Orally administered nicotine induces urothelial hyperplasia in rats and mice

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Dodmane, Puttappa R.; Arnold, Lora L.; Pennington, Karen L.; Cohen, Samuel M.

2014-01-01

Highlights: • Rats and mice orally administered with nicotine tartrate for total of 4 weeks. • No treatment-related death or whole body toxicity observed in any of the groups. • Urothelium showed simple hyperplasia in treated rats and mice. • No significant change in BrdU labeling index or SEM classification of urothelium. - Abstract: Tobacco smoking is a major risk factor for multiple human cancers including urinary bladder carcinoma. Tobacco smoke is a complex mixture containing chemicals that are known carcinogens in humans and/or animals. Aromatic amines a major class of DNA-reactive carcinogens in cigarette smoke, are not present at sufficiently high levels to fully explain the incidence of bladder cancer in cigarette smokers. Other agents in tobacco smoke could be excreted in urine and enhance the carcinogenic process by increasing urothelial cell proliferation. Nicotine is one such major component, as it has been shown to induce cell proliferation in multiple cell types in vitro. However, in vivo evidence specifically for the urothelium is lacking. We previously showed that cigarette smoke induces increased urothelial cell proliferation in mice. In the present study, urothelial proliferative and cytotoxic effects were examined after nicotine treatment in mice and rats. Nicotine hydrogen tartrate was administered in drinking water to rats (52 ppm nicotine) and mice (514 ppm nicotine) for 4 weeks and urothelial changes were evaluated. Histopathologically, 7/10 rats and 4/10 mice showed simple hyperplasia following nicotine treatment compared to none in the controls. Rats had an increased mean BrdU labeling index compared to controls, although it was not statistically significantly elevated in either species. Scanning electron microscopic visualization of the urothelium did not reveal significant cytotoxicity. These findings suggest that oral nicotine administration induced urothelial hyperplasia (increased cell proliferation), possibly due to a

Benfotiamine attenuates nicotine and uric acid-induced vascular endothelial dysfunction in the rat.

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Balakumar, Pitchai; Sharma, Ramica; Singh, Manjeet

2008-01-01

The study has been designed to investigate the effect of benfotiamine, a thiamine derivative, in nicotine and uric acid-induced vascular endothelial dysfunction (VED) in rats. Nicotine (2 mg kg(-1)day(-1), i.p., 4 weeks) and uric acid (150 mg kg(-1)day(-1), i.p., 3 weeks) were administered to produce VED in rats. The development of VED was assessed by employing isolated aortic ring preparation and estimating serum and aortic concentration of nitrite/nitrate. Further, the integrity of vascular endothelium was assessed using the scanning electron microscopy (SEM) of thoracic aorta. Moreover, the oxidative stress was assessed by estimating serum thiobarbituric acid reactive substances (TBARS) and aortic superoxide anion generation. The administration of nicotine and uric acid produced VED by impairing the integrity of vascular endothelium and subsequently decreasing serum and aortic concentration of nitrite/nitrate and attenuating acetylcholine-induced endothelium dependent relaxation. Further, nicotine and uric acid produced oxidative stress, which was assessed in terms of increase in serum TBARS and aortic superoxide generation. However, treatment with benfotiamine (70 mg kg(-1)day(-1), p.o.) or atorvastatin (30 mg kg(-1)day(-1) p.o., a standard agent) markedly prevented nicotine and uric acid-induced VED and oxidative stress by improving the integrity of vascular endothelium, increasing the concentration of serum and aortic nitrite/nitrate, enhancing the acetylcholine-induced endothelium dependent relaxation and decreasing serum TBARS and aortic superoxide anion generation. Thus, it may be concluded that benfotiamine reduces the oxidative stress and consequently improves the integrity of vascular endothelium and enhances the generation of nitric oxide to prevent nicotine and uric acid-induced experimental VED.

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.

Repeated nicotine exposure enhances reward-related learning in the rat.

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Olausson, Peter; Jentsch, J David; Taylor, Jane R

2003-07-01

Repeated exposure to addictive drugs causes neuroadaptive changes in cortico-limbic-striatal circuits that may underlie alterations in incentive-motivational processes and reward-related learning. Such drug-induced alterations may be relevant to drug addiction because enhanced incentive motivation and increased control over behavior by drug-associated stimuli may contribute to aspects of compulsive drug-seeking and drug-taking behaviors. This study investigated the consequences of repeated nicotine treatment on the acquisition and performance of Pavlovian discriminative approach behavior, a measure of reward-related learning, in male rats. Water-restricted rats were trained to associate a compound conditioned stimulus (tone+light) with the availability of water (the unconditioned stimulus) in 15 consecutive daily sessions. In separate experiments, rats were repeatedly treated with nicotine (0.35 mg/kg, s.c.) either (1) prior to the onset of training, (2) after each daily training session was completed (ie postsession injections), or (3) received nicotine both before the onset of training as well as after each daily training session. In this study, all nicotine treatment schedules increased Pavlovian discriminative approach behavior and, thus, prior repeated exposure to nicotine, repeated postsession nicotine injections, or both, facilitated reward-related learning.

The facilitatory effects of intermittent theta burst stimulation on corticospinal excitability are enhanced by nicotine.

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Swayne, Orlando B C; Teo, James T H; Greenwood, Richard J; Rothwell, John C

2009-08-01

Intermittent theta burst stimulation (iTBS) is increasingly widely used as a means of facilitating corticospinal excitability in the human primary motor cortex. This form of facilitatory plasticity within the stimulated cortex may occur by induction of long term potentiation (LTP). In animal models, agonists of nicotinic acetylcholine receptors have been shown to modulate or induce LTP; we thus sought to test whether nicotine may modulate the effects of iTBS on corticospinal excitability in humans. A double-blind placebo-controlled cross-over design study was conducted with 10 healthy subjects. iTBS was delivered 60min after subjects took either 4mg nicotine or placebo lozenges, and motor-evoked potentials (MEPs) were then recorded for 40min after the end of stimulation. In the placebo arm, iTBS produced an increase in the amplitudes of MEPs which lasted for 5min. In the nicotine arm, iTBS produced a more pronounced facilitation of MEPs that was still present at 40min. In a control experiment, nicotine alone had no effect on MEP amplitudes when given in the absence of iTBS. These data indicate that the effects of iTBS can be enhanced and prolonged by nicotine. These results are consistent with animal models demonstrating nicotinic modulation of facilitatory plasticity, and will be of interest to investigators seeking to enhance artificially induced changes in cortical excitability.

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.

REINFORCEMENT ENHANCING EFFECTS OF ACUTE NICOTINE VIA ELECTRONIC CIGARETTES

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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.

Nicotine during pregnancy: changes induced in neurotransmission, which could heighten proclivity to addict and induce maladaptive control of attention.

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Kohlmeier, K A

2015-06-01

Prenatal exposure to nicotine, occurring either via maternal smoking or via use of transdermal nicotine patches to facilitate cigarette abstinence by pregnant women, is associated with ∼ 13% of pregnancies worldwide. Nicotine exposure during gestation has been correlated with several negative physiological and psychosocial outcomes, including heightened risk for aberrant behaviors involving alterations in processing of attention as well as an enhanced liability for development of drug dependency. Nicotine is a terotogen, altering neuronal development of various neurotransmitter systems, and it is likely these alterations participate in postnatal deficits in attention control and facilitate development of drug addiction. This review discusses the alterations in neuronal development within the brain's major neurotransmitter systems, with special emphasis placed on alterations within the laterodorsal tegmental nucleus, in light of the role this cholinergic nucleus plays in attention and addiction. Changes induced within this nucleus by gestational exposure to nicotine, in combination with changes induced in other brain regions, are likely to contribute to the transgenerational burden imposed by nicotine. Although neuroplastic changes induced by nicotine are not likely to act in isolation, and are expected to interact with epigenetic changes induced by preconception exposure to drugs of abuse, unraveling these changes within the developing brain will facilitate eventual development of targeted treatments for the unique vulnerability for arousal disorders and development of addiction within the population of individuals who have been prenatally exposed to nicotine.

Behavioral desensitization to nicotine is enhanced differentially by ethanol in long-sleep and short-sleep mice.

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de Fiebre, C M; Collins, A C

1989-01-01

In order to assess the anticonvulsant potency of ethanol, male and female long-sleep (LS) and short-sleep (SS) mice were pretreated with ethanol 7.5 min prior to challenge with an ED80 dose of nicotine (LS: 4.25 mg/kg; SS: 6.25 mg/kg). LS mice were more sensitive to the anticonvulsant effects of ethanol than were SS mice. In order to assess the effect of ethanol on the nicotine-induced behavioral desensitization to nicotine observed previously in these mice, animals were pretreated with saline, nonanticonvulsant doses of ethanol (0.25 g/kg, 0.75 g/kg or 1.5 g/kg), a subseizure-producing dose of nicotine (2.0 mg/kg) or a combination of these two drugs 15 or 30 min prior to nicotine challenge. Ethanol enhanced the nicotine-induced behavioral desensitization in both mouse lines; however, this effect was seen at lower ethanol doses and was more pronounced in LS mice. Ethanol pretreatment did not affect brain nicotine concentrations; therefore, the ethanol effect probably involves changes in brain sensitivity to nicotine.

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

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

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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.

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.

Camellia sinensis Prevents Perinatal Nicotine-Induced Neurobehavioral Alterations, Tissue Injury, and Oxidative Stress in Male and Female Mice Newborns

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Ajarem, Jamaan S.; Al-Basher, Gadh; Allam, Ahmed A.

2017-01-01

Nicotine exposure during pregnancy induces oxidative stress and leads to behavioral alterations in early childhood and young adulthood. The current study aimed to investigate the possible protective effects of green tea (Camellia sinensis) against perinatal nicotine-induced behavioral alterations and oxidative stress in mice newborns. Pregnant mice received 50 mg/kg C. sinensis on gestational day 1 (PD1) to postnatal day 15 (D15) and were subcutaneously injected with 0.25 mg/kg nicotine from PD12 to D15. Nicotine-exposed newborns showed significant delay in eye opening and hair appearance and declined body weight at birth and at D21. Nicotine induced neuromotor alterations in both male and female newborns evidenced by the suppressed righting, rotating, and cliff avoidance reflexes. Nicotine-exposed newborns exhibited declined memory, learning, and equilibrium capabilities, as well as marked anxiety behavior. C. sinensis significantly improved the physical development, neuromotor maturation, and behavioral performance in nicotine-exposed male and female newborns. In addition, C. sinensis prevented nicotine-induced tissue injury and lipid peroxidation and enhanced antioxidant defenses in the cerebellum and medulla oblongata of male and female newborns. In conclusion, this study shows that C. sinensis confers protective effects against perinatal nicotine-induced neurobehavioral alterations, tissue injury, and oxidative stress in mice newborns. PMID:28588748

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.

