed a sustained decrease in average firing during the SA session relative to a presession baseline period. These session decreases in firing were significantly less prevalent in a group of neurons that were activated during either the operant or the cue than in a group of neurons that were nonresponsive during those events (referred to as task-activated and task-nonactivated neurons, respectively. Moreover, the session decrease in firing was dose-dependent for only the task-nonactivated neurons. The data of the present investigation provide supportive correlational evidence for two hypotheses: (1 excitatory neurophysiological mechanisms mediate the NAc role in cue-maintenance of nicotine SA, and (2 a differential nicotine-induced inhibition of task-activated and task-nonactivated neurons mediates the NAc role in nicotine-induced amplification of cue effects on nicotine SA.

Modulatory action of acetylcholine on the Na+-dependent action potentials in Kenyon cells isolated from the mushroom body of the cricket brain.

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Terazima, E; Yoshino, M

2010-12-01

Kenyon cells, intrinsic neurons of the insect mushroom body, have been assumed to be a site of conditioning stimulus (CS) and unconditioned stimulus (US) association in olfactory learning and memory. Acetylcholine (ACh) has been implicated to be a neurotransmitter mediating CS reception in Kenyon cells, causing rapid membrane depolarization via nicotinic ACh receptors. However, the long-term effects of ACh on the membrane excitability of Kenyon cells are not fully understood. In this study, we examined the effects of ACh on Na(+) dependent action potentials (Na(+) spikes) elicited by depolarizing current injection and on net membrane currents under the voltage clamp condition in Kenyon cells isolated from the mushroom body of the cricket Gryllus bimaculatus. Current-clamp studies using amphotericin B perforated-patch recordings showed that freshly dispersed cricket Kenyon cells could produce repetitive Na(+) spikes in response to prolonged depolarizing current injection. Bath application of ACh increased both the instantaneous frequency and the amplitudes of Na(+) spikes. This excitatory action of ACh on Kenyon cells is attenuated by the pre-treatment of the cells with the muscarinic receptor antagonists, atropine and scopolamine, but not by the nicotinic receptor antagonist mecamylamine. Voltage-clamp studies further showed that bath application of ACh caused an increase in net inward currents that are sensitive to TTX, whereas outward currents were decreased by this treatment. These results indicate that in order to mediate CS, ACh may modulate the firing properties of Na(+) spikes of Kenyon cells through muscarinic receptor activation, thus increasing Na conductance and decreasing K conductance. Copyright © 2010 Elsevier Ltd. All rights reserved.

Effects of nicotine and nicotine expectancy on attentional bias for emotional stimuli.

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Adams, Sally; Attwood, Angela S; Munafò, Marcus R

2015-06-01

Nicotine's effects on mood are thought to enhance its addictive potential. However, the mechanisms underlying the effects of nicotine on affect regulation have not been reliably demonstrated in human laboratory studies. We investigated the effects of nicotine abstinence (Experiment 1), and nicotine challenge and expectancy (Experiment 2) on attentional bias towards facial emotional stimuli differing in emotional valence. In Experiment 1, 46 nicotine-deprived smokers were randomized to either continue to abstain from smoking or to smoke immediately before testing. In Experiment 2, 96 nicotine-deprived smokers were randomized to smoke a nicotinized or denicotinized cigarette and to be told that the cigarette did or did not contain nicotine. In both experiments participants completed a visual probe task, where positively valenced (happy) and negatively valenced (sad) facial expressions were presented, together with neutral facial expressions. In Experiment 1, there was evidence of an interaction between probe location and abstinence on reaction time, indicating that abstinent smokers showed an attentional bias for neutral stimuli. In Experiment 2, there was evidence of an interaction between probe location, nicotine challenge and expectation on reaction time, indicating that smokers receiving nicotine, but told that they did not receive nicotine, showed an attentional bias for emotional stimuli. Our data suggest that nicotine abstinence appears to disrupt attentional bias towards emotional facial stimuli. These data provide support for nicotine's modulation of attentional bias as a central mechanism for maintaining affect regulation in cigarette smoking. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Nicotinic plant poisoning.

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Schep, Leo J; Slaughter, Robin J; Beasley, D Michael G

2009-09-01

A wide range of plants contain nicotinic and nicotinic-like alkaloids. Of this diverse group, those that have been reported to cause human poisoning appear to have similar mechanisms of toxicity and presenting patients therefore have comparable toxidromes. This review describes the taxonomy and principal alkaloids of plants that contain nicotinic and nicotinic-like alkaloids, with particular focus on those that are toxic to humans. The toxicokinetics and mechanisms of toxicity of these alkaloids are reviewed and the clinical features and management of poisoning due to these plants are described. This review was compiled by systematically searching OVID MEDLINE and ISI Web of Science. This identified 9,456 papers, excluding duplicates, all of which were screened. Reviewed plants and their principal alkaloids. Plants containing nicotine and nicotine-like alkaloids that have been reported to be poisonous to humans include Conium maculatum, Nicotiana glauca and Nicotiana tabacum, Laburnum anagyroides, and Caulophyllum thalictroides. They contain the toxic alkaloids nicotine, anabasine, cytisine, n-methylcytisine, coniine, n-methylconiine, and gamma-coniceine. These alkaloids act agonistically at nicotinic-type acetylcholine (cholinergic) receptors (nAChRs). The nicotinic-type acetylcholine receptor can vary both in its subunit composition and in its distribution within the body (the central and autonomic nervous systems, the neuromuscular junctions, and the adrenal medulla). Agonistic interaction at these variable sites may explain why the alkaloids have diverse effects depending on the administered dose and duration of exposure. Nicotine and nicotine-like alkaloids are absorbed readily across all routes of exposure and are rapidly and widely distributed, readily traversing the blood-brain barrier and the placenta, and are freely distributed in breast milk. Metabolism occurs predominantly in the liver followed by rapid renal elimination. Following acute exposure

R-Modafinil Attenuates Nicotine-Taking and Nicotine-Seeking Behavior in Alcohol-Preferring Rats

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Wang, Xiao-Fei; Bi, Guo-Hua; He, Yi; Yang, Hong-Ju; Gao, Jun-Tao; Okunola-Bakare, Oluyomi M; Slack, Rachel D; Gardner, Eliot L; Xi, Zheng-Xiong; Newman, Amy Hauck

2015-01-01

(±)-Modafinil (MOD) is used clinically for the treatment of sleep disorders and has been investigated as a potential medication for the treatment of psychostimulant addiction. However, the therapeutic efficacy of (±)-MOD for addiction is inconclusive. Herein we used animal models of self-administration and in vivo microdialysis to study the pharmacological actions of R-modafinil (R-MOD) and S-modafinil (S-MOD) on nicotine-taking and nicotine-seeking behavior, and mechanisms underlying such actions. We found that R-MOD is more potent and effective than S-MOD in attenuating nicotine self-administration in Long–Evans rats. As Long–Evans rats did not show a robust reinstatement response to nicotine, we used alcohol-preferring rats (P-rats) that display much higher reinstatement responses to nicotine than Long–Evans rats. We found that R-MOD significantly inhibited intravenous nicotine self-administration, nicotine-induced reinstatement, and nicotine-associated cue-induced drug-seeking behavior in P-rats. R-MOD alone neither sustained self-administration in P-rats previously self-administering nicotine nor reinstated extinguished nicotine-seeking behavior. The in vivo brain microdialysis assays demonstrated that R-MOD alone produced a slow-onset moderate increase in extracellular DA. Pretreatment with R-MOD dose-dependently blocked nicotine-induced dopamine (DA) release in the nucleus accumbens (NAc) in both naive and nicotine self-administrating rats, suggesting a DA-dependent mechanism underlying mitigation of nicotine's effects. In conclusion, the present findings support further investigation of R-MOD for treatment of nicotine dependence in humans. PMID:25613829

Nicotine replacement therapy

Science.gov (United States)

Smoking cessation - nicotine replacement; Tobacco - nicotine replacement therapy ... Before you start using a nicotine replacement product, here are some things to know: The more cigarettes you smoke, the higher the dose you may need to ...

Positron emission tomography (PET) imaging of nicotine-induced dopamine release in squirrel monkeys using [18F]Fallypride.

Science.gov (United States)

Naylor, Jennifer E; Hiranita, Takato; Matazel, Katelin S; Zhang, Xuan; Paule, Merle G; Goodwin, Amy K

2017-10-01

Nicotine, the principal psychoactive tobacco constituent, is thought to produce its reinforcing effects via actions within the mesolimbic dopamine (DA) system. The objective of the current study was to examine the effect of nicotine on DA D 2 /D 3 receptor availability in the nonhuman primate brain with the use of the radioligand [ 18 F]fallypride and positron emission tomography (PET). Ten adult male squirrel monkeys were used in the current study. Each subject underwent two PET scans, one with an injection (IV) of saline and subsequently one with an injection of nicotine (0.032mg/kg). The DA D 2 /D 3 antagonist, [ 18 F]fallypride, was delivered IV at the beginning of each scan, and nicotine or saline was delivered at 45min into the scan. Regions of interest (ROI) were drawn on specific brain regions and these were used to quantify standard uptake values (SUVs). The SUV is defined as the average concentration of radioactivity in the ROI x body weight/injected dose. Using the cerebellum as a reference region, SUV ratios (SUV ROI /SUV cerebellum ) were calculated to compare saline and nicotine effects in each ROI. Two-way repeated ANOVA revealed a significant decrease of SUV ratios in both striatal and extrastriatal regions following an injection of nicotine during the PET scans. Like other drugs of abuse, these results indicate that nicotine administration may produce DA release, as suggested by the decrease in [ 18 F]fallypride signal in striatal regions. These findings from a nonhuman primate model provide further evidence that the mesolimbic DA system is affected by the use of products that contain nicotine. Published by Elsevier B.V.

Endogenous opioids inhibit oxytocin release during nicotine-stimulated secretion of vasopressin in man.

Science.gov (United States)

Seckl, J R; Johnson, M; Shakespear, C; Lightman, S L

1988-05-01

The effects of the opioid antagonist naloxone on the vasopressin (AVP) and oxytocin (OT) responses to nicotine were studied in male non-smokers (21-30 years old). Either saline (n = 6) or naloxone (4 mg bolus + 6 mg/h, n = 6) was infused i.v. during the study. After 60 min infusion the subjects smoked one high-nicotine content cigarette. Naloxone infusion for 60 min did not alter basal plasma AVP or OT levels. Smoking led to a significant rise in plasma vasopressin in both saline and naloxone-infused subjects (P less than 0.05). There was no significant difference in the plasma AVP response to smoking between the two groups. Saline-infused subjects did not show any change in plasma OT in response to smoking. Naloxone infusion was associated with a significant rise in OT from 1.3 +/- 0.1 pmol/l to 4.3 +/- 2.4 pmol/l 5 min after smoking (P less than 0.05). We conclude that there is endogenous opioid-mediated inhibition of OT which prevents its release when AVP is secreted in response to nicotine in man.

Orexin 1 receptor antagonists in compulsive behaviour and anxiety: possible therapeutic use.

Directory of Open Access Journals (Sweden)

Emilio eMerlo-Pich

2014-02-01

Full Text Available Fifteen years after the discovery of hypocretin/orexin a large body of evidence has been collected supporting its critical role in the modulation of several regulatory physiological functions. While reduced levels of hypocretin/orexin were early on associated with narcolepsy, increased levels have been linked in recent years to pathological states of hypervigilance and, in particular, to insomnia. The filing to FDA of the dual-activity orexin receptor antagonist (DORA suvorexant for the indication of insomnia further corroborates the robustness of such evidences. However, as excessive vigilance is also typical of anxiety and panic episodes, as well as of abstinence and craving in substance misuse disorders, in this review we briefly discuss the evidence supporting the development of hypocretin/orexin receptor 1 (OX1 antagonists for these indications. Experiments using the OX1 antagonist SB-334867 and mutant mice have involved the OX1 receptor in mediating the compulsive reinstatement of drug seeking for ethanol, nicotine, cocaine, cannabinoids and morphine. More recently, data have been generated with the novel selective OX1 antagonists GSK1059865 and ACT-335827 on behavioural and cardiovascular response to stressors and panic-inducing agents in animals. Concluding, while waiting for pharmacologic data to become available in humans, risks and benefits for the development of an OX1 receptor antagonist for Binge Eating and Anxiety Disorders are discussed.

The Influence of Puff Characteristics, Nicotine Dependence, and Rate of Nicotine Metabolism on Daily Nicotine Exposure in African American Smokers.

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Ross, Kathryn C; Dempsey, Delia A; St Helen, Gideon; Delucchi, Kevin; Benowitz, Neal L

2016-06-01

African American (AA) smokers experience greater tobacco-related disease burden than Whites, despite smoking fewer cigarettes per day (CPD). Understanding factors that influence daily nicotine intake in AA smokers is an important step toward decreasing tobacco-related health disparities. One factor of interest is smoking topography, or the study of puffing behavior. (i) to create a model using puff characteristics, nicotine dependence, and nicotine metabolism to predict daily nicotine exposure, and (ii) to compare puff characteristics and nicotine intake from two cigarettes smoked at different times to ensure the reliability of the puff characteristics included in our model. Sixty AA smokers smoked their preferred brand of cigarette at two time points through a topography device. Plasma nicotine, expired CO, and changes in subjective measures were measured before and after each cigarette. Total nicotine equivalents (TNE) was measured from 24-hour urine collected during ad libitum smoking. In a model predicting daily nicotine exposure, total puff volume, CPD, sex, and menthol status were significant predictors (R(2) = 0.44, P smokers. Cancer Epidemiol Biomarkers Prev; 25(6); 936-43. ©2016 AACR. ©2016 American Association for Cancer Research.

Central estrogenic pathways protect against the depressant action of acute nicotine on reflex tachycardia in female rats

International Nuclear Information System (INIS)

El-Mas, Mahmoud M.; Fouda, Mohamed A.; El-gowilly, Sahar M.; Saad, Evan I.

2012-01-01

We have previously shown that acute exposure of male rats to nicotine preferentially attenuates baroreceptor-mediated control of reflex tachycardia in contrast to no effect on reflex bradycardia. Here, we investigated whether female rats are as sensitive as their male counterparts to the baroreflex depressant effect of nicotine and whether this interaction is modulated by estrogen. Baroreflex curves relating reflex chronotropic responses evoked by i.v. doses (1–16 μg/kg) of phenylephrine (PE) or sodium nitroprusside (SNP), were constructed in conscious freely moving proestrus, ovariectomized (OVX), and estrogen (50 μg/kg/day s.c., 5 days)-replaced OVX (OVXE 2 ) rats. Slopes of the curves were taken as a measure of baroreflex sensitivity (BRS PE and BRS SNP ). Nicotine (100 μg/kg i.v.) reduced BRS SNP in OVX rats but not in proestrus or OVXE 2 rats. The attenuation of reflex tachycardia by nicotine was also evident in diestrus rats, which exhibited plasma estrogen levels similar to those of OVX rats. BRS PE was not affected by nicotine in all rat preparations. Experiments were then extended to determine whether central estrogenic receptors modulate the nicotine–BRS SNP interaction. Intracisteral (i.c.) treatment of OVX rats with estrogen sulfate (0.2 μg/rat) abolished the BRS SNP attenuating effect of i.v. nicotine. This protective effect of estrogen disappeared when OVX rats were pretreated with i.c. ICI 182,780 (50 μg/rat, selective estrogen receptor antagonist). Together, these findings suggest that central neural pools of estrogen receptors underlie the protection offered by E 2 against nicotine-induced baroreceptor dysfunction in female rats. -- Highlights: ► Estrogen protects against the depressant effect of nicotine on reflex tachycardia. ► The baroreflex response and estrogen status affect the nicotine–BRS interaction. ► The protection offered by estrogen is mediated via central estrogen receptors.

Interaction of alpha-conotoxin ImII and its analogs with nicotinic receptors and acetylcholine-binding proteins: additional binding sites on Torpedo receptor

NARCIS (Netherlands)

Kasheverov, I.E.; Zhmak, M.N.; Fish, A.; Rucktooa, P.; Khruschov, A.Y.; Osipov, A.V.; Ziganshin, R.H.; D'Hoedt, D.; Bertrand, D.; Sixma, T.K.; Smit, A.B.; Tsetlin, V.I.

2009-01-01

α-Conotoxins interact with nicotinic acetylcholine receptors (nAChRs) and acetylcholine-binding proteins (AChBPs) at the sites for agonists/competitive antagonists. α-Conotoxins blocking muscle-type or α7 nAChRs compete with α-bungarotoxin. However, α-conotoxin ImII, a close homolog of the α7

Nicotine Withdrawal Disrupts Contextual Learning but Not Recall of Prior Contextual Associations: Implications for Nicotine Addiction

OpenAIRE

Portugal, George S.; Gould, Thomas J.

2008-01-01

Interactions between nicotine and learning could contribute to nicotine addiction. Although previous research indicates that nicotine withdrawal disrupts contextual learning, the effects of nicotine withdrawal on contextual memories acquired before withdrawal are unknown. The present study investigated whether nicotine withdrawal disrupted recall of prior contextual memories by examining the effects of nicotine withdrawal on recall of nicotine conditioned place preference (CPP) and contextual...

Thermochemical Properties of Nicotine Salts

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Riggs DM

2014-12-01

Full Text Available The thermal gravimetric analysis (TGA and differential scanning calorimetry (DSC results presented in this report clearly show that the thermal stability and the endothermic peak nicotine release temperatures are different for different nicotine salts and these temperatures appear to be linked to the general microstructural details of the salt itself. In addition, the peak nicotine release temperatures are highly dependent upon the sample size used. The heat of vaporization for neat (non-protonated nicotine is also sample-size dependent. The TGA data showed that the least stable of the salts tested at elevated temperatures was the liquid salt nicotine triacetate followed by the crystalline materials (e.g., nicotine gallate and finally, the amorphous salts (e.g., nicotine alginate. The DSC results revealed that the liquid and crystalline salts exhibit nicotine release endotherms that are strongly related to the sample weight being tested. The amorphous salts show nicotine endotherm peak temperatures that are nearly independent of the sample weight. The range of peak nicotine release temperatures varied depending upon the specific salts and the sample size from 83 oC to well over 200 oC. Based on these results, the evolution of nicotine from the nicotine salt should be expected to vary based on the composition of the salt, the details of its microstructure, and the amount of nicotine salt tested.

Rapamycin inhibits mTOR/p70S6K activation in CA3 region of the hippocampus of the rat and impairs long term memory.

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Lana, D; Di Russo, J; Mello, T; Wenk, G L; Giovannini, M G

2017-01-01

The present study was aimed at establishing whether the mTOR pathway and its downstream effector p70S6K in CA3 pyramidal neurons are under the modulation of the cholinergic input to trigger the formation of long term memories, similar to what we demonstrated in CA1 hippocampus. We performed in vivo behavioral experiments using the step down inhibitory avoidance test in adult Wistar rats to evaluate memory formation under different conditions. We examined the effects of rapamycin, an inhibitor of mTORC1 formation, scopolamine, a muscarinic receptor antagonist or mecamylamine, a nicotinic receptor antagonist, on short and long term memory formation and on the functionality of the mTOR pathway. Acquisition was conducted 30min after i.c.v. injection of rapamycin. Recall testing was performed 1h, 4h or 24h after acquisition. We found that (1) mTOR and p70S6K activation in CA3 pyramidal neurons were involved in long term memory formation; (2) rapamycin significantly inhibited mTOR and of p70S6K activation at 4h, and long term memory impairment 24h after acquisition; (3) scopolamine impaired short but not long term memory, with an early increase of mTOR/p70S6K activation at 1h followed by stabilization at longer times; (4) mecamylamine and scopolamine co-administration impaired short term memory at 1h and 4h and reduced the scopolamine-induced increase of mTOR/p70S6K activation at 1h and 4h; (5) mecamylamine and scopolamine treatment did not impair long term memory formation; (6) unexpectedly, rapamycin increased mTORC2 activation in microglial cells. Our results demonstrate that in CA3 pyramidal neurons the mTOR/p70S6K pathway is under the modulation of the cholinergic system and is involved in long-term memory encoding, and are consistent with the hypothesis that the CA3 region of the hippocampus is involved in memory mechanisms based on rapid, one-trial object-place learning and recall. Furthermore, our results are in accordance with previous reports that selective

Nicotine dependence and psychiatric disorders.

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Salín-Pascual, Rafael J; Alcocer-Castillejos, Natasha V; Alejo-Galarza, Gabriel

2003-01-01

Nicotine addiction is the single largest preventable cause of morbidity and mortality in the Western World. Smoking is not any more just a bad habit, but a substance addiction problem. The pharmacological aspects of nicotine show that this substance has a broad distribution in the different body compartnents, due mainly to its lipophilic characteristic. There are nicotinic receptors as members of cholinergic receptors' family. They are located in neuromuscular junction and in the central nervous system (CNS). Although they are similar, pentameric structure with an ionic channel to sodium, there are some differences in the protein chains characteristics. Repeated administration of nicotine in rats, results in the sensitization phenomenon, which produces increase in the behavioral locomotor activity response. It has been found that most psychostimulants-induced behavioral sensitization through a nicotine receptor activation. Nicotine receptors in CNS are located mainly in presynaptic membrane and in that way they regulated the release of several neurotransmitters, among them acetylcholine, dopamine, serotonin, and norepinephrine. In some activities like sleep-wake cycle, nicotine receptors have a functional significance. Nicotine receptor stimulation promotes wake time, reduces both, total sleep time and rapid eye movement sleep (REMS). About nicotine dependence, this substance full fills all the criteria for dependence and withdrawal syndrome. There are some people that have more vulnerability for to become nicotine dependent, those are psychiatric patients. Among them schizophrenia, major depression, anxiety disorders and attention deficit disorder, represent the best example in this area. Nicotine may have some beneficial effects, among them are some neuroprotective effects in disorders like Parkinson's disease, and Gilles de la Tourette' syndrome. Also there are several evidences that support the role of nicotine in cognitive improvement functions like attention

Nicotine Dependence and Urinary Nicotine, Cotinine and Hydroxycotinine Levels in Daily Smokers

OpenAIRE

Van Overmeire, Ilse P. I.; De Smedt, Tom; Dendale, Paul; Nackaerts, Kristiaan; Vanacker, Hilde; Vanoeteren, Jan F. A.; Van Laethem, Danny M. G.; Van Loco, Joris; De Cremer, Koen A. J.

2016-01-01

Nicotine dependence and smoking frequency are critical factors for smoking cessation. The aims of this study are (1) to determine if nicotine dependence Fagerstrom Test for Nicotine Dependence (FTND) scores are associated with urinary levels of nicotine metabolites, (2) to assess the relationship of hydroxycotinine/cotinine ratio with FTND score and cigarettes smoked per day (CPD), and (3) to identify significant predictors of cigarettes per day among biomarker concentrations and individual F...

Frequency-Dependent Modulation of Dopamine Release by Nicotine and Dopamine D1 Receptor Ligands: An In Vitro Fast Cyclic Voltammetry Study in Rat Striatum.

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Goutier, W; Lowry, J P; McCreary, A C; O'Connor, J J

2016-05-01

Nicotine is a highly addictive drug and exerts this effect partially through the modulation of dopamine release and increasing extracellular dopamine in regions such as the brain reward systems. Nicotine acts in these regions on nicotinic acetylcholine receptors. The effect of nicotine on the frequency dependent modulation of dopamine release is well established and the purpose of this study was to investigate whether dopamine D1 receptor (D1R) ligands have an influence on this. Using fast cyclic voltammetry and rat corticostriatal slices, we show that D1R ligands are able to modulate the effect of nicotine on dopamine release. Nicotine (500 nM) induced a decrease in dopamine efflux at low frequency (single pulse or five pulses at 10 Hz) and an increase at high frequency (100 Hz) electrical field stimulation. The D1R agonist SKF-38393, whilst having no effect on dopamine release on its own or on the effect of nicotine upon multiple pulse evoked dopamine release, did significantly prevent and reverse the effect of nicotine on single pulse dopamine release. Interestingly similar results were obtained with the D1R antagonist SCH-23390. In this study we have demonstrated that the modulation of dopamine release by nicotine can be altered by D1R ligands, but only when evoked by single pulse stimulation, and are likely working via cholinergic interneuron driven dopamine release.

PACAP Protects Against Ethanol and Nicotine Toxicity in SH-SY5Y Cells: Implications for Drinking-Smoking Co-morbidity.

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Manavalan, Sridharan; Getachew, Bruk; Manaye, Kebreten F; Khundmiri, Syed J; Csoka, Antonei B; McKinley, Raechel; Tamas, Andrea; Reglodi, Dora; Tizabi, Yousef

2017-07-01

The detrimental effects of heavy drinking and smoking are multiplied when the two are combined. Treatment modalities for each and especially for the combination are very limited. Although in low concentration, alcohol and nicotine, each may have beneficial effects including neuroprotection, their combination, instead of providing additive protection, may actually lead to toxicity in cell cultures. Pituitary adenylate cyclase-activating polypeptide (PACAP) is an endogenous 38 amino-acid peptide with demonstrated protection against neuronal injury, trauma as well as various endogenous and exogenous toxic agents. The aim of this study was to investigate whether PACAP may also protect against toxicity induced by high alcohol, high nicotine, or the combination of low alcohol and nicotine concentrations, and if so, whether this effect was mediated via PAC1 receptor. We used the neuroblastoma-derived SH-SY5Y cells and applied various colorimetric assays for determination of cell viability or toxicity. Results indicate that PACAP blocks toxicity induced by high alcohol and high nicotine as well as their combination at low concentrations. The effects of PACAP in turn were blocked by the PACAP antagonist (PACAP 6-38), indicating involvement of the PACAP receptor PAC1 and possibly vasoactive intestinal peptide (VIP) receptors in PACAP's protection. Moreover, no combined toxicity of low alcohol and low nicotine could be detected in calcium-free medium. These findings suggest possible beneficial effects of PACAP in preventing alcohol and nicotine toxicity and that calcium contributes to the damage induced by combination of low alcohol and nicotine in SH-SY5Y cells.

Racial differences in the relationship between rate of nicotine metabolism and nicotine intake from cigarette smoking.

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Ross, Kathryn C; Gubner, Noah R; Tyndale, Rachel F; Hawk, Larry W; Lerman, Caryn; George, Tony P; Cinciripini, Paul; Schnoll, Robert A; Benowitz, Neal L

2016-09-01

Rate of nicotine metabolism has been identified as an important factor influencing nicotine intake and can be estimated using the nicotine metabolite ratio (NMR), a validated biomarker of CYP2A6 enzyme activity. Individuals who metabolize nicotine faster (higher NMR) may alter their smoking behavior to titrate their nicotine intake in order to maintain similar levels of nicotine in the body compared to slower nicotine metabolizers. There are known racial differences in the rate of nicotine metabolism with African Americans on average having a slower rate of nicotine metabolism compared to Whites. The goal of this study was to determine if there are racial differences in the relationship between rate of nicotine metabolism and measures of nicotine intake assessed using multiple biomarkers of nicotine and tobacco smoke exposure. Using secondary analyses of the screening data collected in a recently completed clinical trial, treatment-seeking African American and White daily smokers (10 or more cigarettes per day) were grouped into NMR quartiles so that the races could be compared at the same NMR, even though the distribution of NMR within race differed. The results indicated that rate of nicotine metabolism was a more important factor influencing nicotine intake in White smokers. Specifically, Whites were more likely to titrate their nicotine intake based on the rate at which they metabolize nicotine. However, this relationship was not found in African Americans. Overall there was a greater step-down, linear type relationship between NMR groups and cotinine or cotinine/cigarette in African Americans, which is consistent with the idea that differences in blood cotinine levels between the African American NMR groups were primarily due to differences in CYP2A6 enzyme activity without titration of nicotine intake among faster nicotine metabolizers. Copyright © 2016 Elsevier Inc. All rights reserved.

Influence of cholinesterase inhibitors, donepezil and rivastigmine on the acquisition, expression, and reinstatement of morphine-induced conditioned place preference in rats.

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Gawel, Kinga; Labuz, Krzysztof; Jenda, Malgorzata; Silberring, Jerzy; Kotlinska, Jolanta H

2014-07-15

The influence of systemic administration of cholinesterase inhibitors, donepezil and rivastigmine on the acquisition, expression, and reinstatement of morphine-induced conditioned place preference (CPP) was examined in rats. Additionally, this study aimed to compare the effects of donepezil, which selectively inhibits acetylcholinesterase, and rivastigmine, which inhibits both acetylcholinesterase and butyrylcholinesterase on morphine reward. Morphine-induced CPP (unbiased method) was induced by four injections of morphine (5 mg/kg, i.p.). Donepezil (0.5, 1, and 3 mg/kg, i.p.) or rivastigmine (0.03, 0.5, and 1 mg/kg, i.p.) were given 20 min before morphine during conditioning phase and 20 min before the expression or reinstatement of morphine-induced CPP. Our results indicated that both inhibitors of cholinesterase attenuated the acquisition and expression of morphine CPP. The results were more significant after rivastigmine due to a broader inhibitory spectrum of this drug. Moreover, donepezil (1 mg/kg) and rivastigmine (0.5 mg/kg) attenuated the morphine CPP reinstated by priming injection of 5mg/kg morphine. These properties of both cholinesterase inhibitors were reversed by mecamylamine (3 mg/kg, i.p.), a nicotinic acetylcholine receptor antagonist but not scopolamine (0.5 mg/kg, i.p.), a muscarinic acetylcholine receptor antagonist. All effects of cholinesterase inhibitors were observed at the doses that had no effects on locomotor activity of animals. Our results suggest beneficial role of cholinesterase inhibitors in reduction of morphine reward and morphine-induced seeking behavior. Finally, we found that the efficacy of cholinesterase inhibitors in attenuating reinstatement of morphine CPP provoked by priming injection may be due to stimulation of nicotinic acetylcholine receptors. Copyright © 2014 Elsevier B.V. All rights reserved.

The expression, localization and function of α7 nicotinic acetylcholine receptor in rat corpus cavernosum.

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Faghir-Ghanesefat, Hedyeh; Rahimi, Nastaran; Yarmohammadi, Fatemeh; Mokhtari, Tahmineh; Abdollahi, Ali Reza; Ejtemaei Mehr, Shahram; Dehpour, Ahmad R

2017-12-01

Alpha7 nicotinic acetylcholine receptor (α7-nAChR), an emerging pharmacological target for a variety of medical conditions, is expressed in the most mammalian tissues with different effects. So, this study was designed to investigate the expression, localization and effect of α7-nAChR in rat corpus cavernosum (CC). Reverse transcription polymerase chain reaction (RT-PCR) revealed that α7-nAChR was expressed in rat CC and double immunofluorescence studies demonstrated the presence of α7-nAChR in corporal neurons. The rat CC segments were mounted in organ bath chambers and contracted with phenylephrine (0.1 μm -300 μm) to investigate the relaxation effect of electrical field stimulation (EFS,10 Hz) assessed in the presence of guanethidine (adrenergic blocker, 5 μm) and atropine (muscarinic cholinergic blocker, 1 μm) to obtain non-adrenergic non-cholinergic (NANC) response. Cumulative administration of nicotine significantly potentiated the EFS-induced NANC relaxation (-log EC50 = 7.5 ± 0.057). Whereas, the potentiated NANC relaxation of nicotine was significantly inhibited with different concentrations of methyllycaconitine citrate (α7-nAChR antagonist, P < 0.05) in preincubated strips. L-NAME (non-specific nitric oxide synthase inhibitor, 1 μm) completely blocked the neurogenic relaxation induced by EFS plus nicotine. To conclude α7-nAChR is expressed in rat CC and modulates the neurogenic relaxation response to nicotine. © 2017 Royal Pharmaceutical Society.

Chronic Nicotine Treatment During Adolescence Attenuates the Effects of Acute Nicotine in Adult Contextual Fear Learning.

Science.gov (United States)

Holliday, Erica D; Gould, Thomas J

2017-01-01

Adolescent onset of nicotine abuse is correlated with worse chances at successful abstinence in adulthood. One reason for this may be due to enduring learning deficits resulting from nicotine use during adolescence. Previous work has indicated that chronic nicotine administration beginning in late adolescence (PND38) caused learning deficits in contextual fear when tested in adulthood. The purpose of this study was to determine if chronic nicotine treatment during adolescence would alter sensitivity to nicotine's cognitive enhancing properties in adulthood. C57BL/6J mice received saline or chronic nicotine (12.6mg/kg/day) during adolescence (postnatal day 38) or adulthood (postnatal day 54) for a period of 12 days. Following a 30-day protracted abstinence, mice received either an acute injection of saline or nicotine (0.045, 0.18, and 0.36mg/kg) prior to training and testing a mouse model of contextual fear. It was found that chronic nicotine administration in adult mice did not alter sensitivity to acute nicotine following a protracted abstinence. In adolescent mice, chronic nicotine administration disrupted adult learning and decreased sensitivity to acute nicotine in adulthood as only the highest dose tested (0.36mg/kg) was able to enhance contextual fear learning. These results suggest that adolescent nicotine exposure impairs learning in adulthood, which could increase the risk for continued nicotine use in adulthood by requiring administration of higher doses of nicotine to reverse learning impairments caused by adolescent nicotine exposure. Results from this study add to the growing body of literature suggesting chronic nicotine exposure during adolescence leads to impaired learning in adulthood and demonstrates that nicotine exposure during adolescence attenuates the cognitive enhancing effects of acute nicotine in adulthood, which suggests altered cholinergic function. © The Author 2016. Published by Oxford University Press on behalf of the Society for

Electronic Nicotine Delivery Systems.

Science.gov (United States)

Walley, Susan C; Jenssen, Brian P

2015-11-01

Electronic nicotine delivery systems (ENDS) are rapidly growing in popularity among youth. ENDS are handheld devices that produce an aerosolized mixture from a solution typically containing concentrated nicotine, flavoring chemicals, and propylene glycol to be inhaled by the user. ENDS are marketed under a variety of names, most commonly electronic cigarettes and e-cigarettes. In 2014, more youth reported using ENDS than any other tobacco product. ENDS pose health risks to both users and nonusers. Nicotine, the major psychoactive ingredient in ENDS solutions, is both highly addictive and toxic. In addition to nicotine, other toxicants, carcinogens, and metal particles have been detected in solutions and aerosols of ENDS. Nonusers are involuntarily exposed to the emissions of these devices with secondhand and thirdhand aerosol. The concentrated and often flavored nicotine in ENDS solutions poses a poisoning risk for young children. Reports of acute nicotine toxicity from US poison control centers have been increasing, with at least 1 child death reported from unintentional exposure to a nicotine-containing ENDS solution. With flavors, design, and marketing that appeal to youth, ENDS threaten to renormalize and glamorize nicotine and tobacco product use. There is a critical need for ENDS regulation, legislative action, and counter promotion to protect youth. ENDS have the potential to addict a new generation of youth to nicotine and reverse more than 50 years of progress in tobacco control. Copyright © 2015 by the American Academy of Pediatrics.

Nicotine Dependence and Urinary Nicotine, Cotinine and Hydroxycotinine Levels in Daily Smokers.

Science.gov (United States)

Van Overmeire, Ilse P I; De Smedt, Tom; Dendale, Paul; Nackaerts, Kristiaan; Vanacker, Hilde; Vanoeteren, Jan F A; Van Laethem, Danny M G; Van Loco, Joris; De Cremer, Koen A J

2016-09-01

Nicotine dependence and smoking frequency are critical factors for smoking cessation. The aims of this study are (1) to determine if nicotine dependence Fagerström Test for Nicotine Dependence (FTND) scores are associated with urinary levels of nicotine metabolites, (2) to assess the relationship of hydroxycotinine/cotinine ratio with FTND score and cigarettes smoked per day (CPD), and (3) to identify significant predictors of cigarettes per day among biomarker concentrations and individual FTND items. Urine samples and questionnaire data of 239 daily smokers were obtained. Nicotine, cotinine and hydroxycotinine urinary levels were determined by UPLC MS/MS.Multiple linear regression models were developed to explore the relationship between nicotine, cotinine, hydroxycotinine levels and separate FTND scores (for all six items). We found significant correlations between the different urinary biomarker concentrations, and the FTND score. The time before the first cigarette after waking (TTFC) was significantly associated with the nicotine, cotinine and hydroxycotinine concentrations. No association was found between the ratio of hydroxycotinine to cotinine and either the FTND or the CPD. A model including four FTND questions, sex, age, and the cotinine concentration, accounted for 45% of the variance of CPD. There are significant relationships between urinary levels of nicotine, cotinine, and hydroxycotinine and the FTND score. Especially the FTND question about TTFC is relevant for explaining the biomarker concentrations. CPD (below 15) was significantly explained by four FTND dependence items and urinary cotinine levels in a regression model. We investigated associations between urinary levels of nicotine, cotinine, and hydroxycotinine in daily smokers and the FTND scores for nicotine dependence. We did not find association between the hydroxycotinine/cotinine ratio and CPD. We developed a model that explains the cigarettes smoked daily (CPD) in a group of light

Endogenous cholinergic neurotransmission contributes to behavioral sensitization to morphine.

Directory of Open Access Journals (Sweden)

Dusica Bajic

Full Text Available Neuroplasticity in the mesolimbic dopaminergic system is critical for behavioral adaptations associated with opioid reward and addiction. These processes may be influenced by cholinergic transmission arising from the laterodorsal tegmental nucleus (LDTg, a main source of acetylcholine to mesolimbic dopaminergic neurons. To examine this possibility we asked if chronic systemic morphine administration affects expression of genes in ventral and ventrolateral periaqueductal gray at the level of the LDTg using rtPCR. Specifically, we examined gene expression changes in the area of interest using Neurotransmitters and Receptors PCR array between chronic morphine and saline control groups. Analysis suggested that chronic morphine administration led to changes in expression of genes associated, in part, with cholinergic neurotransmission. Furthermore, using a quantitative immunofluorescent technique, we found that chronic morphine treatment produced a significant increase in immunolabeling of the cholinergic marker (vesicular acetylcholine transporter in neurons of the LDTg. Finally, systemic administration of the nonselective and noncompetitive neuronal nicotinic antagonist mecamylamine (0.5 or 2 mg/kg dose-dependently blocked the expression, and to a lesser extent the development, of locomotor sensitization. The same treatment had no effect on acute morphine antinociception, antinociceptive tolerance or dependence to chronic morphine. Taken together, the results suggest that endogenous nicotinic cholinergic neurotransmission selectively contributes to behavioral sensitization to morphine and this process may, in part, involve cholinergic neurons within the LDTg.

In vivo pharmacological characterization of (+/-)-4-[2-(1-methyl-2-pyrrolidinyl)ethyl]thiophenol hydrochloride (SIB-1553A), a novel cholinergic ligand: microdialysis studies.

Science.gov (United States)

Rao, Tadimeti S; Reid, Richard T; Correa, Lucia D; Santori, Emily M; Gardner, Michael F; Sacaan, Aida I; Lorrain, Daniel; Vernier, Jean-Michel

2003-10-03

SIB-1553A ((+/-)-4-[2-(1-methyl-2-pyrrolidinyl)ethyl]thiophenol HCl) is a neuronal nicotinic acetylcholine receptor (nAChR) ligand which is active in rodent and primate models of cognition. In functional assays, SIB-1553A exhibits marked subtype selectivity for nAChRs as compared to nicotine. In addition SIB-1553A also exhibits affinities to histaminergic (H3) and serotonergic (5-HT1 and 5HT2) receptors and sigma binding sites. In the present investigation, we characterized SIB-1553A-induced neurotransmitter release in vivo. Following subcutaneous injection (s.c., 10 mg/kg), SIB-1553A rapidly entered the brain achieving concentration of approximately 20 microM 15 min post-injection and was eliminated from plasma with a terminal half-life of approximately 32 min. In freely moving rats, SIB-1553A (1-40 mg/kg, s.c.), markedly increased ACh release in the hippocampus and prefrontal cortex. In both regions, the magnitude of SIB-1553A-induced ACh release was greater than that seen with the prototypical nAChR agonist, nicotine (0.4 mg/kg, s.c.). Both isomers of SIB-1553A induced similar levels of increase in hippocampal ACh release. Increased hippocampal ACh release was also observed following oral administration of SIB-1553A (40 mg/kg) or after local perfusion into the hippocampus (1 mM). SIB-1553A-induced hippocampal ACh release was significantly attenuated by two nAChR antagonists, mecamylamine (MEC) and dihydro-beta-erythroidine (DHbetaE), and by the dopamine (DA) (D1) antagonist, SCH-23390, arguing that ACh release, in part, involves activation of nAChRs and a permissive DA synapse. In contrast to its robust effects on ACh release, SIB-1553A (40 mg/kg, s.c.) modestly increased striatal DA release (approximately 180% of baseline). Due to the proposed role of cholinergic pathways in learning and memory, the neurochemical profile of SIB-1553A suggests a potential for it to treat cognitive dysfunction.