Nicotine enhances skin necrosis and expression of inflammatory mediators in a rat pressure ulcer model.

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Tsutakawa, S; Kobayashi, D; Kusama, M; Moriya, T; Nakahata, N

2009-11-01

Many bedridden patients develop pressure ulcers, not only in hospital but also at home. Clinical studies have indicated cigarette smoking to be a risk factor for pressure ulcers. However, the contribution of nicotine to pressure ulcer formation has not been identified. We aimed to clarify the effect of nicotine on pressure ulcer formation, and its mechanism. Ischaemia-reperfusion (I/R) was performed in rat dorsal skin to induce pressure ulcers. The extent of the resulting necrotic area was determined. To clarify the mechanism of the effect of nicotine, mRNA levels of cyclooxygenase-2 (COX-2), interleukin (IL)-1beta, IL-6 and inducible nitric oxide synthase (iNOS) and protein expression of COX-2 and iNOS in the necrotic area were investigated by real-time reverse transcription-polymerase chain reaction and Western blotting, respectively. Furthermore, the effects of the COX-2 inhibitor NS-398 and the iNOS inhibitor aminoguanidine on necrosis were examined. Skin necrosis in the I/R-treated area was significantly increased by intraperitoneal administration of nicotine (0.175 mg kg(-1) daily). Repeated nicotine administration had little effect on systolic and diastolic blood pressure. I/R treatment increased mRNA levels of COX-2, IL-1beta, IL-6 and iNOS, which were further augmented by nicotine in a dose-dependent manner. Correspondingly, nicotine (0.35 mg kg(-1) daily) markedly enhanced the protein expression of COX-2 and iNOS. Moreover, NS-398 and aminoguanidine showed a tendency to abrogate the increase of I/R-induced skin necrosis caused by nicotine. These results suggest that the increased risk of pressure ulcers due to cigarette smoking is mediated, in part, by nicotine. They also indicated that the effect of nicotine is not mediated by a change in blood pressure, but is elicited via an increase of inflammatory mediators in the I/R-treated skin.

Nicotine ameliorates schizophrenia-like cognitive deficits induced by maternal LPS exposure: a study in rats

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Uta Waterhouse

2016-10-01

Full Text Available Maternal exposure to infectious agents is a predisposing factor for schizophrenia with associated cognitive deficits in offspring. A high incidence of smoking in these individuals in adulthood might be, at least in part, due to the cognitive-enhancing effects of nicotine. Here, we have used prenatal exposure to maternal lipopolysaccharide (LPS, bacterial endotoxin at different time points as a model for cognitive deficits in schizophrenia to determine whether nicotine reverses any associated impairments. Pregnant rats were treated subcutaneously with LPS (0.5 mg/kg at one of three neurodevelopmental time periods [gestation days (GD 10-11, 15-16, 18-19]. Cognitive assessment in male offspring commenced in early adulthood [postnatal day (PND 60] and included: prepulse inhibition (PPI, latent inhibition (LI and delayed non-matching to sample (DNMTS. Following PND 100, daily nicotine injections (0.6 mg/kg, subcutaneously were administered, and animals were re-tested in the same tasks (PND 110. Only maternal LPS exposure early during fetal neurodevelopment (GD 10-11 resulted in deficits in all tests compared to animals that had been prenatally exposed to saline at the same gestational time point. Repeated nicotine treatment led to global (PPI and selective (LI improvements in performance. Early but not later prenatal LPS exposure induced consistent deficits in cognitive tests with relevance for schizophrenia. Nicotine reversed the LPS-induced deficits in selective attention (LI and induced a global enhancement of sensorimotor gating (PPI.

Enhancement of cancer stem-like and epithelial−mesenchymal transdifferentiation property in oral epithelial cells with long-term nicotine exposure: Reversal by targeting SNAIL

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Yu, Cheng-Chia; Chang, Yu-Chao

2013-01-01

Cigarette smoking is one of the major risk factors in the development and further progression of tumorigenesis, including oral squamous cell carcinoma (OSCC). Recent studies suggest that interplay cancer stem-like cells (CSCs) and epithelial−mesenchymal transdifferentiation (EMT) properties are responsible for the tumor maintenance and metastasis in OSCC. The aim of the present study was to investigate the effects of long-term exposure with nicotine, a major component in cigarette, on CSCs and EMT characteristics. The possible reversal regulators were further explored in nicotine-induced CSCs and EMT properties in human oral epithelial (OE) cells. Long-term exposure with nicotine was demonstrated to up-regulate ALDH1 population in normal gingival and primary OSCC OE cells dose-dependently. Moreover, long-term nicotine treatment was found to enhance the self-renewal sphere-forming ability and stemness gene signatures expression and EMT regulators in OE cells. The migration/cell invasiveness/anchorage independent growth and in vivo tumor growth by nude mice xenotransplantation assay was enhanced in long-term nicotine-stimulated OE cells. Knockdown of Snail in long-term nicotine-treated OE cells was found to reduce their CSCs properties. Therapeutic delivery of Si-Snail significantly blocked the xenograft tumorigenesis of long-term nicotine-treated OSCC cells and largely significantly improved the recipient survival. The present study demonstrated that the enrichment of CSCs coupled EMT property in oral epithelial cells induced by nicotine is critical for the development of OSCC tumorigenesis. Targeting Snail might offer a new strategy for the treatment of OSCC patients with smoking habit. -- Highlights: ► Sustained nicotine treatment induced CSCs properties of oral epithelial cells. ► Long-term nicotine treatment enhance EMT properties of oral epithelial cells. ► Long-term nicotine exposure increased tumorigenicity of oral epithelial cells. ► Si

Enhancement of cancer stem-like and epithelial−mesenchymal transdifferentiation property in oral epithelial cells with long-term nicotine exposure: Reversal by targeting SNAIL

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Yu, Cheng-Chia [Institute of Oral Science, Chung Shan Medical University, Taichung, Taiwan (China); School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Chang, Yu-Chao, E-mail: cyc@csmu.edu.tw [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China)

2013-02-01

Cigarette smoking is one of the major risk factors in the development and further progression of tumorigenesis, including oral squamous cell carcinoma (OSCC). Recent studies suggest that interplay cancer stem-like cells (CSCs) and epithelial−mesenchymal transdifferentiation (EMT) properties are responsible for the tumor maintenance and metastasis in OSCC. The aim of the present study was to investigate the effects of long-term exposure with nicotine, a major component in cigarette, on CSCs and EMT characteristics. The possible reversal regulators were further explored in nicotine-induced CSCs and EMT properties in human oral epithelial (OE) cells. Long-term exposure with nicotine was demonstrated to up-regulate ALDH1 population in normal gingival and primary OSCC OE cells dose-dependently. Moreover, long-term nicotine treatment was found to enhance the self-renewal sphere-forming ability and stemness gene signatures expression and EMT regulators in OE cells. The migration/cell invasiveness/anchorage independent growth and in vivo tumor growth by nude mice xenotransplantation assay was enhanced in long-term nicotine-stimulated OE cells. Knockdown of Snail in long-term nicotine-treated OE cells was found to reduce their CSCs properties. Therapeutic delivery of Si-Snail significantly blocked the xenograft tumorigenesis of long-term nicotine-treated OSCC cells and largely significantly improved the recipient survival. The present study demonstrated that the enrichment of CSCs coupled EMT property in oral epithelial cells induced by nicotine is critical for the development of OSCC tumorigenesis. Targeting Snail might offer a new strategy for the treatment of OSCC patients with smoking habit. -- Highlights: ► Sustained nicotine treatment induced CSCs properties of oral epithelial cells. ► Long-term nicotine treatment enhance EMT properties of oral epithelial cells. ► Long-term nicotine exposure increased tumorigenicity of oral epithelial cells. ► Si

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.

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.

Nicotine induces fibrogenic changes in human liver via nicotinic acetylcholine receptors expressed on hepatic stellate cells

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Soeda, Junpei; Morgan, Maelle; McKee, Chad; Mouralidarane, Angelina; Lin, ChingI [University College London, Centre for Hepatology, Royal Free Hospital, London NW3 2PF (United Kingdom); Roskams, Tania [Department of Morphology and Molecular Pathology, University of Leuven (Belgium); Oben, Jude A., E-mail: j.oben@ucl.ac.uk [University College London, Centre for Hepatology, Royal Free Hospital, London NW3 2PF (United Kingdom); Department of Gastroenterology and Hepatology, Guy' s and St Thomas' Hospital, London SE1 7EH (United Kingdom)

2012-01-06

Highlights: Black-Right-Pointing-Pointer Cigarette smoke may induce liver fibrosis via nicotine receptors. Black-Right-Pointing-Pointer Nicotine induces proliferation of hepatic stellate cells (HSCs). Black-Right-Pointing-Pointer Nicotine activates hepatic fibrogenic pathways. Black-Right-Pointing-Pointer Nicotine receptor antagonists attenuate HSC proliferation. Black-Right-Pointing-Pointer Nicotinic receptor antagonists may have utility as novel anti-fibrotic agents. -- Abstract: Background and aims: Cigarette smoke (CS) may cause liver fibrosis but possible involved mechanisms are unclear. Among the many chemicals in CS is nicotine - which affects cells through nicotinic acetylcholine receptors (nAChR). We studied the effects of nicotine, and involved pathways, on human primary hepatic stellate cells (hHSCs), the principal fibrogenic cells in the liver. We then determined possible disease relevance by assaying nAChR in liver samples from human non-alcoholic steatohepatitis (NASH). Methods: hHSC were isolated from healthy human livers and nAChR expression analyzed - RT-PCR and Western blotting. Nicotine induction of hHSC proliferation, upregulation of collagen1-{alpha}2 and the pro-fibrogenic cytokine transforming growth factor beta 1 (TGF-{beta}1) was determined along with involved intracellular signaling pathways. nAChR mRNA expression was finally analyzed in whole liver biopsies obtained from patients diagnosed with non-alcoholic steatohepatitis (NASH). Results: hHSCs express muscle type ({alpha}1, {beta}1, delta and epsilon) and neuronal type ({alpha}3, {alpha}6, {alpha}7, {beta}2 and {beta}4) nAChR subunits at the mRNA level. Among these subunits, {alpha}3, {alpha}7, {beta}1 and {epsilon} were predominantly expressed as confirmed by Western blotting. Nicotine induced hHSC proliferation was attenuated by mecamylamine (p < 0.05). Additionally, collagen1-{alpha}2 and TGF-{beta}1 mRNA expression were significantly upregulated by nicotine and inhibited by

Nicotine induces fibrogenic changes in human liver via nicotinic acetylcholine receptors expressed on hepatic stellate cells

International Nuclear Information System (INIS)

Soeda, Junpei; Morgan, Maelle; McKee, Chad; Mouralidarane, Angelina; Lin, ChingI; Roskams, Tania; Oben, Jude A.