Central estrogenic pathways protect against the depressant action of acute nicotine on reflex tachycardia in female rats

Energy Technology Data Exchange (ETDEWEB)

El-Mas, Mahmoud M., E-mail: mahelm@hotmail.com; Fouda, Mohamed A.; El-gowilly, Sahar M.; Saad, Evan I.

2012-02-01

We have previously shown that acute exposure of male rats to nicotine preferentially attenuates baroreceptor-mediated control of reflex tachycardia in contrast to no effect on reflex bradycardia. Here, we investigated whether female rats are as sensitive as their male counterparts to the baroreflex depressant effect of nicotine and whether this interaction is modulated by estrogen. Baroreflex curves relating reflex chronotropic responses evoked by i.v. doses (1–16 μg/kg) of phenylephrine (PE) or sodium nitroprusside (SNP), were constructed in conscious freely moving proestrus, ovariectomized (OVX), and estrogen (50 μg/kg/day s.c., 5 days)-replaced OVX (OVXE{sub 2}) rats. Slopes of the curves were taken as a measure of baroreflex sensitivity (BRS{sub PE} and BRS{sub SNP}). Nicotine (100 μg/kg i.v.) reduced BRS{sub SNP} in OVX rats but not in proestrus or OVXE{sub 2} rats. The attenuation of reflex tachycardia by nicotine was also evident in diestrus rats, which exhibited plasma estrogen levels similar to those of OVX rats. BRS{sub PE} was not affected by nicotine in all rat preparations. Experiments were then extended to determine whether central estrogenic receptors modulate the nicotine–BRS{sub SNP} interaction. Intracisteral (i.c.) treatment of OVX rats with estrogen sulfate (0.2 μg/rat) abolished the BRS{sub SNP} attenuating effect of i.v. nicotine. This protective effect of estrogen disappeared when OVX rats were pretreated with i.c. ICI 182,780 (50 μg/rat, selective estrogen receptor antagonist). Together, these findings suggest that central neural pools of estrogen receptors underlie the protection offered by E{sub 2} against nicotine-induced baroreceptor dysfunction in female rats. -- Highlights: ► Estrogen protects against the depressant effect of nicotine on reflex tachycardia. ► The baroreflex response and estrogen status affect the nicotine–BRS interaction. ► The protection offered by estrogen is mediated via central estrogen receptors.

Electronic cigarettes and nicotine clinical pharmacology.

Science.gov (United States)

Schroeder, Megan J; Hoffman, Allison C

2014-05-01

To review the available literature evaluating electronic cigarette (e-cigarette) nicotine clinical pharmacology in order to understand the potential impact of e-cigarettes on individual users, nicotine dependence and public health. Literature searches were conducted between 1 October 2012 and 30 September 2013 using key terms in five electronic databases. Studies were included in the review if they were in English and publicly available; non-clinical studies, conference abstracts and studies exclusively measuring nicotine content in e-cigarette cartridges were excluded from the review. Nicotine yields from automated smoking machines suggest that e-cigarettes deliver less nicotine per puff than traditional cigarettes, and clinical studies indicate that e-cigarettes deliver only modest nicotine concentrations to the inexperienced e-cigarette user. However, current e-cigarette smokers are able to achieve systemic nicotine and/or cotinine concentrations similar to those produced from traditional cigarettes. Therefore, user experience is critically important for nicotine exposure, and may contribute to the products' ability to support and maintain nicotine dependence. Knowledge about e-cigarette nicotine pharmacology remains limited. Because a user's e-cigarette experience may significantly impact nicotine delivery, future nicotine pharmacokinetic and pharmacodynamic studies should be conducted in experienced users to accurately assess the products' impact on public health.

Electronic cigarettes and nicotine clinical pharmacology

Science.gov (United States)

Schroeder, Megan J; Hoffman, Allison C

2014-01-01

Objective To review the available literature evaluating electronic cigarette (e-cigarette) nicotine clinical pharmacology in order to understand the potential impact of e-cigarettes on individual users, nicotine dependence and public health. Methods Literature searches were conducted between 1 October 2012 and 30 September 2013 using key terms in five electronic databases. Studies were included in the review if they were in English and publicly available; non-clinical studies, conference abstracts and studies exclusively measuring nicotine content in e-cigarette cartridges were excluded from the review. Results Nicotine yields from automated smoking machines suggest that e-cigarettes deliver less nicotine per puff than traditional cigarettes, and clinical studies indicate that e-cigarettes deliver only modest nicotine concentrations to the inexperienced e-cigarette user. However, current e-cigarette smokers are able to achieve systemic nicotine and/or cotinine concentrations similar to those produced from traditional cigarettes. Therefore, user experience is critically important for nicotine exposure, and may contribute to the products’ ability to support and maintain nicotine dependence. Conclusions Knowledge about e-cigarette nicotine pharmacology remains limited. Because a user's e-cigarette experience may significantly impact nicotine delivery, future nicotine pharmacokinetic and pharmacodynamic studies should be conducted in experienced users to accurately assess the products’ impact on public health. PMID:24732160

Decreased sensitivity to nicotine-induced seizures as a consequence of nicotine pretreatment in long-sleep and short-sleep mice.

Science.gov (United States)

de Fiebre, C M; Collins, A C

1988-01-01

Male and female long-sleep (LS) and short-sleep (SS) mice were pretreated with a subseizure-producing dose of nicotine (2.0 mg/kg) 7.5, 15 and 30 minutes prior to challenge with seizure-producing doses of this drug. Nicotine pretreated animals were less susceptible to nicotine-induced seizures than were saline pretreated animals. The latency to seizure following nicotine challenge was greater in nicotine pretreated animals than in saline controls. Nicotine pretreated LS mice show a greater decrease in nicotine-induced seizure susceptibility than do nicotine pretreated SS mice. This decrease in seizure susceptibility is consistent with induction of nicotinic receptor desensitization via nicotine pretreatment. It is hypothesized that LS and SS mice might differ in sensitivity to nicotine in part because they differ in baseline levels of desensitized versus functional nicotinic receptors.

Sympathomimetic Effects of Acute E-Cigarette Use: Role of Nicotine and Non-Nicotine Constituents.

Science.gov (United States)

Moheimani, Roya S; Bhetraratana, May; Peters, Kacey M; Yang, Benjamin K; Yin, Fen; Gornbein, Jeffrey; Araujo, Jesus A; Middlekauff, Holly R

2017-09-20

Chronic electronic (e) cigarette users have increased resting cardiac sympathetic nerve activity and increased susceptibility to oxidative stress. The purpose of the present study is to determine the role of nicotine versus non-nicotine constituents in e-cigarette emissions in causing these pathologies in otherwise healthy humans. Thirty-three healthy volunteers who were not current e-cigarette or tobacco cigarette smokers were studied. On different days, each participant used an e-cigarette with nicotine, an e-cigarette without nicotine, or a sham control. Cardiac sympathetic nerve activity was determined by heart rate variability, and susceptibility to oxidative stress was determined by plasma paraoxonase activity. Following exposure to the e-cigarette with nicotine, but not to the e-cigarette without nicotine or the sham control, there was a significant and marked shift in cardiac sympathovagal balance towards sympathetic predominance. The decrease in high-frequency component and the increases in the low-frequency component and the low-frequency to high-frequency ratio were significantly greater following exposure to the e-cigarette with nicotine compared with exposure to the e-cigarette without nicotine or to sham control. Oxidative stress, as estimated by plasma paraoxonase, did not increase following any of the 3 exposures. The acute sympathomimetic effect of e-cigarettes is attributable to the inhaled nicotine, not to non-nicotine constituents in e-cigarette aerosol, recapitulating the same heart rate variability pattern associated with increased cardiac risk in multiple populations with and without known cardiac disease. Evidence of oxidative stress, as estimated by plasma paraoxonase activity, was not uncovered following acute e-cigarette exposure. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

ANTAGONISM OF PROGESTERONE RECEPTOR SUPPRESSES CAROTID BODY RESPONSES TO HYPOXIA AND NICOTINE IN RAT PUPS

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JOSEPH, V.; NIANE, L. M.; BAIRAM, A.

2012-01-01

We tested the hypothesis that antagonism of progesterone receptor (PR) in newborn rats alters carotid body and respiratory responses to hypoxia and nicotinic receptor agonists. Rats were treated with the PR antagonist mifepristone (daily oral gavage 40 μg/g/d) or vehicle between post-natal days 3 and 15. In 11–14-day-old rats, we used in vitro carotid body/carotid sinus nerve preparation and whole body plethysmography to assess the carotid body and ventilatory responses to hypoxia (65 mmHg in...

Cooperative regulation of non-small cell lung carcinoma by nicotinic and beta-adrenergic receptors: a novel target for intervention.

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Hussein A N Al-Wadei

Full Text Available Lung cancer is the leading cause of cancer death; 80-85% of lung cancer cases are non-small cell lung cancer (NSCLC. Smoking is a documented risk factor for the development of this cancer. Although nicotine does not have the ability to initiate carcinogenic events, recent studies have implicated nicotine in growth stimulation of NSCLC. Using three NSCLC cell lines (NCI-H322, NCI-H441 and NCI-H1299, we identified the cooperation of nicotinic acetylcholine receptors (nAChRs and β-adrenergic receptors (β-ARs as principal regulators of these effects. Proliferation was measured by thymidine incorporation and MTT assays, and Western blots were used to monitor the upregulation of the nAChRs and activation of signaling molecules. Noradrenaline and GABA were measured by immunoassays. Nicotine-treated NSCLC cells showed significant induction of the α7nAChR and α4nAChR, along with significant inductions of p-CREB and p-ERK1/2 accompanied by increases in the stress neurotransmitter noradrenaline, which in turn led to the observed increase in DNA synthesis and cell proliferation. Effects on cell proliferation and signaling proteins were reversed by the α7nAChR antagonist α-BTX or the β-blocker propranolol. Nicotine treatment also down-regulated expression of the GABA synthesizing enzyme GAD 65 and the level of endogenous GABA, while treatment of NSCLC cells with GABA inhibited cell proliferation. Interestingly, GABA acts by reducing β-adrenergic activated cAMP signaling. Our findings suggest that nicotine-induced activation of this autocrine noradrenaline-initiated signaling cascade and concomitant deficiency in inhibitory GABA, similar to modulation of these neurotransmitters in the nicotine-addicted brain, may contribute to the development of NSCLC in smokers. Our data suggest that exposure to nicotine either by tobacco smoke or nicotine supplements facilitates growth and progression of NSCLC and that pharmacological intervention by β blocker may

'Real-world' compensatory behaviour with low nicotine concentration e-liquid: subjective effects and nicotine, acrolein and formaldehyde exposure.

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Dawkins, Lynne; Cox, Sharon; Goniewicz, Maciej; McRobbie, Hayden; Kimber, Catherine; Doig, Mira; Kośmider, Leon

2018-06-07

To compare the effects of i) high versus low nicotine concentration e-liquid, ii) fixed versus adjustable power and iii) the interaction between the two on: a) vaping behaviour, b) subjective effects, c) nicotine intake, and d) exposure to acrolein and formaldehyde in e-cigarette users vaping in their everyday setting. Counterbalanced, repeated measures with four conditions: i) low nicotine (6 mg/mL)/fixed power; ii) low nicotine/adjustable power; iii) high nicotine (18 mg/mL)/fixed power; iv) high nicotine/adjustable power. London and the South East, England. Twenty experienced e-cigarette users (recruited between September 2016 and February 2017) vaped ad libitum using an eVic Supreme™ with a 'Nautilus Aspire' tank over four weeks (one week per condition). Puffing patterns (daily puff number [PN], puff duration [PD], inter-puff interval [IPI]), mL of e-liquid consumed, changes to power (where permitted), and subjective effects (urge to vape, nicotine withdrawal symptoms) were measured in each condition. Nicotine intake was measured via salivary cotinine. 3-hydroxypropylmercapturic acid (3-HPMA), a metabolite of the toxicant acrolein, and formate, a metabolite of the carcinogen formaldehyde, were measured in urine. There was a significant nicotine concentration x power interaction for PD (p<0.01). PD was longer with low nicotine/fixed power compared with i) high nicotine/fixed power (p< 0.001 and ii) low nicotine/adjustable power (p< 0.01). PN and liquid consumed were higher in the low versus high nicotine condition (main effect of nicotine, p<0.05). Urge to vape and withdrawal symptoms were lower, and nicotine intake was higher, in the high nicotine condition (main effects of nicotine: p<0.01). Whilst acrolein levels did not differ, there was a significant nicotine x power interaction for formaldehyde (p<0.05). Use of a lower nicotine concentration e-liquid may be associated with compensatory behaviour (e.g., higher number and duration of puffs) and increases

From Chemotherapy-Induced Emesis to Neuroprotection: Therapeutic Opportunities for 5-HT3 Receptor Antagonists.

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Fakhfouri, Gohar; Mousavizadeh, Kazem; Mehr, Sharam Ejtemaei; Dehpour, Ahmad Reza; Zirak, Mohammad Reza; Ghia, Jean-Eric; Rahimian, Reza

2015-12-01

5-HT3 receptor antagonists are extensively used as efficacious agents in counteracting chemotherapy-induced emesis. Recent investigations have shed light on other potential effects (analgesic, anxiolytic, and anti-psychotic). Some studies have reported neuroprotective properties for the 5-HT3 receptor antagonists in vitro and in vivo. When administered to Aβ-challenged rat cortical neurons, 5-HT3 receptor antagonists substantially abated apoptosis, elevation of cytosolic Ca(2), glutamate release, reactive oxygen species (ROS) generation, and caspase-3 activity. In addition, in vivo studies show that 5-HT3 receptor antagonists possess, alongside their anti-emetic effects, notable immunomodulatory properties in CNS. We found that pretreatment with tropisetron significantly improved neurological deficits and diminished leukocyte transmigration into the brain, TNF-α level, and brain infarction in a murine model of embolic stroke. Our recent investigation revealed that tropisetron protects against Aβ-induced neurotoxicity in vivo through both 5-HT3 receptor-dependent and -independent pathways. Tropisetron, in vitro, was found to be an efficacious inhibitor of the signaling pathway leading to the activation of pro-inflammatory NF-κB, a transcription factor pivotal to the upregulation of several neuroinflammatory mediators in brain. This mini review summarizes novel evidence concerning effects of 5-HT3 antagonists and their possible mechanisms of action in ameliorating neurodegenerative diseases including Alzheimer, multiple sclerosis, and stroke. Further, we discuss some newly synthesized 5-HT3 receptor antagonists with dual properties of 5-HT3 receptor blockade/alpha-7 nicotinic receptor activator and their potential in management of memory impairment. Since 5-HT3 receptor antagonists possess a large therapeutic window, they can constitute a scaffold for design and synthesis of new neuroprotective medications.

Predictors of the nicotine reinforcement threshold, compensation, and elasticity of demand in a rodent model of nicotine reduction policy.

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Grebenstein, Patricia E; Burroughs, Danielle; Roiko, Samuel A; Pentel, Paul R; LeSage, Mark G

2015-06-01

The FDA is considering reducing the nicotine content in tobacco products as a population-based strategy to reduce tobacco addiction. Research is needed to determine the threshold level of nicotine needed to maintain smoking and the extent of compensatory smoking that could occur during nicotine reduction. Sources of variability in these measures across sub-populations also need to be identified so that policies can take into account the risks and benefits of nicotine reduction in vulnerable populations. The present study examined these issues in a rodent nicotine self-administration model of nicotine reduction policy to characterize individual differences in nicotine reinforcement thresholds, degree of compensation, and elasticity of demand during progressive reduction of the unit nicotine dose. The ability of individual differences in baseline nicotine intake and nicotine pharmacokinetics to predict responses to dose reduction was also examined. Considerable variability in the reinforcement threshold, compensation, and elasticity of demand was evident. High baseline nicotine intake was not correlated with the reinforcement threshold, but predicted less compensation and less elastic demand. Higher nicotine clearance predicted low reinforcement thresholds, greater compensation, and less elastic demand. Less elastic demand also predicted lower reinforcement thresholds. These findings suggest that baseline nicotine intake, nicotine clearance, and the essential value of nicotine (i.e. elasticity of demand) moderate the effects of progressive nicotine reduction in rats and warrant further study in humans. They also suggest that smokers with fast nicotine metabolism may be more vulnerable to the risks of nicotine reduction. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Predictors of the nicotine reinforcement threshold, compensation, and elasticity of demand in a rodent model of nicotine reduction policy*

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Grebenstein, Patricia E.; Burroughs, Danielle; Roiko, Samuel A.; Pentel, Paul R.; LeSage, Mark G.

2015-01-01

Background The FDA is considering reducing the nicotine content in tobacco products as a population-based strategy to reduce tobacco addiction. Research is needed to determine the threshold level of nicotine needed to maintain smoking and the extent of compensatory smoking that could occur during nicotine reduction. Sources of variability in these measures across sub-populations also need to be identified so that policies can take into account the risks and benefits of nicotine reduction in vulnerable populations. Methods The present study examined these issues in a rodent nicotine self- administration model of nicotine reduction policy to characterize individual differences in nicotine reinforcement thresholds, degree of compensation, and elasticity of demand during progressive reduction of the unit nicotine dose. The ability of individual differences in baseline nicotine intake and nicotine pharmacokinetics to predict responses to dose reduction was also examined. Results Considerable variability in the reinforcement threshold, compensation, and elasticity of demand was evident. High baseline nicotine intake was not correlated with the reinforcement threshold, but predicted less compensation and less elastic demand. Higher nicotine clearance predicted low reinforcement thresholds, greater compensation, and less elastic demand. Less elastic demand also predicted lower reinforcement thresholds. Conclusions These findings suggest that baseline nicotine intake, nicotine clearance, and the essential value of nicotine (i.e. elasticity of demand) moderate the effects of progressive nicotine reduction in rats and warrant further study in humans. They also suggest that smokers with fast nicotine metabolism may be more vulnerable to the risks of nicotine reduction. PMID:25891231

Toward a comprehensive long term nicotine policy.

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Gray, N; Henningfield, J E; Benowitz, N L; Connolly, G N; Dresler, C; Fagerstrom, K; Jarvis, M J; Boyle, P

2005-06-01

Global tobacco deaths are high and rising. Tobacco use is primarily driven by nicotine addiction. Overall tobacco control policy is relatively well agreed upon but a long term nicotine policy has been less well considered and requires further debate. Reaching consensus is important because a nicotine policy is integral to the target of reducing tobacco caused disease, and the contentious issues need to be resolved before the necessary political changes can be sought. A long term and comprehensive nicotine policy is proposed here. It envisages both reducing the attractiveness and addictiveness of existing tobacco based nicotine delivery systems as well as providing alternative sources of acceptable clean nicotine as competition for tobacco. Clean nicotine is defined as nicotine free enough of tobacco toxicants to pass regulatory approval. A three phase policy is proposed. The initial phase requires regulatory capture of cigarette and smoke constituents liberalising the market for clean nicotine; regulating all nicotine sources from the same agency; and research into nicotine absorption and the role of tobacco additives in this process. The second phase anticipates clean nicotine overtaking tobacco as the primary source of the drug (facilitated by use of regulatory and taxation measures); simplification of tobacco products by limitation of additives which make tobacco attractive and easier to smoke (but tobacco would still be able to provide a satisfying dose of nicotine). The third phase includes a progressive reduction in the nicotine content of cigarettes, with clean nicotine freely available to take the place of tobacco as society's main nicotine source.

Insight into nicotine addiction

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Sahil Handa

2017-01-01

Full Text Available The emergence of the epidemic of nicotine addiction in India and other nations is a global public health tragedy of untoward proportions. Smoking or chewing tobacco can seriously affect general, as well as oral health. Smoking-caused disease is a consequence of exposure to toxins in tobacco smoke and addiction to nicotine is the proximate cause of these diseases. This article focuses on nicotine as a determinant of addiction to tobacco and the pharmacologic effects of nicotine that sustain cigarette smoking. The pharmacologic reasons for nicotine use are an enhancement of mood, either directly or through relief of withdrawal symptoms and augmentation of mental or physical functions. Tobacco cessation is necessary to reduce morbidity and mortality related to tobacco use. Strategies for tobacco cessation involves 5A's and 5R's approach and pharmacotherapy. Dental professionals play an important role in helping patients to quit tobacco at the community and national levels, to promote tobacco prevention and control nicotine addiction. Dentists are in a unique position to educate and motivate patients concerning the hazards of tobacco to their oral and systemic health, and to provide intervention programs as a part of routine patient care.

Surveillance of smokeless tobacco nicotine, pH, moisture, and unprotonated nicotine content.

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Richter, Patricia; Spierto, Francis W

2003-12-01

Smokeless tobacco is a complex chemical mixture, including not only the components of the tobacco leaf but also chemicals added during the manufacturing process. Smokeless tobacco contains the addictive chemical nicotine and more than 20 cancer-causing chemicals, including the potent tobacco-specific nitrosamines. The National Toxicology Program of the National Institutes of Health has concluded that oral use of smokeless tobacco is a human carcinogen. Therefore, smokeless tobacco is not a safe alternative to cigarettes. In fact, smokeless tobacco use begins primarily during early adolescence and can lead to nicotine dependence and increased risk of becoming a cigarette smoker. Under the Comprehensive Smokeless Tobacco Health Education Act of 1986 (15 U.S.C. 4401 et seq., Pub. L. 99-252), tobacco manufacturers report annually to the Centers for Disease Control and Prevention (CDC) on the total nicotine, unprotonated nicotine, pH, and moisture content of their smokeless tobacco products. This information is considered "trade secret," or confidential, in accordance with 5 U.S.C. 552(b)(4) and 18 U.S.C. 1905 and cannot be released to the public. In an effort to provide consumers and researchers with information on the nicotine content of smokeless tobacco, CDC arranged for the analysis of popular brands of smokeless tobacco. The results of this CDC study show that pH is a primary factor in the amount of nicotine that is in the most readily absorbable, unprotonated form. Furthermore, this study found that the brands of moist snuff smokeless tobacco with the largest amount of unprotonated nicotine also are the most frequently sold brands.

The effects of nicotine and non-nicotine smoking factors on working memory and associated brain function.

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McClernon, Francis Joseph; Froeliger, Brett; Rose, Jed E; Kozink, Rachel V; Addicott, Merideth A; Sweitzer, Maggie M; Westman, Eric C; Van Wert, Dana M

2016-07-01

Smoking abstinence impairs executive function, which may promote continued smoking behavior and relapse. The differential influence of nicotine and non-nicotine (i.e. sensory, motor) smoking factors and related neural substrates is not known. In a fully factorial, within-subjects design, 33 smokers underwent fMRI scanning following 24 hours of wearing a nicotine or placebo patch while smoking very low nicotine content cigarettes or remaining abstinent from smoking. During scanning, blood oxygenation level-dependent (BOLD) signal was acquired while participants performed a verbal N-back task. Following 24-hour placebo (versus nicotine) administration, accuracy on the N-back task was significantly worse and task-related BOLD signal lower in dorsomedial frontal cortex. These effects were observed irrespective of smoking. Our data provide novel evidence that abstinence-induced deficits in working memory and changes in underlying brain function are due in large part to abstinence from nicotine compared with non-nicotine factors. This work has implications both for designing interventions that target abstinence-induced cognitive deficits and for nicotine-reduction policy. © 2015 Society for the Study of Addiction.

Activation of Peripheral κ-Opioid Receptors Normalizes Caffeine Effects Modified in Nicotine-Dependent Rats during Nicotine Withdrawal.

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Sudakov, S K; Bogdanova, N G

2016-10-01

The study examined the effect of peripheral (intragastric) ICI-204,448, an agonist of gastric κ-opioid receptors, on the psychostimulating and anxiolytic effects of caffeine in nicotinedependent rats at the stage of nicotine withdrawal. In these rats, the effects of caffeine (10 mg/kg) were perverted. In nicotine-dependent rats, caffeine produced an anxiolytic effect accompanied by pronounced stimulation of motor activity, in contrast to anxiogenic effect induced by caffeine in intact rats without nicotine dependence. During nicotine withdrawal, nicotine-dependent rats demonstrated enhanced sensitivity to nicotine. Intragastric administration of κ-opioid receptor agonist ICI-204,448 normalized the effect of caffeine in nicotinedependent rats. We have previously demonstrated that activation of peripheral κ-opioid receptors inhibited central κ-opioid activity and eliminated manifestations of nicotine withdrawal syndrome in nicotine-dependent rats, e.g. metabolism activation, stimulation of motor activity, and enhancement of food consumption. In its turn, inhibition of central κ-opioid structures activates the brain adenosine system, which can attenuate the caffeine-induced effects in nicotine-dependent rats.

A Multi-Route Model of Nicotine-Cotinine Pharmacokinetics, Pharmacodynamics and Brain Nicotinic Acetylcholine Receptor Binding in Humans

Energy Technology Data Exchange (ETDEWEB)

Teeguarden, Justin G.; Housand, Conrad; Smith, Jordan N.; Hinderliter, Paul M.; Gunawan, Rudy; Timchalk, Charles

2013-02-01

The pharmacokinetics of nicotine, the pharmacologically active alkaloid in tobacco responsible for addiction, are well characterized in humans. We developed a physiologically based pharmacokinetic/pharmacodynamic model of nicotine pharmacokinetics, brain dosimetry and brain nicotinic acetylcholine receptor (nAChRs) occupancy. A Bayesian framework was applied to optimize model parameters against multiple human data sets. The resulting model was consistent with both calibration and test data sets, but in general underestimated variability. A pharmacodynamic model relating nicotine levels to increases in heart rate as a proxy for the pharmacological effects of nicotine accurately described the nicotine related changes in heart rate and the development and decay of tolerance to nicotine. The PBPK model was utilized to quantitatively capture the combined impact of variation in physiological and metabolic parameters, nicotine availability and smoking compensation on the change in number of cigarettes smoked and toxicant exposure in a population of 10,000 people presented with a reduced toxicant (50%), reduced nicotine (50%) cigarette Across the population, toxicant exposure is reduced in some but not all smokers. Reductions are not in proportion to reductions in toxicant yields, largely due to partial compensation in response to reduced nicotine yields. This framework can be used as a key element of a dosimetry-driven risk assessment strategy for cigarette smoke constituents.

Low Nicotine Content Descriptors Reduce Perceived Health Risks and Positive Cigarette Ratings in Participants Using Very Low Nicotine Content Cigarettes.

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Denlinger-Apte, Rachel L; Joel, Danielle L; Strasser, Andrew A; Donny, Eric C

2017-10-01

Understanding how smokers perceive reduced nicotine content cigarettes will be important if the FDA and global regulatory agencies implement reduced nicotine product standards for cigarettes. Prior research has shown that some smokers incorrectly believe "light" cigarettes are less harmful than regular cigarettes. Similar misunderstandings of health risk could also apply to reduced nicotine cigarettes. To date, most studies of reduced nicotine cigarettes have blinded subjects to the nicotine content. Therefore, little is known about how smokers experience reduced nicotine content cigarettes when they are aware of the reduced content, and how use may be impacted. The present study was a within-subjects experiment with 68 adult daily smokers who smoked two identical very low nicotine content Quest 3 (0.05 mg nicotine yield) cigarettes. Subjects were told that one cigarette contained "average" nicotine content, and the other contained "very low" nicotine content. After smoking each cigarette, subjects completed subjective measures about their smoking experience. Subjects rated the "very low" nicotine cigarette as less harmful to their health overall compared to the "average" nicotine cigarette; this effect held true for specific smoking-related diseases. Additionally, they rated the "very low" nicotine cigarette as having less desirable subjective effects than the "average" nicotine cigarette and predicted having greater interest in quitting smoking in the future if only the "very low" nicotine cigarette was available. Explicit knowledge of very low nicotine content changes smokers' perceptions of very low nicotine content cigarettes, resulting in reduced predicted harm, subjective ratings and predicted future use. Before a reduced nicotine product standard for cigarettes can be implemented, it is important to understand how product information impacts how smokers think about and experience very low nicotine content cigarettes. Prior research has shown that smokers

Nicotine concentration of e-cigarettes used by adolescents.

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Morean, Meghan E; Kong, Grace; Cavallo, Dana A; Camenga, Deepa R; Krishnan-Sarin, Suchitra

2016-10-01

E-cigarettes are popular among youth, but little is known about the nicotine concentrations of e-liquids used by adolescents. In Spring, 2014, we conducted cross-sectional surveys in four Connecticut high schools and two middle schools. Among past-30-day e-cigarette users (n=513, 45% female, mean age 15.9 [SD=1.4]), we examined what nicotine concentration adolescents typically used in their e-cigarettes (range 0-30mg/mL and "I don't know"). We first examined whether age, sex, smoking status, e-cigarette use frequency, and/or e-cigarette acquisition source were associated with using nicotine-free e-liquid, nicotine e-liquid, or not knowing the e-liquid nicotine concentration. Among nicotine users (n=185), we then examined whether the aforementioned variables were associated with using higher nicotine concentrations. Adolescents reported using nicotine-free e-liquid (28.5%), nicotine e-liquid (37.4%), or not knowing their e-liquid nicotine concentration (34.1%). Nicotine users comprised more smokers and heavier e-cigarette users compared to nicotine-free e-liquid users and those who did not know their nicotine concentration. Nicotine users also comprised more males and were more likely to purchase e-cigarettes online or from tobacco shops compared to those who did not know their nicotine concentration. Among nicotine users, cigarette smoking, male sex, and purchasing e-cigarettes from tobacco shops predicted using higher nicotine concentrations. Adolescents reported using e-liquids with variable nicotine concentrations. Smokers, males, and those who purchased their own e-cigarettes reported using the highest nicotine levels. Of concern, many adolescents were unaware of the nicotine concentration in their e-liquid, raising concerns about inadvertent nicotine exposure among youth. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Neuroprotective and memory-related actions of novel alpha-7 nicotinic agents with different mixed agonist/antagonist properties.

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Meyer, E M; Tay, E T; Zoltewicz, J A; Meyers, C; King, M A; Papke, R L; De Fiebre, C M

1998-03-01

The goals of this study were to develop compounds that were selective and highly efficacious agonists at alpha-7 receptors, while varying in antagonist activity; and to test the hypothesis that these compounds had memory-related and neuroprotective actions associated with both agonist and antagonist alpha-7 receptor activities. Three compounds were identified; E,E-3-(cinnamylidene)anabaseine (3-CA), E,E-3-(2-methoxycinnamylidene) anabaseine (2-MeOCA) and E,E-3-(4-methoxycinnamylidene) anabaseine (4-MeOCA) each displaced [125I]alpha-bungarotoxin binding from rat brain membranes and activated rat alpha-7 receptors in a Xenopus oocyte expression system fully efficaciously. The potency series for binding and receptor activation was 2-MeOCA > 4-MeOCA = 3-CA and 2-MeOCA = 3-CA > 4-MeOCA, respectively. No compound significantly activated oocyte-expressed alpha-4beta-2 receptors. Although each cinnamylidene-anabaseine caused a long-term inhibition of alpha-7 receptors, as measured by ACh-application 5 min later, this inhibition ranged considerably, from less than 20% (3-CA) to 90% (2-MeOCA) at an identical concentration (10 microM). These compounds improved passive avoidance behavior in nucleus basalis lesioned rats, with 2-MeOCA most potent in this respect. In contrast, only 3-CA was neuroprotective against neurite loss during nerve growth factor deprivation in differentiated rat pheochromocytoma (PC12) cells. Choline, an efficacious alpha-7 agonist without antagonist activity, was also protective in this model. These results suggest that the neurite-protective action of alpha-7 receptor agonists may be more sensitive to potential long-term antagonist properties than acute behavioral actions are.

Nicotine reward and affective nicotine withdrawal signs are attenuated in calcium/calmodulin-dependent protein kinase IV knockout mice.

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Kia J Jackson

Full Text Available The influx of Ca(2+ through calcium-permeable nicotinic acetylcholine receptors (nAChRs leads to activation of various downstream processes that may be relevant to nicotine-mediated behaviors. The calcium activated protein, calcium/calmodulin-dependent protein kinase IV (CaMKIV phosphorylates the downstream transcription factor cyclic AMP response element binding protein (CREB, which mediates nicotine responses; however the role of CaMKIV in nicotine dependence is unknown. Given the proposed role of CaMKIV in CREB activation, we hypothesized that CaMKIV might be a crucial molecular component in the development of nicotine dependence. Using male CaMKIV genetically modified mice, we found that nicotine reward is attenuated in CaMKIV knockout (-/- mice, but cocaine reward is enhanced in these mice. CaMKIV protein levels were also increased in the nucleus accumbens of C57Bl/6 mice after nicotine reward. In a nicotine withdrawal assessment, anxiety-related behavior, but not somatic signs or the hyperalgesia response are attenuated in CaMKIV -/- mice. To complement our animal studies, we also conducted a human genetic association analysis and found that variants in the CaMKIV gene are associated with a protective effect against nicotine dependence. Taken together, our results support an important role for CaMKIV in nicotine reward, and suggest that CaMKIV has opposing roles in nicotine and cocaine reward. Further, CaMKIV mediates affective, but not physical nicotine withdrawal signs, and has a protective effect against nicotine dependence in human genetic association studies. These findings further indicate the importance of calcium-dependent mechanisms in mediating behaviors associated with drugs of abuse.

Neonatal Nicotine Exposure Increases Excitatory Synaptic Transmission and Attenuates Nicotine-stimulated GABA release in the Adult Rat Hippocampus

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Damborsky, Joanne C.; Griffith, William H.; Winzer-Serhan, Ursula H.

2014-01-01

Developmental exposure to nicotine has been linked to long-lasting changes in synaptic transmission which may contribute to behavioral abnormalities seen in offspring of women who smoke during pregnancy. Here, we examined the long-lasting effects of developmental nicotine exposure on glutamatergic and GABAergic neurotransmission, and on acute nicotine-induced glutamate and GABA release in the adult hippocampus, a structure important in cognitive and emotional behaviors. We utilized a chronic neonatal nicotine treatment model to administer nicotine (6 mg/kg/day) to rat pups from postnatal day (P) 1–7, a period that falls developmentally into the third human trimester. Using whole-cell voltage clamp recordings from CA1 pyramidal neurons in hippocampal slices, we measured excitatory and inhibitory postsynaptic currents in neonatally control- and nicotine-treated young adult males. Neonatal nicotine exposure significantly increased AMPA receptor-mediated spontaneous and evoked excitatory signaling, with no change in glutamate release probability in adults. Conversely, there was no increase in spontaneous GABAergic neurotransmission in nicotine-males. Chronic neonatal nicotine treatment had no effect on acute nicotine-stimulated glutamate release in adults, but acute nicotine-stimulated GABA release was significantly attenuated. Thus, neonatal nicotine exposure results in a persistent net increase in excitation and a concurrent loss of nicotinic acetylcholine receptor (nAChR)-mediated regulation of presynaptic GABA but not glutamate release, which would exacerbate excitation following endogenous or exogenous nAChR activation. Our data underscore an important role for nAChRs in hippocampal excitatory synapse development, and suggest selective long-term changes at specific presynaptic nAChRs which together could explain some of the behavioral abnormalities associated with maternal smoking. PMID:24950455

Neuronal nicotinic acetylcholine receptors: Common molecular substrates of nicotine and alcohol dependence

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Linzy M. Hendrickson

2013-04-01

Full Text Available Alcohol and nicotine are often co-abused. As many as 80-95% of alcoholics are also smokers, suggesting that ethanol and nicotine, the primary addictive component of tobacco smoke, may functionally interact in the central nervous system and/or share a common mechanism of action. While nicotine initiates dependence by binding to and activating neuronal nicotinic acetylcholine receptors (nAChRs, ligand-gated cation channels normally activated by endogenous acetylcholine (ACh, ethanol is much less specific with the ability to modulate multiple gene products including those encoding voltage-gated ion channels, and excitatory/inhibitory neurotransmitter receptors. However, emerging data indicate that ethanol interacts with nAChRs, both directly and indirectly, in the mesocorticolimbic dopaminergic (DAergic reward circuitry to affect brain reward systems. Like nicotine, ethanol activates DAergic neurons of the ventral tegmental area (VTA which project to the nucleus accumbens (NAc. Blockade of VTA nAChRs reduces ethanol-mediated activation of DAergic neurons, NAc DA release, consumption, and operant responding for ethanol in rodents. Thus, ethanol may increase ACh release into the VTA driving activation of DAergic neurons through nAChRs. In addition, ethanol potentiates distinct nAChR subtype responses to ACh and nicotine in vitro and in DAergic neurons. The smoking cessation therapeutic and nAChR partial agonist, varenicline, reduces alcohol consumption in heavy drinking smokers and rodent models of alcohol consumption. Finally, single nucleotide polymorphisms in nAChR subunit genes are associated with alcohol dependence phenotypes and smoking behaviors in human populations. Together, results from preclinical, clinical, and genetic studies indicate that nAChRs may have an inherent role in the abusive properties of ethanol, as well as in nicotine and alcohol co-dependence.

Genotoxicity study on nicotine and nicotine-derived nitrosamine by accelerator mass spectrometry

International Nuclear Information System (INIS)

Li, X.S.; Wang, H.F.; Shi, J.Y.; Wang, X.Y.; Liu, Y.F.; Li, K.; Lu, X.Y.; Wang, J.J.; Liu, K.X.; Guo, Z.Y.

1997-01-01

The authors have studied DNA adduction with 14 C-labelled nicotine and nicotine-derived nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), by accelerator mass spectrometry (AMS) in mouse liver at doses equivalent to low-level exposure of humans. The dose ranges of nicotine and NNK administered were from 0.4 μg to 4.0 x 10 2 μg·kg -1 , and from 0.1 μg to 2.0 x 10 4 μg·kg -1 , respectively. In the exposure of mice to either nicotine or NNK, the number of DNA adducts increased linearly with increasing dose. The detection limit of DNA adducts was 1 adduct per 10 11 nucleotide molecules. This limit is 1-4 orders of magnitude lower than that of other techniques used for quantification of DNA adducts. The results of the animal experiments enabled us to speculate that nicotine is a potential carcinogen. According to the procedure for 14 C-labelled-NNK synthesis, the authors discuss the ultimate chemical speciation of NNK bound to DNA. From the animal tests the authors derived a directly perceivable relation between tobacco consumption and DNA adduction as the carcinogenic risk assessment

Pathogenesis of Abdominal Aortic Aneurysms: Role of Nicotine and Nicotinic Acetylcholine Receptors

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Zong-Zhuang Li

2012-01-01

Full Text Available Inflammation, proteolysis, smooth muscle cell apoptosis, and angiogenesis have been implicated in the pathogenesis of abdominal aortic aneurysms (AAAs, although the well-defined initiating mechanism is not fully understood. Matrix metalloproteinases (MMPs such as MMP-2 and -9 and other proteinases degrading elastin and extracellular matrix are the critical pathogenesis of AAAs. Among the risk factors of AAAs, cigarette smoking is an irrefutable one. Cigarette smoke is practically involved in various aspects of the AAA pathogenesis. Nicotine, a major alkaloid in tobacco leaves and a primary component in cigarette smoke, can stimulate the MMPs expression by vascular SMCs, endothelial cells, and inflammatory cells in vascular wall and induce angiogenesis in the aneurysmal tissues. However, for the inflammatory and apoptotic processes in the pathogenesis of AAAs, nicotine seems to be moving in just the opposite direction. Additionally, the effects of nicotine are probably dose dependent or associated with the exposure duration and may be partly exerted by its receptors—nicotinic acetylcholine receptors (nAChRs. In this paper, we will mainly discuss the pathogenesis of AAAs involving inflammation, proteolysis, smooth muscle cell apoptosis and angiogenesis, and the roles of nicotine and nAChRs.

Tribute to: Self-administered nicotine activates the mesolimbic dopamine system through the ventral tegmental area [William Corrigall, Kathleen Coen and Laurel Adamson, Brain Res. 653 (1994) 278-284].

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Leri, Francesco; Vaccarino, Franco J

2016-08-15

In this paper, Dr. Corrigall and collaborators described elegant experiments designed to elucidate the neurobiology of nicotine reinforcement. The nicotinic receptor antagonist dihydro-β-erythroidine (DHβE) was infused in the ventral tegmental area (VTA) or nucleus accumbens (NAC) of rats trained to self-administer nicotine intravenously. Additionally, DHβE was infused in the VTA of rats trained to self-administer food or cocaine, and nicotine self-administration was assessed in rats with lesions to the peduculopontine tegmental nucleus (PPT). A number of key themes emerged from this fundamental study that remain relevant today. The primary finding was that infusions of DHβE in the VTA, but not in the NAC, lowered nicotine self-administration, suggesting that nicotinic receptors in VTA are involved in the reinforcing action of nicotine. This conclusion has been confirmed by subsequent findings, and the nature of the nicotinic receptors has also been elucidated. The authors also reported that DHβE in the VTA had no effect on food or cocaine self-administration, and that lesions to the PPT did not alter nicotine self-administration. Since this initial investigation, the question of whether nicotinic receptors in the VTA are necessary for the reinforcing action of other stimuli, and by which mechanisms, has been extensively explored. Similarly, many groups have further investigated the role of mesopontine cholinergic nuclei in reinforcement. This paper not only contributed in important ways to our understanding of the neurochemical basis of nicotine reinforcement, but was also a key catalyst that gave rise to several research themes central to the neuropharmacology of substance abuse. This article is part of a Special Issue entitled SI:50th Anniversary Issue. Copyright © 2016 Elsevier B.V. All rights reserved.

Habenular expression of rare missense variants of the β4 nicotinic receptor subunit alters nicotine consumption

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Marta A Ślimak

2014-01-01

Full Text Available The CHRNA5-CHRNA3-CHRNB4 gene cluster, encoding the α5, α3 and β4 nicotinic acetylcholine receptor (nAChR subunits, has been linked to nicotine dependence. The habenulo-interpeduncular (Hb-IPN tract is particularly enriched in α3β4 nAChRs. We recently showed that modulation of these receptors in the medial habenula (MHb in mice altered nicotine consumption. Given that β4 is rate-limiting for receptor activity and that single nucleotide polymorphisms (SNPs in CHRNB4 have been linked to altered risk of nicotine dependence in humans, we were interested in determining the contribution of allelic variants of β4 to nicotine receptor activity in the MHb. We screened for missense SNPs with allele frequencies > 0.0005 and introduced the corresponding substitutions in Chrnb4. Fourteen variants were analyzed by co-expression with α3. We found that β4A90I and β4T374I variants, previously shown to associate with reduced risk of smoking, and an additional variant β4D447Y, significantly increased nicotine-evoked current amplitudes, while β4R348C, the mutation most frequently encountered in sporadic amyotrophic lateral sclerosis (sALS, showed reduced nicotine currents. We employed lentiviruses to express β4 or β4 variants in the MHb. Immunoprecipitation studies confirmed that β4 lentiviral-mediated expression leads to specific upregulation of α3β4 but not β2 nAChRs in the Mhb. Mice injected with the β4-containing virus showed pronounced aversion to nicotine as previously observed in transgenic Tabac mice overexpressing Chrnb4 at endogenous sites including the MHb. Habenular expression of the β4 gain-of-function allele T374I also resulted in strong aversion, while transduction with the β4 loss-of function allele R348C failed to induce nicotine aversion. Altogether, these data confirm the critical role of habenular β4 in nicotine consumption, and identify specific SNPs in CHRNB4 that modify nicotine-elicited currents and alter nicotine

NICOTINE EFFECTS ON THE MOTOR ACTIVITY OF MICE EXPOSED PRENATALLY TO THE NICOTINIC AGONIST ANATOXIN-A.

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Several studies in the literature have shown that exposure of mice and rats to nicotine early in development alters its effects when the rodents are subsequently challenged with nicotine. Anatoxin-a is a nicotinic agonist produced by several genera of cyanobacteria, and has caus...

Assessment of nicotine concentration in electronic nicotine delivery system (ENDS) liquids and precision of dosing to aerosol.

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Kosmider, Leon; Sobczak, Andrzej; Szołtysek-Bołdys, Izabela; Prokopowicz, Adam; Skórka, Agnieszka; Abdulafeez, Oluyadi; Koszowski, Bartosz

2015-01-01

Global use of electronic nicotine delivery systems (ENDS; also called electronic cigarettes, e-cigarettes) has increased dramatically in recent years. However, due to the limited safety studies and growing concerns on the potential toxicity from long term use of ENDS, many national and international governments have employed regulatory measures to curtail its use. One of the most significant challenges regulators of ENDS encounter is the lack of quality standards to assess ENDS, e-liquid (solution used with ENDS which contain nicotine--a highly toxic and addictive substance), and amount of nicotine delivery to aerosol during ENDS use. Aims of the study were to (1) measure and compare nicotine concentration in e-liquids to values reported by manufacturers on packaging labels; (2) assess the precision of nicotine delivery from tank during aerosol formation. Methods: Nine popular Polish e-liquids (based on the market share data from October 2014) were purchased for the study. The labelled nicotine concentration for the selected e-liquids ranged between 11-25 mg/mL. All e-liquids were aerosolized in the laboratory using a smoking simulation machine (Palaczbot). Each e-liquid was aerosolized in a series of 6 consecutive bouts. A single bout consisted of 15 puffs with the following puff topography: 65 mL puff volume, 2.8 sec. puff duration, and 19 sec. interpuff interval. A total of 90 puffs were generated from each e-liquid. Nicotine content in the e-liquids and the aerosol generated were determined by gas chromatography with thermionic sensitive detection (GC-TSD). For seven of nine analyzed e-liquids, the difference between measured and manufacturer labeled nicotine concentration was less than 10%. Nicotine dose in aerosol per bout ranged between 0.77-1.49 mg (equivalent to one-half the nicotine a smoker inhales from a single combustible cigarette). Our analysis showed the high consistency between the labeled and measured nicotine concentration for popular on the

Measurement of nicotine in household dust

International Nuclear Information System (INIS)

Kim, Sungroul; Aung, Ther; Berkeley, Emily; Diette, Gregory B.; Breysse, Patrick N.

2008-01-01

An analytical method of measuring nicotine in house dust was optimized and associations among three secondhand smoking exposure markers were evaluated, i.e., nicotine concentrations of both house dust and indoor air, and the self-reported number of cigarettes smoked daily in a household. We obtained seven house dust samples from self-reported nonsmoking homes and 30 samples from smoking homes along with the information on indoor air nicotine concentrations and the number of cigarettes smoked daily from an asthma cohort study conducted by the Johns Hopkins Center for Childhood Asthma in the Urban Environment. House dust nicotine was analyzed by isotope dilution gas chromatography-mass spectrometry (GC/MS). Using our optimized method, the median concentration of nicotine in the dust of self-reported nonsmoking homes was 11.7 ng/mg while that of smoking homes was 43.4 ng/mg. We found a substantially positive association (r=0.67, P<0.0001) between house dust nicotine concentrations and the numbers of cigarettes smoked daily. Optimized analytical methods showed a feasibility to detect nicotine in house dust. Our results indicated that the measurement of nicotine in house dust can be used potentially as a marker of longer term SHS exposure

Rationalization of a nanoparticle-based nicotine nanovaccine as an effective next-generation nicotine vaccine: A focus on hapten localization.

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Zhao, Zongmin; Hu, Yun; Harmon, Theresa; Pentel, Paul; Ehrich, Marion; Zhang, Chenming

2017-09-01

A lipid-polymeric hybrid nanoparticle-based next-generation nicotine nanovaccine was rationalized in this study to combat nicotine addiction. A series of nanovaccines, which had nicotine-haptens localized on carrier protein (LPKN), nanoparticle surface (LPNK), or both (LPNKN), were designed to study the impact of hapten localization on their immunological efficacy. All three nanovaccines were efficiently taken up and processed by dendritic cells. LPNKN induced a significantly higher immunogenicity against nicotine and a significantly lower anti-carrier protein antibody level compared to LPKN and LPNK. Meanwhile, it was found that the anti-nicotine antibodies elicited by LPKN and LPNKN bind nicotine stronger than those elicited by LPKN, and LPNK and LPNKN resulted in a more balanced Th1-Th2 immunity than LPKN. Moreover, LPNKN exhibited the best ability to block nicotine from entering the brain of mice. Collectively, the results demonstrated that the immunological efficacy of the hybrid nanoparticle-based nicotine vaccine could be enhanced by modulating hapten localization, providing a promising strategy to combatting nicotine addiction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quinuclidine compounds differently act as agonists of Kenyon cell nicotinic acetylcholine receptors and induced distinct effect on insect ganglionic depolarizations.

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Mathé-Allainmat, Monique; Swale, Daniel; Leray, Xavier; Benzidane, Yassine; Lebreton, Jacques; Bloomquist, Jeffrey R; Thany, Steeve H

2013-12-01

We have recently demonstrated that a new quinuclidine benzamide compound named LMA10203 acted as an agonist of insect nicotinic acetylcholine receptors. Its specific pharmacological profile on cockroach dorsal unpaired median neurons (DUM) helped to identify alpha-bungarotoxin-insensitive nAChR2 receptors. In the present study, we tested its effect on cockroach Kenyon cells. We found that it induced an inward current demonstrating that it bounds to nicotinic acetylcholine receptors expressed on Kenyon cells. Interestingly, LMA10203-induced currents were completely blocked by the nicotinic antagonist α-bungarotoxin. We suggested that LMA10203 effect occurred through the activation of α-bungarotoxin-sensitive receptors and did not involve α-bungarotoxin-insensitive nAChR2, previously identified in DUM neurons. In addition, we have synthesized two new compounds, LMA10210 and LMA10211, and compared their effects on Kenyon cells. These compounds were members of the 3-quinuclidinyl benzamide or benzoate families. Interestingly, 1 mM LMA10210 was not able to induce an inward current on Kenyon cells compared to LMA10211. Similarly, we did not find any significant effect of LMA10210 on cockroach ganglionic depolarization, whereas these three compounds were able to induce an effect on the central nervous system of the third instar M. domestica larvae. Our data suggested that these three compounds could bind to distinct cockroach nicotinic acetylcholine receptors.

Effects of simultaneous exposure to stress and nicotine on nicotine-induced locomotor activation in adolescent and adult rats

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Zago, A. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Leão, R.M.; Carneiro-de-Oliveira, P.E. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Programa Interinstitucional de Pós-Graduação em Ciências Fisiológicas, Universidade Federal de São Carlos/Universidade Estadual de São Paulo, Araraquara, SP (Brazil); Marin, M.T.; Cruz, F.C. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Planeta, C.S. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Programa Interinstitucional de Pós-Graduação em Ciências Fisiológicas, Universidade Federal de São Carlos/Universidade Estadual de São Paulo, Araraquara, SP (Brazil)

2011-11-18

Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although crosssensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P) 28-37) and adult (P60-67) rats received nicotine (0.4 mg/kg, sc) or saline (0.9% NaCl, sc) and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc) or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats.

Effects of simultaneous exposure to stress and nicotine on nicotine-induced locomotor activation in adolescent and adult rats

International Nuclear Information System (INIS)

Zago, A.; Leão, R.M.; Carneiro-de-Oliveira, P.E.; Marin, M.T.; Cruz, F.C.; Planeta, C.S.

2011-01-01

Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although crosssensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P) 28-37) and adult (P60-67) rats received nicotine (0.4 mg/kg, sc) or saline (0.9% NaCl, sc) and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc) or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats

Effects of simultaneous exposure to stress and nicotine on nicotine-induced locomotor activation in adolescent and adult rats

Directory of Open Access Journals (Sweden)

A. Zago

2012-01-01

Full Text Available Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although cross-sensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P 28-37 and adult (P60-67 rats received nicotine (0.4 mg/kg, sc or saline (0.9% NaCl, sc and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats.

High-affinity α4β2 nicotinic receptors mediate the impairing effects of acute nicotine on contextual fear extinction.

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Kutlu, Munir Gunes; Holliday, Erica; Gould, Thomas J

2016-02-01

Previously, studies from our lab have shown that while acute nicotine administered prior to training and testing enhances contextual fear conditioning, acute nicotine injections prior to extinction sessions impair extinction of contextual fear. Although there is also strong evidence showing that the acute nicotine's enhancing effects on contextual fear conditioning require high-affinity α4β2 nicotinic acetylcholine receptors (nAChRs), it is unknown which nAChR subtypes are involved in the acute nicotine-induced impairment of contextual fear extinction. In this study, we investigated the effects of acute nicotine administration on contextual fear extinction in knock-out (KO) mice lacking α4, β2 or α7 subtypes of nAChRs and their wild-type (WT) littermates. Both KO and WT mice were first trained and tested for contextual fear conditioning and received a daily contextual extinction session for 4 days. Subjects received intraperitoneal injections of nicotine (0.18 mg/kg) or saline 2-4 min prior to each extinction session. Our results showed that the mice that lack α4 and β2 subtypes of nAChRs showed normal contextual fear extinction but not the acute nicotine-induced impairment while the mice that lack the α7 subtype showed both normal contextual extinction and nicotine-induced impairment of contextual extinction. In addition, control experiments showed that acute nicotine-induced impairment of contextual fear extinction persisted when nicotine administration was ceased and repeated acute nicotine administrations alone did not induce freezing behavior in the absence of context-shock learning. These results clearly demonstrate that high-affinity α4β2 nAChRs are necessary for the effects of acute nicotine on contextual fear extinction. Copyright © 2015 Elsevier Inc. All rights reserved.

Renal transport and metabolism of nicotinic acid

International Nuclear Information System (INIS)

Schuette, S.; Rose, R.C.

1986-01-01

Renal metabolism and brush-border transport of nicotinic acid were studied in renal cortical slices and brush-border membrane vesicles exposed to a physiological concentration of vitamin (2.2-3.5 microM). Vesicle transport of [ 3 H]nicotinic acid was found to be Na+ dependent and concentrative. The presence of a Na+ gradient resulted in a fivefold increase in the rate of nicotinic acid uptake over that observed with mannitol and caused a transient nicotinic acid accumulation two- to fourfold above the equilibrium value. The effects of membrane potential, pH, and elimination of Na+-H+ exchange were also studied. Cortical slices and isolated tubules exposed to 2.2 microM [ 14 C]nicotinic acid took up vitamin and rapidly metabolized most of it to intermediates in the Preiss-Handler pathway for NAD biosynthesis; little free nicotinic acid was detectable intracellularly. The replacement of Na+ with Li+ in the bathing medium reduced total accumulation of 14 C label primarily as a result of reduced nicotinic acid uptake. Cortical tissue concentrated free nicotinic acid only when the involved metabolic pathways were saturated by levels of nicotinic acid far in excess of what occurs in vivo

A pilot study on nicotine residues in houses of electronic cigarette users, tobacco smokers, and non-users of nicotine-containing products.

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Bush, Derek; Goniewicz, Maciej L

2015-06-01

Nicotine deposited on the surfaces has been shown to react with airborne chemicals leading to formation of carcinogens and contributing to thirdhand exposure. While prior studies revealed nicotine residues in tobacco smokers' homes, none have examined the nicotine residue in electronic cigarette (e-cigarette) users' homes. We measured nicotine on the surfaces in households of 8 e-cigarette users, 6 cigarette smokers, and 8 non-users of nicotine-containing products in Western New York, USA. Three surface wipe samples were taken from the floor, wall and window. Nicotine was extracted from the wipes and analyzed using gas chromatography. Half of the e-cigarette users' homes had detectable levels of nicotine on surfaces whereas nicotine was found in all of the tobacco cigarette smokers' homes. Trace amounts of nicotine were also detected in half of the homes of non-users of nicotine-containing products. Nicotine levels in e-cigarette users homes was significantly lower than that found in cigarette smokers homes (average concentration 7.7±17.2 vs. 1303±2676 μg/m2; pe-cigarette users and non-users (p>0.05). Nicotine is a common contaminant found on indoor surfaces. Using e-cigarettes indoors leads to significantly less thirdhand exposure to nicotine compared to smoking tobacco cigarettes. Copyright © 2015 Elsevier B.V. All rights reserved.

Nicotine, adolescence, and stress: A review of how stress can modulate the negative consequences of adolescent nicotine abuse.

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Holliday, Erica; Gould, Thomas J

2016-06-01

In order to continue the decline of smoking prevalence, it is imperative to identify factors that contribute to the development of nicotine and tobacco addiction, such as adolescent initiation of nicotine use, adolescent stress, and their interaction. This review highlights the biological differences between adolescent and adults in nicotine use and resulting effects, and examines the enduring consequences of adolescent nicotine administration. A review of both clinical and preclinical literature indicates that adolescent, but not adult, nicotine administration leads to increased susceptibility for development of long-lasting impairments in learning and affect. Finally, the role stress plays in normal adolescent development, the deleterious effects stress has on learning and memory, and the negative consequences resulting from the interaction of stress and nicotine during adolescence is reviewed. The review concludes with ways in which future policies could benefit by addressing adolescent stress as a means of reducing adolescent nicotine abuse. Copyright © 2016 Elsevier Ltd. All rights reserved.

Adolescents' understanding and use of nicotine in e-cigarettes.

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Pepper, Jessica K; Farrelly, Matthew C; Watson, Kimberly A

2018-07-01

Nicotine harms adolescent brain development and contributes to addiction. Some adolescents report using nicotine-free e-cigarettes, but the accuracy of their reporting is unclear. We explored adolescents' use of nicotine-free e-cigarettes and understanding of chemicals in e-cigarettes, including nicotine. Using social media, we recruited 1589 US adolescents (aged 15-17) who reported past 30-day use of e-cigarettes in 2016. We assessed perceptions of the nicotine source in e-liquid and whether e-cigarette aerosol is just "water vapor." We explored differences among adolescents who usually used e-cigarettes with nicotine (n = 473) and without nicotine (n = 452). We used weights to calibrate our sample to the Youth Risk Behavior Survey. Twenty-nine percent usually used e-cigarettes without nicotine, 28% with nicotine, 39% with "both," and 5% were "not sure." Few participants (17% of non-nicotine users vs. 34% of nicotine users, p e-cigarette aerosol was just water vapor were more likely to usually use without nicotine. Older adolescents and current tobacco users were less likely to usually use without nicotine. The adolescents who reported usually using e-cigarettes without nicotine had poorer knowledge of e-cigarettes. This lack of understanding could contribute to inaccurate reporting of nicotine use. Most youth thought the nicotine in e-cigarettes was artificial, potentially indicating a belief that this nicotine is "safer." The US Food & Drug Administration will require nicotine warnings on e-cigarettes in 2018; a complementary educational campaign could address youths' misperceptions about nicotine and other chemicals in e-cigarette aerosol. Copyright © 2018 Elsevier Ltd. All rights reserved.

Vitamin E Nicotinate

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Kimbell R. Duncan

2017-03-01

Full Text Available Vitamin E refers to a family of compounds that function as lipid-soluble antioxidants capable of preventing lipid peroxidation. Naturally occurring forms of vitamin E include tocopherols and tocotrienols. Vitamin E in dietary supplements and fortified foods is often an esterified form of α-tocopherol, the most common esters being acetate and succinate. The vitamin E esters are hydrolyzed and converted into free α-tocopherol prior to absorption in the intestinal tract. Because its functions are relevant to many chronic diseases, vitamin E has been extensively studied in respect to a variety of diseases as well as cosmetic applications. The forms of vitamin E most studied are natural α-tocopherol and the esters α-tocopheryl acetate and α-tocopheryl succinate. A small number of studies include or focus on another ester form, α-tocopheryl nicotinate, an ester of vitamin E and niacin. Some of these studies raise the possibility of differences in metabolism and in efficacy between vitamin E nicotinate and other forms of vitamin E. Recently, through metabolomics studies, we identified that α-tocopheryl nicotinate occurs endogenously in the heart and that its level is dramatically decreased in heart failure, indicating the possible biological importance of this vitamin E ester. Since knowledge about vitamin E nicotinate is not readily available in the literature, the purpose of this review is to summarize and evaluate published reports, specifically with respect to α-tocopheryl nicotinate with an emphasis on the differences from natural α-tocopherol or α-tocopheryl acetate.

Nitric oxide/cGMP/PKG signaling pathway activated by M1-type muscarinic acetylcholine receptor cascade inhibits Na+-activated K+ currents in Kenyon cells

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Hasebe, Masaharu

2016-01-01

The interneurons of the mushroom body, known as Kenyon cells, are essential for the long-term memory of olfactory associative learning in some insects. Some studies have reported that nitric oxide (NO) is strongly related to this long-term memory in Kenyon cells. However, the target molecules and upstream and downstream NO signaling cascades are not completely understood. Here we analyzed the effect of the NO signaling cascade on Na+-activated K+ (KNa) channel activity in Kenyon cells of crickets (Gryllus bimaculatus). We found that two different NO donors, S-nitrosoglutathione (GSNO) and S-nitroso-N-acetyl-dl-penicillamine (SNAP), strongly suppressed KNa channel currents. Additionally, this inhibitory effect of GSNO on KNa channel activity was diminished by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), an inhibitor of soluble guanylate cyclase (sGC), and KT5823, an inhibitor of protein kinase G (PKG). Next, we analyzed the role of ACh in the NO signaling cascade. ACh strongly suppressed KNa channel currents, similar to NO donors. Furthermore, this inhibitory effect of ACh was blocked by pirenzepine, an M1 muscarinic ACh receptor antagonist, but not by 1,1-dimethyl-4-diphenylacetoxypiperidinium iodide (4-DAMP) and mecamylamine, an M3 muscarinic ACh receptor antagonist and a nicotinic ACh receptor antagonist, respectively. The ACh-induced inhibition of KNa channel currents was also diminished by the PLC inhibitor U73122 and the calmodulin antagonist W-7. Finally, we found that ACh inhibition was blocked by the nitric oxide synthase (NOS) inhibitor NG-nitro-l-arginine methyl ester (l-NAME). These results suggested that the ACh signaling cascade promotes NO production by activating NOS and NO inhibits KNa channel currents via the sGC/cGMP/PKG signaling cascade in Kenyon cells. PMID:26984419

Association of nicotine metabolism and sex with relapse following varenicline and nicotine replacement therapy.

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Glatard, Anaïs; Dobrinas, Maria; Gholamrezaee, Mehdi; Lubomirov, Rubin; Cornuz, Jacques; Csajka, Chantal; Eap, Chin B

2017-10-01

Nicotine is metabolized into cotinine and then into trans-3'-hydroxycotinine, mainly by cytochrome P450 2A6. Recent studies reported better effectiveness of varenicline in women and in nicotine normal metabolizers phenotypically determined by nicotine-metabolite ratio. Our objective was to study the influence of nicotine-metabolite ratio, CYP2A6 genotype and sex on the response to nicotine replacement therapy and varenicline. Data were extracted from a longitudinal study which included smokers participating in a smoking cessation program. Response to treatment was defined by the absence of relapse when a set threshold of reduction in cigarettes per day relative to the week before the study was no more reached. The analysis considered total and partial reduction defined by a diminution of 100% and of 90% in cigarettes per day, respectively. The hazard ratio of relapsing was estimated in multivariate Cox regression models including the sex and the nicotine metabolism determined by the phenotype or by CYP2A6 genotyping (rs1801272 and rs28399433). In the normal metabolizers determined by phenotyping and in women, the hazard ratio for relapsing was significantly lower with varenicline for a partial decrease (HR = 0.33, 95% CI [0.12, 0.89] and HR = 0.20, 95% CI [0.04, 0.91], respectively) and nonsignificantly lower for a total cessation (HR = 0.45, 95% CI [0.20, 1.0] and HR = 0.38, 95% CI [0.14, 1.0]). When compared with the normal metabolizers determined by phenotyping, the hazard ratio for a partial decrease was similar in the normal metabolizers determined by genotyping (HR = 0.42, 95% CI [0.18, 0.94]) while it was significantly lower with varenicline for a total cessation (HR = 0.50, 95% CI [0.26, 0.98]). Women and normal nicotine metabolizers may benefit more from varenicline over nicotine replacement therapy. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Nicotine Contamination in Particulate Matter Sampling

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Eric Garshick

2009-02-01

Full Text Available We have addressed potential contamination of PM2.5 filter samples by nicotine from cigarette smoke. We collected two nicotine samples – one nicotine sampling filter was placed in-line after the collection of PM2.5 and the other stood alone. The overall correlation between the two nicotine filter levels was 0.99. The nicotine collected on the “stand-alone” filter was slightly greater than that on the “in-line” filter (mean difference = 1.10 μg/m3, but the difference was statistically significant only when PM2.5 was low (≤ 50 μg/m3. It is therefore important to account for personal and secondhand smoke exposure while assessing occupational and environmental PM.

Fetal Nicotine Exposure Increases Preference for Nicotine Odor in Early Postnatal and Adolescent, but Not Adult, Rats

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Mantella, Nicole M.; Kent, Paul F.; Youngentob, Steven L.

2013-01-01

Human studies demonstrate a four-fold increased possibility of smoking in the children of mothers who smoked during pregnancy. Nicotine is the active addictive component in tobacco-related products, crossing the placenta and contaminating the amniotic fluid. It is known that chemosensory experience in the womb can influence postnatal odor-guided preference behaviors for an exposure stimulus. By means of behavioral and neurophysiologic approaches, we examined whether fetal nicotine exposure, using mini-osmotic pumps, altered the response to nicotine odor in early postnatal (P17), adolescent (P35) and adult (P90) progeny. Compared with controls, fetal exposed rats displayed an altered innate response to nicotine odor that was evident at P17, declined in magnitude by P35 and was absent at P90 - these effects were specific to nicotine odor. The behavioral effect in P17 rats occurred in conjunction with a tuned olfactory mucosal response to nicotine odor along with an untoward consequence on the epithelial response to other stimuli – these P17 neural effects were absent in P35 and P90 animals. The absence of an altered neural effect at P35 suggests that central mechanisms, such as nicotine-induced modifications of the olfactory bulb, bring about the altered behavioral response to nicotine odor. Together, these findings provide insights into how fetal nicotine exposure influences the behavioral preference and responsiveness to the drug later in life. Moreover, they add to a growing literature demonstrating chemosensory mechanisms by which patterns of maternal drug use can be conveyed to offspring, thereby enhancing postnatal vulnerability for subsequent use and abuse. PMID:24358374

Effect of a nicotine vaccine on nicotine binding to the beta2-nAChRs in vivo in human tobacco smokers

Science.gov (United States)

Esterlis, Irina; Hannestad, Jonas O.; Perkins, Evgenia; Bois, Frederic; D’Souza, D. Cyril; Tyndale, Rachel F.; Seibyl, John P.; Hatsukami, Dorothy M.; Cosgrove, Kelly P.; O’Malley, Stephanie S.

2013-01-01

Objective Nicotine acts in the brain to promote smoking in part by binding to the beta2-containing nicotinic acetylcholine receptors (β2*-nAChRs) and acting in the mesolimbic reward pathway. The effects of nicotine from smoking one tobacco cigarette are significant (80% of β2*-nAChRs occupied for >6h). This likely contributes to the maintenance of smoking dependence and low cessation outcomes. Development of nicotine vaccines provides potential for alternative treatments. We used [123I]5IA-85380 SPECT to evaluate the effect of 3′-AmNic-rEPA on the amount of nicotine that binds to the β2*-nAChRs in the cortical and subcortical regions in smokers. Method Eleven smokers (36years (SD=13); 19cig/day (SD=11) for 10years (SD=7) who were dependent on nicotine (Fagerström Test of Nicotine Dependence score =5.5 (SD=3); plasma nicotine 9.1 ng/mL (SD=5)) participated in 2 SPECT scan days: before and after immunization with 4–400μg doses of 3′-AmNic-rEPA. On SPECT scan days, 3 30-min baseline emission scans were obtained, followed by administration of IV nicotine (1.5mg/70kg) and up to 9 30-min emission scans. Results β2*-nAChR availability was quantified as VT/fP and nicotine binding was derived using the Lassen plot approach. Immunization led to a 12.5% reduction in nicotine binding (F=5.19, df=1,10, p=0.05). Significant positive correlations were observed between nicotine bound to β2*-nAChRs and nicotine injected before but not after vaccination (p=0.05 vs. p=0.98). There was a significant reduction in the daily number of cigarettes and desire for a cigarette (p=.01 and p=.04, respectively). Conclusions This proof-of-concept study demonstrates that immunization with nicotine vaccine can reduce the amount of nicotine binding to β2*-nAChRs and disrupt the relationship between nicotine administered vs. nicotine available to occupy β2*-nAChRs. PMID:23429725

In vitro pharmacological characterization of (+/-)-4-[2-(1-methyl-2-pyrrolidinyl)ethyl]thio]phenol hydrochloride (SIB-1553A), a nicotinic acetylcholine receptor ligand.

Science.gov (United States)

Rao, Tadimeti S; Adams, Pamala B; Correa, Lucia D; Santori, Emily M; Sacaan, Aida I; Reid, Richard T; Suto, Carla M; Vernier, Jean Michel

2003-08-15

SIB-1553A ((+/-)-4-[2-(1-methyl-2-pyrrolidinyl)ethyl]thio]phenol HCl) is a neuronal nicotinic acetylcholine receptor (nAChR) ligand which displaced the binding of [3H]nicotine (NIC) to the rat brain nAChRs with an IC(50) value of 110 nM with no appreciable affinity to the alpha7 nAhRs. SIB-1553A showed modest affinity for histaminergic (H3) and serotonergic (5-HT1 and 5-HT2) receptors, and sigma binding sites. In calcium flux assays, SIB-1553A (0.1-5 microM), in contrast to nicotine, showed a greater selectivity for beta4-subunit containing recombinant hnAChRs (alpha2beta4, alpha3beta4 and alpha4beta4) vs. beta2-subunit containing nAChRs (alpha4beta2 and alpha3beta2) both in terms of efficacy and potency. While NIC (10-30 microM) and epibatidine (0.01-0.1 microM) fully activated human muscle-type AChRs expressed by RD cell line, SIB-1553A was virtually ineffective for up to >100 microM and elicited less than 10% of the response due to suberyldicholine. SIB-1553A (< or =30 microM) evoked [3H]DA release from striatum, olfactory tubercles and prefrontal cortex (PFC), and [3H]NE release from hippocampus and PFC, and this evoked release was sensitive to mecamylamine (MEC). SIB-1553A-evoked neurotransmitter release exhibited region- and transmitter-specific antagonism by dehydro-beta-erythroidine (DHbetaE). SIB-1553A was less efficacious than NIC at evoking [3H]NE from the rat hippocampus and antagonized NIC response upon co-application implying partial agonist properties. SIB-1553A did not evoke basal [3H]ACh release from the rat striatum or hippocampus, but attenuated NMDA-evoked [3H]ACh release from the rat striatum. SIB-1553A did not inhibit rat brain cholinesterase for up to 1 mM. Multiple receptor affinities and release of several neurotransmitters may underlie the cognitive-enhancing effects of SIB-1553A documented in rodent and primate models.

Gut-Sourced Vasoactive Intestinal Polypeptide Induced by the Activation of α7 Nicotinic Acetylcholine Receptor Substantially Contributes to the Anti-inflammatory Effect of Sinomenine in Collagen-Induced Arthritis

Directory of Open Access Journals (Sweden)

MengFan Yue

2018-06-01

Full Text Available Sinomenine has long been used for the treatment of rheumatoid arthritis in China. However, its anti-inflammatory mechanism is still debatable because the in vitro minimal effective concentration (≥250 μM is hardly reached in either synovium or serum after oral administration at a therapeutic dose. Recent findings suggest that the α7 nicotinic acetylcholine receptor (α7nAChR might mediate the inhibitory effect of sinomenine on macrophage activation, which attracts us to explore the anti-arthritis mechanism of sinomenine by taking neuroendocrine-inflammation axis into consideration. Here, we showed that orally administered sinomenine ameliorated the systemic inflammation of collagen-induced arthritis (CIA rats, which was significantly diminished by either vagotomy or the antagonists of nicotinic acetylcholine receptors (especially the antagonist of α7nAChR, but not by the antagonists of muscarinic receptor. Sinomenine might bind to α7nAChR through interacting with the residues Tyr184 and Tyr191 in the pocket. In addition, the generation of vasoactive intestinal polypeptide (VIP from the gut of CIA rats and cultured neuron-like cells was selectively enhanced by sinomenine through the activation of α7nAChR-PI3K/Akt/mTOR pathway. The elevated levels of VIP in the serum and small intestine of rats were negatively correlated with the scores of joint destruction. The crucial role of VIP in the anti-arthritic effect of sinomenine was confirmed by using VIP hybrid, a non-specific antagonist of VIP receptor. Taken together, intestine-sourced VIP mediates the anti-arthritic effect of sinomenine, which is generated by the activation of α7nAChR.

Nicotine transport in lung and non-lung epithelial cells.

Science.gov (United States)

Takano, Mikihisa; Kamei, Hidetaka; Nagahiro, Machi; Kawami, Masashi; Yumoto, Ryoko

2017-11-01

Nicotine is rapidly absorbed from the lung alveoli into systemic circulation during cigarette smoking. However, mechanism underlying nicotine transport in alveolar epithelial cells is not well understood to date. In the present study, we characterized nicotine uptake in lung epithelial cell lines A549 and NCI-H441 and in non-lung epithelial cell lines HepG2 and MCF-7. Characteristics of [ 3 H]nicotine uptake was studied using these cell lines. Nicotine uptake in A549 cells occurred in a time- and temperature-dependent manner and showed saturation kinetics, with a Km value of 0.31mM. Treatment with some organic cations such as diphenhydramine and pyrilamine inhibited nicotine uptake, whereas treatment with organic cations such as carnitine and tetraethylammonium did not affect nicotine uptake. Extracellular pH markedly affected nicotine uptake, with high nicotine uptake being observed at high pH up to 11.0. Modulation of intracellular pH with ammonium chloride also affected nicotine uptake. Treatment with valinomycin, a potassium ionophore, did not significantly affect nicotine uptake, indicating that nicotine uptake is an electroneutral process. For comparison, we assessed the characteristics of nicotine uptake in another lung epithelial cell line NCI-H441 and in non-lung epithelial cell lines HepG2 and MCF-7. Interestingly, these cell lines showed similar characteristics of nicotine uptake with respect to pH dependency and inhibition by various organic cations. The present findings suggest that a similar or the same pH-dependent transport system is involved in nicotine uptake in these cell lines. A novel molecular mechanism of nicotine transport is proposed. Copyright © 2017 Elsevier Inc. All rights reserved.

Compound list: nicotinic acid [Open TG-GATEs

Lifescience Database Archive (English)

Full Text Available nicotinic acid NIC 00081 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Hum...an/in_vitro/nicotinic_acid.Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/R...at/in_vitro/nicotinic_acid.Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat.../in_vivo/Liver/Single/nicotinic_acid.Rat.in_vivo.Liver.Single.zip ftp://ftp.biosc

Discriminating nicotine and non-nicotine containing e-liquids using infrared spectroscopy.

Science.gov (United States)

Deconinck, E; Bothy, J L; Barhdadi, S; Courselle, P

2016-02-20

In a few countries, including Belgium, nicotine-containing e-cigarettes and e-liquids are considered medicines, and therefore cannot freely be sold, but should be distributed in a pharmacy. The fact that in the neighbouring countries these products are freely available, poses a problem for custom personnel, the more the nicotine content of the products is not always labelled, especially when they are bought through internet. Therefore there is a need for easy-to-use equipment and methods to perform a first on site screening of intercepted samples, both for border control as to check label compliance of the sample. The use of attenuated total reflectance-infrared spectroscopy (ATR-IR) and near infrared spectroscopy (NIR), combined with chemometrics was evaluated for the discrimination between nicotine containing and non-nicotine containing samples. It could be concluded that both ATR-IR and NIR could be used for the discrimination when combined with the appropriate chemometric techniques. The presented techniques do not need sample preparation and result in models with a minimum of false negative samples. If a large enough training set can be established the interpretation can be fully automated, making the presented approach suitable for on-site screening of e-liquid samples. Copyright © 2015 Elsevier B.V. All rights reserved.

In vivo imaging of nicotinic receptor upregulation following chronic (-)-nicotine treatment in baboon using SPECT

International Nuclear Information System (INIS)

Kassiou, Michael; Eberl, Stefan; Meikle, Steven R.; Birrell, Alex; Constable, Chris; Fulham, Michael J.; Wong, Dean F.; Musachio, John L.

2001-01-01

To quantify changes in neuronal nAChR binding in vivo, quantitative dynamic SPECT studies were performed with 5-[ 123 I]-iodo-A-85380 in baboons pre and post chronic treatment with (-)-nicotine or saline control. Infusion of (-)-nicotine at a dose of 2.0 mg/kg/24h for 14 days resulted in plasma (-)-nicotine levels of 27.3 ng/mL. This is equivalent to that found in an average human smoker (20 cigarettes a day). In the baboon brain the regional distribution of 5-[ 123 I]-iodo-A-85380 was consistent with the known densities of nAChRs (thalamus > frontal cortex > cerebellum). Changes in nAChR binding were estimated from the volume of distribution (V d ) and binding potential (BP) derived from 3-compartment model fits. In the (-)-nicotine treated animal V d was significantly increased in the thalamus (52%) and cerebellum (50%) seven days post cessation of (-)-nicotine treatment, suggesting upregulation of nAChRs. The observed 33% increase in the frontal cortex failed to reach significance. A significant increase in BP was seen in the thalamus. In the saline control animal no changes were observed in V d or BP under any experimental conditions. In this preliminary study, we have demonstrated for the first time in vivo upregulation of neuronal nAChR binding following chronic (-)-nicotine treatment

In vivo human buccal permeability of nicotine

DEFF Research Database (Denmark)

Adrian, Charlotte L; Olin, Helle B D; Dalhoff, Kim

2006-01-01

The aim was to examine the in vivo buccal pH-dependent permeability of nicotine in humans and furthermore compare the in vivo permeability of nicotine to previous in vitro permeability data. The buccal permeability of nicotine was examined in a three-way cross-over study in eight healthy non......-smokers using a buccal perfusion cell. The disappearance of nicotine from perfusion solutions with pH 6.0, 7.4, and 8.1 was studied for 3h. The apparent permeability of nicotine (P(app)) was determined at each pH value. Parotid saliva was collected in an attempt to assess systemic levels of nicotine....... The disappearance rate of nicotine increased significantly as the pH increased, which resulted in P(app) values of 0.57+/-0.55 x 10(-4), 2.10+/-0.23 x 10(-4), and 3.96+/-0.54 x 10(-4)cms(-1) (mean+/-S.D.) at pH 6.0, 7.4, and 8.1, respectively. A linear relationship (R(2)=0.993) was obtained between the P...

Bioelectronic sniffer for nicotine using enzyme inhibition.