2012-01-01

Highlights: ► Cigarette smoke may induce liver fibrosis via nicotine receptors. ► Nicotine induces proliferation of hepatic stellate cells (HSCs). ► Nicotine activates hepatic fibrogenic pathways. ► Nicotine receptor antagonists attenuate HSC proliferation. ► Nicotinic receptor antagonists may have utility as novel anti-fibrotic agents. -- Abstract: Background and aims: Cigarette smoke (CS) may cause liver fibrosis but possible involved mechanisms are unclear. Among the many chemicals in CS is nicotine – which affects cells through nicotinic acetylcholine receptors (nAChR). We studied the effects of nicotine, and involved pathways, on human primary hepatic stellate cells (hHSCs), the principal fibrogenic cells in the liver. We then determined possible disease relevance by assaying nAChR in liver samples from human non-alcoholic steatohepatitis (NASH). Methods: hHSC were isolated from healthy human livers and nAChR expression analyzed – RT-PCR and Western blotting. Nicotine induction of hHSC proliferation, upregulation of collagen1-α2 and the pro-fibrogenic cytokine transforming growth factor beta 1 (TGF-β1) was determined along with involved intracellular signaling pathways. nAChR mRNA expression was finally analyzed in whole liver biopsies obtained from patients diagnosed with non-alcoholic steatohepatitis (NASH). Results: hHSCs express muscle type (α1, β1, delta and epsilon) and neuronal type (α3, α6, α7, β2 and β4) nAChR subunits at the mRNA level. Among these subunits, α3, α7, β1 and ε were predominantly expressed as confirmed by Western blotting. Nicotine induced hHSC proliferation was attenuated by mecamylamine (p < 0.05). Additionally, collagen1-α2 and TGF-β1 mRNA expression were significantly upregulated by nicotine and inhibited by mecamylamine. α1 and α3-nAChR mRNA expression was significantly upregulated in NASH fibrosis compared to normal livers. Conclusion: Nicotine at levels in smokers’ blood is pro-fibrogenic, through

The role of adrenergic receptors in nicotine-induced hyperglycemia ...

African Journals Online (AJOL)

The role of adrenergic receptors in nicotine-induced hyperglycaemia has not been well studied in amphibians. Thus, this study investigates the effects of alpha and beta adrenergic receptor blockers in nicotine-induced hyperglycaemia in the common African toad Bufo regularis. Toads fasted for 24 h were anaesthetized with ...

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

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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

[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.

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

Immunomodulatory Role of Ocimum gratissimum and Ascorbic Acid against Nicotine-Induced Murine Peritoneal Macrophages In Vitro

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Santanu Kar Mahapatra

2011-01-01

Full Text Available The aim of this present study was to evaluate the immune functions and immune responses in nicotine-induced (10 mM macrophages and concurrently establish the immunomodulatory role of aqueous extract of Ocimum gratissimum (Ae-Og and ascorbic acid. In this study, nitrite generations and some phenotype functions by macrophages were studied. Beside that, release of Th1 cytokines (TNF-α, IL-12 and Th2 cytokines (IL-10, TGF-β was measured by ELISA, and the expression of these cytokines at mRNA level was analyzed by real-time PCR. Ae-Og, at a dose of 10 μg/mL, significantly reduced the nicotine-induced NO generation and iNOSII expression. Similar kinds of response were observed with supplementation of ascorbic acid (0.01 mM. The administration of Ae-Og and ascorbic acid increased the decreased adherence, chemotaxis, phagocytosis, and intracellular killing of bacteria in nicotine-treated macrophages. Ae-Og and ascorbic acid were found to protect the murine peritoneal macrophages through downregulation of Th1 cytokines in nicotine-treated macrophages with concurrent activation of Th2 responses. These findings strongly enhanced our understanding of the molecular mechanism leading to nicotine-induced suppression of immune functions and provide additional rationale for application of anti-inflammatory therapeutic approaches by O. gratissimum and ascorbic acid for different inflammatory disease prevention and treatment during nicotine toxicity.

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.

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.

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

Testing environment shape differentially modulates baseline and nicotine-induced changes in behavior: Sex differences, hypoactivity, and behavioral sensitization.

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Illenberger, J M; Mactutus, C F; Booze, R M; Harrod, S B

2018-02-01

In those who use nicotine, the likelihood of dependence, negative health consequences, and failed treatment outcomes differ as a function of gender. Women may be more sensitive to learning processes driven by repeated nicotine exposure that influence conditioned approach and craving. Sex differences in nicotine's influence over overt behaviors (i.e. hypoactivity or behavioral sensitization) can be examined using passive drug administration models in male and female rats. Following repeated intravenous (IV) nicotine injections, behavioral sensitization is enhanced in female rats compared to males. Nonetheless, characteristics of the testing environment also mediate rodent behavior following drug administration. The current experiment used a within-subjects design to determine if nicotine-induced changes in horizontal activity, center entries, and rearing displayed by male and female rats is detected when behavior was recorded in round vs. square chambers. Behaviors were recorded from each group (males-round: n=19; males-square: n=18; females-square: n=19; and females-round: n=19) immediately following IV injection of saline, acute nicotine, and repeated nicotine (0.05mg/kg/injection). Prior to nicotine treatment, sex differences were apparent only in round chambers. Following nicotine administration, the order of magnitude for the chamber that provided enhanced detection of hypoactivity or sensitization was contingent upon both the dependent measure under examination and the animal's biological sex. As such, round and square testing chambers provide different, and sometimes contradictory, accounts of how male and female rats respond to nicotine treatment. It is possible that a central mechanism such as stress or cue sensitivity is impacted by both drug exposure and environment to drive the sex differences observed in the current experiment. Until these complex relations are better understood, experiments considering sex differences in drug responses should balance

alpha7 Nicotinic acetylcholine receptor knockout selectively enhances ethanol-, but not beta-amyloid-induced neurotoxicity.

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de Fiebre, Nancyellen C; de Fiebre, Christopher M

2005-01-03

The alpha7 subtype of nicotinic acetylcholine receptor (nAChR) has been implicated as a potential site of action for two neurotoxins, ethanol and the Alzheimer's disease related peptide, beta-amyloid. Here, we utilized primary neuronal cultures of cerebral cortex from alpha7 nAChR null mutant mice to examine the role of this receptor in modulating the neurotoxic properties of subchronic, "binge" ethanol and beta-amyloid. Knockout of the alpha7 nAChR gene selectively enhanced ethanol-induced neurotoxicity in a gene dosage-related fashion. Susceptibility of cultures to beta-amyloid induced toxicity, however, was unaffected by alpha7 nAChR gene null mutation. Further, beta-amyloid did not inhibit the binding of the highly alpha7-selective radioligand, [(125)I]alpha-bungarotoxin. On the other hand, in studies in Xenopus oocytes ethanol efficaciously inhibited alpha7 nAChR function. These data suggest that alpha7 nAChRs modulate the neurotoxic effects of binge ethanol, but not the neurotoxicity produced by beta-amyloid. It is hypothesized that inhibition of alpha7 nAChRs by ethanol provides partial protection against the neurotoxic properties of subchronic ethanol.

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

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.

Long-term nicotine exposure dampens LPS-induced nerve-mediated airway hyperreactivity in murine airways.

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Xu, Yuan; Cardell, Lars-Olaf

2017-09-01

Nicotine is a major component of cigarette smoke. It causes addiction and is used clinically to aid smoke cessation. The aim of the present study is to investigate the effect of nicotine on lipopolysaccharide (LPS)-induced airway hyperreactivity (AHR) and to explore the potential involvement of neuronal mechanisms behind nicotine's effects in murine models in vivo and in vitro. BALB/c mice were exposed to nicotine in vivo via subcutaneous Alzet osmotic minipumps containing nicotine tartate salt solution (24 mg·kg -1 ·day -1 ) for 28 days. LPS (0.1 mg/ml, 20 µl) was administered intranasally for 3 consecutive days during the end of this period. Lung functions were measured with flexiVent. For the in vitro experiments, mice tracheae were organcultured with either nicotine (10 μM) or vehicle (DMSO, 0.1%) for 4 days. Contractile responses of the tracheal segments were measured in myographs following electric field stimulation (EFS; increasing frequencies of 0.2 to 12.8 Hz) before and after incubation with 10 µg/ml LPS for 1 h. Results showed that LPS induced AHR to methacholine in vivo and increased contractile responses to EFS in vitro. Interestingly, long-term nicotine exposure markedly dampened this LPS-induced AHR both in vitro and in vivo. Tetrodotoxin (TTX) inhibited LPS-induced AHR but did not further inhibit nicotine-suppressed AHR in vivo. In conclusion, long-term nicotine exposure dampened LPS-induced AHR. The effect of nicotine was mimicked by TTX, suggesting the involvement of neuronal mechanisms. This information might be used for evaluating the long-term effects of nicotine and further exploring of how tobacco products interact with bacterial airway infections. Copyright © 2017 the American Physiological 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.

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

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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.

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.

Nicotine shifts the temporal activation of hippocampal protein kinase A and extracellular signal-regulated kinase 1/2 to enhance long-term, but not short-term, hippocampus-dependent memory.

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Gould, Thomas J; Wilkinson, Derek S; Yildirim, Emre; Poole, Rachel L F; Leach, Prescott T; Simmons, Steven J

2014-03-01

Acute nicotine enhances hippocampus-dependent learning through nicotine binding to β2-containing nicotinic acetylcholine receptors (nAChRs), but it is unclear if nicotine is targeting processes involved in short-term memory (STM) leading to a strong long-term memory (LTM) or directly targeting LTM. In addition, the molecular mechanisms involved in the effects of nicotine on learning are unknown. Previous research indicates that protein kinase A (PKA), extracellular signal-regulated kinase 1/2 (ERK1/2), and protein synthesis are crucial for LTM. Therefore, the present study examined the effects of nicotine on STM and LTM and the involvement of PKA, ERK1/2, and protein synthesis in the nicotine-induced enhancement of hippocampus-dependent contextual learning in C57BL/6J mice. The protein synthesis inhibitor anisomycin impaired contextual conditioning assessed at 4 h but not 2 h post-training, delineating time points for STM (2 h) and LTM (4 h and beyond). Nicotine enhanced contextual conditioning at 4, 8, and 24 h but not 2 h post-training, indicating nicotine specifically enhances LTM but not STM. Furthermore, nicotine did not rescue deficits in contextual conditioning produced by anisomycin, suggesting that the nicotine enhancement of contextual conditioning occurs through a protein synthesis-dependent mechanism. In addition, inhibition of dorsal hippocampal PKA activity blocked the effect of acute nicotine on learning, and nicotine shifted the timing of learning-related PKA and ERK1/2 activity in the dorsal and ventral hippocampus. Thus, the present results suggest that nicotine specifically enhances LTM through altering the timing of PKA and ERK1/2 signaling in the hippocampus, and suggests that the timing of PKA and ERK1/2 activity could contribute to the strength of memories. Copyright © 2014 Elsevier Inc. All rights reserved.

Nicotine Enhances Interspecies Relationship between Streptococcus mutans and Candida albicans.

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Liu, Shiyu; Qiu, Wei; Zhang, Keke; Zhou, Xuedong; Ren, Biao; He, Jinzhi; Xu, Xin; Cheng, Lei; Li, Mingyun

2017-01-01

Streptococcus mutans and Candida albicans are common microorganisms in the human oral cavity. The synergistic relationship between these two species has been deeply explored in many studies. In the present study, the effect of alkaloid nicotine on the interspecies between S. mutans and C. albicans is explored. We developed a dual-species biofilm model and studied biofilm biomass, biofilm structure, synthesis of extracellular polysaccharides (EPS), and expression of glucosyltransferases (Gtfs). Biofilm formation and bacterial and fungal cell numbers in dual-species biofilms increased in the presence of nicotine. More C. albicans cells were present in the dual-species biofilms in the nicotine-treated groups as determined by scanning electron microscopy. The synthesis of EPS was increased by 1 mg/ml of nicotine as detected by confocal laser scanning microscopy. The result of qRT-PCR showed gtfs expression was upregulated when 1 mg/ml of nicotine was used. We speculate that nicotine promoted the growth of S. mutans , and more S. mutans cells attracted more C. albicans cells due to the interaction between two species. Since S. mutans and C. albicans are putative pathogens for dental caries, the enhancement of the synergistic relationship by nicotine may contribute to caries development in smokers.

Clomipramine counteracts lipid raft disturbance due to short-term muscle disuse.

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Bryndina, Irina G; Shalagina, Maria N; Sekunov, Alexey V; Zefirov, Andrei L; Petrov, Alexey M

2018-01-18

Disuse-induced skeletal muscle dysfunction is a serious consequence of long-term spaceflight, numerous diseases and conditions for which treatment possibilities are still strictly limited. We have previously shown that acute hindlimb suspension (HS)-mediated disuse disrupts membrane lipid rafts in the unloaded muscle. Here, we investigated whether pretreatment of rats with the inhibitor of acid sphingomyelinase, clomipramine (1.25mg/g/day, intramuscularly, for 5days before HS), is able to hinder the loss in lipid raft integrity in response to 12h of HS. Clomipramine pretreatment significantly counteracted the decrease in labeling of the plasma membranes with lipid raft markers (fluorescent cholera toxin B subunit and bodipy-GM1-ganglioside) specifically in the junctional regions of the suspended soleus muscle. This was associated with: a) enhancing raft disrupting potential of exogenous sphingomyelinase in the junctional membranes; b) prevention of both ceramide accumulation and cholesterol loss; c) prevention of decline in nicotinic acetylcholine receptor labeling in the unloaded muscle. Our data suggest that sphingomyelinase-mediated raft disturbance serves as one of the earlier events in HS effects. Copyright © 2017 Elsevier B.V. All rights reserved.

Neurosteroid 3α-androstanediol efficiently counteracts paclitaxel-induced peripheral neuropathy and painful symptoms.

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Laurence Meyer

Full Text Available Painful peripheral neuropathy belongs to major side-effects limiting cancer chemotherapy. Paclitaxel, widely used to treat several cancers, induces neurological symptoms including burning pain, allodynia, hyperalgesia and numbness. Therefore, identification of drugs that may effectively counteract paclitaxel-induced neuropathic symptoms is crucial. Here, we combined histopathological, neurochemical, behavioral and electrophysiological methods to investigate the natural neurosteroid 3α-androstanediol (3α-DIOL ability to counteract paclitaxel-evoked peripheral nerve tissue damages and neurological symptoms. Prophylactic or corrective 3α-DIOL treatment (4 mg/kg/2 days prevented or suppressed PAC-evoked heat-thermal hyperalgesia, cold-allodynia and mechanical allodynia/hyperalgesia, by reversing to normal, decreased thermal and mechanical pain thresholds of PAC-treated rats. Electrophysiological studies demonstrated that 3α-DIOL restored control values of nerve conduction velocity and action potential peak amplitude significantly altered by PAC-treatment. 3α-DIOL also repaired PAC-induced nerve damages by restoring normal neurofilament-200 level in peripheral axons and control amount of 2',3'-cyclic-nucleotide-3'-phosphodiesterase in myelin sheaths. Decreased density of intraepidermal nerve fibers evoked by PAC-therapy was also counteracted by 3α-DIOL treatment. More importantly, 3α-DIOL beneficial effects were not sedation-dependent but resulted from its neuroprotective ability, nerve tissue repairing capacity and long-term analgesic action. Altogether, our results showing that 3α-DIOL efficiently counteracted PAC-evoked painful symptoms, also offer interesting possibilities to develop neurosteroid-based strategies against chemotherapy-induced peripheral neuropathy. This article shows that the prophylactic or corrective treatment with 3α-androstanediol prevents or suppresses PAC-evoked painful symptoms and peripheral nerve dysfunctions in

Nicotine-induced damages in testicular tissue of rats; evidences for bcl-2, p53 and caspase-3 expression

Directory of Open Access Journals (Sweden)

Maryam Mosadegh

2017-02-01

Full Text Available Objective(s: Present study was performed in order to uncover new aspects for nicotine-induced damages on spermatogenesis cell lineage. Materials and Methods: For this purpose, 36 mature male Wistar rats were divided into three groups as; control-sham (0.2 ml, saline normal, IP, low dose (0.2 mg/kg BW-1, IP nicotine-received and high dose (0.4 mg/kg BW-1, IP nicotine-received groups. Following 7 weeks, the expression of bcl-2, p53 and caspase-3 at mRNA and protein levels were investigated by using reverse-transcriptase PCR (RT-PCR and immunohistochemical (IHC analyses, respectively. Moreover, the serum level of FSH, LH and testosterone were evaluated. Finally, the mRNA damage was analyzed by using special fluorescent staining. Results: Nicotine, at both dose levels, decreased tubular differentiation, spermiogenesis and repopulation indices and enhanced cellular depletion. Animals in nicotine-received groups exhibited a significant (P

Nicotine Significantly Improves Chronic Stress-Induced Impairments of Cognition and Synaptic Plasticity in Mice.

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Shang, Xueliang; Shang, Yingchun; Fu, Jingxuan; Zhang, Tao

2017-08-01

The aim of this study was to examine if nicotine was able to improve cognition deficits in a mouse model of chronic mild stress. Twenty-four male C57BL/6 mice were divided into three groups: control, stress, and stress with nicotine treatment. The animal model was established by combining chronic unpredictable mild stress (CUMS) and isolated feeding. Mice were exposed to CUMS continued for 28 days, while nicotine (0.2 mg/kg) was also administrated for 28 days. Weight and sucrose consumption were measured during model establishing period. The anxiety and behavioral despair were analyzed using the forced swim test (FST) and open-field test (OFT). Spatial cognition was evaluated using Morris water maze (MWM) test. Following behavioral assessment, both long-term potentiation (LTP) and depotentiation (DEP) were recorded in the hippocampal dentate gyrus (DG) region. Both synaptic and Notch1 proteins were measured by Western. Nicotine increased stressed mouse's sucrose consumption. The MWM test showed that spatial learning and reversal learning in stressed animals were remarkably affected relative to controls, whereas nicotine partially rescued cognitive functions. Additionally, nicotine considerably alleviated the level of anxiety and the degree of behavioral despair in stressed mice. It effectively mitigated the depression-induced impairment of hippocampal synaptic plasticity, in which both the LTP and DEP were significantly inhibited in stressed mice. Moreover, nicotine enhanced the expression of synaptic and Notch1 proteins in stressed animals. The results suggest that nicotine ameliorates the depression-like symptoms and improves the hippocampal synaptic plasticity closely associated with activating transmembrane ion channel receptors and Notch signaling components. Graphical Abstract ᅟ.

Effect of ginseng saponina on nicotine-induced dopamine release in the rat nucleus accumbens and striatum

International Nuclear Information System (INIS)

Kim, Sang Eun; Shim, In Sop; Chung, June Key; Lee, Myung Chul

2002-01-01

We investigated the effect of ginseng total saponin (GTS) on nicotine-induced dopamine (DA) release in the striatum and nucleus accumbens of freely moving rats using in vivo microdialysis technique. Systemic pretreatment with GTS decreased striatal DA release induced by local infusion of nicotine into the striatum. However, GTS had no effect on the resting levels of extracellular DA in the striatum. GTS also blocked nicotine-induced DA release in the nucleus accumbens. The results of the present study suggest that GTS acts on the DA terminals to prevent DA release induced by nicotine. This may reflect the blocking effect of GTS on behavioral hyperactivity induced by psychostimulants

Effect of ginseng saponina on nicotine-induced dopamine release in the rat nucleus accumbens and striatum

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Kim, Sang Eun [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Shim, In Sop [Kyunghee University, Seoul (Korea, Republic of); Chung, June Key; Lee, Myung Chul [Seoul National University College of Medicine, Seoul (Korea, Republic of)

2002-10-01

We investigated the effect of ginseng total saponin (GTS) on nicotine-induced dopamine (DA) release in the striatum and nucleus accumbens of freely moving rats using in vivo microdialysis technique. Systemic pretreatment with GTS decreased striatal DA release induced by local infusion of nicotine into the striatum. However, GTS had no effect on the resting levels of extracellular DA in the striatum. GTS also blocked nicotine-induced DA release in the nucleus accumbens. The results of the present study suggest that GTS acts on the DA terminals to prevent DA release induced by nicotine. This may reflect the blocking effect of GTS on behavioral hyperactivity induced by psychostimulants.