Science.gov (United States)

Mitsubayashi, Kohji; Nakayama, Kazumi; Taniguchi, Midori; Saito, Hirokazu; Otsuka, Kimio; Kudo, Hiroyuki

2006-07-28

A novel bioelectronic sniffer for nicotine in the gas phase was developed with enzyme inhibition principle to butyrylcholinesterase activity. The bioelectronic devices for nicotine in the gas and liquid phases were constructed using a Clark-type dissolved oxygen electrode and a membrane immobilized butyrylcholinesterase and choline oxidase. After the assessment of the sensor performances to choline and butyrylcholine as pre-examinations, the characteristics of the biosensor and bio-sniffer for nicotine were evaluated in the liquid and gas phases, respectively. The sensor signal of the bio-devices with 300 micromol l(-1) of butyrylcholine decreased quickly following application of nicotine and reached to the steady-state current, thus relating the concentration of nicotine in the liquid and gas phases. The biosensor was used to measure nicotine solution from 10 to 300 micromol l(-1). In the gas-phase experiment, the current signal of the bio-sniffer was also found to be linearly to the nicotine concentration over the range of 10.0-1000 ppb including 75.0 ppb as threshold limit value (TLV) by American Conference of Governmental Industrial Hygienists (ACGIH).

Nicotine adsorption on single wall carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Girao, Eduardo C. [Departamento de Fisica, Universidade Federal do Ceara, Caixa Postal 6030, Campus do Pici, 60455-900 Fortaleza, Ceara (Brazil); Fagan, Solange B.; Zanella, Ivana [Area de Ciencias Tecnologicas, Centro Universitario Franciscano - UNIFRA, 97010-032 Santa Maria, RS (Brazil); Filho, Antonio G. Souza, E-mail: agsf@fisica.ufc.br [Departamento de Fisica, Universidade Federal do Ceara, Caixa Postal 6030, Campus do Pici, 60455-900 Fortaleza, Ceara (Brazil)

2010-12-15

This work reports a theoretical study of nicotine molecules interacting with single wall carbon nanotubes (SWCNTs) through ab initio calculations within the framework of density functional theory (DFT). Different adsorption sites for nicotine on the surface of pristine and defective (8,0) SWCNTs were analyzed and the total energy curves, as a function of molecular position relative to the SWCNT surface, were evaluated. The nicotine adsorption process is found to be energetically favorable and the molecule-nanotube interaction is intermediated by the tri-coordinated nitrogen atom from the nicotine. It is also predicted the possibility of a chemical bonding between nicotine and SWCNT through the di-coordinated nitrogen.

Effects of Electronic Cigarette Liquid Nicotine Concentration on Plasma Nicotine and Puff Topography in Tobacco Cigarette Smokers: A Preliminary Report.

Science.gov (United States)

Lopez, Alexa A; Hiler, Marzena M; Soule, Eric K; Ramôa, Carolina P; Karaoghlanian, Nareg V; Lipato, Thokozeni; Breland, Alison B; Shihadeh, Alan L; Eissenberg, Thomas

2016-05-01

Electronic cigarettes (ECIGs) aerosolize a liquid that usually contains propylene glycol and/or vegetable glycerin, flavorants, and the dependence-producing drug nicotine in various concentrations. This study examined the extent to which ECIG liquid nicotine concentration is related to user plasma nicotine concentration in ECIG-naïve tobacco cigarette smokers. Sixteen ECIG-naïve cigarette smokers completed four laboratory sessions that differed by the nicotine concentration of the liquid (0, 8, 18, or 36 mg/ml) that was placed into a 1.5 Ohm, dual coil "cartomizer" powered by a 3.3V battery. In each session, participants completed two, 10-puff ECIG use bouts with a 30-second inter-puff interval; bouts were separated by 60 minutes. Venous blood was sampled before and after bouts for later analysis of plasma nicotine concentration; puff duration, volume, and average flow rate were measured during each bout. In bout 1, relative to the 0mg/ml nicotine condition (mean = 3.8 ng/ml, SD = 3.3), plasma nicotine concentration increased significantly immediately after the bout for the 8 (mean = 8.8 ng/ml, SD = 6.3), 18 (mean = 13.2 ng/ml, SD = 13.2), and 36 mg/ml (mean = 17.0 ng/ml, SD = 17.9) liquid concentration. A similar pattern was observed after bout 2. Average puff duration in the 36 mg/ml condition was significantly shorter compared to the 0mg/ml nicotine condition. Puff volume increased during the second bout for 8 and 18 mg/ml conditions. For a given ECIG device, nicotine delivery may be directly related to liquid concentration. ECIG-naïve cigarette smokers can, from their first use bout, attain cigarette-like nicotine delivery profiles with some currently available ECIG products. Liquid nicotine concentration can influence plasma nicotine concentration in ECIG-naïve cigarette smokers, and, at some concentrations, the nicotine delivery profile of a 3.3V ECIG with a dual coil, 1.5-Ohm cartomizer approaches that of a combustible tobacco cigarette in this

Stable isotope studies of nicotine kinetics and bioavailability

International Nuclear Information System (INIS)

Benowitz, N.L.; Jacob, P. III; Denaro, C.; Jenkins, R.

1991-01-01

The stable isotope-labeled compound 3',3'-dideuteronicotine was used to investigate the disposition kinetics of nicotine in smokers, the systemic absorption of nicotine from cigarette smoke, and the bioavailability of nicotine ingested as oral capsules. Blood levels of labeled nicotine could be measured for 9 hours after a 30-minute intravenous infusion. Analysis of disposition kinetics in 10 healthy men revealed a multiexponential decline after the end of an infusion, with an elimination half-life averaging 203 minutes. This half-life was longer than that previously reported, indicating the presence of a shallow elimination phase. Plasma clearance averaged 14.6 ml/min/kg. The average intake of nicotine per cigarette was 2.29 mg. A cigarette smoke-monitoring system that directly measured particulate matter in smoke was evaluated in these subjects. Total particulate matter, number of puffs on the cigarette, total puff volume, and time of puffing correlated with the intake of nicotine from smoking. The oral bioavailability of nicotine averaged 44%. This bioavailability is higher than expected based on the systemic clearance of nicotine and suggests that there may be significant extrahepatic metabolism of nicotine

Characterization and Genome Analysis of a Nicotine and Nicotinic Acid-Degrading Strain Pseudomonas putida JQ581 Isolated from Marine.

Science.gov (United States)

Li, Aiwen; Qiu, Jiguo; Chen, Dongzhi; Ye, Jiexu; Wang, Yuhong; Tong, Lu; Jiang, Jiandong; Chen, Jianmeng

2017-05-31

The presence of nicotine and nicotinic acid (NA) in the marine environment has caused great harm to human health and the natural environment. Therefore, there is an urgent need to use efficient and economical methods to remove such pollutants from the environment. In this study, a nicotine and NA-degrading bacterium-strain JQ581-was isolated from sediment from the East China Sea and identified as a member of Pseudomonas putida based on morphology, physio-biochemical characteristics, and 16S rDNA gene analysis. The relationship between growth and nicotine/NA degradation suggested that strain JQ581 was a good candidate for applications in the bioaugmentation treatment of nicotine/NA contamination. The degradation intermediates of nicotine are pseudooxynicotine (PN) and 3-succinoyl-pyridine (SP) based on UV, high performance liquid chromatography, and liquid chromatography-mass spectrometry analyses. However, 6-hydroxy-3-succinoyl-pyridine (HSP) was not detected. NA degradation intermediates were identified as 6-hydroxynicotinic acid (6HNA). The whole genome of strain JQ581 was sequenced and analyzed. Genome sequence analysis revealed that strain JQ581 contained the gene clusters for nicotine and NA degradation. This is the first report where a marine-derived Pseudomonas strain had the ability to degrade nicotine and NA simultaneously.

Inside-out neuropharmacology of nicotinic drugs.

Science.gov (United States)

Henderson, Brandon J; Lester, Henry A

2015-09-01

Upregulation of neuronal nicotinic acetylcholine receptors (AChRs) is a venerable result of chronic exposure to nicotine; but it is one of several consequences of pharmacological chaperoning by nicotine and by some other nicotinic ligands, especially agonists. Nicotinic ligands permeate through cell membranes, bind to immature AChR oligomers, elicit incompletely understood conformational reorganizations, increase the interaction between adjacent AChR subunits, and enhance the maturation process toward stable AChR pentamers. These changes and stabilizations in turn lead to increases in both anterograde and retrograde traffic within the early secretory pathway. In addition to the eventual upregulation of AChRs at the plasma membrane, other effects of pharmacological chaperoning include modifications to endoplasmic reticulum stress and to the unfolded protein response. Because these processes depend on pharmacological chaperoning within intracellular organelles, we group them as "inside-out pharmacology". This term contrasts with the better-known, acute, "outside-in" effects of activating and desensitizing plasma membrane AChRs. We review current knowledge concerning the mechanisms and consequences of inside-out pharmacology. This article is part of the Special Issue entitled 'The Nicotinic Acetylcholine Receptor: From Molecular Biology to Cognition'. Copyright © 2015 Elsevier Ltd. All rights reserved.

Tolerance to and cross tolerance between ethanol and nicotine.

Science.gov (United States)

Collins, A C; Burch, J B; de Fiebre, C M; Marks, M J

1988-02-01

Female DBA mice were subjected to one of four treatments: ethanol-containing or control diets, nicotine (0.2, 1.0, 5.0 mg/kg/hr) infusion or saline infusion. After removal from the liquid diets or cessation of infusion, the animals were challenged with an acute dose of ethanol or nicotine. Chronic ethanol-fed mice were tolerant to the effects of ethanol on body temperature and open field activity and were cross tolerant to the effects of nicotine on body temperature and heart rate. Nicotine infused animals were tolerant to the effects of nicotine on body temperature and rotarod performance and were cross tolerant to the effects of ethanol on body temperature. Ethanol-induced sleep time was decreased in chronic ethanol- but not chronic nicotine-treated mice. Chronic drug treatment did not alter the elimination rate of either drug. Chronic ethanol treatment did not alter the number or affinity of brain nicotinic receptors whereas chronic nicotine treatment elicited an increase in the number of [3H]-nicotine binding sites. Tolerance and cross tolerance between ethanol and nicotine is discussed in terms of potential effects on desensitization of brain nicotinic receptors.

Transdermal nicotine absorption handling e-cigarette refill liquids.

Science.gov (United States)

Maina, Giovanni; Castagnoli, Carlotta; Passini, Valter; Crosera, Matteo; Adami, Gianpiero; Mauro, Marcella; Filon, Francesca Larese

2016-02-01

The concentrated nicotine in e-cigarette refill liquids can be toxic if inadvertently ingested or absorbed through the skin. Reports of poisonings due to accidental ingestion of nicotine on refill liquids are rapidly increasing, while the evaluation of nicotine dermally absorbed still lacks. For that reason we studied transdermal nicotine absorption after the skin contamination with e-liquid. Donor chambers of eight Franz diffusion cells were filled with 1 mL of 0.8 mg/mL nicotine e-liquid for 24 h. The concentration of nicotine in the receiving phase was determined by high-performance liquid chromatography (LOD:0.1 μg/mL). Nicotine was detectable in receiving solution 2 h after the start of exposure and increased progressively. The medium flux calculated was 4.82 ± 1.05 μg/cm(2)/h with a lag time of 3.9 ± 0.1 h. After 24 h, the nicotine concentration in the receiving compartment was 101.02 ± 22.35 μg/cm(2) corresponding to 3.04 mg of absorbed nicotine after contamination of a skin surface of 100 cm(2). Skin contamination with e-liquid can cause nicotine skin absorption: caution must be paid when handling refill e-liquids. Copyright © 2015 Elsevier Inc. All rights reserved.

A simple physiologically based pharmacokinetic model evaluating the effect of anti-nicotine antibodies on nicotine disposition in the brains of rats and humans

Energy Technology Data Exchange (ETDEWEB)

Saylor, Kyle, E-mail: saylor@vt.edu; Zhang, Chenming, E-mail: chzhang2@vt.edu

2016-09-15

Physiologically based pharmacokinetic (PBPK) modeling was applied to investigate the effects of anti-nicotine antibodies on nicotine disposition in the brains of rats and humans. Successful construction of both rat and human models was achieved by fitting model outputs to published nicotine concentration time course data in the blood and in the brain. Key parameters presumed to have the most effect on the ability of these antibodies to prevent nicotine from entering the brain were selected for investigation using the human model. These parameters, which included antibody affinity for nicotine, antibody cross-reactivity with cotinine, and antibody concentration, were broken down into different, clinically-derived in silico treatment levels and fed into the human PBPK model. Model predictions suggested that all three parameters, in addition to smoking status, have a sizable impact on anti-nicotine antibodies' ability to prevent nicotine from entering the brain and that the antibodies elicited by current human vaccines do not have sufficient binding characteristics to reduce brain nicotine concentrations. If the antibody binding characteristics achieved in animal studies can similarly be achieved in human studies, however, nicotine vaccine efficacy in terms of brain nicotine concentration reduction is predicted to meet threshold values for alleviating nicotine dependence. - Highlights: • Modelling of nicotine disposition in the presence of anti-nicotine antibodies • Key vaccine efficacy factors are evaluated in silico in rats and in humans. • Model predicts insufficient antibody binding in past human nicotine vaccines. • Improving immunogenicity and antibody specificity may lead to vaccine success.

A simple physiologically based pharmacokinetic model evaluating the effect of anti-nicotine antibodies on nicotine disposition in the brains of rats and humans

International Nuclear Information System (INIS)

Saylor, Kyle; Zhang, Chenming

2016-01-01

Physiologically based pharmacokinetic (PBPK) modeling was applied to investigate the effects of anti-nicotine antibodies on nicotine disposition in the brains of rats and humans. Successful construction of both rat and human models was achieved by fitting model outputs to published nicotine concentration time course data in the blood and in the brain. Key parameters presumed to have the most effect on the ability of these antibodies to prevent nicotine from entering the brain were selected for investigation using the human model. These parameters, which included antibody affinity for nicotine, antibody cross-reactivity with cotinine, and antibody concentration, were broken down into different, clinically-derived in silico treatment levels and fed into the human PBPK model. Model predictions suggested that all three parameters, in addition to smoking status, have a sizable impact on anti-nicotine antibodies' ability to prevent nicotine from entering the brain and that the antibodies elicited by current human vaccines do not have sufficient binding characteristics to reduce brain nicotine concentrations. If the antibody binding characteristics achieved in animal studies can similarly be achieved in human studies, however, nicotine vaccine efficacy in terms of brain nicotine concentration reduction is predicted to meet threshold values for alleviating nicotine dependence. - Highlights: • Modelling of nicotine disposition in the presence of anti-nicotine antibodies • Key vaccine efficacy factors are evaluated in silico in rats and in humans. • Model predicts insufficient antibody binding in past human nicotine vaccines. • Improving immunogenicity and antibody specificity may lead to vaccine success.

REINFORCEMENT ENHANCING EFFECTS OF ACUTE NICOTINE VIA ELECTRONIC CIGARETTES

Science.gov (United States)

Perkins, Kenneth A.; Karelitz, Joshua L.; Michael, Valerie C.

2015-01-01

Background Recent human studies confirm animal research showing that nicotine enhances reinforcement from rewards unrelated to nicotine. These effects of acute nicotine via tobacco smoking may also occur when consumed from non-tobacco products. Methods We assessed acute effects of nicotine via electronic cigarettes (“e-cigarettes”) on responding reinforced by music, video, or monetary rewards, or for no reward (control). In a fully within-subjects design, adult dependent smokers (N=28) participated in three similar experimental sessions, each following overnight abstinence (verified by CO≤10 ppm). Varying only in e-cigarette condition, sessions involved controlled exposure to a nicotine (labeled “36 mg/ml”) or placebo (“0”) e-cigarette, or no e-cigarette use. A fourth session involved smoking one’s own tobacco cigarette brand after no abstinence, specifically to compare responses under typical nicotine satiation with these acute e-cigarette conditions after abstinence. Results Reinforced responding for video reward, but not the other rewards, was greater due to use of the nicotine versus placebo e-cigarette (i.e., nicotine per se), while no differences were found between the placebo e-cigarette and no e-cigarette conditions (i.e., e-cigarette use per se). For nicotine via tobacco smoking, responding compared to the nicotine e-cigarette was similar for video but greater for music, while both video and music reward were enhanced relative to the non-nicotine conditions (placebo and no e-cigarette). Conclusions Acute nicotine from a non-tobacco product has some reinforcement enhancing effects in humans, in a manner partly consistent with nicotine via tobacco smoking and perhaps contributing to the rising popularity of nicotine e-cigarette use. PMID:26070455

Reinforcement enhancing effects of acute nicotine via electronic cigarettes.

Science.gov (United States)

Perkins, Kenneth A; Karelitz, Joshua L; Michael, Valerie C

2015-08-01

Recent human studies confirm animal research showing that nicotine enhances reinforcement from rewards unrelated to nicotine. These effects of acute nicotine via tobacco smoking may also occur when consumed from non-tobacco products. We assessed acute effects of nicotine via electronic cigarettes ("e-cigarettes") on responding reinforced by music, video, or monetary rewards, or for no reward (control). In a fully within-subjects design, adult dependent smokers (N=28) participated in three similar experimental sessions, each following overnight abstinence (verified by CO≤10ppm). Varying only in e-cigarette condition, sessions involved controlled exposure to a nicotine (labeled "36mg/ml") or placebo ("0″) e-cigarette, or no e-cigarette use. A fourth session involved smoking one's own tobacco cigarette brand after no abstinence, specifically to compare responses under typical nicotine satiation with these acute e-cigarette conditions after abstinence. Reinforced responding for video reward, but not the other rewards, was greater due to use of the nicotine versus placebo e-cigarette (i.e., nicotine per se), while no differences were found between the placebo e-cigarette and no e-cigarette conditions (i.e., e-cigarette use per se). For nicotine via tobacco smoking, responding compared to the nicotine e-cigarette was similar for video but greater for music, while both video and music reward were enhanced relative to the non-nicotine conditions (placebo and no e-cigarette). Acute nicotine from a non-tobacco product has some reinforcement enhancing effects in humans, in a manner partly consistent with nicotine via tobacco smoking and perhaps contributing to the rising popularity of nicotine e-cigarette use. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Detoxification and elimination of nicotine by nectar-feeding birds.

Science.gov (United States)

Lerch-Henning, S; Du Rand, E E; Nicolson, S W

2017-05-01

Many dilute nectars consumed by bird pollinators contain secondary metabolites, potentially toxic chemicals produced by plants as defences against herbivores. Consequently, nectar-feeding birds are challenged not only by frequent water excess, but also by the toxin content of their diet. High water turnover, however, could be advantageous to nectar consumers by enabling them to excrete secondary metabolites or their transformation products more easily. We investigated how the alkaloid nicotine, naturally present in nectar of Nicotiana species, influences osmoregulation in white-bellied sunbirds Cinnyris talatala and Cape white-eyes Zosterops virens. We also examined the metabolic fate of nicotine in these two species to shed more light on the post-ingestive mechanisms that allow nectar-feeding birds to tolerate nectar nicotine. A high concentration of nicotine (50 µM) decreased cloacal fluid output and increased its osmolality in both species, due to reduced food intake that led to dehydration. White-eyes excreted a higher proportion of the ingested nicotine-containing diet than sunbirds. However, sugar concentration did not affect nicotine detoxification and elimination. Both species metabolised nicotine, excreting very little unchanged nicotine. Cape white-eyes mainly metabolised nicotine through the cotinine metabolic pathway, with norcotinine being the most abundant metabolite in the excreta, while white-bellied sunbirds excreted mainly nornicotine. Both species also utilized phase II conjugation reactions to detoxify nicotine, with Cape white-eyes depending more on the mercapturic acid pathway to detoxify nicotine than white-bellied sunbirds. We found that sunbirds and white-eyes, despite having a similar nicotine tolerance, responded differently and used different nicotine-derived metabolites to excrete nicotine.

Menthol Enhances Nicotine Reward-Related Behavior by Potentiating Nicotine-Induced Changes in nAChR Function, nAChR Upregulation, and DA Neuron Excitability.

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Henderson, Brandon J; Wall, Teagan R; Henley, Beverley M; Kim, Charlene H; McKinney, Sheri; Lester, Henry A

2017-11-01

Understanding why the quit rate among smokers of menthol cigarettes is lower than non-menthol smokers requires identifying the neurons that are altered by nicotine, menthol, and acetylcholine. Dopaminergic (DA) neurons in the ventral tegmental area (VTA) mediate the positive reinforcing effects of nicotine. Using mouse models, we show that menthol enhances nicotine-induced changes in nicotinic acetylcholine receptors (nAChRs) expressed on midbrain DA neurons. Menthol plus nicotine upregulates nAChR number and function on midbrain DA neurons more than nicotine alone. Menthol also enhances nicotine-induced changes in DA neuron excitability. In a conditioned place preference (CPP) assay, we observed that menthol plus nicotine produces greater reward-related behavior than nicotine alone. Our results connect changes in midbrain DA neurons to menthol-induced enhancements of nicotine reward-related behavior and may help explain how smokers of menthol cigarettes exhibit reduced cessation rates.

Opioid Analgesics and Nicotine: More Than Blowing Smoke.

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Yoon, Jin H; Lane, Scott D; Weaver, Michael F

2015-09-01

Practitioners are highly likely to encounter patients with concurrent use of nicotine products and opioid analgesics. Smokers present with more severe and extended chronic pain outcomes and have a higher frequency of prescription opioid use. Current tobacco smoking is a strong predictor of risk for nonmedical use of prescription opioids. Opioid and nicotinic-cholinergic neurotransmitter systems interact in important ways to modulate opioid and nicotine effects: dopamine release induced by nicotine is dependent on facilitation by the opioid system, and the nicotinic-acetylcholine system modulates self-administration of several classes of abused drugs-including opioids. Nicotine can serve as a prime for the use of other drugs, which in the case of the opioid system may be bidirectional. Opioids and compounds in tobacco, including nicotine, are metabolized by the cytochrome P450 enzyme system, but the metabolism of opioids and tobacco products can be complicated. Accordingly, drug interactions are possible but not always clear. Because of these issues, asking about nicotine use in patients taking opioids for pain is recommended. When assessing patient tobacco use, practitioners should also obtain information on products other than cigarettes, such as cigars, pipes, smokeless tobacco, and electronic nicotine delivery systems (ENDS, or e-cigarettes). There are multiple forms of behavioral therapy and pharmacotherapy available to assist patients with smoking cessation, and opioid agonist maintenance and pain clinics represent underutilized opportunities for nicotine intervention programs.

Airborne Nicotine, Secondhand Smoke, and Precursors to Adolescent Smoking.

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McGrath, Jennifer J; Racicot, Simon; Okoli, Chizimuzo T C; Hammond, S Katharine; O'Loughlin, Jennifer

2018-01-01

Secondhand smoke (SHS) directly increases exposure to airborne nicotine, tobacco's main psychoactive substance. When exposed to SHS, nonsmokers inhale 60% to 80% of airborne nicotine, absorb concentrations similar to those absorbed by smokers, and display high levels of nicotine biomarkers. Social modeling, or observing other smokers, is a well-established predictor of smoking during adolescence. Observing smokers also leads to increased pharmacological exposure to airborne nicotine via SHS. The objective of this study is to investigate whether greater exposure to airborne nicotine via SHS increases the risk for smoking initiation precursors among never-smoking adolescents. Secondary students ( N = 406; never-smokers: n = 338, 53% girls, mean age = 12.9, SD = 0.4) participated in the AdoQuest II longitudinal cohort. They answered questionnaires about social exposure to smoking (parents, siblings, peers) and known smoking precursors (eg, expected benefits and/or costs, SHS aversion, smoking susceptibility, and nicotine dependence symptoms). Saliva and hair samples were collected to derive biomarkers of cotinine and nicotine. Adolescents wore a passive monitor for 1 week to measure airborne nicotine. Higher airborne nicotine was significantly associated with greater expected benefits ( R 2 = 0.024) and lower expected costs ( R 2 = 0.014). Higher social exposure was significantly associated with more temptation to try smoking ( R 2 = 0.025), lower aversion to SHS ( R 2 = 0.038), and greater smoking susceptibility ( R 2 = 0.071). Greater social exposure was significantly associated with more nicotine dependence symptoms; this relation worsened with higher nicotine exposure (cotinine R 2 = 0.096; airborne nicotine R 2 = 0.088). Airborne nicotine exposure via SHS is a plausible risk factor for smoking initiation during adolescence. Public health implications include limiting airborne nicotine through smoking bans in homes and cars, in addition to stringent restrictions

Antinociception induced by stimulating amygdaloid nuclei in rats: changes produced by systemically administered antagonists

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M.A. Oliveira

1998-05-01

Full Text Available The antinociceptive effects of stimulating the medial (ME and central (CE nuclei of the amygdala in rats were evaluated by the changes in the latency for the tail withdrawal reflex to noxious heating of the skin. A 30-s period of sine-wave stimulation of the ME or CE produced a significant and short increase in the duration of tail flick latency. A 15-s period of stimulation was ineffective. Repeated stimulation of these nuclei at 48-h intervals produced progressively smaller effects. The antinociception evoked from the ME was significantly reduced by the previous systemic administration of naloxone, methysergide, atropine, phenoxybenzamine, and propranolol, but not by mecamylamine, all given at the dose of 1.0 mg/kg. Previous systemic administration of naloxone, atropine, and propranolol, but not methysergide, phenoxybenzamine, or mecamylamine, was effective against the effects of stimulating the CE. We conclude that the antinociceptive effects of stimulating the ME involve at least opioid, serotonergic, adrenergic, and muscarinic cholinergic descending mechanisms. The effects of stimulating the CE involve at least opioid, ß-adrenergic, and muscarinic cholinergic descending mechanisms.

Nicotine pharmacokinetics and its application to intake from smoking.

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Feyerabend, C; Ings, R M; Russel, M A

1985-01-01

Five subjects were given 25 micrograms/kg nicotine intravenously over 1 min, before and after a loading period involving the smoking of six cigarettes. Plasma nicotine concentrations declined in a biphasic manner, the half-lives of the initial and terminal phases averaging 9 min and 133 min respectively. Terminal half-lives before and after the loading period were essentially the same suggesting the absence of saturation kinetics at nicotine concentrations that build up during smoking. The plasma clearance of nicotine and the volume of distribution were very high averaging 915 ml/min and 1731, respectively. Two approaches were used to calculate the nicotine intake from smoking. The average dose of nicotine absorbed from one cigarette was 1.06 mg which was 82% of the standard machine-smoked yield of 1.3 mg. To illustrate their potential use in 'nicotine titration' studies, these approaches were used to compare nicotine intake from smoking a high (2.4 mg) and low (0.6 mg) nicotine cigarette. The dose of nicotine absorbed averaged 1.14 mg and 0.86 mg per cigarette respectively, being 48% and 143% of the machine-smoked yields. PMID:3986082

The effect of ketamine on intraspinal acetylcholine release

DEFF Research Database (Denmark)

Abelson, Klas S P; Goldkuhl, Renée Röstlinger; Nylund, Anders

2006-01-01

The general anaesthetic ketamine affects the central cholinergic system in several manners, but its effect on spinal acetylcholine release, which may be an important transmitter in spinal antinociception, is unknown. This study aimed to investigate the effect of ketamine on spinal acetylcholine...... release. Microdialysis probes were placed intraspinally in male rats, and acetylcholine was quantified with HPLC. Anaesthesia was switched from isoflurane (1.3%) to ketamine (150 mg/kg h), which resulted in a 500% increased acetylcholine release. The increase was attenuated during nicotinic receptor...... blockade (50 microM mecamylamine). The nicotinic receptor agonist epibatidine (175 microM) produced a ten-fold higher relative increase of acetylcholine release during isoflurane anaesthesia compared to ketamine anaesthesia (270% to 27%). Intraspinal administration of ketamine and norketamine both...

NICOTINE EFFECTS ON THE ACTIVITY OF MICE EXPOSED PRENATALLY TO THE NICOTINIC AGONIST ANATOXIN-A.

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Considerable research has shown long-lasting effects of early exposure in experimental animals to nicotine. Anatoxin-a is produced by cyanobacteria and has been shown to be a potent nicotinic agonist. This experiment evaluated the motor activity of adult mice, and their respons...

Effect of nicotine on negative affect among more impulsive smokers.

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Doran, Neal; McChargue, Dennis; Spring, Bonnie; VanderVeen, Joe; Cook, Jessica Werth; Richmond, Malia

2006-08-01

In the present study, the authors tested the hypothesis that nicotine would provide greater relief from negative affect for more impulsive smokers than for less impulsive smokers. Euthymic adult smokers (N=70) participated in 2 laboratory sessions, during which they underwent a negative mood induction (music + autobiographical memory), then smoked either a nicotinized or de-nicotinized cigarette. Mixed-effects regression yielded a significant Impulsivity x Condition (nicotinized vs. de-nicotinized) x Time interaction. Simple effects analyses showed that heightened impulsivity predicted greater negative affect relief after smoking a nicotinized cigarette but not after smoking a de-nicotinized cigarette. These data suggest that nicotine may be a disproportionately powerful negative reinforcer for highly impulsive smokers, promoting higher levels of nicotine dependence and inhibiting smoking cessation.

Beta3 subunits promote expression and nicotine-induced up-regulation of human nicotinic alpha6* nicotinic acetylcholine receptors expressed in transfected cell lines.

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Tumkosit, Prem; Kuryatov, Alexander; Luo, Jie; Lindstrom, Jon

2006-10-01

Nicotinic acetylcholine receptors (AChRs) containing alpha6 subunits are typically found at aminergic nerve endings where they play important roles in nicotine addiction and Parkinson's disease. alpha6* AChRs usually contain beta3 subunits. beta3 subunits are presumed to assemble only in the accessory subunit position within AChRs where they do not participate in forming acetylcholine binding sites. Assembly of subunits in the accessory position may be a critical final step in assembly of mature AChRs. Human alpha6 AChRs subtypes were permanently transfected into human tsA201 human embryonic kidney (HEK) cell lines. alpha6beta2beta3 and alpha6beta4beta3 cell lines were found to express much larger amounts of AChRs and were more sensitive to nicotine-induced increase in the amount of AChRs than were alpha6beta2 or alpha6beta4 cell lines. The increased sensitivity to nicotine-induced up-regulation was due not to a beta3-induced increase in affinity for nicotine but probably to a direct effect on assembly of AChR subunits. HEK cells express only a small amount of mature alpha6beta2 AChRs, but many of these subunits are on the cell surface. This contrasts with Xenopus laevis oocytes, which express a large amount of incorrectly assembled alpha6beta2 subunits that bind cholinergic ligands but form large amorphous intracellular aggregates. Monoclonal antibodies (mAbs) were made to the alpha6 and beta3 subunits to aid in the characterization of these AChRs. The alpha6 mAbs bind to epitopes C-terminal of the extracellular domain. These data demonstrate that both cell type and the accessory subunit beta3 can play important roles in alpha6* AChR expression, stability, and up-regulation by nicotine.

Differential Gene Expression Profile in the Rat Caudal Vestibular Nucleus is Associated with Individual Differences in Motion Sickness Susceptibility.

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Jun-Qin Wang

Full Text Available To identify differentially expressed genes associated with motion sickness (MS susceptibility in the rat caudal vestibular nucleus.We identified MS susceptible (MSS and insusceptible (inMSS rats by quantifying rotation-induced MS symptoms: defecation and spontaneous locomotion activity. Microarray analysis was used to screen differentially expressed genes in the caudal vestibular nucleus (CVN after rotation. Plasma stress hormones were identified by radioimmunoassay. Candidate genes were selected by bioinformatics analysis and the microarray results were verified by real-time quantitative-PCR (RT-qPCR methods. By using Elvax implantation, receptor antagonists or recombinant adenovirus targeting the candidate genes were applied to the CVN to evaluate their contribution to MS susceptibility variability. Validity of gene expression manipulation was verified by RT-qPCR and western blot analysis.A total of 304 transcripts were differentially expressed in the MSS group compared with the inMSS group. RT-qPCR analysis verified the expression pattern of candidate genes, including nicotinic cholinergic receptor (nAchR α3 subunit, 5-hydroxytryptamine receptor 4 (5-HT4R, tachykinin neurokinin-1 (NK1R, γ-aminobutyric acid A receptor (GABAAR α6 subunit, olfactory receptor 81 (Olr81 and homology 2 domain-containing transforming protein 1 (Shc1. In MSS animals, the nAchR antagonist mecamylamine significantly alleviated rotation-induced MS symptoms and the plasma β-endorphin response. The NK1R antagonist CP99994 and Olr81 knock-down were effective for the defecation response, while the 5-HT4R antagonist RS39604 and Shc1 over-expression showed no therapeutic effect. In inMSS animals, rotation-induced changes in spontaneous locomotion activity and the plasma β-endorphin level occurred in the presence of the GABAAR antagonist gabazine.Our findings suggested that the variability of the CVN gene expression profile after motion stimulation might be a putative

Nicotine Reduction Revisited: Science and Future Directions

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Hatsukami, Dorothy K.; Perkins, Kenneth A.; LeSage, Mark G.; Ashley, David L.; Henningfield, Jack E.; Benowitz, Neal L.; Backinger, Cathy; Zeller, Mitch

2015-01-01

Regulation of nicotine levels in cigarettes and other tobacco products is now possible with the passage of the Family Smoking Prevention and Tobacco Control Act (FSPTCA) in 2009 giving the U.S. Food and Drug Administration authority to regulate tobacco products, and with Articles 9-11 of the World Health Organization Framework Convention on Tobacco Control.[1-2] Both regulatory approaches allow establishing product standards for tobacco constituents, including nicotine. The FSPTCA does not allow nicotine levels to be decreased to zero, although FDA has the authority to reduce nicotine yields to very low, presumably non-addicting levels. The proposal to reduce levels of nicotine to a level that is non-addicting was originally suggested in 1994.[3] Reduction of nicotine in tobacco products could potentially have a profound impact on reducing tobacco-related morbidity and mortality. To examine this issue, two meetings were convened in the United States with non-tobacco-industry scientists of varied disciplines, tobacco control policy-makers and representatives of government agencies. This article provides an overview of the current science in the area of reduced nicotine content cigarettes and key conclusions and recommendations for research and policy that emerged from the deliberations of the meeting members. PMID:20876072

Nicotine and endogenous opioids: neurochemical and pharmacological evidence.

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Hadjiconstantinou, Maria; Neff, Norton H

2011-06-01

Although the mesolimbic dopamine hypothesis is the most influential theory of nicotine reward and reinforcement, there has been a consensus that other neurotransmitter systems contribute to the addictive properties of nicotine as well. In this regard, the brain opioidergic system is of interest. Striatum is rich in opioid peptides and opioid receptors, and striatal opioidergic neurons are engaged in a bidirectional communication with midbrain dopaminergic neurons, closely regulating each other's activity. Enkephalins and dynorphins exert opposing actions on dopaminergic neurons, increasing and decreasing dopamine release respectively, and are components of circuits promoting positive or negative motivational and affective states. Moreover, dopamine controls the synthesis of striatal enkephalins and dynorphins. Evidence suggests that opioidergic function is altered after nicotine and endogenous opioids are involved in nicotine's behavioral effects. 1) The synthesis and release of β-endorphin, met-enkephalin and dynorphin in brain, especially nucleus accumbens (NAc), are altered after acute or chronic nicotine treatment and during nicotine withdrawal. 2) Although opioid receptor binding and mRNA do not appear to change in the striatum during nicotine withdrawal, the activity of κ-opioid (KOPr) and δ-opioid (DOPr) receptors is attenuated in NAc. 3) The nicotine withdrawal syndrome reminisces that of opiates, and naloxone precipitates some of its somatic, motivational, and affective signs. 4) Genetic and pharmacological studies indicate that μ-opioid (MOPr) receptors are mainly involved in nicotine reward, while DOPrs contribute to the emotional and KOPrs to the aversive responses of nicotine. 5) Finally, MOPrs and enkephalin, but not β-endorphin or dynorphin, are necessary for the physical manifestations of nicotine withdrawal. This article is part of a Special Issue entitled 'Trends in neuropharmacology: in memory of Erminio Costa'. Copyright © 2010 Elsevier

Nicotine Analysis in Several Non-Tobacco Plant Materials

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Moldoveanu Serban C.

2016-04-01

Full Text Available Present study describes the determination of nicotine in various plant samples with a low content of this compound. Nicotine is found naturally in plants from the Solanaceae family. The plants from Nicotiana genus contain large levels of nicotine. However, only low levels are present in plants from Solanum genus including potato, tomato, eggplant, and from Capsicum genus, which are used as food. Because the levels of nicotine in these materials are in the range of parts per billion, the measurements are difficult and the results are very different from study to study. The present study evaluated the level of nicotine in a number of plants (fruits, roots, leaves, tubers from Solanaceae family (not including Nicotiana genus and from several other vegetables commonly used as food. The analysis consisted of the treatment of plant material with an aqueous solution 5% NaOH at 70°C for 30 min, followed by extraction with TBME containing d3-nicotine as an internal standard. The TBME organic layer was analyzed on a 7890B/7000C GC-MS/MS system with a 30 m × 0.25 mm, 0.25 μm film CAM column. The MS/MS system worked in MRM positive ionization mode monitoring the transition 162 - 84 for nicotine and 165 - 87 for d3-nicotine. Particular attention was given to the preservation of the intact levels of nicotine in the plant material. The plant material was analyzed as is, without drying and with minimal exposure to contaminations. Separately, the moisture of the plant material was measured in order to report the nicotine level on a dry-basis. Levels of nicotine around 180 ng/g dry material were obtained for tomatoes and eggplant (fruit and lower levels were obtained for green pepper and potato. Similar levels to that in the tomato fruit were detected in tomato leaves. Materials from other plant families also showed traces of nicotine. [Beitr. Tabakforsch. Int. 27 (2016 54-59

Nicotine-selective radiation-induced poly(acrylamide/maleic acid) hydrogels

International Nuclear Information System (INIS)

Saraydin, D.; Karadag, E.; Caldiran, Y.; Gueven, O.

2001-01-01

Nicotine-selective poly(acrylamide/maleic acid) (AAm/MA) hydrogels prepared by γ-irradiation were used in experiments on swelling, diffusion, and interactions of the pharmaceuticals nicotine, nicotinic acid, nicotinamide, and nikethamide. For AAm/MA hydrogel containing 60 mg maleic acid and irradiated at 5.2 kGy, the studies indicated that swelling increased in the following order; nicotine>nicotinamide>nikethamide>nicotinic acid>water. Diffusions of water and the pharmaceuticals within the hydrogels were found to be non-Fickian in character. AAm/MA hydrogel sorbed only nicotine and did not sorb nicotinamide, nikethamide and nicotinic acid in the binding experiments. S-type adsorption in Giles's classification system was observed. Some binding and thermodynamic parameters for AAm/MA hydrogel-nicotine system were calculated using the Scatchard method. The values of adsorption heat and free energy of this system were found to be negative whereas adsorption entropy was found to be positive. (author)

Brain activation by short-term nicotine exposure in anesthetized wild-type and beta2-nicotinic receptors knockout mice: a BOLD fMRI study

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Suarez, S.V.; Changeux, J.P.; Granon, S. [Unite de Neurobiologie Integrative du Systeme Cholinergique, URA CNRS 2182, Institut Pasteur, Departement de Neuroscience, 25 rue du Dr Roux, 75015 Paris (France); Amadon, A.; Giacomini, E.; Le Bihan, D. [Service Hospitalier Frederic Joliot, 4 place du general Leclerc, 91400 Orsay (France); Wiklund, A. [Section of Anaesthesiology and Intensive Care Medicine, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm (Sweden)

2009-07-01

Rationale: The behavioral effects of nicotine and the role of the beta2-containing nicotinic receptors in these behaviors are well documented. However, the behaviors altered by nicotine rely on the functioning on multiple brain circuits where the high-affinity {beta}2-containing nicotinic receptors ({beta}2*nAChRs) are located. Objectives We intend to see which brain circuits are activated when nicotine is given in animals naive for nicotine and whether the {beta}2*nAChRs are needed for its activation of the blood oxygen level dependent (BOLD) signal in all brain areas. Materials and methods: We used functional magnetic resonance imaging (fMRI) to measure the brain activation evoked by nicotine (1 mg/kg delivered at a slow rate for 45 min) in anesthetized C57BL/6J mice and {beta}2 knockout (KO) mice. Results: Acute nicotine injection results in a significant increased activation in anterior frontal, motor, and somatosensory cortices and in the ventral tegmental area and the substantia nigra. Anesthetized mice receiving no nicotine injection exhibited a major decreased activation in all cortical and subcortical structures, likely due to prolonged anesthesia. At a global level, {beta}2 KO mice were not rescued from the globally declining BOLD signal. However, nicotine still activated regions of a meso-cortico-limbic circuit likely via {alpha}7 nicotinic receptors. Conclusions: Acute nicotine exposure compensates for the drop in brain activation due to anesthesia through the meso-cortico-limbic network via the action of nicotine on {beta}2*nAChRs. The developed fMRI method is suitable for comparing responses in wild-type and mutant mice. (authors)

Brain activation by short-term nicotine exposure in anesthetized wild-type and beta2-nicotinic receptors knockout mice: a BOLD fMRI study

International Nuclear Information System (INIS)

Suarez, S.V.; Changeux, J.P.; Granon, S.; Amadon, A.; Giacomini, E.; Le Bihan, D.; Wiklund, A.