Nicotine impairs cyclooxygenase-2-dependent kinin-receptor-mediated murine airway relaxations

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Xu, Yuan; Cardell, Lars-Olaf

2014-01-01

Introduction: Cigarette smoke induces local inflammation and airway hyperreactivity. In asthmatics, it worsens the symptoms and increases the risk for exacerbation. The present study investigates the effects of nicotine on airway relaxations in isolated murine tracheal segments. Methods: Segments were cultured for 24 h in the presence of vehicle, nicotine (10 μM) and/or dexamethasone (1 μM). Airway relaxations were assessed in myographs after pre-contraction with carbachol (1 μM). Kinin receptors, cyclooxygenase (COX) and inflammatory mediator expressions were assessed by real-time PCR and confocal-microscopy-based immunohistochemistry. Results: The organ culture procedure markedly increased bradykinin- (selective B 2 receptor agonist) and des-Arg 9 -bradykinin- (selective B 1 receptor agonist) induced relaxations, and slightly increased relaxation induced by isoprenaline, but not that induced by PGE 2 . The kinin receptor mediated relaxations were epithelium-, COX-2- and EP2-receptor-dependent and accompanied by drastically enhanced mRNA levels of kinin receptors, as well as inflammatory mediators MCP-1 and iNOS. Increase in COX-2 and mPGES-1 was verified both at mRNA and protein levels. Nicotine selectively suppressed the organ-culture-enhanced relaxations induced by des-Arg 9 -bradykinin and bradykinin, at the same time reducing mPGES-1 mRNA and protein expressions. α7-nicotinic acetylcholine receptor inhibitors α-bungarotoxin and MG624 both blocked the nicotine effects on kinin B 2 receptors, but not those on B 1 . Dexamethasone completely abolished kinin-induced relaxations. Conclusion: It is tempting to conclude that a local inflammatory process per se could have a bronchoprotective component by increasing COX-2 mediated airway relaxations and that nicotine could impede this safety mechanism. Dexamethasone further reduced airway inflammation together with relaxations. This might contribute to the steroid resistance seen in some patients with asthma

Nicotine impairs cyclooxygenase-2-dependent kinin-receptor-mediated murine airway relaxations

Energy Technology Data Exchange (ETDEWEB)

Xu, Yuan, E-mail: yuan.xu@ki.se; Cardell, Lars-Olaf

2014-02-15

Introduction: Cigarette smoke induces local inflammation and airway hyperreactivity. In asthmatics, it worsens the symptoms and increases the risk for exacerbation. The present study investigates the effects of nicotine on airway relaxations in isolated murine tracheal segments. Methods: Segments were cultured for 24 h in the presence of vehicle, nicotine (10 μM) and/or dexamethasone (1 μM). Airway relaxations were assessed in myographs after pre-contraction with carbachol (1 μM). Kinin receptors, cyclooxygenase (COX) and inflammatory mediator expressions were assessed by real-time PCR and confocal-microscopy-based immunohistochemistry. Results: The organ culture procedure markedly increased bradykinin- (selective B{sub 2} receptor agonist) and des-Arg{sup 9}-bradykinin- (selective B{sub 1} receptor agonist) induced relaxations, and slightly increased relaxation induced by isoprenaline, but not that induced by PGE{sub 2}. The kinin receptor mediated relaxations were epithelium-, COX-2- and EP2-receptor-dependent and accompanied by drastically enhanced mRNA levels of kinin receptors, as well as inflammatory mediators MCP-1 and iNOS. Increase in COX-2 and mPGES-1 was verified both at mRNA and protein levels. Nicotine selectively suppressed the organ-culture-enhanced relaxations induced by des-Arg{sup 9}-bradykinin and bradykinin, at the same time reducing mPGES-1 mRNA and protein expressions. α7-nicotinic acetylcholine receptor inhibitors α-bungarotoxin and MG624 both blocked the nicotine effects on kinin B{sub 2} receptors, but not those on B{sub 1}. Dexamethasone completely abolished kinin-induced relaxations. Conclusion: It is tempting to conclude that a local inflammatory process per se could have a bronchoprotective component by increasing COX-2 mediated airway relaxations and that nicotine could impede this safety mechanism. Dexamethasone further reduced airway inflammation together with relaxations. This might contribute to the steroid resistance seen in

Nicotine enhances modulation of food-cue reactivity by leptin and ghrelin in the ventromedial prefrontal cortex.

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Kroemer, Nils B; Wuttig, Franziska; Bidlingmaier, Martin; Zimmermann, Ulrich S; Smolka, Michael N

2015-07-01

Endocrine signals such as ghrelin and leptin are known to modulate the mesocorticolimbic dopaminergic system and, consequently, show associations with food and drug reward. In animal models, nicotine was demonstrated to reduce body weight by attenuating food intake and effects of leptin and ghrelin are partly modulated by nicotinic acetylcholine receptors which hint at potential interactions. However, the neuropharmacological modulation of endocrine signals by nicotine in healthy humans remains to be tested experimentally. We used functional magnetic resonance imaging to investigate food-cue reactivity after an overnight fast and following a caloric load (oral glucose tolerance test, OGTT) in 26 healthy normal-weight never-smokers. Moreover, we administered either nicotine (2 mg) or placebo gums using a randomized cross-over design and assessed blood plasma levels of ghrelin and leptin. During fasting, nicotine administration decreased correlations with ghrelin levels in the mesocorticolimbic system whereas correlations with leptin were increased. After the OGTT, nicotine increased the modulatory effects of ghrelin and leptin on food-cue reactivity, particularly in the ventromedial prefrontal cortex (vmPFC) and the amygdala. Critically, this led to an indirect modulation of the behavioral 'appetizer effect' (i.e. cue-induced increases in subjective appetite) by homeostatic feedback signals via food-cue reactivity in vmPFC. We conclude that nicotine enhances the effect of ghrelin and leptin in the valuation and relevance network which might, in turn, reduce appetite. This highlights that amplifying the impact of homeostatic signals such as ghrelin and leptin in normal-weight individuals might hint at a mechanism contributing to nicotine's anorexic potential. © 2014 Society for the Study of Addiction.

Time of erythema onset after application of methyl nicotinate ointments as response parameter: influence of penetration kinetics and enhancing agents.

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Remane, Y; Leopold, C S

2006-01-01

The time of erythema onset may be used as a response parameter for quantification of the cutaneous erythema response induced by methyl nicotinate. The vehicles light mineral oil (LMO; test) and medium chain triglycerides (MCT; standard) were compared with regard to the pharmacodynamic response. Moreover, the influence of penetration enhancers on the time of erythema onset was investigated under zero order penetration kinetics. The enhancers dimethyl sulfoxide, diethylene glycol monoethyl ether and three different glycerides in different concentrations were added to MCT as a standard vehicle. All preparations were applied to the forearms of volunteers under infinite dose conditions at different thermodynamic drug activity levels (0.2-3.2% of the saturation level) and different drug concentrations (0.051-0.816%), respectively. Different penetration kinetics do not influence data of erythema onset, as these data are comparable to those obtained under finite dose conditions (first order penetration kinetics). With regard to the penetration enhancers, a significantly enhanced penetration of methyl nicotinate could be observed only for diethylene glycol monoethyl ether and dimethyl sulfoxide. However, no significant difference between light mineral oil and MCT could be found with regard to penetration enhancement. The time of erythema onset is an easy and efficient parameter for quantification of the pharmacodynamic response caused by nicotinates.

Kefir protective effects against nicotine cessation-induced anxiety and cognition impairments in rats.

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Noori, Negin; Bangash, Mohammad Yasan; Motaghinejad, Majid; Hosseini, Pantea; Noudoost, Behshad

2014-01-01

Nicotine as one of the potent psychostimulant drugs is characterized by its parasympathomimetic activity. Upon the abrupt discontinuation of nicotine intake, a number of symptoms such as anxiety, depression and cognition impairment develop. Kefir as a food supplement is rich in tryptophan. In this study, we have evaluated the effects of Kefir on nicotine cessation-induced anxiety, depression and cognition impairment. Forty adult male rats were divided into four groups. All the groups received 6 mg/kg/day of nicotine for 17 days and then the negative control groups got 5 mg/kg/day of normal saline. The positive control groups were given 40 mg/kg/day of Sertraline HCl for 7 days. The group treated with Cow Milk Kefir (CMK) and Soy Milk Kefir (SMK) received 5 mg/kg/day for 7 days. On the 25(th) day, Elevated Plus Maze (EPM), Open Field Test (OFT) and Forced Swim Test (FST) were used to investigate anxiety and depression. In addition, Moris Water Maze was applied to evaluate learning and memory in the animals between the 20(th) and 25(th) days. The results showed that administration of CMK, SMK and Sertraline had higher anti-depression and anxiolytic effects on nicotine withdrawal-induced depression and anxiety in rats (P Kefir had a potential effect on the treatment of nicotine cessation-induced depression, anxiety and cognition impairment in the animal model. Kefir may be useful for adjunct therapy for nicotine abandonment treatment protocols.

Nicotine-induced chondrogenic differentiation of human bone marrow stromal cells in vitro.

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Ying, Xiaozhou; Zhang, Wei; Cheng, Shaowen; Nie, Pengfei; Cheng, Xiaojie; Shen, Yue; Wang, Wei; Xue, Enxing; Chen, Qingyu; Kou, Dongquan; Peng, Lei; Zhang, Yu; Lu, Chuanzhu

2012-11-01

Nicotine has been reported that it has a dose-dependent effect on matrix mineralization by human bone marrow cells. However, there is no relevant research concerning on chondrogenic differentiation potential of bone marrow stromal stem cells (BMSCs) treated with nicotine in vitro. The aims of the study were to examine the effects of nicotine (0, 10(-7), 10(-6) and 10(-5) M) on the proliferation and chondrogenic differentiation of BMSCs from three healthy donors in vitro. BMSCs proliferation was analyzed by CCK8 assay and real-time polymerase chain reaction was used to assay the expression of type II collagen, aggrecan, type I collagen and type X collagen. The proteoglycan content was stained by Alcian blue, and the sulfated glycosaminoglycan (sGAG) content of BMSCs was quantified spectrofluorometrically using dimethylmethylene blue. The cell viability was not significantly impaired until up to a concentration of 10(-5) M nicotine. Nicotine promoted the proliferation and enhanced the expression of type II collagen at the level up to 10(-6) M (P < 0.05). The expression of aggrecan was reduced at the concentration of 10(-5) M nicotine at day 14 (P < 0.05), and there was no significant difference in aggrecan gene expression at 10(-7) and 10(-6) M nicotine levels compared to control group (n.s.). Also the fibroblastic and hypertrophic gene expressions were down-regulated in the chondrogenic medium with 10(-7)-10(-5) M nicotine (P < 0.05). It was implied that local application of nicotine at an appropriate concentration may be a promising approach for enhancing chondrogenic differentiation capacity of BMSCs in cell-based cartilage tissue engineering. Also these results indicate that nicotine maybe a potentially useful drug for the treatment of Osteoarthritis.

Nicotine-Induced Effects on Nicotinic Acetylcholine Receptors (nAChRs), Ca2+ and Brain-Derived Neurotrophic Factor (BDNF) in STC-1 Cells.

Science.gov (United States)

Qian, Jie; Mummalaneni, Shobha K; Alkahtani, Reem M; Mahavadi, Sunila; Murthy, Karnam S; Grider, John R; Lyall, Vijay

2016-01-01

In addition to the T2R bitter taste receptors, neuronal nicotinic acetylcholine receptors (nAChRs) have recently been shown to be involved in the bitter taste transduction of nicotine, acetylcholine and ethanol. However, at present it is not clear if nAChRs are expressed in enteroendocrine cells other than beta cells of the pancreas and enterochromaffin cells, and if they play a role in the synthesis and release of neurohumoral peptides. Accordingly, we investigated the expression and functional role of nAChRs in enteroendocrine STC-1 cells. Our studies using RT-PCR, qRT-PCR, immunohistochemical and Western blotting techniques demonstrate that STC-1 cells express several α and β nAChR subunits. Exposing STC-1 cells to nicotine acutely (24h) or chronically (4 days) induced a differential increase in the expression of nAChR subunit mRNA and protein in a dose- and time-dependent fashion. Mecamylamine, a non-selective antagonist of nAChRs, inhibited the nicotine-induced increase in mRNA expression of nAChRs. Exposing STC-1 cells to nicotine increased intracellular Ca2+ in a dose-dependent manner that was inhibited in the presence of mecamylamine or dihydro-β-erythroidine, a α4β2 nAChR antagonist. Brain-derived neurotrophic factor (BDNF) mRNA and protein were detected in STC-1 cells using RT-PCR, specific BDNF antibody, and enzyme-linked immunosorbent assay. Acute nicotine exposure (30 min) decreased the cellular content of BDNF in STC-1 cells. The nicotine-induced decrease in BDNF was inhibited in the presence of mecamylamine. We also detected α3 and β4 mRNA in intestinal mucosal cells and α3 protein expression in intestinal enteroendocrine cells. We conclude that STC-1 cells and intestinal enteroendocrine cells express nAChRs. In STC-1 cells nAChR expression is modulated by exposure to nicotine in a dose- and time-dependent manner. Nicotine interacts with nAChRs and inhibits BDNF expression in STC-1 cells.

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.

The effects of nicotine on ethanol-induced conditioned taste aversions in Long-Evans rats.

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Rinker, Jennifer A; Busse, Gregory D; Roma, Peter G; Chen, Scott A; Barr, Christina S; Riley, Anthony L

2008-04-01

Overall drug acceptability is thought to be a function of the balance between its rewarding and aversive effects, the latter of which is reportedly affected by polydrug use. Given that nicotine and alcohol are commonly co-used, the present experiments sought to assess nicotine's impact on ethanol's aversive effects within a conditioned taste aversion design. Experiment 1 examined various doses of nicotine (0, 0.4, 0.8, 1.2 mg/kg) to determine a behaviorally active dose, and experiment 2 examined various doses of ethanol (0, 0.5, 1.0, 1.5 g/kg) to determine a dose that produced intermediate aversions. Experiment 3 then examined the aversive effects of nicotine (0.8 mg/kg) and ethanol (1.0 g/kg) alone and in combination. Additionally, nicotine's effects on blood alcohol concentrations (BAC) and ethanol-induced hypothermia were examined. Nicotine and ethanol combined produced aversions significantly greater than those produced by either drug alone or the summed aversive effects of the individual compounds. These effects were unrelated to changes in BAC, but nicotine and ethanol combined produced a prolonged hypothermic effect which may contribute to the increased aversions induced by the combination. These data demonstrate that nicotine may interact with ethanol, increasing ethanol's aversive effects. Although the rewarding effects of concurrently administered nicotine and ethanol were not assessed, these data do indicate that the reported high incidence of nicotine and ethanol co-use is unlikely due to reductions in the aversiveness of ethanol with concurrently administered nicotine. It is more likely attributable to nicotine-related changes in ethanol's rewarding effects.

The Neuroprotective Effect of Curcumin Against Nicotine-Induced Neurotoxicity is Mediated by CREB-BDNF Signaling Pathway.

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Motaghinejad, Majid; Motevalian, Manijeh; Fatima, Sulail; Faraji, Fahimeh; Mozaffari, Shiva

2017-10-01

Nicotine abuse adversely affects brain and causes apoptotic neurodegeneration. Curcumin- a bright yellow chemical compound found in turmeric is associated with neuroprotective properties. The current study was designed to evaluate the role of CREB-BDNF signaling in mediating the neuroprotective effects of curcumin against nicotine-induced apoptosis, oxidative stress and inflammation in rats. Sixty adult male rats were divided randomly into six groups. Group 1 received 0.7 ml/rat normal saline, group 2 received 6 mg/kg nicotine. Groups 3, 4, 5 and 6 were treated concurrently with nicotine (6 mg/kg) and curcumin (10, 20, 40 and 60 mg/kg i.p. respectively) for 21 days. Open Field Test (OFT) was used to evaluate the motor activity. Hippocampal oxidative, anti-oxidant, inflammatory and apoptotic factors were evaluated. Furthermore, phosphorylated brain cyclic adenosine monophosphate (cAMP) response element binding protein (P-CREB) and brain derived neurotrophic factor (BDNF) levels were studied at gene and protein levels. We found that nicotine disturbed the motor activity in OFT and simultaneous treatment with curcumin (40 and 60 mg/kg) reduced the nicotine-induced motor activity disturbances. In addition, nicotine treatment increased lipid peroxidation and the levels of GSH, IL-1β, TNF-α and Bax, while reducing Bcl-2, P-CREB and BDNF levels in the hippocampus. Nicotine also reduced the activity of superoxide dismutase, glutathione peroxidase and glutathione reductase in hippocampus. In contrast, various doses of curcumin attenuated nicotine-induced apoptosis, oxidative stress and inflammation; while elevating P-CREB and BDNF levels. Thus, curcumin via activation of P-CREB/BDNF signaling pathway, confers neuroprotection against nicotine-induced inflammation, apoptosis and oxidative stress.

Enhancement of a visual reinforcer by D-amphetamine and nicotine in adult rats: relation to habituation and food restriction.

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Wright, Jennifer M; Ren, Suelynn; Constantin, Annie; Clarke, Paul B S

2018-03-01

Nicotine and D-amphetamine can strengthen reinforcing effects of unconditioned visual stimuli. We investigated whether these reinforcement-enhancing effects reflect a slowing of stimulus habituation and depend on food restriction. Adult male rats pressed an active lever to illuminate a cue light during daily 60-min sessions. Depending on the experiment, rats were challenged with fixed or varying doses of D-amphetamine (0.25-2 mg/kg IP) and nicotine (0.025-0.2 mg/kg SC) or with the tobacco constituent norharman (0.03-10 μg/kg IV). Experiment 1 tested for possible reinforcement-enhancing effects of D-amphetamine and norharman. Experiment 2 investigated whether nicotine and amphetamine inhibited the spontaneous within-session decline in lever pressing. Experiment 3 assessed the effects of food restriction. Amphetamine (0.25-1 mg/kg) and nicotine (0.1 mg/kg) increased active lever pressing specifically (two- to threefold increase). The highest doses of nicotine and amphetamine also affected inactive lever responding (increase and decrease, respectively). With the visual reinforcer omitted, responding was largely extinguished. Neither drug appeared to slow habituation, as assessed by the within-session decline in lever pressing, and reinforcement-enhancing effects still occurred if the drugs were given after this decline had occurred. Food restriction enhanced the reinforcement-enhancing effect of amphetamine but not that of nicotine. Responding remained goal-directed after several weeks of testing. Low doses of D-amphetamine and nicotine produced reinforcement enhancement even in free-feeding subjects, independent of the spontaneous within-session decline in responding. Reinforcement enhancement by amphetamine, but not nicotine, was enhanced by concurrent subchronic food restriction.

Kefir protective effects against nicotine cessation-induced anxiety and cognition impairments in rats

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Negin Noori

2014-01-01

Conclusion: This study revealed that Kefir had a potential effect on the treatment of nicotine cessation-induced depression, anxiety and cognition impairment in the animal model. Kefir may be useful for adjunct therapy for nicotine abandonment treatment protocols.

Protective Effect of Vitamin E on Nicotine Induced Reproductive ...

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Protective Effect of Vitamin E on Nicotine Induced Reproductive Toxicity in ... The health implications of cigarette smoking and ..... toxic byproducts of many metabolic processes in ... Male infertility, clinical ... rats: A possible role of cessation.

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.

Alcohol's actions on neuronal nicotinic acetylcholine receptors.

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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.

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

Vitamin E and Hippophea rhamnoides L. extract reduce nicotine-induced oxidative stress in rat heart.

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Gumustekin, Kenan; Taysi, Seyithan; Alp, Hamit Hakan; Aktas, Omer; Oztasan, Nuray; Akcay, Fatih; Suleyman, Halis; Akar, Sedat; Dane, Senol; Gul, Mustafa

2010-06-01

The effects of vitamin E and Hippophea rhamnoides L. extract (HRe-1) on nicotine-induced oxidative stress in rat heart were investigated. There were eight rats per group and supplementation period was 3 weeks. The groups were: nicotine [0.5 mg kg(-1)day(-1), intraperitoneal (i.p.)]; nicotine plus vitamin E [75 mg kg(-1)day(-1), intragastric (i.g.)]; nicotine plus HRe-1 (250 mg kg(-1)day(-1), i.g.); and the control group (receiving only vehicles). Nicotine increased the malondialdehyde level, which was prevented by both vitamin E and HRe-1. Glutathione peroxidase (GPx) activity in nicotine plus vitamin E supplemented group was higher than the others. Glutathione S-transferase (GST) activity in nicotine plus HRe-1 supplemented group was increased compared with the control group. Catalase activity was higher in nicotine group compared with others. GPx activity in nicotine plus vitamin E supplemented group was elevated compared with the others. Total and non-enzymatic superoxide scavenger activities in nicotine plus vitamin E supplemented group were lower than nicotine plus HRe-1 supplemented group. Superoxide dismutase (SOD) activity was higher in nicotine plus HRe-1 supplemented group compared with others. Glutathione reductase activity and nitric oxide level were not affected. Increased SOD and GST activities might have taken part in the prevention of nicotine-induced oxidative stress in HRe-1 supplemented group in rat heart. Flavonols such as quercetin, and isorahmnetin, tocopherols such as alpha-tocopherol and beta-tocopherol and carotenoids such as alpha-carotene and beta-carotene, reported to be present in H. rhamnoides L. extracts may be responsible for the antioxidant effects of this plant extract. 2010 John Wiley & Sons, Ltd.

Mechanisms of metabonomic for a gateway drug: nicotine priming enhances behavioral response to cocaine with modification in energy metabolism and neurotransmitter level.