2009-01-01

Rationale: The behavioral effects of nicotine and the role of the beta2-containing nicotinic receptors in these behaviors are well documented. However, the behaviors altered by nicotine rely on the functioning on multiple brain circuits where the high-affinity β2-containing nicotinic receptors (β2*nAChRs) are located. Objectives We intend to see which brain circuits are activated when nicotine is given in animals naive for nicotine and whether the β2*nAChRs are needed for its activation of the blood oxygen level dependent (BOLD) signal in all brain areas. Materials and methods: We used functional magnetic resonance imaging (fMRI) to measure the brain activation evoked by nicotine (1 mg/kg delivered at a slow rate for 45 min) in anesthetized C57BL/6J mice and β2 knockout (KO) mice. Results: Acute nicotine injection results in a significant increased activation in anterior frontal, motor, and somatosensory cortices and in the ventral tegmental area and the substantia nigra. Anesthetized mice receiving no nicotine injection exhibited a major decreased activation in all cortical and subcortical structures, likely due to prolonged anesthesia. At a global level, β2 KO mice were not rescued from the globally declining BOLD signal. However, nicotine still activated regions of a meso-cortico-limbic circuit likely via α7 nicotinic receptors. Conclusions: Acute nicotine exposure compensates for the drop in brain activation due to anesthesia through the meso-cortico-limbic network via the action of nicotine on β2*nAChRs. The developed fMRI method is suitable for comparing responses in wild-type and mutant mice. (authors)

Cholinergic modulation of dopamine pathways through nicotinic acetylcholine receptors.

NARCIS (Netherlands)

de Kloet, S.F.; Mansvelder, H.D.; de Vries, T.J.

2015-01-01

Nicotine addiction is highly prevalent in current society and is often comorbid with other diseases. In the central nervous system, nicotine acts as an agonist for nicotinic acetylcholine receptors (nAChRs) and its effects depend on location and receptor composition. Although nicotinic receptors are

The metabolic fate of nectar nicotine in worker honey bees.

Science.gov (United States)

du Rand, Esther E; Pirk, Christian W W; Nicolson, Susan W; Apostolides, Zeno

2017-04-01

Honey bees (Apis mellifera) are generalist pollinators that forage for nectar and pollen of a very large variety of plant species, exposing them to a diverse range of secondary metabolites produced as chemical defences against herbivory. Honey bees can tolerate high levels of many of these toxic compounds, including the alkaloid nicotine, in their diet without incurring apparent fitness costs. Very little is known about the underlying detoxification processes mediating this tolerance. We examined the metabolic fate of nicotine in newly emerged worker bees using radiolabeled nicotine and LC-MS/MS analysis to determine the kinetic distribution profile of nicotine as well as the absence or presence and identity of any nicotine-derived metabolites. Nicotine metabolism was extensive; virtually no unmetabolised nicotine were recovered from the rectum. The major metabolite found was 4-hydroxy-4-(3-pyridyl) butanoic acid, the end product of 2'C-oxidation of nicotine. It is the first time that 4-hydroxy-4-(3-pyridyl) butanoic acid has been identified in an insect as a catabolite of nicotine. Lower levels of cotinine, cotinine N-oxide, 3'hydroxy-cotinine, nicotine N-oxide and norcotinine were also detected. Our results demonstrated that formation of 4-hydroxy-4-(3-pyridyl) butanoic acid is quantitatively the most significant pathway of nicotine metabolism in honey bees and that the rapid excretion of unmetabolised nicotine does not contribute significantly to nicotine tolerance in honey bees. In nicotine-tolerant insects that do not rely on the rapid excretion of nicotine like the Lepidoptera, it is possible that the 2'C-oxidation of nicotine is the conserved metabolic pathway instead of the generally assumed 5'C-oxidation pathway. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nicotine increases brain functional network efficiency.

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Wylie, Korey P; Rojas, Donald C; Tanabe, Jody; Martin, Laura F; Tregellas, Jason R

2012-10-15

Despite the use of cholinergic therapies in Alzheimer's disease and the development of cholinergic strategies for schizophrenia, relatively little is known about how the system modulates the connectivity and structure of large-scale brain networks. To better understand how nicotinic cholinergic systems alter these networks, this study examined the effects of nicotine on measures of whole-brain network communication efficiency. Resting state fMRI was acquired from fifteen healthy subjects before and after the application of nicotine or placebo transdermal patches in a single blind, crossover design. Data, which were previously examined for default network activity, were analyzed with network topology techniques to measure changes in the communication efficiency of whole-brain networks. Nicotine significantly increased local efficiency, a parameter that estimates the network's tolerance to local errors in communication. Nicotine also significantly enhanced the regional efficiency of limbic and paralimbic areas of the brain, areas which are especially altered in diseases such as Alzheimer's disease and schizophrenia. These changes in network topology may be one mechanism by which cholinergic therapies improve brain function. Published by Elsevier Inc.

Slower nicotine metabolism among postmenopausal Polish smokers.

Science.gov (United States)

Kosmider, Leon; Delijewski, Marcin; Koszowski, Bartosz; Sobczak, Andrzej; Benowitz, Neal L; Goniewicz, Maciej L

2018-06-01

A non-invasive phenotypic indicator of the rate of nicotine metabolism is nicotine metabolite ratio (NMR) defined as a ratio of two major metabolites of nicotine - trans-3'-hydroxycotinine/cotinine. The rate of nicotine metabolism has important clinical implications for the likelihood of successful quitting with nicotine replacement therapy (NRT). We conducted a study to measure NMR among Polish smokers. In a cross-sectional study of 180 daily cigarette smokers (42% men; average age 34.6±13.0), we collected spot urine samples and measured trans-3'-hydroxycotinine (3-HC) and cotinine levels with LC-MS/MS method. We calculated NMR (molar ratio) and analyzed variations in NMR among groups of smokers. In the whole study group, an average NMR was 4.8 (IQR 3.4-7.3). The group of women below 51 years had significantly greater NMR compared to the rest of the population (6.4; IQR 4.1-8.8 vs. 4.3; IQR 2.8-6.4). No differences were found among group ages of male smokers. This is a first study to describe variations in nicotine metabolism among Polish smokers. Our findings indicate that young women metabolize nicotine faster than the rest of population. This finding is consistent with the known effects of estrogen to induce CYP2A6 activity. Young women may require higher doses of NRT or non-nicotine medications for most effective smoking cessation treatment. Copyright © 2017 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Binding, uptake, and release of nicotine by human gingival fibroblasts

International Nuclear Information System (INIS)

Hanes, P.J.; Schuster, G.S.; Lubas, S.

1991-01-01

Previous studies of the effects of nicotine on fibroblasts have reported an altered morphology and attachment of fibroblasts to substrates and disturbances in protein synthesis and secretion. This altered functional and attachment response may be associated with changes in the cell membrane resulting from binding of the nicotine, or to disturbances in cell metabolism as a result of high intracellular levels of nicotine. The purpose of the present study, therefore, was to (1) determine whether gingival fibroblasts bound nicotine and if any binding observed was specific or non-specific in nature; (2) determine whether gingival fibroblasts internalized nicotine, and if so, at what rate; (3) determine whether gingival fibroblasts also released nicotine back into the extracellular environment; and (4) if gingival fibroblasts release nicotine intact or as a metabolite. Cultures of gingival fibroblasts were prepared from gingival connective tissue biopsies. Binding was evaluated at 4 degree C using a mixture of 3 H-nicotine and unlabeled nicotine. Specific binding was calculated as the difference between 3 H-nicotine bound in the presence and absence of unlabeled nicotine. The cells bound 1.44 (+/- 0.42) pmols/10(6) cells in the presence of unlabeled nicotine and 1.66 (+/- 0.55) pmols/10(6) cells in the absence of unlabeled nicotine. The difference was not significant. Uptake of nicotine was measured at 37 degree C after treating cells with 3 H-nicotine for time periods up to 4 hours. Uptake in pmols/10(6) cells was 4.90 (+/- 0.34) at 15 minutes, 8.30 (+/- 0.75) at 30 minutes, 12.28 (+/- 2.62) at 1 hour and 26.31 (+/- 1.15) at 4 hours

What Are Tobacco, Nicotine, and E-Cigarette Products?

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... Drug Facts / Tobacco, Nicotine, & E-Cigarettes Tobacco, Nicotine, & E-Cigarettes Street names: Chew, Dip, Snuff Print Expand All Revised July 2017 What are tobacco, nicotine, and e-cigarette products? ©Shutterstock/ CatherineL-Prod Also known as: Cigarettes: ...

Counterfeit Electronic Cigarette Products with Mislabeled Nicotine Concentrations.

Science.gov (United States)

Omaiye, Esther E; Cordova, Iliana; Davis, Barbara; Talbot, Prue

2017-07-01

We compared nicotine concentrations in one brand of refill fluids that were purchased in 4 countries and labeled 0 mg of nicotine/mL. We then identified counterfeit e-cigarette products from these countries. Overall, 125 e-cigarette refill fluids were purchased in Nigeria, the United States (US), England, and China. Nicotine concentrations were measured using high performance liquid chromatography and compared to labeled concentrations. Refill fluids were examined to identify physical differences and grouped into authentic and counterfeit products. Whereas nicotine was in 51.7% (15/29) of the Nigerian, 3.7% (1/27) of the Chinese and 1.6% (1/61) of the American refill fluids (range = 0.4 - 20.4 mg/mL), 8 British products did not contain nicotine. Products from China, the US, and Nigeria with trace amounts of nicotine (0.4 to 0.6 mg/mL) were authentic; however, all products from Nigeria with more than 3.7 mg/mL were counterfeit. We introduce 2 novel issues in the e-cigarette industry, the production of counterfeit refill fluids under a brandjacked label and inclusion of nicotine in 81.3% of the counterfeit products labeled 0 mg/mL. This study emphasizes the need for better control and monitoring of nicotine containing products and sales outlets.

α-4 subunit of nicotinic acetylcholine receptor polymorphisms exhibit ...

African Journals Online (AJOL)

Background: Smoking behavior is influenced by both genetic and environmental factors. Nicotine is the major addictive substance in cigarettes. Nicotinic acetylcholine receptors (nAChRs) are thought to play an important role in nicotine addiction of smokers. One of the genes, α-4 subunit of nicotinic acetylcholine receptor ...

Antifungal activity of nicotine and its cadmium complex

International Nuclear Information System (INIS)

Zaidi, I.M.; Gul, A.

2005-01-01

Nicotine and its metal complex; Cd(II)-nicotine were isolated from leaves of Nicotiana tabacum using various metal ions by the reported techniques and studied for their antifungal activities against fourteen different species of fungi. For comparative study, pure sample of nicotine and metal salt used for complexation; cadmium(II) iodide was also subjected to antifungal tests with the same species of fungus under similar conditions. Results indicated that nicotine is quite effective against the rare pathogenic and Non pathogenic fungi but comparatively less effective against Pathogenic fungi. Nicotine was found to be completely ineffective against the selected species of Occasional pathogenic fungi. Cadmium(II) iodide effectively inhibited Pathogenic and Non pathogenic fungi whereas relatively ineffective against the Occasional pathogenic and Rare pathogenic fungi. On the other hand, Cadmium(II) nicotine complex inhibited all the selected species of fungi except Fusarium solani. (author)

Nicotine aversion: Neurobiological mechanisms and relevance to tobacco dependence vulnerability

Science.gov (United States)

Fowler, Christie D.; Kenny, Paul J.

2013-01-01

Nicotine stimulates brain reward circuitries, most prominently the mesocorticolimbic dopamine system, and this action is considered critical in establishing and maintaining the tobacco smoking habit. Compounds that attenuate nicotine reward are considered promising therapeutic candidates for tobacco dependence, but many of these agents have other actions that limit their potential utility. Nicotine is also highly noxious, particularly at higher doses, and aversive reactions to nicotine after initial exposure can decrease the likelihood of developing a tobacco habit in many first time smokers. Nevertheless, relatively little is known about the mechanisms of nicotine aversion. The purpose of this review is to present recent new insights into the neurobiological mechanisms that regulate avoidance of nicotine. First, the role of the mesocorticolimbic system, so often associated with nicotine reward, in regulating nicotine aversion is highlighted. Second, genetic variation that modifies noxious responses to nicotine and thereby influences vulnerability to tobacco dependence, in particular variation in the CHRNA5-CHRNA3-CHRNB4 nicotinic acetylcholine receptor (nAChR) subunit gene cluster, will be discussed. Third, the role of the habenular complex in nicotine aversion, primarily medial habenular projections to the interpeduncular nucleus (IPN) but also lateral habenular projections to rostromedial tegmental nucleus (RMTg) and ventral tegmental area (VTA) are reviewed. Forth, brain circuits that are enriched in nAChRs, but whose role in nicotine avoidance has not yet been assessed, will be proposed. Finally, the feasibility of developing novel therapeutic agents for tobacco dependence that act not by blocking nicotine reward but by enhancing nicotine avoidance will be considered. PMID:24055497

Opname van nicotine door kippen en overdracht naar eieren bij toepassing van nicotine tegen bloedluis

NARCIS (Netherlands)

Traag, W.A.; Rijk, de T.C.; Zomer, P.; Vos Van Avezathe, A.; Kan, C.A.; Zeilmaker, M.; Hoogenboom, L.A.P.

2005-01-01

Uit onderzoek van de AID blijkt nicotine gebruikt te worden voor de bestrijding van bloedluis bij kippen. Dit levert mogelijk gezondheidsrisico's op voor de consument van het kippenvlees of de eieren. Omdat niet duidelijk is of het nicotine na de bestrijding van bloedluis in het vlees of eieren

Design, formulation and evaluation of nicotine chewing gum

OpenAIRE

Abolfazl Aslani; Sahar Rafiei

2012-01-01

Background: Nicotine replacement therapy (NRT) can help smokers to quit smoking. Nicotine chewing gum has attracted the attention from pharmaceutical industries to offer it to consumers as an easily accessible NRT product. However, the bitter taste of such gums may compromise their acceptability by patients. This study was, therefore, designed to develop 2 and 4 mg nicotine chewing gums of pleasant taste, which satisfy the consumers the most. Materials and Methods: Nicotine, sugar, liquid...

A behavioral economic analysis of the value-enhancing effects of nicotine and varenicline and the role of nicotinic acetylcholine receptors in male and female rats.

Science.gov (United States)

Barrett, Scott T; Geary, Trevor N; Steiner, Amy N; Bevins, Rick A

2018-04-09

Reinforcement value enhancement by nicotine of non-nicotine rewards is believed to partially motivate smoking behavior. Recently, we showed that the value-enhancing effects of nicotine are well characterized by reinforcer demand models and that the value-enhancing effects of the smoking-cessation aid bupropion (Zyban) are distinct from those of nicotine and differ between the sexes. The present study evaluated potential sex differences in the enhancement effects of nicotine and varenicline (Chantix) using a reinforcer demand methodology. The role of α4β2* and α7 nicotinic acetylcholine receptors (nAChRs) in the enhancing effects of nicotine and varenicline is also evaluated. Male and female rats (n=12/sex) were trained to lever press maintained by sensory reinforcement by visual stimulus (VS) presentations. Changes in the VS value following nicotine and varenicline administration were assessed using an established reinforcer demand approach. Subsequently, the effects of antagonism of α4β2* and α7 nAChRs on varenicline and nicotine-induced enhancement active lever-pressing were assessed using a progressive ratio schedule. Nicotine and varenicline enhanced VS demand equivalently between the sexes as evaluated by reinforcer demand. However, α4β2* receptor antagonism attenuated value enhancement by nicotine and varenicline in females, but only of nicotine in males.

Nicotinic activation of laterodorsal tegmental neurons

DEFF Research Database (Denmark)

Ishibashi, Masaru; Leonard, Christopher S; Kohlmeier, Kristi A

2009-01-01

Identifying the neurological mechanisms underlying nicotine reinforcement is a healthcare imperative, if society is to effectively combat tobacco addiction. The majority of studies of the neurobiology of addiction have focused on dopamine (DA)-containing neurons of the ventral tegmental area (VTA......). However, recent data suggest that neurons of the laterodorsal tegmental (LDT) nucleus, which sends cholinergic, GABAergic, and glutamatergic-containing projections to DA-containing neurons of the VTA, are critical to gating normal functioning of this nucleus. The actions of nicotine on LDT neurons...... are unknown. We addressed this issue by examining the effects of nicotine on identified cholinergic and non-cholinergic LDT neurons using whole-cell patch clamp and Ca(2+)-imaging methods in brain slices from mice (P12-P45). Nicotine applied by puffer pipette or bath superfusion elicited membrane...

Nicotine Withdrawal Induces Neural Deficits in Reward Processing.

Science.gov (United States)

Oliver, Jason A; Evans, David E; Addicott, Merideth A; Potts, Geoffrey F; Brandon, Thomas H; Drobes, David J

2017-06-01

Nicotine withdrawal reduces neurobiological responses to nonsmoking rewards. Insight into these reward deficits could inform the development of targeted interventions. This study examined the effect of withdrawal on neural and behavioral responses during a reward prediction task. Smokers (N = 48) attended two laboratory sessions following overnight abstinence. Withdrawal was manipulated by having participants smoke three regular nicotine (0.6 mg yield; satiation) or very low nicotine (0.05 mg yield; withdrawal) cigarettes. Electrophysiological recordings of neural activity were obtained while participants completed a reward prediction task that involved viewing four combinations of predictive and reward-determining stimuli: (1) Unexpected Reward; (2) Predicted Reward; (3) Predicted Punishment; (4) Unexpected Punishment. The task evokes a medial frontal negativity that mimics the phasic pattern of dopaminergic firing in ventral tegmental regions associated with reward prediction errors. Nicotine withdrawal decreased the amplitude of the medial frontal negativity equally across all trial types (p nicotine dependence (p Nicotine withdrawal had equivocal impact across trial types, suggesting reward processing deficits are unlikely to stem from changes in phasic dopaminergic activity during prediction errors. Effects on tonic activity may be more pronounced. Pharmacological interventions directly targeting the dopamine system and behavioral interventions designed to increase reward motivation and responsiveness (eg, behavioral activation) may aid in mitigating withdrawal symptoms and potentially improving smoking cessation outcomes. Findings from this study indicate nicotine withdrawal impacts reward processing signals that are observable in smokers' neural activity. This may play a role in the subjective aversive experience of nicotine withdrawal and potentially contribute to smoking relapse. Interventions that address abnormal responding to both pleasant and

Alcohol's actions on neuronal nicotinic acetylcholine receptors.

Science.gov (United States)

Davis, Tiffany J; de Fiebre, Christopher M

2006-01-01

Although it has been known for many years that alcoholism and tobacco addiction often co-occur, relatively little information is available on the biological factors that regulate the co-use and abuse of nicotine and alcohol. In the brain, nicotine acts at several different types of receptors collectively known as nicotinic acetylcholine receptors (nAChRs). Alcohol also acts on at least some of these receptors, enhancing the function of some nAChR subtypes and inhibiting the activity of others. Chronic alcohol and nicotine administration also lead to changes in the numbers of nAChRs. Natural variations (i.e., polymorphisms) in the genes encoding different nAChR subunits may be associated with individual differences in the sensitivity to some of alcohol's and nicotine's effects. Finally, at least one subtype of nAChR may help protect cells against alcohol-induced neurotoxicity.

Neurotensin Agonist Attenuates Nicotine Potentiation to Cocaine Sensitization

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Paul Fredrickson

2014-01-01

Full Text Available Tobacco usage typically precedes illicit drug use in adolescent and young adult populations. Several animal studies suggest nicotine increases the risk for subsequent cocaine abuse, and may be a negative prognostic factor for treatment of cocaine addiction; i.e., a “gateway drug”. Neurotensin (NT is a 13-amino acid neuropeptide that modulates dopamine, acetylcholine, glutamate, and GABA neurotransmission in brain reward pathways. NT69L, a NT(8-13 analog, blocks behavioral sensitization (an animal model for psychostimulant addiction to nicotine, and nicotine self-administration in rats. The present study tested the effect of NT69L on the potentiating effects of nicotine on cocaine-induced locomotor sensitization. Male Wistar rats were injected daily for seven days with nicotine or saline (control followed by four daily injections of cocaine. NT69L was administered 30 min prior to the last cocaine injection. Behavior was recorded with the use of activity chambers. Subchronic administration of nicotine enhanced cocaine-induced behavioral sensitization in Wistar rats, consistent with an hypothesized gateway effect. These behavioral effects of cocaine were attenuated by pretreatment with NT69L. The effect of the neurotensin agonist on cocaine sensitization in the nicotine treated group indicated a possible therapeutic effect for cocaine addiction, even in the presence of enhanced behavioral sensitization induced by nicotine.

Nicotinic and iso nicotinic acids: interactions with gamma radiation and acid-base equilibrium

International Nuclear Information System (INIS)

Ribeiro, Z.A.

1984-01-01

The values of pKa 1 and pKa 2 for nicotinic and iso nicotinic acids in aqueous medium were determined. The effects of gamma radiation about these acids by infrared and ultraviolet spectrophotometry and thermal gravimetric analysis were also studied. It was verified that the radiolysis of acids occurred by the two process of first order, determining the degradation constant and the degradation factors for each one of the solutions. (C.G.C.)

Reduced Nicotine Content Expectancies Affect Initial Responses to Smoking.

Science.gov (United States)

Mercincavage, Melissa; Smyth, Joshua M; Strasser, Andrew A; Branstetter, Steven A

2016-10-01

We sought to determine if negative responses to reduced nicotine content (RNC) cigarettes during open-label trials result from smokers' (negative) expectancies. We examined the effects of nicotine content description - independent of actual nicotine content - on subjective responses (craving reduction, withdrawal suppression, mood changes, and sensory ratings) and smoking behaviors (topography measures and carbon monoxide [CO] boost). Thirty-six 12-hour-abstinent daily smokers completed a 3-session crossover trial. During each session, participants smoked their preferred brand cigarette - blinded and described as containing "usual," "low," and "very low" nicotine content - through a topography device and completed CO and subjective response assessments. Although nicotine content was identical, compared to the "usual" content cigarette, participants experienced less craving reduction after smoking the "very low" nicotine cigarette, and rated its smoke as weaker (p marketing and labeling are likely important considerations if a federal nicotine reduction policy is initiated.

Replicated Risk Nicotinic Cholinergic Receptor Genes for Nicotine Dependence

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Lingjun Zuo

2016-11-01

Full Text Available It has been hypothesized that the nicotinic acetylcholine receptors (nAChRs play important roles in nicotine dependence (ND and influence the number of cigarettes smoked per day (CPD in smokers. We compiled the associations between nicotinic cholinergic receptor genes (CHRNs and ND/CPD that were replicated across different studies, reviewed the expression of these risk genes in human/mouse brains, and verified their expression using independent samples of both human and mouse brains. The potential functions of the replicated risk variants were examined using cis-eQTL analysis or predicted using a series of bioinformatics analyses. We found replicated and significant associations for ND/CPD at 19 SNPs in six genes in three genomic regions (CHRNB3-A6, CHRNA5-A3-B4 and CHRNA4. These six risk genes are expressed in at least 18 distinct areas of the human/mouse brain, with verification in our independent human and mouse brain samples. The risk variants might influence the transcription, expression and splicing of the risk genes, alter RNA secondary or protein structure. We conclude that the replicated associations between CHRNB3-A6, CHRNA5-A3-B4, CHRNA4 and ND/CPD are very robust. More research is needed to examine how these genetic variants contribute to the risk for ND/CPD.

Prior nicotine self-administration attenuates subsequent dopaminergic deficits of methamphetamine in rats: role of nicotinic acetylcholine receptors.

Science.gov (United States)

Baladi, Michelle G; Nielsen, Shannon M; McIntosh, J Michael; Hanson, Glen R; Fleckenstein, Annette E

2016-08-01

Preclinical studies have demonstrated that oral nicotine exposure attenuates long-term dopaminergic damage induced by toxins, including repeated, high doses of methamphetamine. It is suggested that alterations in nicotinic acetylcholine receptor (nAChR) expression, including α4β2* and α6β2* subtypes, likely contribute to this protection. The current study extended these findings by investigating whether nicotine self-administration in male, Sprague-Dawley rats (a) attenuates short-term dopaminergic damage induced by methamphetamine and (b) causes alterations in levels of α4β2* and α6β2* nAChR subtypes. The findings indicate that nicotine self-administration (0.032 mg/kg/infusion for 14 days) per se did not alter α4β2* and α6β2* nAChR expression or dopamine transporter (DAT) expression and function. Interestingly, prior nicotine self-administration attenuated methamphetamine-induced decreases in DAT function when assessed 24 h, but not 1 h, after methamphetamine treatment (4×7.5 mg/kg/injection). The ability of nicotine to attenuate the effects of methamphetamine on DAT function corresponded with increases in α4β2*, but not α6β2*, nAChR binding density. Understanding the role of nAChRs in methamphetamine-induced damage has the potential to elucidate mechanisms underlying the etiology of disorders involving dopaminergic dysfunction, as well as to highlight potential new therapeutic strategies for prevention or reduction of dopaminergic neurodegeneration.

Nicotine Gum

Science.gov (United States)

... with a smoking cessation program, which may include support groups, counseling, or specific behavioral change techniques. Nicotine gum ... and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or ...

Animal Research on Nicotine Reduction: Current Evidence and Research Gaps.

Science.gov (United States)

Smith, Tracy T; Rupprecht, Laura E; Denlinger-Apte, Rachel L; Weeks, Jillian J; Panas, Rachel S; Donny, Eric C; Sved, Alan F

2017-09-01

A mandated reduction in the nicotine content of cigarettes may improve public health by reducing the prevalence of smoking. Animal self-administration research is an important complement to clinical research on nicotine reduction. It can fill research gaps that may be difficult to address with clinical research, guide clinical researchers about variables that are likely to be important in their own research, and provide policy makers with converging evidence between clinical and preclinical studies about the potential impact of a nicotine reduction policy. Convergence between clinical and preclinical research is important, given the ease with which clinical trial participants can access nonstudy tobacco products in the current marketplace. Herein, we review contributions of preclinical animal research, with a focus on rodent self-administration, to the science of nicotine reduction. Throughout this review, we highlight areas where clinical and preclinical research converge and areas where the two differ. Preclinical research has provided data on many important topics such as the threshold for nicotine reinforcement, the likelihood of compensation, moderators of the impact of nicotine reduction, the impact of environmental stimuli on nicotine reduction, the impact of nonnicotine cigarette smoke constituents on nicotine reduction, and the impact of nicotine reduction on vulnerable populations. Special attention is paid to current research gaps including the dramatic rise in alternative tobacco products, including electronic nicotine delivery systems (ie, e-cigarettes). The evidence reviewed here will be critical for policy makers as well as clinical researchers interested in nicotine reduction. This review will provide policy makers and clinical researchers interested in nicotine reduction with an overview of the preclinical animal research conducted on nicotine reduction and the regulatory implications of that research. The review also highlights the utility of

Antifungal activity of nicotine and its cobalt complex

International Nuclear Information System (INIS)

Zaidi, M.I.; Gul, A.

2005-01-01

Nicotine and its metal complex; Co(II)-nicotine were isolated from leaves of Nicotiana tabacum using various metal ions by the reported techniques and studied for their antifungal activity against fourteen different species of fungi. For comparative study, pure sample of nicotine and metal salt used for complexation; cobalt(II) chloride was also subjected to antifungal tests with the same species of fungus under similar conditions. Results indicated that nicotine had antifungal activity against all species of fungi studied except Candida albicans, Microsporum canis, Epidermophyton floccosum, Candida tropicalis, and Alternaria infectoria. Cobalt(II) nicotine was found to be effective against all selected species of fungi but ineffective against Candida solani, Penicillium notalum, Microsporum canis, Fusarium solani and Fusarium moniliforme. (author)

Knowledge and Perceptions about Nicotine, Nicotine Replacement Therapies and Electronic Cigarettes among Healthcare Professionals in Greece

Directory of Open Access Journals (Sweden)

Anastasia Moysidou

2016-05-01

Full Text Available Introduction. The purpose of this study was to evaluate the knowledge and perceptions of Greek healthcare professionals about nicotine, nicotine replacement therapies and electronic cigarettes. Methods. An online survey was performed, in which physicians and nurses working in private and public healthcare sectors in Athens-Greece were asked to participate through email invitations. A knowledge score was calculated by scoring the correct answers to specific questions with 1 point. Results. A total of 262 healthcare professionals were included to the analysis. Most had daily contact with smokers in their working environment. About half of them considered that nicotine has an extremely or very important contribution to smoking-related disease. More than 30% considered nicotine replacement therapies equally or more addictive than smoking, 76.7% overestimated their smoking cessation efficacy and only 21.0% would recommend them as long-term smoking substitutes. For electronic cigarettes, 45.0% considered them equally or more addictive than smoking and 24.4% equally or more harmful than tobacco cigarettes. Additionally, 35.5% thought they involve combustion while the majority responded that nicotine in electronic cigarettes is synthetically produced. Only 14.5% knew about the pending European regulation, but 33.2% have recommended them to smokers in the past. Still, more than 40% would not recommend electronic cigarettes to smokers unwilling or unable to quit smoking with currently approved medications. Cardiologists and respiratory physicians, who are responsible for smoking cessation therapy in Greece, were even more reluctant to recommend electronic cigarettes to this subpopulation of smokers compared to all other participants. The knowledge score of the whole study sample was 7.7 (SD: 2.4 out of a maximum score of 16. Higher score was associated with specific physician specialties. Conclusions. Greek healthcare professionals appear to overestimate

Age-related changes in nicotine response of cholinergic and non-cholinergic laterodorsal tegmental neurons: implications for the heightened adolescent susceptibility to nicotine addiction

Science.gov (United States)

Christensen, Mark H.; Ishibashi, Masaru; Nielsen, Michael L.; Leonard, Christopher S.; Kohlmeier, Kristi A.

2015-01-01

The younger an individual starts smoking, the greater the likelihood that addiction to nicotine will develop, suggesting that neurobiological responses vary across age to the addictive component of cigarettes. Cholinergic neurons of the laterodorsal tegmental nucleus (LDT) are importantly involved in the development of addiction, however, the effects of nicotine on LDT neuronal excitability across ontogeny are unknown. Nicotinic effects on several parameters affecting LDT cells across different age groups were examined using calcium imaging and whole-cell patch clamping. Within the youngest age group (P7-P15), nicotine was found to induce larger intracellular calcium transients and inward currents. Nicotine induced a greater number of excitatory synaptic currents in the youngest animals, whereas larger amplitude inhibitory synaptic events were induced in cells from the oldest animals (P15-P34). Nicotine increased neuronal firing of cholinergic cells to a greater degree in younger animals, possibly linked to development associated differences found in nicotinic effects on action potential shape and afterhyperpolarization. We conclude that in addition to age-associated alterations of several properties expected to affect resting cell excitability, parameters affecting cell excitability are altered by nicotine differentially across ontogeny. Taken together, our data suggest that nicotine induces a larger excitatory response in cholinergic LDT neurons from the youngest animals, which could result in a greater excitatory output from these cells to target regions involved in development of addiction. Such output would be expected to be promotive of addiction; therefore, ontogenetic differences in nicotine-mediated increases in the excitability of the LDT could contribute to the differential susceptibility to nicotine addiction seen across age. PMID:24863041

Alpha5 nicotinic acetylcholine receptor mediates nicotine-induced HIF-1α and VEGF expression in non-small cell lung cancer

Energy Technology Data Exchange (ETDEWEB)

Ma, Xiaoli; Jia, Yanfei; Zu, Shanshan [Central Laboratory, Jinan Central Hospital Affiliated to Shandong University, Jinan 250013 (China); Li, Ruisheng [Institute of Infectious Diseases, 302 Military Hospital, Beijing 100039 (China); Jia, Ying; Zhao, Yun; Xiao, Dongjie [Central Laboratory, Jinan Central Hospital Affiliated to Shandong University, Jinan 250013 (China); Dang, Ningning [Department of Dermatology, Jinan Central Hospital Affiliated to Shandong University, Jinan 250013 (China); Wang, Yunshan [Central Laboratory, Jinan Central Hospital Affiliated to Shandong University, Jinan 250013 (China)

2014-07-15

By binding to nicotinic acetylcholine receptors (nAChRs), nicotine induces the proliferation and apoptosis of non-small cell lung cancer (NSCLC). Previous studies have indicated that α5-nAChR is highly associated with lung cancer risk and nicotine dependence. However, the mechanisms through which α5-nAChRs may influence lung carcinogenesis are far from clear. In the present study, we investigated the roles of α5-nAChR in the nicotine-induced expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF). Immunohistochemistry was used to detect the expression of α5-nAChR and HIF-1α in 60 specimens of lung cancer and para-carcinoma tissue. The correlations between the expression levels of α5-nAChR and HIF-1α and other clinicopathological data were analyzed. In a cell line that highly expressed α5-nAChR, the loss of α5-nAChR function by siRNA was used to study whether α5-nAChR is involved in the nicotine-induced expression of HIF-1α and VEGF through the activation of the ERK1/2 and PI3K/Akt signaling pathways. Cell growth was detected using the cell counting kit-8 (CCK-8). α5-nAChR (78.3%) and HIF-1α (88.3%) were both overexpressed in NSCLC, and their expression levels were found to be correlated with each other (P < 0.05). In the A549 cell line, α5-nAChR and HIF-1α were found to be expressed under normal conditions, and their expression levels were significantly increased in response to nicotine treatment. The silencing of α5-nAChR significantly inhibited the nicotine-induced cell proliferation compared with the control group and attenuated the nicotine-induced upregulation of HIF-1α and VEGF, and these effects required the cooperation of the ERK1/2 and PI3K/Akt signaling pathways. These results show that the α5-nAChR/HIF-1α/VEGF axis is involved in nicotine-induced tumor cell proliferation, which suggests that α5-nAChR may serve as a potential anticancer target in nicotine-associated lung cancer. - Highlights

Alpha5 nicotinic acetylcholine receptor mediates nicotine-induced HIF-1α and VEGF expression in non-small cell lung cancer

International Nuclear Information System (INIS)

Ma, Xiaoli; Jia, Yanfei; Zu, Shanshan; Li, Ruisheng; Jia, Ying; Zhao, Yun; Xiao, Dongjie; Dang, Ningning; Wang, Yunshan

2014-01-01

By binding to nicotinic acetylcholine receptors (nAChRs), nicotine induces the proliferation and apoptosis of non-small cell lung cancer (NSCLC). Previous studies have indicated that α5-nAChR is highly associated with lung cancer risk and nicotine dependence. However, the mechanisms through which α5-nAChRs may influence lung carcinogenesis are far from clear. In the present study, we investigated the roles of α5-nAChR in the nicotine-induced expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF). Immunohistochemistry was used to detect the expression of α5-nAChR and HIF-1α in 60 specimens of lung cancer and para-carcinoma tissue. The correlations between the expression levels of α5-nAChR and HIF-1α and other clinicopathological data were analyzed. In a cell line that highly expressed α5-nAChR, the loss of α5-nAChR function by siRNA was used to study whether α5-nAChR is involved in the nicotine-induced expression of HIF-1α and VEGF through the activation of the ERK1/2 and PI3K/Akt signaling pathways. Cell growth was detected using the cell counting kit-8 (CCK-8). α5-nAChR (78.3%) and HIF-1α (88.3%) were both overexpressed in NSCLC, and their expression levels were found to be correlated with each other (P < 0.05). In the A549 cell line, α5-nAChR and HIF-1α were found to be expressed under normal conditions, and their expression levels were significantly increased in response to nicotine treatment. The silencing of α5-nAChR significantly inhibited the nicotine-induced cell proliferation compared with the control group and attenuated the nicotine-induced upregulation of HIF-1α and VEGF, and these effects required the cooperation of the ERK1/2 and PI3K/Akt signaling pathways. These results show that the α5-nAChR/HIF-1α/VEGF axis is involved in nicotine-induced tumor cell proliferation, which suggests that α5-nAChR may serve as a potential anticancer target in nicotine-associated lung cancer. - Highlights

Lipid-drug-conjugate (LDC) solid lipid nanoparticles (SLN) for the delivery of nicotine to the oral cavity - optimization of nicotine loading efficiency.

Science.gov (United States)

Ding, Yuan; Nielsen, Kent A; Nielsen, Bruno P; Bøje, Niels W; Müller, Rainer H; Pyo, Sung Min

2018-03-12

Nicotine, obtained from tobacco leaves, has been used to promote the cessation of smoking and reduce the risk of COPD and lung cancer. Incorporating the active in lipid nanoparticles is an effective tool to minimize its irritation potential and to use the particles as intermediate to produce final products. However, as a hydrophilic active, it is a challenge to prepare nicotine loaded lipid nanoparticles with high drug loading. In this study, lipid-drug-conjugates (LDC) were formed by nicotine and different fatty acids to enable the production of sufficiently loaded nicotine lipid nanoparticles. The encapsulation efficiency of nicotine in LDC-containing SLN was about 50%, which increased at least fourfold compared to the non-LDC formulations (around 10%) due to the increased lipophilicity of nicotine by strong interactions between positively charged nicotine and negatively charged fatty acids (formation of LDCs). The z-average of all formulations (150 to 350 nm) proved to be in the required submicron size range with a narrow size distribution. In summary, nicotine loaded LDC lipid nanoparticles with high drug loading were successfully developed with Kolliwax® S and stearic acid as counter-ion forming the LDC and hydrogenated sunflower oil (HSO) as lipid particle matrix. Copyright © 2018. Published by Elsevier B.V.

Epidemiology, radiology, and genetics of nicotine dependence in COPD

Directory of Open Access Journals (Sweden)

Hokanson John E

2011-01-01

Full Text Available Abstract Background Cigarette smoking is the principal environmental risk factor for developing COPD, and nicotine dependence strongly influences smoking behavior. This study was performed to elucidate the relationship between nicotine dependence, genetic susceptibility to nicotine dependence, and volumetric CT findings in smokers. Methods Current smokers with COPD (GOLD stage ≥ 2 or normal spirometry were analyzed from the COPDGene Study, a prospective observational study. Nicotine dependence was determined by the Fagerstrom test for nicotine dependence (FTND. Volumetric CT acquisitions measuring the percent of emphysema on inspiratory CT (% of lung Results Among 842 currently smoking subjects (335 COPD cases and 507 controls, 329 subjects (39.1% showed high nicotine dependence. Subjects with high nicotine dependence had greater cumulative and current amounts of smoking. However, emphysema severity was negatively correlated with the FTND score in controls (ρ = -0.19, p Conclusions Nicotine dependence was a negative predictor for emphysema on CT in COPD and control smokers. Increased inflammation in more highly addicted current smokers could influence the CT lung density distribution, which may influence genetic association studies of emphysema phenotypes. Trial registration ClinicalTrials (NCT: NCT00608764

Nasal nicotine solution: a potential aid to giving up smoking?