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Hongyu Li

Full Text Available Nicotine, one of the most commonly used drugs, has become a major concern because tobacco serves as a gateway drug and is linked to illicit drug abuse, such as cocaine and marijuana. However, previous studies mainly focused on certain genes or neurotransmitters which have already been known to participate in drug addiction, lacking endogenous metabolic profiling in a global view. To further explore the mechanism by which nicotine modifies the response to cocaine, we developed two conditioned place preference (CPP models in mice. In threshold dose model, mice were pretreated with nicotine, followed by cocaine treatment at the dose of 2 mg/kg, a threshold dose of cocaine to induce CPP in mice. In high-dose model, mice were only treated with 20 mg/kg cocaine, which induced a significant CPP. (1H nuclear magnetic resonance based on metabonomics was used to investigate metabolic profiles of the nucleus accumbens (NAc and striatum. We found that nicotine pretreatment dramatically increased CPP induced by 2 mg/kg cocaine, which was similar to 20 mg/kg cocaine-induced CPP. Interestingly, metabolic profiles showed considerable overlap between these two models. These overlapped metabolites mainly included neurotransmitters as well as the molecules participating in energy homeostasis and cellular metabolism. Our results show that the reinforcing effect of nicotine on behavioral response to cocaine may attribute to the modification of some specific metabolites in NAc and striatum, thus creating a favorable metabolic environment for enhancing conditioned rewarding effect of cocaine. Our findings provide an insight into the effect of cigarette smoking on cocaine dependence and the underlying mechanism.

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.

Protective effects of quercetin on nicotine induced oxidative stress in 'HepG2 cells'.

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Yarahmadi, Amir; Zal, Fatemeh; Bolouki, Ayeh

2017-10-01

Nicotine is a natural component of tobacco plants and is responsible for the addictive properties of tobacco. Nicotine has been recognized to result in oxidative stress by inducing the generation of reactive oxygen species (ROS). The purpose of this work was to estimate the hepatotoxicity effect of nicotine on viability and on antioxidant defense system in cultures of HepG2 cell line and the other hand, ameliorative effect of quercetin (Q) as an antioxidant was analyzed. Nicotine induced concentration dependent loss in HepG2 cell line viability. The results indicated that nicotine decreased activity of superoxide dismutase (SOD) and glutathione reductase (GR) and increased activities of catalase (CAT) and glutathione peroxidase (GPx) and glutathione (GSH) content in the HepG2 cells. Q significantly increased activity of SOD, GR and GSH content and decreased activity of GPX in nicotine + Q groups. Our data demonstrate that Q plays a protective role against the imbalance elicited by nicotine between the production of free radicals and antioxidant defense systems, and suggest that administration of this antioxidant may find clinical application where cellular damage is a consequence of ROS.

Activation of the GABAB receptor prevents nicotine-induced locomotor stimulation in mice

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Carla eLobina

2011-12-01

Full Text Available Recent studies demonstrated that activation of the GABAB receptor, either by means of orthosteric agonists or positive allosteric modulators (PAMs, inhibited different nicotine-related behaviors, including intravenous self-administration and conditioned place preference, in rodents. The present study investigated whether the anti-nicotine effects of the GABAB receptor agonist, baclofen, and GABAB PAMs, CGP7930 and GS39783, extend to nicotine stimulant effects. To this end, CD1 mice were initially treated with baclofen (0, 1.25, and 2.5 mg/kg, i.p., CGP7930 (0, 25, and 50 mg/kg, i.g., or GS39783 (0, 25, and 50 mg/kg, i.g., then treated with nicotine (0 and 0.05 mg/kg, s.c., and finally exposed to an automated apparatus for recording of locomotor activity. Pretreatment with doses of baclofen, CGP7930, or GS39783 that did not alter locomotor activity when given with nicotine vehicle fully prevented hyperlocomotion induced by 0.05 mg/kg nicotine. These data extend to nicotine stimulant effects the capacity of baclofen and GABAB PAMs to block the reinforcing, motivational, and rewarding properties of nicotine. These data strengthen the hypothesis that activation of the GABAB receptor may represent a potentially useful, anti-smoking therapeutic strategy.

Chronic Nicotine Exposure Initiated in Adolescence and Unpaired to Behavioral Context Fails to Enhance Sweetened Ethanol Seeking

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Aric C. Madayag

2017-08-01

Full Text Available Nicotine use in adolescence is pervasive in the United States and, according to the Gateway Hypothesis, may lead to progression towards other addictive substances. Given the prevalence of nicotine and ethanol comorbidity, it is difficult to ascertain if nicotine is a gateway drug for ethanol. Our study investigated the relationship between adolescent exposure to nicotine and whether this exposure alters subsequent alcohol seeking behavior. We hypothesized that rats exposed to nicotine beginning in adolescence would exhibit greater alcohol seeking behavior than non-exposed siblings. To test our hypothesis, beginning at P28, female rats were initially exposed to once daily nicotine (0.4 mg/kg, SC or saline for 5 days. Following these five initial injections, animals were trained to nose-poke for sucrose reinforcement (10%, w/v, gradually increasing to sweetened ethanol (10% sucrose; 10% ethanol, w/v on an FR5 reinforcement schedule. Nicotine injections were administered after the behavioral sessions to minimize acute effects of nicotine on operant self-administration. We measured the effects of nicotine exposure on the following aspects of ethanol seeking: self-administration, naltrexone (NTX-induced decreases, habit-directed behavior, motivation, extinction and reinstatement. Nicotine exposure did not alter self-administration or the effectiveness of NTX to reduce alcohol seeking. Nicotine exposure blocked habit-directed ethanol seeking. Finally, nicotine did not alter extinction learning or cue-induced reinstatement to sweetened ethanol seeking. Our findings suggest that nicotine exposure outside the behavioral context does not escalate ethanol seeking. Further, the Gateway Hypothesis likely applies to scenarios in which nicotine is either self-administered or physiologically active during the behavioral session.

Quantitative Determination of Nicotine in a PDMS Microfluidic Channel Using Surface Enhanced Raman Spectroscopy

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Jung, Jae Hyun; Choo, Jae Bum [Hanyang University, Ansan (Korea, Republic of); Kim, Duck Joong [Dankook University, Cheonan (Korea, Republic of); Lee, Sang Hoon [Korea University, Seoul (Korea, Republic of)

2006-02-15

Rapid and highly sensitive determination of nicotine in a PDMS microfluidic channel was investigated using surface enhanced Raman spectroscopy (SERS). A three-dimensional PDMS microfluidic channel was fabricated for this purpose. This channel shows a high mixing efficiency because the transverse and vertical dispersions of the fluid occur simultaneously through the upper and lower zig zag-type blocks. A higher efficiency of mixing could also be obtained by splitting each of the confluent streams into two sub-streams that then joined and recombined. The SERS signal was measured after nicotine molecules were effectively adsorbed onto silver nanoparticles by passing through the three-dimensional channel. A quantitative analysis of nicotine was performed based on the measured peak area at 1030 cm{sup -1}. The detection limit was estimated to be below 0.1 ppm. In this work, the SERS detection, in combination with a PDMS microfluidic channel, has been applied to the quantitative analysis of nicotine in aqueous solution. Compared to the other conventional analytical methods, the detection sensitivity was enhanced up to several orders of magnitude.

Protective Effect of Nicotine on Sepsis-Induced Oxidative Multiorgan Damage: Role of Neutrophils.

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Özdemir-Kumral, Zarife N; Özbeyli, Dilek; Özdemir, Ahmet F; Karaaslan, Bugra M; Kaytaz, Kübra; Kara, Mustafa F; Tok, Olgu E; Ercan, Feriha; Yegen, Berrak Ç

2017-07-01

Despite its adverse health consequences, tobacco smoking is associated with lower incidence of several neurodegenerative and inflammatory diseases. The present study is aimed to show the effects of nicotine, major tobacco constituent, on five organs targeted by sepsis. Male Wistar albino rats received tap water with (5mg/kg) or without nicotine for 14 days. Under ketamine anesthesia, sepsis (n = 50) was induced by ligation and puncture of the cecum, while sham group (n = 8) had only laparotomy. In other rats, nicotine drink was withdrawn for 5 days before sepsis induction, while in acute nicotine group, rats were injected with nicotine (30mg/kg, i.p.) before sepsis, but had no oral intake. Rats were decapitated 24 hours after surgery to obtain lung, liver, ileum, heart, and kidney tissues to determine malondialdehyde (MDA) and glutathione (GSH) levels and myeloperoxidase (MPO) activities. Data were analyzed by one-way analysis of variance and Tukey multiple comparison tests or Student's t test. Chronic nicotine administration or its withdrawal reduced lipid peroxidation and MPO activity and prevented GSH depletion with some varying results in different target tissues. Nicotine injection prior to sepsis depressed MPO activity in all tissues and reduced MDA levels except for the lung, while GSH levels were elevated only in the hepatic and ileal tissues. Histologically observed injury was ameliorated by all nicotine treatments at varying degrees. The findings of the present study indicate that long-term nicotine administration reduces sepsis-induced oxidative damage in several tissues, which appears to involve inhibition of neutrophil activity in the inflamed tissues. Nicotine administration or its withdrawal reduced lipid peroxidation and neutrophil content and prevented GSH depletion with some varying results in different target tissues. A single injection prior to sepsis induction depressed MPO activity in all the tissues and reduced all tissue MDA levels except

iTRAQ proteomic analysis of the hippocampus in a rat model of nicotine-induced conditioned place preference.

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Zhu, Beibei; Li, Xiangyu; Chen, Huan; Wang, Hongjuan; Zhu, Xinchao; Hou, Hongwei; Hu, Qingyuan

2017-05-13

Repeated exposures to nicotine are known to result in persistent changes in proteins expression in addiction-related brain regions, such as the striatum, nucleus accumbens and prefrontal cortex, but the changes induced in the protein content of the hippocampus remain poorly studied. This study established a rat model of nicotine-induced conditioned place preference (CPP), and screened for proteins that were differentially expressed in the hippocampus of these rats using isobaric tags for relative and absolute quantitation labeling (iTRAQ) coupled with 2D-LC MS/MS. The nicotine-induced CPP was established by subcutaneously injecting rats with 0.2 mg/kg nicotine. Relative to the control (saline) group, the nicotine group showed 0.67- and 1.5-fold changes in 117 and 10 hippocampal proteins, respectively. These differentially expressed proteins are mainly involved in calcium-mediated signaling, neurotransmitter transport, GABAergic synapse function, long-term synaptic potentiation and nervous system development. Furthermore, RT-PCR was used to confirmed the results of the proteomic analysis. Our findings identify several proteins and cellular signaling pathways potentially involved in the molecular mechanisms in the hippocampus that underlie nicotine addiction. These results provide insights into the mechanisms of nicotine treatment in hippocampus. Copyright © 2017 Elsevier Inc. All rights reserved.