Science.gov (United States)

Russell, M A; Jarvis, M J; Feyerabend, C; Fernö, O

1983-01-01

A nasal solution was developed containing 2 mg nicotine for use as a kind of liquid snuff. Its absorption was studied in three subjects. An average peak of plasma nicotine concentrations of 86.9 nmol/l (14.1 ng/ml) was reached seven and a half minutes after taking the solution. This compared with an average peak of 158.4 nmol/l (25.7 ng/ml) one and a half minutes after completing (but seven and a half minutes after starting) a middle tar cigarette (1.4 mg nicotine) and an average peak of 52.4 nmol/l (8.5 ng/ml) after chewing nicotine gum (2 mg nicotine) for 30 minutes. The more rapid and efficient absorption of nicotine from the nasal nicotine solution than from nicotine chewing gum suggests that it might prove a useful aid to giving up smoking. Nasal nicotine solution might be particularly useful in smokers for whom the gum is less suitable on account of dentures or peptic ulcers or who experience nausea and dyspeptic symptoms from the gum. PMID:6402202

Nicotine promotes cell proliferation and induces resistance to cisplatin by α7 nicotinic acetylcholine receptor‑mediated activation in Raw264.7 and El4 cells.

Science.gov (United States)

Wang, Yan Yan; Liu, Yao; Ni, Xiao Yan; Bai, Zhen Huan; Chen, Qiong Yun; Zhang, Ye; Gao, Feng Guang

2014-03-01

Although nicotine is a risk factor for carcinogenesis and atherosclerosis, epidemiological data indicate that nicotine has therapeutic benefits in treating Alzheimer's disease. Our previous studies also showed that nicotine-treated dendritic cells have potential antitumor effects. Hence, the precise effects of nicotine on the biological characterizations of cells are controversial. The aim of the present study was to assess the roles of α7 nicotinic acetylcholine receptors (nAChRs), Erk1/2-p38-JNK and PI3K-Akt pathway in nicotine-mediated proliferation and anti-apoptosis effects. The results firstly showed that nicotine treatment clearly augmented cell viability and upregulated PCNA expression in both Raw264.7 and El4 cells. Meanwhile, nicotine afforded protection against cisplatin-induced toxicity through inhibiting caspase-3 activation and upregulating anti-apoptotic protein expression. Further exploration demonstrated that nicotine efficiently abolished cisplatin-promoted mitochondria translocation of Bax and the release of cytochrome c. The pretreatment of α-bungarotoxin and tubocurarine chloride significantly attenuated nicotine-augmented cell viability, abolished caspase-3 activation and α7 nAChR upregulation. Both Erk-JNK-p38 and PI3K-Akt signaling pathways could be activated by nicotine treatment in Raw264.7 and El4 cells. Notably, when Erk-JNK and PI3K-Akt activities were inhibited, nicotine-augmented cell proliferation and anti-apoptotic effects were abolished accordingly. The results presented here indicate that nicotine could achieve α7 nAChR-mediated proliferation and anti-apoptotic effects by activating Erk-JNK and PI3K-Akt pathways respectively, providing potential therapeutic molecules to deal with smoking-associated human diseases.

Human Secreted Ly-6/uPAR Related Protein-1 (SLURP-1) Is a Selective Allosteric Antagonist of α7 Nicotinic Acetylcholine Receptor

DEFF Research Database (Denmark)

Lyukmanova, Ekaterina N; Shulepko, Mikhail A; Kudryavtsev, Denis

2016-01-01

of nicotinic acetylcholine receptors (nAChRs) and muscarinic acetylcholine receptors, respectively, and anti-α7-nAChRs antibodies revealed α7 type nAChRs as an rSLURP-1 target in keratinocytes. Using affinity purification from human cortical extracts, we confirmed that rSLURP-1 binds selectively to the α7-n...

The tendency to sign-track predicts cue-induced reinstatement during nicotine self-administration, and is enhanced by nicotine but not ethanol

Science.gov (United States)

Versaggi, Cassandra L.; King, Christopher P.; Meyer, Paul J.

2016-01-01

Rationale Some individuals are particularly responsive to reward-associated stimuli (“cues”), including the effects of these cues on craving and relapse to drug-seeking behavior. In the cases of nicotine and alcohol, cues may acquire these abilities via the incentive-enhancing properties of the drug. Objectives To determine the interaction between cue-responsivity and nicotine reinforcement, we studied the patterns of nicotine self-administration in rats categorized based on their tendency to approach a food predictive cue (“sign-trackers”) or a reward-delivery location (“goal-trackers”). In a second experiment, we determined whether nicotine and ethanol altered the incentive value of a food cue. Methods Rats were classified as sign- or goal-trackers during a Pavlovian conditioned approach paradigm. Rats then self-administered intravenous nicotine (0.03 mg/kg infusions) followed by extinction and cue induced reinstatement tests. We also tested the effects of nicotine (0.4 mg/kg base s.c.) or ethanol (0.7 g/kg i.p.) on the approach to, and reinforcing efficacy of, a food cue. Results Sign-trackers showed greater reinstatement in response to a nicotine cue. Further, nicotine enhanced sign-tracking but not goal-tracking to a food cue, and also enhanced responding for the food cue during the conditioned reinforcement test. Conversely, ethanol reduced sign-tracking and increased goal-tracking, but had no effect on conditioned reinforcement. Conclusions Our studies demonstrate that the tendency to attribute incentive value to a food cue predicts enhanced cue-induced reinstatement. Additionally, the incentive value of food cues is differentially modulated by nicotine and ethanol, which may be related to the reinforcing effects of these drugs. PMID:27282365

The tendency to sign-track predicts cue-induced reinstatement during nicotine self-administration, and is enhanced by nicotine but not ethanol.

Science.gov (United States)

Versaggi, Cassandra L; King, Christopher P; Meyer, Paul J

2016-08-01

Some individuals are particularly responsive to reward-associated stimuli ("cues"), including the effects of these cues on craving and relapse to drug-seeking behavior. In the cases of nicotine and alcohol, cues may acquire these abilities via the incentive-enhancing properties of the drug. To determine the interaction between cue-responsivity and nicotine reinforcement, we studied the patterns of nicotine self-administration in rats categorized based on their tendency to approach a food-predictive cue ("sign-trackers") or a reward-delivery location ("goal-trackers"). In a second experiment, we determined whether nicotine and ethanol altered the incentive value of a food cue. Rats were classified as sign- or goal-trackers during a Pavlovian conditioned approach paradigm. Rats then self-administered intravenous nicotine (0.03 mg/kg infusions) followed by extinction and cue-induced reinstatement tests. We also tested the effects of nicotine (0.4 mg/kg base s.c.) or ethanol (0.7 g/kg i.p.) on the approach to, and reinforcing efficacy of, a food cue. Sign-trackers showed greater reinstatement in response to a nicotine cue. Further, nicotine enhanced sign-tracking but not goal-tracking to a food cue and also enhanced responding for the food cue during the conditioned reinforcement test. Conversely, ethanol reduced sign-tracking and increased goal-tracking, but had no effect on conditioned reinforcement. Our studies demonstrate that the tendency to attribute incentive value to a food cue predicts enhanced cue-induced reinstatement. Additionally, the incentive value of food cues is differentially modulated by nicotine and ethanol, which may be related to the reinforcing effects of these drugs.

Effects of NPY and the specific Y1 receptor agonist [D-His(26)]-NPY on the deficit in brain reward function and somatic signs associated with nicotine withdrawal in rats.

Science.gov (United States)

Rylkova, Daria; Boissoneault, Jeffrey; Isaac, Shani; Prado, Melissa; Shah, Hina P; Bruijnzeel, Adrie W

2008-06-01

Tobacco addiction is a chronic disorder that is characterized by dysphoria upon smoking cessation and relapse after periods of abstinence. Previous research suggests that Neuropeptide Y (NPY) and Y1 receptor agonists attenuate negative affective states and somatic withdrawal signs. The aim of the present experiments was to investigate the effects of NPY and the specific Y1 receptor agonist [D-His(26)]-NPY on the deficit in brain reward function and somatic signs associated with nicotine withdrawal in rats. The intracranial self-stimulation procedure was used to assess the effects of nicotine withdrawal on brain reward function as this procedure can provide a quantitative measure of emotional states in rodents. Elevations in brain reward thresholds are indicative of a deficit in brain reward function. In the first experiment, NPY did not prevent the elevations in brain reward thresholds associated with precipitated nicotine withdrawal and elevated the brain reward thresholds of the saline-treated control rats. Similar to NPY, [D-His(26)]-NPY did not prevent the elevations in brain reward thresholds associated with precipitated nicotine withdrawal and elevated the brain reward thresholds of the saline-treated control rats. Neither NPY nor [D-His(26)]-NPY affected the response latencies. In a separate experiment, it was demonstrated that the specific Y1 receptor antagonist BIBP-3226 prevented the NPY-induced elevations in brain reward thresholds. NPY attenuated the overall somatic signs associated with precipitated nicotine withdrawal. [D-His(26)]-NPY did not affect the overall somatic signs associated with precipitated nicotine withdrawal, but decreased the number of abdominal constrictions. Both NPY and [D-His(26)]-NPY attenuated the overall somatic signs associated with spontaneous nicotine withdrawal. These findings indicate that NPY and [D-His(26)]-NPY attenuate somatic nicotine withdrawal signs, but do not prevent the deficit in brain reward function associated

GLP-1 acts on habenular avoidance circuits to control nicotine intake.

Science.gov (United States)

Tuesta, Luis M; Chen, Zuxin; Duncan, Alexander; Fowler, Christie D; Ishikawa, Masago; Lee, Brian R; Liu, Xin-An; Lu, Qun; Cameron, Michael; Hayes, Matthew R; Kamenecka, Theodore M; Pletcher, Matthew; Kenny, Paul J

2017-05-01

Tobacco smokers titrate their nicotine intake to avoid its noxious effects, sensitivity to which may influence vulnerability to tobacco dependence, yet mechanisms of nicotine avoidance are poorly understood. Here we show that nicotine activates glucagon-like peptide-1 (GLP-1) neurons in the nucleus tractus solitarius (NTS). The antidiabetic drugs sitagliptin and exenatide, which inhibit GLP-1 breakdown and stimulate GLP-1 receptors, respectively, decreased nicotine intake in mice. Chemogenetic activation of GLP-1 neurons in NTS similarly decreased nicotine intake. Conversely, Glp1r knockout mice consumed greater quantities of nicotine than wild-type mice. Using optogenetic stimulation, we show that GLP-1 excites medial habenular (MHb) projections to the interpeduncular nucleus (IPN). Activation of GLP-1 receptors in the MHb-IPN circuit abolished nicotine reward and decreased nicotine intake, whereas their knockdown or pharmacological blockade increased intake. GLP-1 neurons may therefore serve as 'satiety sensors' for nicotine that stimulate habenular systems to promote nicotine avoidance before its aversive effects are encountered.

The effect of coniine on presynaptic nicotinic receptors.

Science.gov (United States)

Erkent, Ulkem; Iskit, Alper B; Onur, Rustu; Ilhan, Mustafa

2016-01-01

Toxicity of coniine, an alkaloid of Conium maculatum (poison hemlock), is manifested by characteristic nicotinic clinical signs including excitement, depression, hypermetria, seizures, opisthotonos via postsynaptic nicotinic receptors. There is limited knowledge about the role of presynaptic nicotinic receptors on the pharmacological and toxicological effects of coniine in the literature. The present study was undertaken to evaluate the possible role of presynaptic nicotinic receptors on the pharmacological and toxicological effects of coniine. For this purpose, the rat anococcygeus muscle and guinea-pig atria were used in vitro. Nicotine (100 μM) elicited a biphasic response composed of a relaxation followed by contraction through the activation of nitrergic and noradrenergic nerve terminals in the phenylephrine-contracted rat anococcygeus muscle. Coniine inhibited both the nitrergic and noradrenergic response in the muscle (-logIC(50) = 3.79 ± 0.11 and -logIC(50) = 4.57 ± 0.12 M, respectively). The effect of coniine on nicotinic receptor-mediated noradrenergic transmission was also evaluated in the guinea-pig atrium (-logIC(50) = 4.47 ± 0.12 M) and did not differ from the -logIC(50) value obtained in the rat anococcygeus muscle. This study demonstrated that coniine exerts inhibitory effects on nicotinic receptor-mediated nitrergic and noradrenergic transmitter response.

Neuronal effects of nicotine during auditory selective attention.

Science.gov (United States)

Smucny, Jason; Olincy, Ann; Eichman, Lindsay S; Tregellas, Jason R

2015-06-01

Although the attention-enhancing effects of nicotine have been behaviorally and neurophysiologically well-documented, its localized functional effects during selective attention are poorly understood. In this study, we examined the neuronal effects of nicotine during auditory selective attention in healthy human nonsmokers. We hypothesized to observe significant effects of nicotine in attention-associated brain areas, driven by nicotine-induced increases in activity as a function of increasing task demands. A single-blind, prospective, randomized crossover design was used to examine neuronal response associated with a go/no-go task after 7 mg nicotine or placebo patch administration in 20 individuals who underwent functional magnetic resonance imaging at 3T. The task design included two levels of difficulty (ordered vs. random stimuli) and two levels of auditory distraction (silence vs. noise). Significant treatment × difficulty × distraction interaction effects on neuronal response were observed in the hippocampus, ventral parietal cortex, and anterior cingulate. In contrast to our hypothesis, U and inverted U-shaped dependencies were observed between the effects of nicotine on response and task demands, depending on the brain area. These results suggest that nicotine may differentially affect neuronal response depending on task conditions. These results have important theoretical implications for understanding how cholinergic tone may influence the neurobiology of selective attention.

The effects of Nicotinic Acid and Xanthinol Nicotinate on human memory in different categories of age

NARCIS (Netherlands)

Loriaux, S.M.; Deijen, J.B.; Orlebeke, J.F.; de Swart, J.H.

1985-01-01

The treatment effect of nicotinic acid and xanthinol nicotinate on human memory was compared with placebo in 96 healthy subjects. Forty-three subjects were young (35-45 years), 30 subjects middle aged (55-65 years) and 23 subjects were old aged (75-85 years). Pre- and post-treatment scores were

21 CFR 172.310 - Aluminum nicotinate.

Science.gov (United States)

2010-04-01

... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.310 Aluminum nicotinate. Aluminum nicotinate may be safely...

VOLTAMMETRIC DETERMINATION OF NICOTINE IN CIGARETTE ...

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determination of nicotine in two brands of commercial cigarettes and ... to disruption of arteries and cardiovascular risk factors [8, 9]. Smoking .... e d. Figure 2. Cyclic voltammetric response (scan rate of 100 mV/s) of 1.0 mM nicotine at AGCE in.

Chronic oral nicotine increases brain [3H]epibatidine binding and responsiveness to antidepressant drugs, but not nicotine, in the mouse forced swim test

DEFF Research Database (Denmark)

Andreasen T., Jesper; Nielsen, Elsebet O; Redrobe, John P

2009-01-01

Smoking rates among depressed individuals is higher than among healthy subjects, and nicotine alleviates depressive symptoms. Nicotine increases serotonergic and noradrenergic neuronal activity and facilitates serotonin and noradrenaline release. In mice, acute nicotine administration enhances...... the activity of antidepressants in the mouse forced swim (mFST) and tail suspension tests. Here, we investigated if this action of nicotine is also reflected in a chronic treatment regimen....

Electronic Nicotine Delivery Systems Key Facts Infographic

Data.gov (United States)

U.S. Department of Health & Human Services — Explore the Electronic Nicotine Delivery Systems Key Facts Infographic which outlines key facts related to electronic nicotine delivery systems (ENDS), including...

Effect of chronic (-)-nicotine treatment on rat cerebral benzodiazepine receptors

International Nuclear Information System (INIS)

Magata, Yasuhiro; Kitano, Haruhiro; Shiozaki, Toshiki; Iida, Yasuhiko; Nishizawa, Sadahiko; Saji, Hideo; Konishi, Junji

2000-01-01

The purpose of this study was to clarify the effect of (-)-nicotine on cerebral benzodiazepine receptors (BzR) with radiotracer methods. The effect of (-)-nicotine on BzR was examined in in vitro studies using chronic (-)-nicotine-treated rats using 3 H-diazepam. The in vitro radioreceptor assay showed a 14% increase in the maximum number of binding sites of BzR in chronic (-)-nicotine-treated rats in comparison with the control rats. Moreover, a convenient in vivo uptake index of 125 I-iomazenil was calculated and a higher uptake of the radioactivity was observed in the chronic (-)-nicotine-treated group than in the control group. Although further studies of the mechanism of (-)-nicotine on such BzR changes are required, an increase in the amount of BzR in the cerebral cortex was found in rats that underwent chronic (-)-nicotine treatment, and this result contributed to the understanding of the effects of (-)-nicotine and smoking on neural functions

Thermal behaviour of nicotinic acid, sodium nicotinate and its compounds with some bivalent transition metal ions

Energy Technology Data Exchange (ETDEWEB)

Nascimento, A.L.C.S. do; Caires, F.J., E-mail: caires.flavio@yahoo.com.br; Gomes, D.J.C.; Gigante, A.C.; Ionashiro, M.

2014-01-10

Graphical abstract: - Highlights: • The transition metal ion nicotinates were synthesized. • The TG–DTA curves provided previously unreported information about thermal behaviour. • The gaseous products released were detected by TG–DSC coupled to FTIR. - Abstract: Solid-state M(L){sub 2}·nH{sub 2}O compounds, where M stands for bivalent transition metals (Mn, Fe, Co, Ni, Cu and Zn), L is nicotinate and n = 0–4.5, have been synthesized. Characterization and thermal behaviour of these compounds were investigated employing elemental analysis based on the mass losses observed in the TG–DTA curves, complexometry, X-ray diffractometry, infrared spectroscopy (FTIR), simultaneous thermogravimetric and differential thermal analysis (TG–DTA) and TG–DSC coupled to FTIR. The thermal behaviour of nicotinic acid and its sodium salt was also investigated. For the hydrated transition metal compounds, the dehydration and thermal decomposition of the anhydrous compounds occur in a single step. For the sodium nicotinate, the final residue up to 765 °C is sodium carbonate and for the transition metal nicotinates, the final residues are Mn{sub 3}O{sub 4}, Fe{sub 2}O{sub 3}, Co{sub 3}O{sub 4}, NiO, CuO and ZnO. The results also provided information concerning the thermal stability, thermal decomposition and identification of the gaseous products evolved during the thermal decomposition of the compounds.

Thermal behaviour of nicotinic acid, sodium nicotinate and its compounds with some bivalent transition metal ions

International Nuclear Information System (INIS)

Nascimento, A.L.C.S. do; Caires, F.J.; Gomes, D.J.C.; Gigante, A.C.; Ionashiro, M.

2014-01-01

Graphical abstract: - Highlights: • The transition metal ion nicotinates were synthesized. • The TG–DTA curves provided previously unreported information about thermal behaviour. • The gaseous products released were detected by TG–DSC coupled to FTIR. - Abstract: Solid-state M(L) 2 ·nH 2 O compounds, where M stands for bivalent transition metals (Mn, Fe, Co, Ni, Cu and Zn), L is nicotinate and n = 0–4.5, have been synthesized. Characterization and thermal behaviour of these compounds were investigated employing elemental analysis based on the mass losses observed in the TG–DTA curves, complexometry, X-ray diffractometry, infrared spectroscopy (FTIR), simultaneous thermogravimetric and differential thermal analysis (TG–DTA) and TG–DSC coupled to FTIR. The thermal behaviour of nicotinic acid and its sodium salt was also investigated. For the hydrated transition metal compounds, the dehydration and thermal decomposition of the anhydrous compounds occur in a single step. For the sodium nicotinate, the final residue up to 765 °C is sodium carbonate and for the transition metal nicotinates, the final residues are Mn 3 O 4 , Fe 2 O 3 , Co 3 O 4 , NiO, CuO and ZnO. The results also provided information concerning the thermal stability, thermal decomposition and identification of the gaseous products evolved during the thermal decomposition of the compounds

Design, formulation and evaluation of nicotine chewing gum.

Science.gov (United States)

Aslani, Abolfazl; Rafiei, Sahar

2012-01-01

Nicotine replacement therapy (NRT) can help smokers to quit smoking. Nicotine chewing gum has attracted the attention from pharmaceutical industries to offer it to consumers as an easily accessible NRT product. However, the bitter taste of such gums may compromise their acceptability by patients. This study was, therefore, designed to develop 2 and 4 mg nicotine chewing gums of pleasant taste, which satisfy the consumers the most. Nicotine, sugar, liquid glucose, glycerin, different sweetening and taste-masking agents, and a flavoring agent were added to the gum bases at appropriate temperature. The medicated gums were cut into pieces of suitable size and coated by acacia aqueous solution (2% w/v), sugar dusting, followed by acacia-sugar-calcium carbonate until a smooth surface was produced. The gums' weight variation and content uniformity were determined. The release of nicotine was studied in pH 6.8 phosphate buffer using a mastication device which simulated the mastication of chewing gum in human. The Latin Square design was used for the evaluation of organoleptic characteristics of the formulations at different stages of development. Most formulations released 79-83% of their nicotine content within 20 min. Nicotine-containing sugar-coated gums in which aspartame as sweetener and cherry and eucalyptus as flavoring agents were incorporated (i.e. formulations F(19-SC) and F(20-SC), respectively) had optimal chewing hardness, adhering to teeth, and plumpness characteristics, as well as the most pleasant taste and highest acceptability to smokers. Taste enhancement of nicotine gums was achieved where formulations comprised aspartame as the sweetener and cherry and eucalyptus as the flavoring agents. Nicotine gums of pleasant taste may, therefore, be used as NRT to assist smokers quit smoking.

Age-related changes in nicotine response of cholinergic and non-cholinergic laterodorsal tegmental neurons: implications for the heightened adolescent susceptibility to nicotine addiction

DEFF Research Database (Denmark)

Christensen, Mark Holm; Ishibashi, Masaru; Nielsen, Michael Linnemann

2014-01-01

The younger an individual starts smoking, the greater the likelihood that addiction to nicotine will develop, suggesting that neurobiological responses vary across age to the addictive component of cigarettes. Cholinergic neurons of the laterodorsal tegmental nucleus (LDT) are importantly involved...... in the development of addiction, however, the effects of nicotine on LDT neuronal excitability across ontogeny are unknown. Nicotinic effects on LDT cells across different age groups were examined using calcium imaging and whole-cell patch clamping. Within the youngest age group (P7–P15), nicotine induced larger...... intracellular calcium transients and inward currents. Nicotine induced a greater number of excitatory synaptic currents in the youngest animals, whereas larger amplitude inhibitory synaptic events were induced in cells from the oldest animals (P15–P34). Nicotine increased neuronal firing of cholinergic cells...

Ethanol-nicotine interactions in long-sleep and short-sleep mice.

Science.gov (United States)

de Fiebre, C M; Marks, M J; Collins, A C

1990-01-01

The possibility that common genetic factors regulate initial sensitivities to ethanol and nicotine as well as the development of cross-tolerance between these agents was explored using the long-sleep (LS) and short-sleep (SS) mice. The LS mice proved to be more sensitive to an acute challenge with nicotine than were the SS mice. Segregation analysis (F1, F2, backcross) indicated that ethanol sensitivity and nicotine sensitivity segregate together. Acute pretreatment with nicotine did not significantly affect sensitivity to ethanol, but ethanol pretreatment altered nicotine responsiveness. The LS mice develop more tolerance to nicotine and ethanol than do the SS and they also develop more cross-tolerance. These genetically determined differences in initial sensitivities, and tolerance and cross-tolerance development are not readily explained by differences in brain nicotinic receptor numbers.

Ethanol-nicotine interactions in long-sleep and short-sleep mice

Energy Technology Data Exchange (ETDEWEB)

de Fiebre, C.M.; Marks, M.J.; Collins, A.C. (Univ. of Colorado, Boulder (USA))

1990-05-01

The possibility that common genetic factors regulate initial sensitivities to ethanol and nicotine as well as the development of cross-tolerance between these agents was explored using the long-sleep (LS) and short-sleep (SS) mice. The LS mice proved to be more sensitive to an acute challenge with nicotine than were the SS mice. Segregation analysis (F1, F2, backcross) indicated that ethanol sensitivity and nicotine sensitivity segregate together. Acute pretreatment with nicotine did not significantly affect sensitivity to ethanol, but ethanol pretreatment altered nicotine responsiveness. The LS mice develop more tolerance to nicotine and ethanol than do the SS and they also develop more cross-tolerance. These genetically determined differences in initial sensitivities, and tolerance and cross-tolerance development are not readily explained by differences in brain nicotinic receptor numbers.

Sex differences in nicotine intravenous self-administration: A meta-analytic review.

Science.gov (United States)

Flores, Rodolfo J; Uribe, Kevin P; Swalve, Natashia; O'Dell, Laura E

2017-11-21

This report reflects a meta-analysis that systematically reviewed the literature on intravenous self-administration (IVSA) of nicotine in female and male rats. The goal was to determine if sex differences in nicotine IVSA exist, estimate the magnitude of the effect, and identify potential moderators of the relationship between sex differences and nicotine consumption. Extensive search procedures identified 20 studies that met the inclusion criteria of employing both female and male rats in nicotine IVSA procedures. The meta-analysis was conducted on effect size values that were calculated from mean total intake or nicotine deliveries using the Hedges' unbiased g u statistic. A random effects analysis revealed that overall females self-administered more nicotine than males (weighted g u =0.18, 95% CI [0.003, 0.34]). Subsequent moderator variable analyses revealed that certain procedural conditions influenced the magnitude of sex differences in nicotine IVSA. Specifically, higher reinforcement requirements (>FR1) and extended-access sessions (23h) were associated with greater nicotine IVSA in females versus males. Females also displayed higher nicotine intake than males when the experiment included a light cue that signaled nicotine delivery. Sex differences were not influenced by the diurnal phase of testing, dose of nicotine, or prior operant training. Overall, the results revealed that female rats display higher levels of nicotine IVSA than males, suggesting that the strong reinforcing effects of nicotine promote tobacco use in women. Copyright © 2017 Elsevier Inc. All rights reserved.

Racial differences in hair nicotine concentrations among smokers.

Science.gov (United States)

Apelberg, Benjamin J; Hepp, Lisa M; Avila-Tang, Erika; Kim, Sungroul; Madsen, Camille; Ma, Jiemin; Samet, Jonathan M; Breysse, Patrick N

2012-08-01

In the United States, race/ethnicity is a strong determinant of tobacco use patterns, biomarkers of tobacco smoke components and metabolites, and likelihood of successful cessation. Although Black smokers tend to smoke fewer cigarettes than White smokers, they have higher cotinine levels and disease risk and lower cessation success. We examined racial differences in hair nicotine concentrations among daily tobacco smokers (n = 103) in Baltimore, Maryland. Participants completed a survey, and hair samples were collected and analyzed for nicotine concentration using gas chromatography coupled with mass spectrometry. After adjustment, hair nicotine concentrations among Black smokers were more than 5 times higher than among White smokers (95% CI 3.0, 10.5). Smokers reporting hair treatments other than coloring (bleaching, permanent, or straightening) in the past 12 months had 66% lower (95% CI 32%, 83%) hair nicotine concentrations. Smokers reporting smoking their first cigarette within 30 min of waking had twice the hair nicotine concentrations of those whose time to first cigarette was greater than 30 min after waking (95% CI 1.1, 4.2). For every additional cigarette smoked per day up to 20, mean hair nicotine concentration among all smokers increased by 4% (95% CI -1%, 9%). This study demonstrates that Black smokers have substantially higher hair nicotine levels than White smokers, after controlling for cigarettes smoked per day and other exposure sources. Time to first cigarette, cigarettes smoked per day, and use of hair treatments other than coloring were also associated with hair nicotine concentrations among smokers.

Upregulation of Nicotinic Acetylcholine Receptor alph4+beta2 through a Ligand-Independent PI3Kbeta Mechanism That Is Enhanced by TNFalpha and the Jak2/p38Mapk Pathways.

Science.gov (United States)

Rogers, Scott W; Gahring, Lorise C

2015-01-01

High affinity nicotine-binding sites in the mammalian brain are neuronal nicotinic acetylcholine receptors (nAChR) assembled from at least alpha4 and beta2 subunits into pentameric ion channels. When exposed to ligands such as nicotine, these receptors respond by undergoing upregulation, a correlate of nicotine addiction. Upregulation can be measured using HEK293 (293) cells that stably express alpha4 and beta2 subunits using quantification of [3H]epibatidine ([3H]Eb) binding to measure mature receptors. Treatment of these cells with choline also produces upregulation through a hemicholinium3 (HC3)-sensitive (choline kinase) and an HC3-insensitive pathway which are both independent of the mechanism used by nicotine for upregulation. In both cases, upregulation is significantly enhanced by the pro-inflammatory cytokine tumor necrosis factor alpha (TNFα) which signals through its receptor Tnfr1 to activate p38Mapk. Here we report that the inhibition of class1 phosphoinositide 3-kinases isoform PI3Kbeta using the selective antagonist PI828 is alone sufficient to produce upregulation and enhance both nicotine and choline HC3-sensitive mediated upregulation. Further, these processes are impacted upon by an AG-490 sensitive Jak2-associated pathway. Both PI3Kbeta (negative) and Jak2 (positive) modulation of upregulation converge through p38Mapk and both overlap with TNFalpha enhancement of this process. Upregulation through the PI3Kbeta pathway did not require Akt. Collectively these findings support upregulation of endogenous alpha4beta2 as a balance among cellular signaling networks that are highly responsive to multiple environmental, inflammatory and metabolic agents. The findings also suggest how illness and metabolic stress could alter the expression of this important nicotinic receptor and novel avenues to intercede in modifying its expression.

Age-related changes in functional postsynaptic nicotinic acetylcholine receptor subunits in neurons of the laterodorsal tegmental nucleus, a nucleus important in drug addiction.

Science.gov (United States)

Christensen, Mark H; Kohlmeier, Kristi A

2016-03-01

The earlier an individual initiates cigarette smoking, the higher the likelihood of development of dependency to nicotine, the addictive ingredient in cigarettes. One possible mechanism underlying this higher addiction liability is an ontogenetically differential cellular response induced by nicotine in neurons mediating the reinforcing or euphoric effects of this drug, which could arise from age-related differences in the composition of nicotinic acetylcholine receptor (nAChR) subunits. In the current study, we examined whether the subunit composition of nAChRs differed between neurons within the laterodorsal tegmentum (LDT), a nucleus importantly involved in drug addiction associated behaviours, across two periods of ontogeny in which nicotine-mediated excitatory responses were shown to depend on age. To this end, whole-cell patch-clamp recordings in mouse brain slices from identified LDT neurons, in combination with nAChR subunit-specific receptor antagonists, were conducted. Comparison of the contribution of different nAChR subunits to acetylcholine (ACh)-induced inward currents indicated that the contributions of the β2 and/or β4 and α7 nAChR subunits alter across age. Taken together, we conclude that across a limited ontogenetic period, there is plasticity in the subunit composition of nAChRs in LDT neurons. In addition, our data indicate, for the first time, functional presence of α6 nAChR subunits in LDT neurons within the age ranges studied. Changes in subunit composition of nAChRs across ontogeny could contribute to the age-related differential excitability induced by nicotine. Differences in the subunit composition of nAChRs within the LDT would be expected to contribute to ontogenetic-dependent outflow from the LDT to target regions, which include reward-related circuitry. © 2014 Society for the Study of Addiction.

Activation of adenosine low-affinity A3 receptors inhibits the enteric short interplexus neural circuit triggered by histamine.

Science.gov (United States)

Bozarov, Andrey; Wang, Yu-Zhong; Yu, Jun Ge; Wunderlich, Jacqueline; Hassanain, Hamdy H; Alhaj, Mazin; Cooke, Helen J; Grants, Iveta; Ren, Tianhua; Christofi, Fievos L

2009-12-01

We tested the novel hypothesis that endogenous adenosine (eADO) activates low-affinity A3 receptors in a model of neurogenic diarrhea in the guinea pig colon. Dimaprit activation of H2 receptors was used to trigger a cyclic coordinated response of contraction and Cl(-) secretion. Contraction-relaxation was monitored by sonomicrometry (via intracrystal distance) simultaneously with short-circuit current (I(sc), Cl(-) secretion). The short interplexus reflex coordinated response was attenuated or abolished by antagonists at H2 (cimetidine), 5-hydroxytryptamine 4 receptor (RS39604), neurokinin-1 receptor (GR82334), or nicotinic (mecamylamine) receptors. The A1 agonist 2-chloro-N(6)-cyclopentyladenosine (CCPA) abolished coordinated responses, and A1 antagonists could restore normal responses. A1-selective antagonists alone [8-cyclopentyltheophylline (CPT), 1,3-dipropyl-8-(2-amino-4-chlorophenyl)xanthine (PACPX), or 8-cyclopentyl-N(3)-[3-(4-(fluorosulfonyl)benzoyloxy)propyl]-xanthine (FSCPX)] caused a concentration-dependent augmentation of crypt cell secretion or contraction and acted at nanomolar concentrations. The A3 agonist N(6)-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (IB-MECA) abolished coordinated responses and the A3 antagonist 3-ethyl-5-benzyl-2-methyl-4-phenylethynyl-6-phenyl-1,4-(+/-)-dihydropyridine-3,5-dicarboxylate (MRS1191) could restore and further augment responses. The IB-MECA effect was resistant to knockdown of adenosine A1 receptor with the irreversible antagonist FSCPX; the IC(50) for IB-MECA was 0.8 microM. MRS1191 alone could augment or unmask coordinated responses to dimaprit, and IB-MECA suppressed them. MRS1191 augmented distension-evoked reflex I(sc) responses. Adenosine deaminase mimicked actions of adenosine receptor antagonists. A3 receptor immunoreactivity was differentially expressed in enteric neurons of different parts of colon. After tetrodotoxin, IB-MECA caused circular muscle relaxation. The data support the novel concept that

Evaluating nicotine dependence levels in e-cigarette users.

Science.gov (United States)

González Roz, Alba; Secades Villa, Roberto; Weidberg, Sara

2017-01-11

Despite the fact that electronic cigarettes (e-cigarettes) are rapidly growing in popularity and use worldwide, there is scarce scientific data on abuse liability among e-cigarette users, and about whether e-cigarette use is related to nicotine dependence or not. The aim of this study is to explore nicotine dependence levels in a sample of experienced e-cigarette users (n= 39) and to compare them with current tobacco cigarette smokers (n=42). We conducted several face-to-face interviews in order to assess sociodemographic and dependence related characteristics in both e-cigarette users and in smokers. Adapted versions of both the Fagerström test for nicotine dependence (FTND) and the nicotine dependence syndrome scale (NDSS) were used to analyze nicotine dependence in each of the groups. Biochemical markers of carbon monoxide and urinary cotinine analysis were also collected. Results showed that e-cigarette users scored lower than cigarette smokers in both FTND and all NDSS subscales. Our findings extend previous research on e-cigarette use and nicotine addiction and suggest that e-cigarette users are less dependent on nicotine than current tobacco cigarette smokers. Further prospective studies are needed to better ascertain their addictiveness potential, comparing those smokers who switched to e-cigarettes from smoking cigarettes, and those who had never been tobacco cigarette smokers.

Protection against MDMA-induced dopaminergic neurotoxicity in mice by methyllycaconitine: involvement of nicotinic receptors.

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Chipana, C; Camarasa, J; Pubill, D; Escubedo, E

2006-09-01

Methylenedioxymethamphetamine (MDMA) is a relatively selective dopaminergic neurotoxin in mice. Previous studies demonstrated the participation of alpha-7 nicotinic receptors (nAChR) in the neurotoxic effect of methamphetamine. The aim of this paper was to study the role of this receptor type in the acute effects and neurotoxicity of MDMA in mice. In vivo, methyllycaconitine (MLA), a specific alpha-7 nAChR antagonist, significantly prevented MDMA-induced neurotoxicity at dopaminergic but not at serotonergic level, without affecting MDMA-induced hyperthermia. Glial activation was also fully prevented by MLA. In vitro, MDMA induced intrasynaptosomal reactive oxygen species (ROS) generation, which was calcium-, nitric-oxide synthase-, and protein kinase C-dependent. Also, the increase in ROS was prevented by MLA and alpha-bungarotoxin. Experiments with reserpine point to endogenous dopamine (DA) as the main source of MDMA-induced ROS. MLA also brought the MDMA-induced inhibition of [3H]DA uptake down, from 73% to 11%. We demonstrate that a coordinated activation of alpha-7 nAChR, blockade of DA transporter function and displacement of DA from intracellular stores induced by MDMA produces a neurotoxic effect that can be prevented by MLA, suggesting that alpha-7 nAChR have a key role in the MDMA neurotoxicity in mice; however, the involvement of nicotinic receptors containing the beta2 subunit cannot be conclusively ruled out.

Adsorption of nicotine on different zeolite types, from aqueous solutions

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Stošić Dušan K.

2007-01-01

Full Text Available The plant alkaloid, nicotine, is a strongly toxic heterocyclic compound: the lethal dose for an adult human being (40-60 mg is importantly lower in comparison with the other known poisons such as arsenic or strychni­ne. Cigarettes represent "the most toxic and addictive form of nicotine". Besides the negative effects of nicotine on public health produced by self-administration, recently another potentially very dangerous effect has been recognized: because of its miscibility with water, nicotine can be found in industrial wastewaters, and consequently, in groundwater. Therefore, the problem of nicotine removal from aqueous solutions has became an interesting topic. In this work, the removal of nicotine has been probed by adsorption on solid materials. Adsorption of nicotine on different zeolites (clinoptilolite, ZSM-5 and β zeolite and on activated carbon was investigated from aqueous solutions, at 298 K. The obtained results are presented as adsorption isotherms: the amount of adsorbed nicotine as a function of equilibrium concentration. These data were obtained from the residual amount of nicotine in the aqueous phase, by the use of UV spectroscopy. The highest amounts of adsorbed nicotine was found for activated carbon and p zeolite (~ mmol·g-1. The attempt to modify the adsorption properties of ZSM-5 zeolite has been also done: ZSM-5 was modified by ion-exchange with VIII group metal (Cu2+ and Fe3+. In addition, the adsorption of nicotine on ZSM-5 zeolite with different Si/Al ratios has been done. It has been noticed that ion-exchange did not improve the adsorption possibilities, while the adsorption was importantly lower in the case of higher silicon content in ZMS-5 structure. 13C NMR spectra were collected for suspensions formed of solid adsorbent and aqueous solution of nicotine; in this way, the part of nicotine molecule which is most probably connected with the adsorbent was recognized.

Pharmacokinetic characterization of three novel 4-mg nicotine lozenges
.

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Sukhija, Manpreet; Srivastava, Reena; Kaushik, Aditya

2018-03-01

Nicotine replacement therapy (NRT) increases the probability of smoking cessation. This study was conducted to determine if three prototype 4-mg nicotine lozenges produced locally in India were bioequivalent to a globally marketed reference product, Nicorette® 4-mg nicotine lozenge. Healthy adult smokers (N = 39) were treated with three prototype 4-mg nicotine lozenges in comparison with a reference 4-mg lozenge in this single-center, randomized, open-label, single-dose, 4-way crossover study. Pharmacokinetic sampling was obtained to test for bioequivalence using maximal plasma concentration (Cmax) and extent of absorption (AUC0-t). Secondarily, AUC;0-∞, time to maximal plasma concentration (tmax), half-life (T1/2), elimination rate constant (Kel), and safety of the prototype lozenges versus the reference lozenge were compared. Each prototype 4-mg nicotine lozenge was found to be bioequivalent to the reference 4-mg nicotine lozenge based on the ratio of geometric means and 90% confidence intervals for Cmax, AUC0-t, and AUC;0-∞. Although tmax; was significantly longer for prototype III, all four lozenges achieved maximum plasma nicotine concentrations at a median of 1.5 hours. The safety profiles of the three prototype 4-mg lozenges did not differ from that of the 4-mg reference product. Each prototype 4-mg nicotine lozenge was bioequivalent to the reference 4-mg nicotine lozenge and was well tolerated. Furthermore, as these bioequivalent prototypes differed in in-vitro dissolution profiles, these data suggest that performance from the in -vitro method deployed is not a firm predictor of pharmacokinetic behavior.
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T100. NICOTINE USE IMPACTS NEGATIVE SYMPTOMS SEVERITY IN SCHIZOPHRENIA

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Oliveira, Hianna; Coutinho, Luccas; Higuchi, Cinthia; Noto, Cristiano; Bressan, Rodrigo; Gadelha, Ary

2018-01-01

Abstract Background Nicotine use is higher among patients with schizophrenia (50–98%) than in general population (25–30%). This association can reflect a non-specific liability to substance use or specific effects of tobacco on symptoms severity or side effects. Studies about nicotine use and schizophrenia symptoms dimensions are controversial. Some of them showed a relation between severe nicotine use and higher positive symptoms and others presented a correlation between lower negative symptoms and nicotine use. That is why we aimed to verify whether nicotine use is associated with symptoms dimensions in patients with schizophrenia. Methods Two hundred and seven outpatients were enrolled from the Programa de Esquizofrenia da Universidade Federal de São Paulo (PROESQ/UNIFESP). Schizophrenia diagnosis was confirmed by Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I). Dimensional psychopathology was assessed with Positive and Negative Syndrome Scale (PANSS) and Fagerstrom Test for Nicotine Dependence. The PANSS items were grouped in five dimensions: positive, negative, disorganized/cognitive, mood/depression and excitement/hostility. The total score of Fagerstrom Test for Nicotine Dependence was the index used for severity in nicotine dependence. We used Wilcoxon-mann- whitney test to compare the means of PANSS dimensions between nicotine users versus non nicotine use. Results The patients mean age was 36.75 (SD 10.648), 69.1% were male, 48.3% reported lifetime tobacco use and 34.3% reported current tobacco use. Lower scores on negative dimension were associated with nicotine use (W = 5642.5, p-value = 0.046, effect size = 0.446). All p-values were corrected by Bonferroni test. Tests that evaluated the relationship between nicotine use and the total PANSS score or other dimensions were not statistically significant. Discussion This study shows that nicotine use impacts negative symptoms of schizophrenia. Increase in hepatic metabolism leading

Emerging nicotine delivery products. Implications for public health.

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Benowitz, Neal L

2014-02-01

The idea of clean nicotine delivery systems that would satisfy nicotine craving and promote smoking cessation has been considered as a possible public health tool for many years. Nicotine medications have been useful for smoking cessation but have not found widespread popularity among smokers, perhaps because of slow nicotine delivery and other sensory characteristics that differ from cigarettes. Traditional smokeless tobacco delivers as much nicotine as cigarettes and has been advocated for harm reduction but contains carcinogenic nitrosamines and has not been proven to promote cessation. Furthermore, there is concern that dual use of smokeless tobacco and cigarettes may inhibit quitting smoking. Newer oral dissolvable tobacco products contain lower levels of toxicants than other smokeless tobacco but also deliver much less nicotine and have not been popular with consumers. Electronic cigarettes that aerosolize nicotine without generating toxic tobacco combustion products have become quite popular and hold promise as a way to attract smokers away from cigarettes, although efficacy in promoting smoking cessation has not yet been demonstrated. There are concerns about safety of long-term use, and there is evidence that youth, including nonsmokers, are taking up e-cigarette use. E-cigarettes are marketed for use when one cannot smoke conventional cigarettes, and such use might result in more persistent cigarette smoking. Although their benefits and risks are being vigorously debated, e-cigarettes or other clean nicotine delivery devices could play an important role as an adjunct to a U.S. Food and Drug Administration regulatory intervention to make cigarettes less addictive and in this context could contribute to the end of cigarette smoking and smoking-induced disease.

Nicotine affects protein complex rearrangement in Caenorhabditis elegans cells.

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Sobkowiak, Robert; Zielezinski, Andrzej; Karlowski, Wojciech M; Lesicki, Andrzej

2017-10-01

Nicotine may affect cell function by rearranging protein complexes. We aimed to determine nicotine-induced alterations of protein complexes in Caenorhabditis elegans (C. elegans) cells, thereby revealing links between nicotine exposure and protein complex modulation. We compared the proteomic alterations induced by low and high nicotine concentrations (0.01 mM and 1 mM) with the control (no nicotine) in vivo by using mass spectrometry (MS)-based techniques, specifically the cetyltrimethylammonium bromide (CTAB) discontinuous gel electrophoresis coupled with liquid chromatography (LC)-MS/MS and spectral counting. As a result, we identified dozens of C. elegans proteins that are present exclusively or in higher abundance in either nicotine-treated or untreated worms. Based on these results, we report a possible network that captures the key protein components of nicotine-induced protein complexes and speculate how the different protein modules relate to their distinct physiological roles. Using functional annotation of detected proteins, we hypothesize that the identified complexes can modulate the energy metabolism and level of oxidative stress. These proteins can also be involved in modulation of gene expression and may be crucial in Alzheimer's disease. The findings reported in our study reveal putative intracellular interactions of many proteins with the cytoskeleton and may contribute to the understanding of the mechanisms of nicotinic acetylcholine receptor (nAChR) signaling and trafficking in cells.

E-cigarette versus nicotine inhaler: comparing the perceptions and experiences of inhaled nicotine devices.

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Steinberg, Michael B; Zimmermann, Mia Hanos; Delnevo, Cristine D; Lewis, M Jane; Shukla, Parth; Coups, Elliot J; Foulds, Jonathan

2014-11-01

Novel nicotine delivery products, such as electronic cigarettes (e-cigarettes), have dramatically grown in popularity despite limited data on safety and benefit. In contrast, the similar U.S. Food and Drug Administration (FDA)-approved nicotine inhaler is rarely utilized by smokers. Understanding this paradox could be helpful to determine the potential for e-cigarettes as an alternative to tobacco smoking. To compare the e-cigarette with the nicotine inhaler in terms of perceived benefits, harms, appeal, and role in assisting with smoking cessation. A cross-over trial was conducted from 2012 to 2013 PARTICIPANTS/INTERVENTIONS: Forty-one current smokers age 18 and older used the e-cigarette and nicotine inhaler each for 3 days, in random order, with a washout period in between. Thirty-eight participants provided data on product use, perceptions, and experiences. The Modified Cigarette Evaluation Questionnaire (mCEQ) measured satisfaction, reward, and aversion. Subjects were also asked about each product's helpfulness, similarity to cigarettes, acceptability, image, and effectiveness in quitting smoking. Cigarette use was also recorded during the product-use periods. The e-cigarette had a higher total satisfaction score (13.9 vs. 6.8 [p e-cigarette received higher ratings for helpfulness, acceptability, and "coolness." More subjects would use the e-cigarette to make a quit attempt (76 %) than the inhaler (24 %) (p e-cigarette vs. 10 % (4/38) using the inhaler (p = 0.18). The e-cigarette was more acceptable, provided more satisfaction, and had higher perceived benefit than the inhaler during this trial. E-cigarettes have the potential to be important nicotine delivery products owing to their high acceptance and perceived benefit, but more data are needed to evaluate their actual efficacy and safety. Providers should be aware of these issues, as patients will increasingly inquire about them.

Electronic cigarettes are a source of thirdhand exposure to nicotine.

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Goniewicz, Maciej L; Lee, Lily

2015-02-01

Substances remaining on the surfaces in areas where people have smoked contribute to thirdhand exposure. Nicotine from tobacco smoke has been shown to react with oxidizing chemicals in the air to form secondary pollutants, such as carcinogenic nitrosamines. While previous studies have demonstrated thirdhand exposure to nicotine from tobacco smoke, none have investigated whether nicotine from electronic cigarettes (e-cigarettes) can also be deposited on various surfaces. Three brands of e-cigarettes were refilled with varying nicotine concentrations. We released 100 puffs from each product directly into an exposure chamber. Surface wipe samples were taken from 5 indoor 100 cm(2) surfaces (window, walls, floor, wood, and metal) pre- and post-release of vapors. Nicotine was extracted from the wipes and was analyzed using gas chromatography. Three of the 4 experiments showed significant increases in the amount of nicotine on all five surfaces. The floor and glass windows had the greatest increases in nicotine, on average by a factor of 47 and 6, respectively (p risk for thirdhand exposure to nicotine from e-cigarettes. Thirdhand exposure levels differ depending on the surface and the e-cigarette brand. Future research should explore the potential risks of thirdhand exposure to carcinogens formed from the nicotine that is released from e-cigarettes. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Adverse effects of perinatal nicotine exposure on reproductive outcomes.

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Wong, Michael K; Barra, Nicole G; Alfaidy, Nadia; Hardy, Daniel B; Holloway, Alison C

2015-12-01

Nicotine exposure during pregnancy through cigarette smoking, nicotine replacement therapies or e-cigarette use continues to be a widespread public health problem, impacting both fetal and postnatal health. Yet, at this time, there remains limited data regarding the safety and efficacy in using these nicotine products during pregnancy. Notably, reports assessing the effect of nicotine exposure on postnatal health outcomes in humans, including reproductive health, are severely lacking. Our current understanding regarding the consequences of nicotine exposure during pregnancy is limited to a few animal studies, which do not comprehensively address the underlying cellular mechanisms involved. This paper aims to critically review the current knowledge from human and animal studies regarding the direct and indirect effects (e.g. obesity) of maternal nicotine exposure, regardless of its source, on reproductive outcomes in pregnancy and postnatal life. Furthermore, this review highlights several key cellular mechanisms involved in these adverse reproductive deficits including oxidative stress, inflammation, and endoplasmic reticulum (ER) stress. By understanding the interplay of the cellular mechanisms involved, further strategies could be developed to prevent the reproductive abnormalities resulting from exposure to nicotine in utero and influence informed clinical guidelines for pregnant women. © 2015 Society for Reproduction and Fertility.

Environmental fate and effects of nicotine released during cigarette production.

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Seckar, Joel A; Stavanja, Mari S; Harp, Paul R; Yi, Yongsheng; Garner, Charles D; Doi, Jon

2008-07-01

A variety of test methods were used to study the gradation, bioaccumulation, and toxicity of nicotine. Studies included determination of the octanol-water partition coefficient, conversion to CO2 in soil and activated sludge, and evaluation of the effects on microbiological and algal inhibition as well as plant germination and root elongation. The partitioning of nicotine between octanol and water indicated that nicotine will not bioaccumulate regardless of the pH of the medium. The aqueous and soil-based biodegradation studies indicated that nicotine is readily biodegradable in both types of media. The microbiological inhibition and aquatic and terrestrial toxicity tests indicated that nicotine has low toxicity. The U.S. Environmental Protection Agency Persistence, Bioaccumulation, and Toxicity Profiler model, based on the structure of nicotine and the predictive rates of hydroxyl radical and ozone reactions, estimated an atmospheric half-life of less than 5.0 h. Using this value in the Canadian Environmental Modeling Center level III model, the half-life of nicotine was estimated as 3.0 d in water and 0.5 d in soil. This model also estimated nicotine discharge into the environment; nicotine would be expected to be found predominantly in water (93%), followed by soil (4%), air (3%), and sediment (0.4%). Using the estimated nicotine concentrations in water, soil, and sediment and the proper median effective concentrations derived from the algal growth, biomass inhibition, and buttercrunch lettuce (Lactuca sativa) seed germination and root elongation studies, hazard quotients of between 10(-7) and 10(-8) were calculated, providing further support for the conclusion that the potential for nicotine toxicity to aquatic and terrestrial species in the environment is extremely low.

Effect of nicotine on melanogenesis and antioxidant status in HEMn-LP melanocytes

International Nuclear Information System (INIS)

Delijewski, Marcin; Beberok, Artur; Otręba, Michał; Wrześniok, Dorota; Rok, Jakub; Buszman, Ewa

2014-01-01

Nicotine is a natural ingredient of tobacco plants and is responsible for the addictive properties of tobacco. Nowadays nicotine is also commonly used as a form of smoking cessation therapy. It is suggested that nicotine may be accumulated in human tissues containing melanin. This may in turn affect biochemical processes in human cells producing melanin. The aim of this study was to examine the effect of nicotine on melanogenesis and antioxidant status in cultured normal human melanocytes HEMn-LP. Nicotine induced concentration-dependent loss in melanocytes viability. The value of EC 50 was determined to be 7.43 mM. Nicotine inhibited a melanization process in human light pigmented melanocytes and caused alterations of antioxidant defense system. Significant changes in cellular antioxidant enzymes: superoxide dismutase and catalase activities and in hydrogen peroxide content were stated. The obtained results may explain a potential influence of nicotine on biochemical processes in melanocytes in vivo during long term exposition to nicotine. - Graphical abstract: Nicotine inhibits melanogenesis and induces oxidative stress in HEMn-LP melanocytes. - Highlights: • Nicotine induces concentration-dependent loss in melanocytes viability. • Nicotine in non-cytotoxic concentrations inhibits melanogenesis. • Nicotine in higher concentrations induces oxidative stress

Effect of nicotine on melanogenesis and antioxidant status in HEMn-LP melanocytes

Energy Technology Data Exchange (ETDEWEB)

Delijewski, Marcin; Beberok, Artur; Otręba, Michał; Wrześniok, Dorota; Rok, Jakub; Buszman, Ewa, E-mail: ebuszman@sum.edu.pl

2014-10-15

Nicotine is a natural ingredient of tobacco plants and is responsible for the addictive properties of tobacco. Nowadays nicotine is also commonly used as a form of smoking cessation therapy. It is suggested that nicotine may be accumulated in human tissues containing melanin. This may in turn affect biochemical processes in human cells producing melanin. The aim of this study was to examine the effect of nicotine on melanogenesis and antioxidant status in cultured normal human melanocytes HEMn-LP. Nicotine induced concentration-dependent loss in melanocytes viability. The value of EC{sub 50} was determined to be 7.43 mM. Nicotine inhibited a melanization process in human light pigmented melanocytes and caused alterations of antioxidant defense system. Significant changes in cellular antioxidant enzymes: superoxide dismutase and catalase activities and in hydrogen peroxide content were stated. The obtained results may explain a potential influence of nicotine on biochemical processes in melanocytes in vivo during long term exposition to nicotine. - Graphical abstract: Nicotine inhibits melanogenesis and induces oxidative stress in HEMn-LP melanocytes. - Highlights: • Nicotine induces concentration-dependent loss in melanocytes viability. • Nicotine in non-cytotoxic concentrations inhibits melanogenesis. • Nicotine in higher concentrations induces oxidative stress.

Validation of a LC-MS/MS method for quantifying urinary nicotine, six nicotine metabolites and the minor tobacco alkaloids--anatabine and anabasine--in smokers' urine.

Directory of Open Access Journals (Sweden)

James E McGuffey

Full Text Available Tobacco use is a major contributor to premature morbidity and mortality. The measurement of nicotine and its metabolites in urine is a valuable tool for evaluating nicotine exposure and for nicotine metabolic profiling--i.e., metabolite ratios. In addition, the minor tobacco alkaloids--anabasine and anatabine--can be useful for monitoring compliance in smoking cessation programs that use nicotine replacement therapy. Because of an increasing demand for the measurement of urinary nicotine metabolites, we developed a rapid, low-cost method that uses isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS for simultaneously quantifying nicotine, six nicotine metabolites, and two minor tobacco alkaloids in smokers' urine. This method enzymatically hydrolyzes conjugated nicotine (primarily glucuronides and its metabolites. We then use acetone pretreatment to precipitate matrix components (endogenous proteins, salts, phospholipids, and exogenous enzyme that may interfere with LC-MS/MS analysis. Subsequently, analytes (nicotine, cotinine, hydroxycotinine, norcotinine, nornicotine, cotinine N-oxide, nicotine 1'-N-oxide, anatabine, and anabasine are chromatographically resolved within a cycle time of 13.5 minutes. The optimized assay produces linear responses across the analyte concentrations typically found in urine collected from daily smokers. Because matrix ion suppression may influence accuracy, we include a discussion of conventions employed in this procedure to minimize matrix interferences. Simplicity, low cost, low maintenance combined with high mean metabolite recovery (76-99%, specificity, accuracy (0-10% bias and reproducibility (2-9% C.V. make this method ideal for large high through-put studies.

Nicotine pharmacokinetic profiles of the Tobacco Heating System 2.2, cigarettes and nicotine gum in Japanese smokers.

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Brossard, Patrick; Weitkunat, Rolf; Poux, Valerie; Lama, Nicola; Haziza, Christelle; Picavet, Patrick; Baker, Gizelle; Lüdicke, Frank

2017-10-01

Two open-label randomized cross-over studies in Japanese smokers investigated the single-use nicotine pharmacokinetic profile of the Tobacco Heating System (THS) 2.2, cigarettes (CC) and nicotine replacement therapy (Gum). In each study, one on the regular and one on the menthol variants of the THS and CC, both using Gum as reference, 62 subjects were randomized to four sequences: Sequence 1: THS - CC (n = 22); Sequence 2: CC - THS (n = 22); Sequence 3: THS - Gum (n = 9); Sequence 4: Gum - THS (n = 9). Plasma nicotine concentrations were measured in 16 blood samples collected over 24 h after single use. Maximal nicotine concentration (C max ) and area under the curve from start of product use to time of last quantifiable concentration (AUC 0-last ) were similar between THS and CC in both studies, with ratios varying from 88 to 104% for C max and from 96 to 98% for AUC 0-last . Urge-to-smoke total scores were comparable between THS and CC. The THS nicotine pharmacokinetic profile was close to CC, with similar levels of urge-to-smoke. This suggests that THS can satisfy smokers and be a viable alternative to cigarettes for adult smokers who want to continue using tobacco. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

The Activity and Enthalpy of Vaporization of Nicotine from Tobacco at Moderate Temperatures

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St.Charles F. Kelley

2016-01-01

Full Text Available The vapor pressure of nicotine has been reported for unprotonated nicotine and for nicotine-water solutions. Yet no published values exist for nicotine in any commercially relevant matrix or for protonated forms (e.g., tobacco, smoke, electronic cigarette solutions, nicotine replacement products, nicotine salts. Therefore a methodology was developed to measure nicotine activity (defined as the vapor pressure from a matrix divided by the vapor pressure of pure nicotine. The headspace concentration of nicotine was measured for pure nicotine and tobacco stored at 23, 30, and 40 °C which allowed for conversion to vapor pressure and nicotine activity and for the estimation of enthalpy of vaporization. Burley, Flue-cured, Oriental, and cigarette blends were tested. Experiments were conducted with pure nicotine initially until the storage and sampling techniques were validated by comparison with previously published values. We found that the nicotine activity from tobacco was less than 1% with Burley > Flue-cured > Oriental. At 23 °C the nicotine vapor pressure averaged by tobacco type was 0.45 mPa for Oriental tobacco, 1.8 mPa for Flue-cured, 13 mPa for Burley while pure nicotine was 2.95 Pa. In general, the nicotine activity increased as the (calculated unprotonated nicotine concentration increased. The nicotine enthalpy of vaporization from tobacco ranged from 77 kJ/mol to 92 kJ/mol with no obvious trends with regard to tobacco origin, type, stalk position or even the wide range of nicotine activity. The mean value for all tobacco types was 86.7 kJ/mol with a relative standard deviation of 6.5% indicating that this was an intrinsic property of the nicotine form in tobacco rather than the specific tobacco properties. This value was about 30 kJ/mol greater than that of pure nicotine and is similar to the energy needed to remove a proton from monoprotonated nicotine.

The impact of nicotine on bone healing and osseointegration

DEFF Research Database (Denmark)

Balatsouka, Dimitra; Gotfredsen, Klaus; Lindh, Christian H

2005-01-01

OBJECTIVES: To examine the short-term effect of nicotine on bone healing and osseointegration. MATERIAL AND METHODS: Sixteen female rabbits were divided into two groups. The test group was exposed to nicotine tartrate for 8 weeks and the control group was exposed to placebo. Nicotine or placebo...... was administered via a miniosmotic pump and plasma cotinine levels were measured weekly. The pump delivered 15 mg of nicotine/day for the animals in the test group. All rabbits had three tibial bone preparations. In the proximal and distal bone bed, implants were placed after 4 weeks (right tibia) and after 6...... and the control group. CONCLUSION: Nicotine exposure in a short period of time did not have a significant impact on bone healing or implant osseointegration in rabbits....

Sales of Nicotine-Containing Electronic Cigarette Products: United States, 2015.

Science.gov (United States)

Marynak, Kristy L; Gammon, Doris G; Rogers, Todd; Coats, Ellen M; Singh, Tushar; King, Brian A

2017-05-01

To assess the proportion of electronic cigarette (e-cigarette) products sold in the United States that contain nicotine according to retail scanner data. We obtained unit sales data from January 11, 2015, to December 12, 2015, from The Nielsen Company for convenience stores; supermarkets; mass merchandisers; drug, club, and dollar stores; and Department of Defense commissaries. The data did not include purchases from tobacco specialty shops, "vape shops," or online sources. Nicotine content was assessed by product type (disposables, rechargeables, and refills), region, and flavor status based on nicotine strength listed in the Universal Product Codes. For the 36.7% of entries lacking nicotine content information, we conducted Internet searches by brand, product, and flavor. In 2015, 99.0% of e-cigarette products sold contained nicotine, including 99.0% of disposables, 99.7% of rechargeables, and 98.8% of refills. Overall, 98.7% of flavored e-cigarette products and 99.4% of nonflavored e-cigarette products contained nicotine. In 2015, almost all e-cigarette products sold in US convenience stores and other assessed channels contained nicotine. Public Health Implications. Findings reinforce the importance of warning labels for nicotine-containing products, ingredient reporting, and restrictions on sales to minors.

Nicotine Dependence, Physical Activity, and Sedentary Behavior among Adult Smokers.

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Loprinzi, Paul D; Walker, Jerome F

2015-03-01

Research has previously demonstrated an inverse association between smoking status and physical activity; however, few studies have examined the association between nicotine dependence and physical activity or sedentary behavior. This study examined the association between nicotine dependence and accelerometer-determined physical activity and sedentary behavior. Data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) were used. A total of 851 adult (≥20 years) smokers wore an accelerometer for ≥4 days and completed the Fagerstrom Test for Nicotine Dependence scale. Regression models were used to examine the association between nicotine dependence and physical activity/sedentary behavior. After adjusting for age, gender, race-ethnicity, poverty level, hypertension, emphysema, bronchitis, body mass index (BMI), cotinine, and accelerometer wear time, smokers 50 + years of age with greater nicotine dependence engaged in more sedentary behavior (β = 11.4, P = 0.02) and less light-intensity physical activity (β = -9.6, P = 0.03) and moderate-to-vigorous physical activity (MVPA; β = -0.14, P = 0.003) than their less nicotine dependent counterparts. Older adults who are more nicotine dependent engage in less physical activity (both MVPA and light-intensity) and more sedentary behavior than their less nicotine dependent counterparts.

Increased hepatic nicotine elimination after phenobarbital induction in the conscious rat

International Nuclear Information System (INIS)

Foth, H.; Walther, U.I.; Kahl, G.F.

1990-01-01

Elimination parameters of [14C]nicotine in conscious rats receiving nicotine (0.3 mg/kg) either intravenously or orally were studied. The oral availability of unchanged nicotine, derived by comparison of the respective areas under the concentration vs time curves (AUC), was 89%, indicating low hepatic extraction ratios of about 10%. Pretreatment of rats with phenobarbital (PB) markedly increased hepatic first-pass extraction of nicotine. The oral availability of unchanged nicotine in plasma dropped to 1.4% of the corresponding values obtained from PB-treated rats receiving nicotine iv. After PB pretreatment, the clearance of iv nicotine was increased approximately twofold over controls, much less than the observed more than ninefold increase of hepatic first-pass extraction. It is assumed that extrahepatic metabolism contributed significantly to the rapid removal of nicotine from the plasma. The elimination of cotinine, originating from nicotine administered either po or iv, was significantly increased by PB pretreatment, as determined by the ratio of corresponding AUCs. The pattern of nicotine metabolites in urine also indicated an increase in the rate of cotinine metabolic turnover. The amount of norcotinine in the organic extract of urine paralleled PB microsomal enzyme induction. The ratio between urinary concentrations of the normetabolite and cotinine correlated strongly with the PB-induced state of rat liver. This may be a suitable indicator of PB-inducible hepatic cytochrome P450 isoenzyme(s). Since smoking habits in man are feedback-regulated by nicotine plasma concentrations, a similar increase of nicotine elimination by microsomal enzyme induction in man may be of relevance for tobacco consumption

Nicotinic mechanisms influencing synaptic plasticity in the hippocampus

Institute of Scientific and Technical Information of China (English)

Andon Nicholas PLACZEK; Tao A ZHANG; John Anthony DANI

2009-01-01

Nicotinic acetylcholine receptors (nAChRs) are expressed throughout the hippocampus, and nicotinic signaling plays an important role in neuronal function. In the context of learning and memory related behaviors associated with hippocampal function, a potentially significant feature of nAChR activity is the impact it has on synaptic plasticity. Synaptic plasticity in hippocampal neurons has long been considered a contributing cellular mechanism of learning and memory. These same kinds of cellular mechanisms are a factor in the development of nicotine addiction. Nicotinic signaling has been demonstrated by in vitro studies to affect synaptic plasticity in hippocampal neurons via multiple steps, and the signaling has also been shown to evoke synaptic plasticity in vivo. This review focuses on the nAChRs subtypes that contribute to hippocampal synaptic plasticity at the cellular and circuit level. It also considers nicotinic influences over long-term changes in the hippocampus that may contribute to addiction.

Dependence on the nicotine gum in former smokers.

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Etter, Jean-François

2009-03-01

We conducted an Internet survey in 2004-2007 in 526 daily users of the nicotine gum, to assess use of, and dependence on the nicotine gum in former smokers. We used modified versions of the Nicotine Dependence Syndrome Scale (NDSS-G), the Cigarette Dependence Scale (CDS-G) and the Fagerström Test (FTND-G). After 30 days, 155 participants (29%) indicated their gum use. Higher dependence on the gum predicted a lower chance of stopping using it at follow-up (odds ratio=0.36 for each standard deviation unit on CDS-G, p=0.001). More long-term (>3 months) than short-term (dependence on the gum than short-term users, as assessed with NDSS-Gum, CDS-Gum and FTND-Gum (all pdependence on the nicotine gum. Lower levels of dependence on the gum predicted cessation of gum use. However, long term use of the nicotine gum has no known serious adverse consequence, and may be beneficial if it prevents late relapse.

Nicotine patches improve mood and response speed in a lexical decision task.

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Gentry, M V; Hammersley, J J; Hale, C R; Nuwer, P K; Meliska, C J

2000-01-01

The effects of smoking a cigarette or wearing a transdermal nicotine patch on mood and lexical decision-making were tested in eight smokers. Each participant was tested after 4 hours of smoking abstinence, under 4 conditions: placebo (very low nicotine) cigarette, nicotine cigarette, placebo patch, and nicotine patch. Relative to placebo, wearing the nicotine patch reduced Profile of Mood States (POMS) Total Mood Disturbance and Fatigue/Inertia scores, while increasing the speed of some types of lexical decisions. Smoking a nicotine cigarette did not affect reaction times, but unexpectedly decreased the accuracy of Word/ Nonword lexical decisions. Thus, transdermal nicotine may improve mood and facilitate longterm memory search and/or attentional processes in nicotine-deprived smokers.

Effects of nicotine on homeostatic and hedonic components of food intake.

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Stojakovic, Andrea; Espinosa, Enma P; Farhad, Osman T; Lutfy, Kabirullah

2017-10-01

Chronic tobacco use leads to nicotine addiction that is characterized by exaggerated urges to use the drug despite the accompanying negative health and socioeconomic burdens. Interestingly, nicotine users are found to be leaner than the general population. Review of the existing literature revealed that nicotine affects energy homeostasis and food consumption via altering the activity of neurons containing orexigenic and anorexigenic peptides in the brain. Hypothalamus is one of the critical brain areas that regulates energy balance via the action of these neuropeptides. The equilibrium between these two groups of peptides can be shifted by nicotine leading to decreased food intake and weight loss. The aim of this article is to review the existing literature on the effect of nicotine on food intake and energy homeostasis and report on the changes that nicotine brings about in the level of these peptides and their receptors that may explain changes in food intake and body weight induced by nicotine. Furthermore, we review the effect of nicotine on the hedonic aspect of food intake. Finally, we discuss the involvement of different subtypes of nicotinic acetylcholine receptors in the regulatory action of nicotine on food intake and energy homeostasis. © 2017 Society for Endocrinology.

Endothelial disruptive proinflammatory effects of nicotine and e-cigarette vapor exposures.

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Schweitzer, Kelly S; Chen, Steven X; Law, Sarah; Van Demark, Mary; Poirier, Christophe; Justice, Matthew J; Hubbard, Walter C; Kim, Elena S; Lai, Xianyin; Wang, Mu; Kranz, William D; Carroll, Clinton J; Ray, Bruce D; Bittman, Robert; Goodpaster, John; Petrache, Irina

2015-07-15

The increased use of inhaled nicotine via e-cigarettes has unknown risks to lung health. Having previously shown that cigarette smoke (CS) extract disrupts the lung microvasculature barrier function by endothelial cell activation and cytoskeletal rearrangement, we investigated the contribution of nicotine in CS or e-cigarettes (e-Cig) to lung endothelial injury. Primary lung microvascular endothelial cells were exposed to nicotine, e-Cig solution, or condensed e-Cig vapor (1-20 mM nicotine) or to nicotine-free CS extract or e-Cig solutions. Compared with nicotine-containing extract, nicotine free-CS extract (10-20%) caused significantly less endothelial permeability as measured with electric cell-substrate impedance sensing. Nicotine exposures triggered dose-dependent loss of endothelial barrier in cultured cell monolayers and rapidly increased lung inflammation and oxidative stress in mice. The endothelial barrier disruptive effects were associated with increased intracellular ceramides, p38 MAPK activation, and myosin light chain (MLC) phosphorylation, and was critically mediated by Rho-activated kinase via inhibition of MLC-phosphatase unit MYPT1. Although nicotine at sufficient concentrations to cause endothelial barrier loss did not trigger cell necrosis, it markedly inhibited cell proliferation. Augmentation of sphingosine-1-phosphate (S1P) signaling via S1P1 improved both endothelial cell proliferation and barrier function during nicotine exposures. Nicotine-independent effects of e-Cig solutions were noted, which may be attributable to acrolein, detected along with propylene glycol, glycerol, and nicotine by NMR, mass spectrometry, and gas chromatography, in both e-Cig solutions and vapor. These results suggest that soluble components of e-Cig, including nicotine, cause dose-dependent loss of lung endothelial barrier function, which is associated with oxidative stress and brisk inflammation.

Nicotine Addiction

NARCIS (Netherlands)

Andel I van; Rambali AB; Amsterdam JGC van; Wolterink G; Aerts LAGJM van; Vleeming W; TOX; SIR; BMT

2003-01-01

This report discusses the current knowledge on nicotine dependence, devoting a special chapter to smoking among youths, given that most smoking careers start in adolescence. The transition period, in which youths go from elementary to high school (ages 13-14), showes to be particularly risky for

Sensory Effects of Menthol and Nicotine in an E-Cigarette.

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Rosbrook, Kathryn; Green, Barry G

2016-07-01

Despite the longstanding use and popularity of menthol as a flavorant in tobacco products, its sensory interactions with inhaled nicotine have never been measured independently of the other irritants in tobacco smoke. We therefore measured the perception of menthol in an E-cigarette with the primary goal of assessing its analgesic effect on the sensory irritation produced by inhaled nicotine. Adult cigarette smokers sampled aerosolized E-liquids containing five different concentrations of nicotine with 0%, 0.5%, or 3.5% l-menthol, as well as two commercial menthol flavors with and without nicotine. For each of the E-liquids participants used a labeled magnitude scale to rate the Overall Sensation intensity, Coolness/Cold, and Irritation/Harshness they experienced, and a Labeled Hedonic Scale to indicate how much they liked/disliked the overall flavor. The main findings were that (1) perceived Irritation/Harshness was unaffected by a low (0.5%) menthol concentration, whereas a high menthol concentration (3.5%) led to higher perceived Irritation/Harshness at low nicotine concentrations but to lower Irritation/Harshness at the highest nicotine concentration (24mg/ml); (2) a commercial Menthol-Mint flavor produced similar results; (3) nicotine tended to enhance rather than suppress sensations of Coolness/Cold; and (4) menthol tended to slightly increase liking independently of nicotine concentration. In addition to adding a sensation of coolness, menthol can reduce perceived airway irritation and harshness produced by inhalation when nicotine concentration is high, and contributes to the sensory impact of E-liquids when nicotine concentration is low. The evidence presented here indicates that menthol can potentially improve the appeal of E-cigarettes not only via its coolness and minty flavor, but also by reducing the harshness from high concentrations of nicotine. As the first direct demonstration of an analgesic effect of menthol on inhaled nicotine in humans, these

Unpredictability of nectar nicotine promotes outcrossing by hummingbirds in Nicotiana attenuata.

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Kessler, Danny; Bhattacharya, Samik; Diezel, Celia; Rothe, Eva; Gase, Klaus; Schöttner, Matthias; Baldwin, Ian T

2012-08-01

Many plants use sophisticated strategies to maximize their reproductive success via outcrossing. Nicotiana attenuata flowers produce nectar with nicotine at concentrations that are repellent to hummingbirds, increasing the number of flowers visited per plant. In choice tests using native hummingbirds, we show that these important pollinators learn to tolerate high-nicotine nectar but prefer low-nicotine nectar, and show no signs of nicotine addiction. Nectar nicotine concentrations, unlike those of other vegetative tissues, are unpredictably variable among flowers, not only among populations, but also within populations, and even among flowers within an inflorescence. To evaluate whether variations in nectar nicotine concentrations increase outcrossing, polymorphic microsatellite markers, optimized to evaluate paternity in native N. attenuata populations, were used to compare outcrossing in plants silenced for expression of a biosynthetic gene for nicotine production (Napmt1/2) and in control empty vector plants, which were antherectomized and transplanted into native populations. When only exposed to hummingbird pollinators, seeds produced by flowers with nicotine in their nectar had a greater number of genetically different sires, compared to seeds from nicotine-free flowers. As the variation in nectar nicotine levels among flowers in an inflorescence decreased in N. attenuata plants silenced in various combinations of three Dicer-like (DCL) proteins, small RNAs are probably involved in the unpredictable variation in nectar nicotine levels within a plant. © 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd.

Degradation of Nicotine in Chlorinated Water: Pathways and ...

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Report The objective of the study is to illustrate how drinking water would affect alkaloid pesticides, and to address the issue by (a) investigating the fate of nicotine in chlorinated drinking water and deionized water, (b) determining the reaction rate and pathway of the reaction between nicotine and aqueous chlorine, (c) identifying nicotine’s degradation products, and (d) providing data that can be used to assess the potential threat from nicotine in drinking water.

Nicotine and Cotinine Levels With Electronic Cigarette: A Review.

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Marsot, A; Simon, N

2016-01-01

Since their introduction in 2004, electronic cigarettes (e-cigarettes) have gained popularity worldwide. E-cigarettes are marketed as nicotine delivery devices. Commonly reported reasons for use include to quit smoking, to reduce urge to smoke, or the perceived lower risk alternative to smoking. But what are the actual amounts of nicotine delivered? This review summarizes all the published studies concerning nicotine or cotinine levels following e-cigarette use. A literature search was conducted from the PubMed database, from 1985 to January 2014, using the following terms: electronic cigarette(s), e-cigarette(s), electronic nicotine delivery system, cotinine, and nicotine. Articles were excluded if they were not pertinent according to our criteria. References of all relevant articles were also evaluated. Eight studies were included in this review. The following information was extracted from the articles: population size, age of participants, recruitment, inclusion and exclusion criteria, concentration of nicotine in refills liquids, study sample design, and observed concentrations. Following design of studies, plasma nicotine Cmax was observed between 0 and 5 ng/mL (no significant changes) or between 13.9 and 16.3 ng/mL (similar to a tobacco cigarette) with a Tmax between 70 and 75 minutes. Cotinine levels after "vaping" an e-cigarette are similar to a tobacco cigarette. This review summarizes e-cigarette studies that contain information on nicotine or cotinine levels. The peak concentration of nicotine appears to be dependent on the use and dose level of e-cigarette cartridge. The value of this peak concentration is similar to the value found with a tobacco cigarette. However, the time corresponding to the peak concentration is delayed compared to a tobacco cigarette. © The Author(s) 2015.

Key issues surrounding the health impacts of electronic nicotine delivery systems (ENDS) and other sources of nicotine.

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Drope, Jeffrey; Cahn, Zachary; Kennedy, Rosemary; Liber, Alex C; Stoklosa, Michal; Henson, Rosemarie; Douglas, Clifford E; Drope, Jacqui

2017-11-01

Answer questions and earn CME/CNE Over the last decade, the use of electronic nicotine delivery systems (ENDS), including the electronic cigarette or e-cigarette, has grown rapidly. More youth now use ENDS than any tobacco product. This extensive research review shows that there are scientifically sound, sometimes competing arguments about ENDS that are not immediately and/or completely resolvable. However, the preponderance of the scientific evidence to date suggests that current-generation ENDS products are demonstrably less harmful than combustible tobacco products such as conventional cigarettes in several key ways, including by generating far lower levels of carcinogens and other toxic compounds than combustible products or those that contain tobacco. To place ENDS in context, the authors begin by reviewing the trends in use of major nicotine-containing products. Because nicotine is the common core-and highly addictive-constituent across all tobacco products, its toxicology is examined. With its long history as the only nicotine product widely accepted as being relatively safe, nicotine-replacement therapy (NRT) is also examined. A section is also included that examines snus, the most debated potential harm-reduction product before ENDS. Between discussions of NRT and snus, ENDS are extensively examined: what they are, knowledge about their level of "harm," their relationship to smoking cessation, the so-called gateway effect, and dual use/poly-use. CA Cancer J Clin 2017;67:449-471. © 2017 American Cancer Society. © 2017 American Cancer Society.

Skin contamination as pathway for nicotine intoxication in vapers.

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Maina, Giovanni; Castagnoli, Carlotta; Ghione, Giordana; Passini, Valter; Adami, Gianpiero; Larese Filon, Francesca; Crosera, Matteo

2017-06-01

Growing warnings on health effects related to electronic cigarettes have met inconclusive findings at present. This study analyzed the in vitro percutaneous absorption of nicotine resulting by skin contamination with two e-liquids (refill 1 and 2) containing nicotine at 1.8%. Donor chambers of 6 Franz cells for each refill liquid were filled with 1mL of nicotine e-liquid for 24h; at selected intervals, 1.5mL of the receptor solutions were collected for nicotine concentration analysis by mean gas chromatography-mass spectrometry (LOD: 0.01μg/mL). The experiment was repeated removing the nicotine donor solution after 10min from the application and rinsing the skin surface three times with 3.0mL of milliQ water. A total of 12 cells with 24h exposure and 12 cells washed were studied. The mean concentration of nicotine in the receiving phase at the end of the experiment was 54.9±29.5 and 30.2±18.4μg/cm 2 for refill 1 and 2 respectively and significantly lower in washed cells (4.7±2.4 and 3.5±1.3μg/cm 2 ). The skin absorption of nicotine can lead to minor health illness in vapers, while caution must be paid to dermal contamination by e liquids in children. The skin cleaning significantly reduced the transdermal absorption kinetic and intradermal deposition of nicotine. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessing nicotine dependence in adolescent E-cigarette users: The 4-item Patient-Reported Outcomes Measurement Information System (PROMIS) Nicotine Dependence Item Bank for electronic cigarettes.

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Morean, Meghan E; Krishnan-Sarin, Suchitra; S O'Malley, Stephanie

2018-04-26

Adolescent e-cigarette use (i.e., "vaping") likely confers risk for developing nicotine dependence. However, there have been no studies assessing e-cigarette nicotine dependence in youth. We evaluated the psychometric properties of the 4-item Patient-Reported Outcomes Measurement Information System Nicotine Dependence Item Bank for E-cigarettes (PROMIS-E) for assessing youth e-cigarette nicotine dependence and examined risk factors for experiencing stronger dependence symptoms. In 2017, 520 adolescent past-month e-cigarette users completed the PROMIS-E during a school-based survey (50.5% female, 84.8% White, 16.22[1.19] years old). Adolescents also reported on sex, grade, race, age at e-cigarette use onset, vaping frequency, nicotine e-liquid use, and past-month cigarette smoking. Analyses included conducting confirmatory factor analysis and examining the internal consistency of the PROMIS-E. Bivariate correlations and independent-samples t-tests were used to examine unadjusted relationships between e-cigarette nicotine dependence and the proposed risk factors. Regression models were run in which all potential risk factors were entered as simultaneous predictors of PROMIS-E scores. The single-factor structure of the PROMIS-E was confirmed and evidenced good internal consistency. Across models, larger PROMIS-E scores were associated with being in a higher grade, initiating e-cigarette use at an earlier age, vaping more frequently, using nicotine e-liquid (and higher nicotine concentrations), and smoking cigarettes. Adolescent e-cigarette users reported experiencing nicotine dependence, which was assessed using the psychometrically sound PROMIS-E. Experiencing stronger nicotine dependence symptoms was associated with characteristics that previously have been shown to confer risk for frequent vaping and tobacco cigarette dependence. Copyright © 2018 Elsevier B.V. All rights reserved.

Jasmonate mediates salt-induced nicotine biosynthesis in tobacco (Nicotiana tabacum L.

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Xiaodong Chen

2016-04-01

Full Text Available Jasmonate (JA, as an important signal, plays a key role in multiple processes of plant growth, development and stress response. Nicotine and related pyridine alkaloids in tobacco (Nicotiana tabacum L. are essential secondary metabolites. Whether environmental factors control nicotine biosynthesis and the underlying mechanism remains previously unreported. Here, we applied physiological and biochemical approaches to investigate how salt stress affects nicotine biosynthesis in tobacco. We found that salt stress induced the biosynthesis of JA, which subsequently triggered the activation of JA-responsive gene expression and, ultimately, nicotine synthesis. Bioinformatics analysis revealed the existence of many NtMYC2a-recognized G-box motifs in the promoter regions of NtLOX, NtAOS, NtAOC and NtOPR genes. Applying exogenous JA increased nicotine content, while suppressing JA biosynthesis reduced nicotine biosynthesis. Salt treatment could not efficiently induce nicotine biosynthesis in transgenic anti-COI1 tobacco plants. These results demonstrate that JA acts as the essential signal which triggers nicotine biosynthesis in tobacco after salt stress.

Antibacterial activity of nicotine and its copper complex

International Nuclear Information System (INIS)

Zaidi, M.I.; Gul, A.

2005-01-01

Nicotine and its metal complex; Cu(II)-nicotine was isolated from leaves of Nicotiana tabacum using metal ions following the method of Munir et al., 1994. Their antibacterial activity against ten different species of gram positive and gram negative bacteria were studied. For comparative study, pure sample of nicotine and metal salts used for complexation; Copper(II) chloride were also subjected to antibacterial tests with the same species of bacteria under similar conditions. Results indicated that nicotine had no effect on all the bacteria tested except Escherichia coli, Pseudomonas aeroginosa and Enterococcus faecalis, which showed 14 mm zone of inhibition at 200 mu g l00 mul/sup -1/ Copper(II) chloride was found to be effective against seven species and ineffective against three species of selected bacteria. On the other hand, Cu(II)-nicotine complex was ineffective against five species of bacteria at lower level while at higher level, only one species of bacteria showed resistance against this complex. The complex was compared with three standard antibiotics. Thus, this complex can be used against a variety of microorganisms at higher level. (author)

Race, gender, and nicotine metabolism in adolescent smokers.

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Rubinstein, Mark L; Shiffman, Saul; Rait, Michelle A; Benowitz, Neal L

2013-07-01

Differences in the rate of nicotine metabolism between genders and different races have been hypothesized to contribute to disparities in smoking rate, susceptibility to addiction, and ability to quit smoking. The purpose of this study was to determine the effect of race and gender on the rate of nicotine metabolism as indicated by the nicotine metabolite ratio (NMR) in adolescent smokers. One hundred and fifty-nine adolescent smokers aged 13-17 were given 2mg of deuterium-labeled cotinine (cotinine-d4). The NMR was calculated as the ratio of concentrations of deuterium-labeled 3'-hydroxycotinine (ng/ml) to cotinine-d4 (ng/ml) in saliva and is a validated biomarker of the rate of nicotine metabolism. The sample was 67.3% female and racially mixed. On average, Whites had the fastest rates of metabolism compared with both Blacks/African Americans (p smokers, racial variations in rates of nicotine metabolism were similar to those that have been reported in adult smokers. In contrast to findings in adult smokers, the NMR did not vary significantly by gender or self-reported hormone use.

Nicotine Acutely Enhances Reinforcement from Non-Drug Rewards in Humans

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Kenneth A. Perkins

2017-05-01

Full Text Available Preclinical research documents that, aside from the primary and secondary reinforcing effects of nicotine intake itself, nicotine also acutely enhances the reinforcing efficacy of non-drug reinforcers (“rewards”. Study of these effects in humans has largely been overlooked, but very recent findings suggest they may have clinical implications for more fully understanding the persistence of tobacco dependence. This overview first outlines the topic and notes some recent human studies indirectly addressing nicotine effects on related responses (e.g., subjective ratings, explaining why those findings do not directly confirm enhancement of behavioral reinforcement per se due to nicotine. Then, the methodology used in the subsequently presented studies is described, demonstrating how those studies specifically did demonstrate enhancement of reinforced responding for non-drug rewards. The main section focuses on the limited controlled research to date directly assessing nicotine’s acute reinforcement-enhancing effects in humans, particularly as it relates to reinforced behavioral responding for non-drug rewards in non-human animal models. After detailing those few existing human studies, we address potential consequences of these effects for dependence and tobacco cessation efforts and then suggest directions for future research. This research indicates that nicotine per se increases responding in humans that is reinforced by some rewards (auditory stimuli via music, visual stimuli via video, but perhaps not by others (e.g., money. These reinforcement-enhancing effects in smokers are not due to dependence or withdrawal relief and can be restored by a small amount of nicotine (similar to a smoking lapse, including from e-cigarettes, a non-tobacco nicotine product. Future clinical research should examine factors determining which types of rewards are (or are not enhanced by nicotine, consequences of the loss of these nicotine effects after quitting

Nicotine Nasal Spray

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... with a smoking cessation program, which may include support groups, counseling, or specific behavior change techniques. Nicotine nasal ... and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or ...

Nicotine Oral Inhalation

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... with a smoking cessation program, which may include support groups, counseling, or specific behavioral change techniques. Nicotine inhalation ... and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or ...

In vivo positron emission tomography studies on the novel nicotinic receptor agonist [11C]MPA compared with [11C]ABT-418 and (S)(-)[11C]nicotine in Rhesus monkeys

International Nuclear Information System (INIS)

Sihver, Wiebke; Fasth, Karl-Johan; Oegren, Matthias; Lundqvist, Hans; Bergstroem, Mats; Watanabe, Yasuyoshi; Laangstroem, Bengt; Nordberg, Agneta

1999-01-01

The novel 11 C-labeled nicotinic agonist (R,S)-1-[ 11 C]methyl-2(3-pyridyl)azetidine ([ 11 C]MPA) was evaluated as a positron emission tomography (PET) ligand for in vivo characterization of nicotinic acetylcholine receptors in the brain of Rhesus monkeys in comparison with the nicotinic ligands (S)-3-methyl-5-(1-[ 11 C]methyl-2-pyrrolidinyl)isoxazol ([ 11 C]ABT-418) and (S)(-)[ 11 C]nicotine. The nicotinic receptor agonist [ 11 C]MPA demonstrated rapid uptake into the brain to a similar extent as (S)(-) [ 11 C]nicotine and [ 11 C]ABT-418. When unlabeled (S)(-)nicotine (0.02 mg/kg) was administered 5 min before the radioactive tracers, the uptake of [ 11 C]MPA was decreased by 25% in the thalamus, 19% in the temporal cortex, and 11% in the cerebellum, whereas an increase was found for the uptake of (S)(-)[ 11 C]nicotine and [ 11 C]ABT-418. This finding indicates specific binding of [ 11 C]MPA to nicotinic receptors in the brain in a simple classical displacement study. [ 11 C]MPA seems to be a more promising radiotracer than (S)(-)[ 11 C]nicotine or [ 11 C]ABT-418 for PET studies to characterize nicotinic receptors in the brain

Nicotine enhances the reconsolidation of novel object recognition memory in rats.

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Tian, Shaowen; Pan, Si; You, Yong

2015-02-01

There is increasing evidence that nicotine is involved in learning and memory. However, there are only few studies that have evaluated the relationship between nicotine and memory reconsolidation. In this study, we investigated the effects of nicotine on the reconsolidation of novel object recognition memory in rats. Behavior procedure involved four training phases: habituation (Days 1 and 2), sample (Day 3), reactivation (Day 4) and test (Day 6). Rats were injected with saline or nicotine (0.1, 0.2 and 0.4 mg/kg) immediately or 6h after reactivation. The discrimination index was used to assess memory performance and calculated as the difference in time exploring on the novel and familiar objects. Results showed that nicotine administration immediately but not 6 h after reactivation significantly enhanced memory performance of rats. Further results showed that the enhancing effect of nicotine on memory performance was dependent on memory reactivation, and was not attributed to the changes of the nonspecific responses (locomotor activity and anxiety level) 48 h after nicotine administration. The results suggest that post-reactivation nicotine administration enhances the reconsolidation of novel object recognition memory. Our present finding extends previous research on the nicotinic effects on learning and memory. Copyright © 2014 Elsevier Inc. All rights reserved.

Differential effects of α4β2 nicotinic receptor antagonists and partial-agonists on contextual fear extinction in male C57BL/6 mice.

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Kutlu, Munir Gunes; Tumolo, Jessica M; Cann, Courtney; Gould, Thomas J

2018-04-01

Numerous studies have attributed the psychopathology of post-traumatic stress disorder (PTSD) to maladaptive behavioral responses such as an inability to extinguish fear. While exposure therapies are mostly effective in treating these disorders by enhancing extinction learning, relapse of PTSD symptoms is common. Although several studies indicated a role for cholinergic transmission and nicotinic acetylcholine receptors (nAChRs) in anxiety and stress disorder symptomatology, very little is known about the specific contribution of nAChRs to fear extinction OBJECTIVES: In the present study, we examined the effects of inhibition and desensitization of α4β2 nAChRs via a full antagonist (Dihydro-beta-erythroidine (DhβE)) and two α4β2 nAChR partial-agonists (varenicline and sazetidine-A) on contextual fear extinction, locomotor activity, and spontaneous recovery of contextual fear in mice. We trained and tested the subjects in a contextual fear extinction as well as an open field paradigm and spontaneous recovery following injections of DhβE, varenicline, and sazetidine-A. Our results demonstrated that lower doses of DhβE (1 mg/kg) and sazetidine-A (0.01 mg/kg) enhanced contextual fear extinction whereas higher doses of varenicline (0.1 mg/kg) and sazetidine-A (0.1 mg/kg) resulted in impaired contextual fear extinction. However, the higher dose of sazetidine-A (0.1 mg/kg) decreased locomotor activity, which may contribute to increased freezing response observed during fear extinction. Finally, we found that the low dose of DhβE, but not sazetidine-A, also decreased spontaneous recovery of contextual fear following fear extinction. Overall, these results suggest that inhibition and desensitization of α4β2 nAChRs enhance extinction of contextual fear memories. This suggests that modulation of α4β2 nAChRs may be employed as an alternative pharmacological strategy to aid exposure therapies associated with PTSD by augmenting contextual fear extinction

Meningitic Escherichia coli K1 penetration and neutrophil transmigration across the blood-brain barrier are modulated by alpha7 nicotinic receptor.

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Feng Chi

Full Text Available Alpha7 nicotinic acetylcholine receptor (nAChR, an essential regulator of inflammation, is abundantly expressed in hippocampal neurons, which are vulnerable to bacterial meningitis. However, it is unknown whether α7 nAChR contributes to the regulation of these events. In this report, an aggravating role of α7 nAChR in host defense against meningitic E. coli infection was demonstrated by using α7-deficient (α7(-/- mouse brain microvascular endothelial cells (BMEC and animal model systems. As shown in our in vitro and in vivo studies, E. coli K1 invasion and polymorphonuclear neutrophil (PMN transmigration across the blood-brain barrier (BBB were significantly reduced in α7(-/- BMEC and α7(-/- mice. Stimulation by nicotine was abolished in the α7(-/- cells and animals. The same blocking effect was achieved by methyllycaconitine (α7 antagonist. The tight junction molecules occludin and ZO-1 were significantly reduced in the brain cortex of wildtype mice infected with E. coli and treated with nicotine, compared to α7(-/- cells and animals. Decreased neuronal injury in the hippocampal dentate gyrus was observed in α7(-/- mice with meningitis. Proinflammatory cytokines (IL-1β, IL-6, TNFα, MCP-1, MIP-1alpha, and RANTES and adhesion molecules (CD44 and ICAM-1 were significantly reduced in the cerebrospinal fluids of the α7(-/- mice with E. coli meningitis. Furthermore, α7 nAChR is the major calcium channel for nicotine- and E. coli K1-increased intracellular calcium concentrations of mouse BMEC. Taken together, our data suggest that α7 nAChR plays a detrimental role in the host defense against meningitic infection by modulation of pathogen invasion, PMN recruitment, calcium signaling and neuronal inflammation.

Nicotine and Cotinine Exposure from Electronic Cigarettes: A Population Approach

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de Mendizábal, Nieves Vélez; Jones, David R.; Jahn, Andy; Bies, Robert R.; Brown, Joshua W.

2015-01-01

Background and Objectives Electronic cigarettes (e-cigarettes) are a recent technology that has gained rapid acceptance. Still, little is known about them in terms of safety and effectiveness. A basic question is how effectively they deliver nicotine, however the literature is surprisingly unclear on this point. Here, a population pharmacokinetic (PK) model was developed for nicotine and its major metabolite cotinine with the aim to provide a reliable framework for the simulation of nicotine and cotinine concentrations over time, based solely on inhalation airflow recordings and individual covariates (i.e. weight and breath carbon monoxide CO levels). Methods This study included 10 adults self-identified as heavy smokers (at least one pack per day). Plasma nicotine and cotinine concentrations were measured at regular 10-minute intervals for 90 minutes while human subjects inhaled nicotine vapor from a modified e-cigarette. Airflow measurements were recorded every 200 milliseconds throughout the session. A population PK model for nicotine and cotinine was developed based on previously published PK parameters and the airflow recordings. All the analyses were performed with the nonlinear mixed-effect modelling software NONMEM 7.2. Results The results show that e-cigarettes deliver nicotine effectively, although the pharmacokinetic profiles are lower than those achieved with regular cigarettes. Our PK model effectively predicts plasma nicotine and cotinine concentrations from the inhalation volume, and initial breath CO. Conclusion E-cigarettes are effective at delivering nicotine. This new PK model of e-cigarette usage might be used for pharmacodynamic analysis where the PK profiles are not available. PMID:25503588

Nicotinic receptors modulate the onset of reactive oxygen species production and mitochondrial dysfunction evoked by glutamate uptake block in the rat hypoglossal nucleus.

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Tortora, Maria; Corsini, Silvia; Nistri, Andrea

2017-02-03

In several neurodegenerative diseases, glutamate-mediated excitotoxicity is considered to be a major process to initiate cell degeneration. Indeed, subsequent to excessive glutamate receptor stimulation, reactive oxygen species (ROS) generation and mitochondrial dysfunction are regarded as two major gateways leading to neuron death. These processes are mimicked in an in vitro model of rat brainstem slice when excitotoxicity is induced by DL-threo-β-benzyloxyaspartate (TBOA), a specific glutamate-uptake blocker that increases extracellular glutamate. Our recent study has demonstrated that brainstem hypoglossal motoneurons, which are very vulnerable to this damage, were neuroprotected from excitotoxicity with nicotine application through the activation of nicotinic acetylcholine receptors (nAChRs) and subsequent inhibition of ROS and mitochondrial dysfunction. The present study examined if endogenous cholinergic activity exerted any protective effect in this pathophysiological model and how ROS production (estimated with rhodamine fluorescence) and mitochondrial dysfunction (measured as methyltetrazolium reduction) were time-related during the early phase of excitotoxicity (0-4h). nAChR antagonists did not modify TBOA-evoked ROS production (that was nearly doubled over control) or mitochondrial impairment (25% decline), suggesting that intrinsic nAChR activity was insufficient to contrast excitotoxicity and needed further stimulation with nicotine to become effective. ROS production always preceded mitochondrial dysfunction by about 2h. Nicotine prevented both ROS production and mitochondrial metabolic depression with a delayed action that alluded to a complex chain of events targeting these two lesional processes. The present data indicate a relatively wide time frame during which strong nAChR activation can arrest a runaway neurotoxic process leading to cell death. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Nicotine and tobacco

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... ease your withdrawal symptoms. Health experts warn that e-cigarettes are not a replacement therapy for cigarette smoking. ... not known exactly how much nicotine is in e-cigarette cartridges, because information on labels is often wrong.

Revisiting nicotine's role in the ageing brain and cognitive impairment

DEFF Research Database (Denmark)

Majdi, Alireza; Kamari, Farzin; Vafaee, Manouchehr Seyedi

2017-01-01

stress, excitotoxicity, amyloid-β toxicity, apoptosis, neuroinflammation, and perturb neurotrophic factors in the brain. Nicotine is an exogenous agonist of nicotinic acetylcholine receptors (nAChRs) and acts as a pharmacological chaperone in the regulation of nAChR expression, potentially intervening...... in age-related changes in diverse molecular pathways leading to pathology. Although nicotine has therapeutic potential, paradoxical effects have been reported, possibly due to its inverted U-shape dose-response effects or pharmacokinetic factors. Additionally, nicotine administration should result...... in optimum therapeutic effects without imparting abuse potential or toxicity. Overall, this review aims to compile the previous and most recent data on nicotine and its effects on cognition-related mechanisms and age-related cognitive impairment....

Melatonin protects uterus and oviduct exposed to nicotine in mice

Directory of Open Access Journals (Sweden)

Seyed Saadat Seyedeh Nazanin

2014-03-01

Full Text Available Smoking is associated with higher infertility risk. The aim of this study was to evaluate protective effects of melatonin on the uterus and oviduct in mice exposed to nicotine. Adult female mice (n=32 were divided into four groups. Group A: control animals received normal saline, Group B: injected with nicotine 40 μg/kg, Group C: injected with melatonin 10 μg, Group D: injected with nicotine 40 μg/kg and melatonin 10 μg. All animals were treated over 15 days intraperitoneally. On the 16th day, animals in the estrus phase were dissected and their uterus and oviducts were removed. Immunohistochemistry was recruited for studying apoptosis and for detection of estrogen receptor (ER alpha in luminal epithelium of the uterus and oviduct. Enzyme-linked immunosorbent assay was used for serum estradiol level determination. Nicotine in group B decreased estradiol level and ERalpha numbers both in the uterus and oviduct (p<0.05. Co-administration of melatonin-nicotine in Group D ameliorated the histology of the uterus and oviduct, increased ERalpha numbers and reduced apoptosis in the uterus and oviduct compared with the nicotine Group B (p<0.05. This study indicates that nicotine impairs the histology of the uterus and oviduct and co-administration of melatonin-nicotine ameliorates these findings, partly through alteration in ERalpha numbers and reduction of apoptosis

Uncoupling nicotine mediated motoneuron axonal pathfinding errors and muscle degeneration in zebrafish

International Nuclear Information System (INIS)

Welsh, Lillian; Tanguay, Robert L.; Svoboda, Kurt R.

2009-01-01

Zebrafish embryos offer a unique opportunity to investigate the mechanisms by which nicotine exposure impacts early vertebrate development. Embryos exposed to nicotine become functionally paralyzed by 42 hpf suggesting that the neuromuscular system is compromised in exposed embryos. We previously demonstrated that secondary spinal motoneurons in nicotine-exposed embryos were delayed in development and that their axons made pathfinding errors (Svoboda, K.R., Vijayaraghaven, S., Tanguay, R.L., 2002. Nicotinic receptors mediate changes in spinal motoneuron development and axonal pathfinding in embryonic zebrafish exposed to nicotine. J. Neurosci. 22, 10731-10741). In that study, we did not consider the potential role that altered skeletal muscle development caused by nicotine exposure could play in contributing to the errors in spinal motoneuron axon pathfinding. In this study, we show that an alteration in skeletal muscle development occurs in tandem with alterations in spinal motoneuron development upon exposure to nicotine. The alteration in the muscle involves the binding of nicotine to the muscle-specific AChRs. The nicotine-induced alteration in muscle development does not occur in the zebrafish mutant (sofa potato, [sop]), which lacks muscle-specific AChRs. Even though muscle development is unaffected by nicotine exposure in sop mutants, motoneuron axonal pathfinding errors still occur in these mutants, indicating a direct effect of nicotine exposure on nervous system development.

E-Cigarette Users' Attitudes on the Banning of Sales of Nicotine E-Liquid, Its Implication on E-Cigarette Use Behaviours and Alternative Sources of Nicotine E-Liquid.

Science.gov (United States)

Wong, Li Ping; Alias, Haridah; Agha Mohammadi, Nasrin; Ghadimi, Azadeh; Hoe, Victor Chee Wai

2017-12-01

The banning of sales of nicotine e-liquid in e-cigarette shops has been implemented in several states in Malaysia. The distribution of nicotine e-liquid can only be allowed by licensed pharmacies or registered medical practitioners. This study aimed to evaluate e-cigarette users' responses to the control policy in a cross-sectional survey of 851 e-cigarette users by utilizing a self-report questionnaire that assessed (1) attitudes on regulation policy of e-cigarette banning; (2) e-cigarette use behaviors; and (3) sources of e-liquid after the regulation policy has been implemented. Participants from the state of Selangor where the banning policy was implemented were surveyed. The majority (95.8%) opposed the banning and believed e-cigarettes should be sold to anyone aged 18 years or above as with tobacco cigarettes, only a minority believed that nicotine e-liquid should only be available for sale over the counter in pharmacy stores (14.6%) and in clinics with a doctor's prescription (11.8%). The majority (44.2%) reported that they would continue their e-cigarette use as before the banning policy, while 20% plan to completely stop e-cigarette usage without replacing it with any alternatives. The vast majority (87.9%) was still able to obtained nicotine e-liquid from e-cigarette shops in spite of the ban and the second most common source was from online purchase (63.1%). The sales of nicotine e-liquid from black-market were evidenced as many reported obtaining zero nicotine e-liquid from the black market (54.4%). Self- or home-made (30.8%) nicotine e-liquid was also reported. Majority of respondents that self-made e-liquid were from the average monthly income group (below MYR3000). Obtaining nicotine from the pharmacy was least preferred (21.4%). Provision of professional advice to nicotine e-liquid users along with the ban may lessen the likelihood of users switching to tobacco cigarettes or other nicotine alternatives. Banning of sales of nicotine e-liquid in e

Menthol's potential effects on nicotine dependence: a tobacco industry perspective.

Science.gov (United States)

Yerger, Valerie B

2011-05-01

To examine what the tobacco industry knows about the potential effects menthol may have on nicotine dependence. A snowball strategy was used to systematically search the Legacy Tobacco Documents Library (http://legacy.library.ucsf.edu/) between 22 February and 29 April, 2010. Of the approximately 11 million documents available in the Legacy Tobacco Documents Library, the iterative searches returned tens of thousands of results. We qualitatively analysed a final collection of 309 documents relevant the effects of menthol on nicotine dependence. The tobacco industry knows that menthol overrides the harsh taste of tobacco and alleviates nicotine's irritating effects, synergistically interacts with nicotine, stimulates the trigeminal nerve to elicit a 'liking' response for a tobacco product, and makes low tar, low nicotine tobacco products more acceptable to smokers than non-mentholated low delivery products. Menthol is not only used in cigarettes as a flavour additive; tobacco companies know that menthol also has sensory effects and interacts with nicotine to produce tobacco products that are easier to smoke, thereby making it easier to expose smokers, especially those who are new and uninitiated, to the addictive power of nicotine.

E-Cigarette and Liquid Nicotine Exposures Among Young Children.

Science.gov (United States)

Govindarajan, Preethi; Spiller, Henry A; Casavant, Marcel J; Chounthirath, Thitphalak; Smith, Gary A

2018-04-23

To investigate exposures to liquid nicotine (including electronic cigarette devices and liquids) among children <6 years old in the United States and evaluate the impact of legislation requiring child-resistant packaging for liquid nicotine containers. Liquid nicotine exposure data from the National Poison Data System for January 2012 through April 2017 were analyzed. There were 8269 liquid nicotine exposures among children <6 years old reported to US poison control centers during the study period. Most (92.5%) children were exposed through ingestion and 83.9% were children <3 years old. Among children exposed to liquid nicotine, 35.1% were treated and released from a health care facility, and 1.4% were admitted. The annual exposure rate per 100 000 children increased by 1398.2% from 0.7 in 2012 to 10.4 in 2015, and subsequently decreased by 19.8% from 2015 to 8.3 in 2016. Among states without a preexisting law requiring child-resistant packaging for liquid nicotine containers, there was a significant decrease in the mean number of exposures during the 9 months before compared with the 9 months after the federal child-resistant packaging law went into effect, averaging 4.4 (95% confidence interval: -7.1 to -1.7) fewer exposures per state after implementation of the law. Pediatric exposures to liquid nicotine have decreased since January 2015, which may, in part, be attributable to legislation requiring child-resistant packaging and greater public awareness of risks associated with electronic cigarette products. Liquid nicotine continues to pose a serious risk for young children. Additional regulation of these products is warranted. Copyright © 2018 by the American Academy of Pediatrics.

Oxytocin attenuates aversive response to nicotine and anxiety-like behavior in adolescent rats.

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Lee, Hyunchan; Jang, Minji; Noh, Jihyun

2017-02-01

Initial tobacco use is initiated with rewarding and aversive properties of nicotine and aversive response to nicotine plays a critical role in nicotine dependency. Decrease of nicotine aversion increases the nicotine use that causes behavioral and neuronal changes of animals. Oxytocin influences drug abuse and reciprocally affect vulnerability to drug use. To assess the effect of oxytocin on initial nicotine aversion and anxiety, we examined voluntary oral nicotine intake and anxiety-like behavior following oxytocin treatment in adolescent rats. Sprague-Dawley male rats (4 weeks old) were used. For oxytocin administration, rats were injected subcutaneously with saline or oxytocin (0.01, 0.1 and 1mg/kg) according to the assigned groups. Voluntary oral nicotine consumption test was performed by two bottle free-choice paradigm. To examine anxiety-like behavior in rats, we performed a light/dark box test. Oxytocin not only significantly increased the nicotine intake but also alleviated nicotine aversion after acclimation to nicotine solution in a concentration dependent manner. Meanwhile, oxytocin significantly reduced anxiety-like behavior. We suggest that oxytocin itself mitigates aversive response toward initial nicotine intake and anxiety-like behavior. These results widen the psychophysiological perspective on oxytocin for better understanding of nicotine addiction related behaviors influenced by diverse social factors. Copyright © 2016 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

Functional interaction between Lypd6 and nicotinic acetylcholine receptors

DEFF Research Database (Denmark)

Arvaniti, Maria; Jensen, Majbrit M; Soni, Neeraj

2016-01-01

Nicotinic acetylcholine receptors (nAChRs) affect multiple physiological functions in the brain and their functions are modulated by regulatory proteins of the Lynx family. Here, we report for the first time a direct interaction of the Lynx protein LY6/PLAUR domain-containing 6 (Lypd6) with n...... brain. Additionally, soluble recombinant Lypd6 protein attenuates nicotine-induced hippocampal inward currents in rat brain slices and decreases nicotine-induced extracellular signal-regulated kinase phosphorylation in PC12 cells, suggesting that binding of Lypd6 is sufficient to inhibit n......AChR-mediated intracellular signaling. We further show that perinatal nicotine exposure in rats (4 mg/kg/day through minipumps to dams from embryonic day 7 to post-natal day 21) significantly increases Lypd6 protein levels in the hippocampus in adulthood, which did not occur after exposure to nicotine in adulthood only. Our...

Progressive and Lasting Amplilfication of Accumbal Nicotine-Seeking Neural Signals

NARCIS (Netherlands)

Guillem, K.; Peoples, L.L.

2010-01-01

Although neuroadaptations in the nucleus accumbens (NAc) are thought to contribute to nicotine addiction, little is known about the chronic effects of nicotine on NAc neuronal activity. In the present experiment, rats were exposed to a 23 d period of nicotine selfadministration (SA), a 30 d

Influence of Methionine Supplementation on Nicotine Teratogenicity ...

African Journals Online (AJOL)

Human and animal studies have shown that maternal tobacco smoking during pregnancy adversely affects pre and postnatal growth and increases the risk of fetal mortality. The aim of the present study was to determine the toxicity of nicotine and protective effect of methionine on the toxic effects of nicotine. Pregnant ...

Nicotinic acid-induced flushing is mediated by activation of epidermal langerhans cells

NARCIS (Netherlands)

Benyó, Zoltán; Gille, Andreas; Bennett, Clare L.; Clausen, Björn E.; Offermanns, Stefan

2006-01-01

The antidyslipidemic drug nicotinic acid (niacin) has been used for decades. One of the major problems of the therapeutical use of nicotinic acid is a strong cutaneous vasodilation called flushing, which develops in almost every patient taking nicotinic acid. Nicotinic acid-induced flushing has been

Nicotine Delivery and Vaping Behavior During ad Libitum E-cigarette Access

Science.gov (United States)

St.Helen, Gideon; Ross, Kathryn C.; Dempsey, Delia A.; Havel, Christopher M.; Jacob, Peyton; Benowitz, Neal L.

2017-01-01

Objective To characterize vaping behavior and nicotine intake during ad libitum e-cigarette access. Methods Thirteen adult e-cigarette users had 90 minutes of videotaped ad libitum access to their usual e-cigarette. Plasma nicotine was measured before and every 15 minutes after the first puff; subjective effects were measured before and after the session. Results Average puff duration and interpuff interval were 3.5±1.4 seconds (±SD) and 118±141 seconds, respectively. 12% of puffs were unclustered puffs while 43%, 28%, and 17% were clustered in groups of 2–5, 6–10, and >10 puffs, respectively. On average, 4.0±3.3 mg of nicotine was inhaled; the maximum plasma nicotine concentration (Cmax) was 12.8±8.5 ng/mL. Among the 8 tank users, number of puffs was positively correlated with amount of nicotine inhaled, Cmax, and area under the plasma nicotine concentration-time curve (AUC0→90min) while interpuff interval was negatively correlated with Cmax and AUC0→90. Conclusion Vaping patterns differ from cigarette smoking. Plasma nicotine levels were consistent with intermittent dosing of nicotine from e-cigarettes compared to the more bolus dosing from cigarettes. Differences in delivery patterns and peak levels of nicotine achieved could influence the addictiveness of e-cigarettes compared to conventional cigarettes. PMID:28393086

Nicotine Delivery and Vaping Behavior During ad Libitum E-cigarette Access.

Science.gov (United States)

St Helen, Gideon; Ross, Kathryn C; Dempsey, Delia A; Havel, Christopher M; Jacob, Peyton; Benowitz, Neal L

2016-10-01

To characterize vaping behavior and nicotine intake during ad libitum e-cigarette access. Thirteen adult e-cigarette users had 90 minutes of videotaped ad libitum access to their usual e-cigarette. Plasma nicotine was measured before and every 15 minutes after the first puff; subjective effects were measured before and after the session. Average puff duration and interpuff interval were 3.5±1.4 seconds (±SD) and 118±141 seconds, respectively. 12% of puffs were unclustered puffs while 43%, 28%, and 17% were clustered in groups of 2-5, 6-10, and >10 puffs, respectively. On average, 4.0±3.3 mg of nicotine was inhaled; the maximum plasma nicotine concentration (C max ) was 12.8±8.5 ng/mL. Among the 8 tank users, number of puffs was positively correlated with amount of nicotine inhaled, C max , and area under the plasma nicotine concentration-time curve (AUC 0 → 90min ) while interpuff interval was negatively correlated with C max and AUC 0 → 90 . Vaping patterns differ from cigarette smoking. Plasma nicotine levels were consistent with intermittent dosing of nicotine from e-cigarettes compared to the more bolus dosing from cigarettes. Differences in delivery patterns and peak levels of nicotine achieved could influence the addictiveness of e-cigarettes compared to conventional cigarettes.

Oxidative mechanisms contributing to the developmental neurotoxicity of nicotine and chlorpyrifos

International Nuclear Information System (INIS)

Qiao, Dan; Seidler, Frederic J.; Slotkin, Theodore A.

2005-01-01

Nicotine and chlorpyrifos are developmental neurotoxicants that, despite their differences in structure and mechanism of action, share many aspects for damage to the developing brain. Both are thought to generate oxidative radicals; in the current study, we evaluated their ability to produce lipid peroxidation in two in vitro models of neural cell development (PC12 and SH-SY5Y cells) and for nicotine, with treatment of adolescent rats in vivo. Nicotine and chlorpyrifos, in concentrations relevant to human exposures, elicited an increase in thiobarbituric-acid-reactive species (TBARS) in undifferentiated cells, an effect that was prevented by addition of the antioxidant, Vitamin E. Initiating differentiation with nerve growth factor, which enhances nicotinic acetylcholine receptor expression, increased the TBARS response to nicotine but not chlorpyrifos, suggesting that the two agents act by different originating mechanisms to converge on the endpoint of oxidative damage. Furthermore, nicotine protected the cells from oxidative damage evoked by chlorpyrifos and similarly blocked the antimitotic effect of chlorpyrifos. Treatment of adolescent rats with nicotine elicited increases in TBARS in multiple brain regions when given in doses that simulate plasma nicotine concentrations found in smokers or at one-tenth the dose. Our results indicate that nicotine and chlorpyrifos elicit oxidative damage to developing neural cells both in vitro and in vivo, a mechanism that explains some of the neurodevelopmental endpoints that are common to the two agents. The balance between neuroprotectant and neurotoxicant actions of nicotine may be particularly important in situations where exposure to tobacco smoke is combined with other prooxidant insults

Expression and function of nicotinic acetylcholine receptors in stem cells

Directory of Open Access Journals (Sweden)

Herman S. Cheung

2016-07-01

Full Text Available Nicotinic acetylcholine receptors are prototypical ligand gated ion channels typically found in muscular and neuronal tissues. Functional nicotinic acetylcholine receptors, however, have also recently been identified on other cell types, including stem cells. Activation of these receptors by the binding of agonists like choline, acetylcholine, or nicotine has been implicated in many cellular changes. In regards to stem cell function, nicotinic acetylcholine receptor activation leads to changes in stem cell proliferation, migration and differentiation potential. In this review we summarize the expression and function of known nicotinic acetylcholine receptors in different classes of stem cells including: pluripotent stem cells, mesenchymal stem cells, periodontal ligament derived stem cells, and neural progenitor cells and discuss the potential downstream effects of receptor activation on stem cell function.

Electronic cigarettes and nicotine clinical pharmacology

OpenAIRE

Schroeder, Megan J; Hoffman, Allison C

2014-01-01

Objective To review the available literature evaluating electronic cigarette (e-cigarette) nicotine clinical pharmacology in order to understand the potential impact of e-cigarettes on individual users, nicotine dependence and public health. Methods Literature searches were conducted between 1 October 2012 and 30 September 2013 using key terms in five electronic databases. Studies were included in the review if they were in English and publicly available; non-clinical studies, conference abst...

Spanish adaptation of the NDSS (Nicotine Dependence Syndrome Scale) and assessment of nicotine-dependent individuals at primary care health centers in Spain.

Science.gov (United States)

Becoña, Elisardo; López, Ana; Fernández del Río, Elena; Míguez, Ma Carmen; Castro, Josefina

2010-11-01

The availability of adequate instruments for the assessment of nicotine dependence is an important factor that is relevant in the area of tobacco addiction. In this study, we present a Spanish validation of the Nicotine Dependence Syndrome Scale (NDSS) (Shiffman, Waters, & Hickcox, 2004). The sample was composed ofpatients, all daily smokers, who visited their General Practitioner (GP) at five Primary Health Care Centers in different cities of Spain (N = 637). The results indicated adequate reliability for the general factor that assesses nicotine dependence (NDSS-Total) (Cronbach's alpha = .76). Factor analysis confirms the five factors of the original validation: Drive, Continuity, Stereotypy, Priority, and Tolerance. It must be noted that reliability is adequate for the first, and moderate or low for the rest. The NDSS-T and its scales correlate significantly with the Fagerström Test for Nicotine Dependence (FTND), with the nicotine dependence criteria of the Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV) as assessed through the Structured Clinical Interview for DSM-IV (SCID), with carbon monoxide levels in expired air (CO), and with the number of cigarettes smoked. The ROC curve indicates that the NDSS-T has a score of .79 which is under the curve (.69 for the FTND), thus the prediction of nicotine dependence is adequate. We conclude that this instrument is useful (in terms of its total score NDSS-T) for assessing nicotine dependence for Spanish smokers (in Spain), as has been found in other countries, language groups, and cultures.

Physical and psychological nicotine dependence in Greeks: an epidemiological study.

Science.gov (United States)

Margaritis, Vasileios; Mamai-Homata, Eleni

2010-01-01

Smoking is the most widespread addictive behaviour in the world, as it causes physical and psychological dependence on nicotine. The objective of the present study was to discern the prevalence and the relative risks of nicotine dependence of adult people in Athens, Greece, as this country holds first place in cigarette consumption in the European Union. A random sample of 202 current smokers (82 men and 120 women) was drawn from residents aged v 18 years in Athens, the capital of Greece. A questionnaire on the physical (Fagerstrom Test of Nicotine Dependence) and psychological (American Psychiatric Association's diagnostic criteria of nicotine abuse) nicotine dependence was used. According to the results of the present study, 12.4% of the sample reported null physical nicotine dependence, and 31.7% had low, 25.7% had moderate and 30.2% had high nicotine dependence. Multiple logistic regression analysis revealed that younger people (aged 18 to 24 and 25 to 34, odds ratio [OR] = 0.047, P physical dependence. Women tended to be systematically less dependent than men (25% and 37.8% high dependence, respectively). Furthermore, 75.7% of the sample had psychological nicotine dependence. Binary logistic regression analysis and chi-square test revealed that younger people (18- to 24-year-olds, OR = 0.081, P dependence. In addition, women showed a higher percentage of withdrawal symptoms compared with men (80% and 68%, respectively). The results of the present study provided compelling evidence that physical and, in particular, psychological nicotine dependence of adult people in Athens, Greece, was significant, and this calls for a course of action that should be taken by public health policy-makers to reduce smoke consumption.

Neuroscience of nicotine for addiction medicine: novel targets for smoking cessation medications.

Science.gov (United States)

D'Souza, Manoranjan S

2016-01-01

Morbidity and mortality associated with tobacco smoking constitutes a significant burden on healthcare budgets all over the world. Therefore, promoting smoking cessation is an important goal of health professionals and policy makers throughout the world. Nicotine is a major psychoactive component in tobacco that is largely responsible for the widespread addiction to tobacco. A majority of the currently available FDA-approved smoking cessation medications act via neuronal nicotinic receptors. These medications are effective in approximately half of all the smokers, who want to quit and relapse among abstinent smokers continues to be high. In addition to relapse among abstinent smokers, unpleasant effects associated with nicotine withdrawal are a major motivational factor in continued tobacco smoking. Over the last two decades, animal studies have helped in identifying several neural substrates that are involved in nicotine-dependent behaviors including those associated with nicotine withdrawal and relapse to tobacco smoking. In this review, first the role of specific brain regions/circuits that are involved in nicotine dependence will be discussed. Next, the review will describe the role of specific nicotinic receptor subunits in nicotine dependence. Finally, the review will discuss the role of classical neurotransmitters (dopamine, serotonin, noradrenaline, glutamate, and γ-aminobutyric acid) as well as endogenous opioid and endocannabinoid signaling in nicotine dependence. The nicotinic and nonnicotinic neural substrates involved in nicotine-dependent behaviors can serve as possible targets for future smoking cessation medications. © 2016 Elsevier B.V. All rights reserved.