Nicotine-Mediated Regulation of Nicotinic Acetylcholine Receptors in Non-Small Cell Lung Adenocarcinoma by E2F1 and STAT1 Transcription Factors.

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Courtney Schaal

Full Text Available Cigarette smoking is the major risk factor for non-small cell lung cancer (NSCLC, which accounts for 80% of all lung cancers. Nicotine, the addictive component of tobacco smoke, can induce proliferation, migration, invasion, epithelial-mesenchymal transition (EMT, angiogenesis, and survival in NSCLC cell lines, as well as growth and metastasis of NSCLC in mice. This nicotine-mediated tumor progression is facilitated through activation of nicotinic acetylcholine receptors (nAChRs, specifically the α7 subunit; however, how the α7 nAChR gene is regulated in lung adenocarcinoma is not fully clear. Here we demonstrate that the α7 nAChR gene promoter is differentially regulated by E2F and STAT transcription factors through a competitive interplay; E2F1 induces the promoter, while STAT transcription factors repress it by binding to an overlapping site at a region -294 through -463bp upstream of the transcription start site. Treatment of cells with nicotine induced the mRNA and protein levels of α7 nAChR; this could be abrogated by treatment with inhibitors targeting Src, PI3K, MEK, α7 nAChR, CDK4/6 or a disruptor of the Rb-Raf-1 interaction. Further, nicotine-mediated induction of α7 nAChR was reduced when E2F1 was depleted and in contrast elevated when STAT1 was depleted by siRNAs. Interestingly, extracts from e-cigarettes, which have recently emerged as healthier alternatives to traditional cigarette smoking, can also induce α7 nAChR expression in a manner similar to nicotine. These results suggest an autoregulatory feed-forward loop that induces the levels of α7 nAChR upon exposure to nicotine, which enhances the strength of the signal. It can be imagined that such an induction of α7 nAChR contributes to the tumor-promoting functions of nicotine.

A Role for Matrix Metalloproteinases in Nicotine-Induced Conditioned Place Preference and Relapse in Adolescent Female Rats

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Reka Natarajan

2013-01-01

Full Text Available Reconfiguration of extracellular matrix proteins appears to be necessary for the synaptic plasticity that underlies memory consolidation. The primary candidates involved in controlling this process are a family of endopeptidases called matrix metalloproteinases (MMPs; however, the potential role of MMPs in nicotine addiction-related memories has not been adequately tested. Present results indicate transient changes in hippocampal MMP-2, -3, and -9 expression following context dependent learning of nicotine-induced conditioned place preference (CPP. Members of a CPP procedural control group also indicated similar MMP changes, suggesting that memory activation occurred in these animals as well. However, hippocampal MMP-9 expression was differentially elevated in members of the nicotine-induced CPP group on days 4 and 5 of training. Inhibition of MMPs using a broad spectrum MMP inhibitor (FN439 during nicotine-induced CPP training blocked the acquisition of CPP. Elevations in hippocampal and prefrontal cortex MMP-3 expression—but not MMP-2 and -9—accompanied reactivation of a previously learned drug related memory. Decreases in the actin regulatory cytoskeletal protein cortactin were measured in the HIP and PFC during the initial two days of acquisition of CPP; however, no changes were seen following re-exposure to the drug related environment. These results suggest that MMP-9 may be involved in facilitating the intracellular and extracellular events required for the synaptic plasticity underlying the acquisition of nicotine-induced CPP. Furthermore, MMP-3 appears to be important during re-exposure to the drug associated environment. However, rats introduced into the CPP apparatus and given injections of vehicle rather than nicotine during training also revealed a pattern of MMP expression similar to nicotine-induced CPP animals.

Nicotine enhances proliferation, migration, and radioresistance of human malignant glioma cells through EGFR activation

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Khalil, A.A.; Jameson, M.J.; Broaddus, W.C.; Lin, P.S.; Chung, T.D.

2013-01-01

It has been suggested that continued tobacco use during radiation therapy contributes to maintenance of neoplastic growth despite treatment with radiation. Nicotine is a cigarette component that is an established risk factor for many diseases, neoplastic and otherwise. The hypothesis of this work is that nicotine promotes the proliferation, migration, and radioresistance of human malignant glioma cells. The effect of nicotine on cellular proliferation, migration, signaling, and radiation sensitivity were evaluated for malignant glioma U87 and GBM12 cells by use of the AlamarBlue, scratch healing, and clonogenic survival assays. Signal transduction was assessed by immunoblotting for activated EGFR, extracellular regulated kinase (ERK), and AKT. At concentrations comparable with those found in chronic smokers, nicotine induced malignant glioma cell migration, growth, colony formation, and radioresistance. Nicotine increased phosphorylation of EGFR tyr992 , AKT ser473 , and ERK. These molecular effects were reduced by pharmacological inhibitors of EGFR, PI3K, and MEK. It was therefore concluded that nicotine stimulates the malignant behavior of glioma cells in vitro by activation of the EGFR and downstream AKT and ERK pathways. (author)

Alpha 7 nicotinic acetylcholine receptor-mediated protection against ethanol-induced neurotoxicity.

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de Fiebre, NancyEllen C; de Fiebre, Christopher M

2003-11-01

The alpha(7)-selective nicotinic partial agonist 3-[2,4-dimethoxybenzylidene]anabaseine (DMXB) was examined for its ability to modulate ethanol-induced neurotoxicity in primary cultures of rat neurons. Primary cultures of hippocampal neurons were established from Long-Evans, embryonic day (E)-18 rat fetuses and maintained for 7 days. Ethanol (0-150 mM), DMXB (0-56 microM), or both were subsequently co-applied to cultures. Ethanol was added two additional times to the cultures to compensate for evaporation. After 5 days, neuronal viability was assessed with the MTT cell proliferation assay. Results demonstrated that ethanol reduces neuronal viability in a concentration-dependent fashion and that DMXB protects against this ethanol-induced neurotoxicity, also in a concentration-dependent fashion. These results support the suggestion that nicotinic partial agonists may be useful in treating binge drinking-induced neurotoxicity and may provide clues as to why heavy drinkers are usually smokers.

Timing of nicotine lozenge administration to minimize trigger induced craving and withdrawal symptoms.

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Kotlyar, Michael; Lindgren, Bruce R; Vuchetich, John P; Le, Chap; Mills, Anne M; Amiot, Elizabeth; Hatsukami, Dorothy K

2017-08-01

Smokers are often advised to use nicotine lozenge when craving or withdrawal symptoms occur. This may be too late to prevent lapses. This study assessed if nicotine lozenge use prior to a common smoking trigger can minimize trigger induced increases in craving and withdrawal symptoms. Eighty-four smokers completed two laboratory sessions in random order. At one session, nicotine lozenge was given immediately after a stressor (to approximate current recommended use - i.e., after craving and withdrawal symptoms occur); at the other session subjects were randomized to receive nicotine lozenge at time points ranging from immediately to 30min prior to the stressor. Withdrawal symptoms and urge to smoke were measured using the Minnesota Nicotine Withdrawal Scale and the Questionnaire of Smoking Urges (QSU). Relative to receiving lozenge after the stressor, a smaller increase in pre-stressor to post-stressor withdrawal symptom scores occurred when lozenge was used immediately (p=0.03) and 10min prior (p=0.044) to the stressor. Results were similar for factors 1 and 2 of the QSU when lozenge was used immediately prior to the stressor (pnicotine lozenge prior to a smoking trigger can decrease trigger induced craving and withdrawal symptoms. Future studies are needed to determine if such use would increase cessation rates. Clinicaltrials.gov # NCT01522963. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nicotine enhances an auditory Event-Related Potential component which is inversely related to habituation.

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Veltri, Theresa; Taroyan, Naira; Overton, Paul G

2017-07-01

Nicotine is a psychoactive substance that is commonly consumed in the context of music. However, the reason why music and nicotine are co-consumed is uncertain. One possibility is that nicotine affects cognitive processes relevant to aspects of music appreciation in a beneficial way. Here we investigated this possibility using Event-Related Potentials. Participants underwent a simple decision-making task (to maintain attentional focus), responses to which were signalled by auditory stimuli. Unlike previous research looking at the effects of nicotine on auditory processing, we used complex tones that varied in pitch, a fundamental element of music. In addition, unlike most other studies, we tested non-smoking subjects to avoid withdrawal-related complications. We found that nicotine (4.0 mg, administered as gum) increased P2 amplitude in the frontal region. Since a decrease in P2 amplitude and latency is related to habituation processes, and an enhanced ability to disengage from irrelevant stimuli, our findings suggest that nicotine may cause a reduction in habituation, resulting in non-smokers being less able to adapt to repeated stimuli. A corollary of that decrease in adaptation may be that nicotine extends the temporal window during which a listener is able and willing to engage with a piece of music.

The glucagon-like peptide 1 analogue Exendin-4 attenuates the nicotine-induced locomotor stimulation, accumbal dopamine release, conditioned place preference as well as the expression of locomotor sensitization in mice.

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Emil Egecioglu

Full Text Available The gastrointestinal peptide glucagon-like peptide 1 (GLP-1 is known to regulate consummatory behavior and is released in response to nutrient ingestion. Analogues of this peptide recently emerged as novel pharmacotherapies for treatment of type II diabetes since they reduce gastric emptying, glucagon secretion as well as enhance glucose-dependent insulin secretion. The findings that GLP-1 targets reward related areas including mesolimbic dopamine areas indicate that the physiological role of GLP-1 extends beyond food intake and glucose homeostasis control to include reward regulation. The present series of experiments was therefore designed to investigate the effects of the GLP-1 receptor agonist, Exendin-4 (Ex4, on established nicotine-induced effects on the mesolimbic dopamine system in mice. Specifically, we show that treatment with Ex4, at a dose with no effect per se, attenuate nicotine-induced locomotor stimulation, accumbal dopamine release as well as the expression of conditioned place preference in mice. In accordance, Ex4 also blocks nicotine-induced expression of locomotor sensitization in mice. Given that development of nicotine addiction largely depends on the effects of nicotine on the mesolimbic dopamine system these findings indicate that the GLP-1 receptor may be a potential target for the development of novel treatment strategies for nicotine cessations in humans.

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

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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

Protective efficacy of folic acid and vitamin B12 against nicotine-induced toxicity in pancreatic islets of the rat

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Bhattacharjee Ankita

2015-06-01

Full Text Available Although cigarette smoking is associated with insulin resistance and an increased risk for type 2 diabetes, few studies have examined the effect of nicotine on the adult endocrine pancreas. In this study, male Wister rats were treated with nicotine (3 mg/kg body weight/day with or without supplementation of folic acid (36 μg/kg body weight/day or vitamin B12 (0.63 μg/kg body weight/day alone or in combination. Fasting blood glucose, insulin and HBA1C level and different oxidative and anti-oxidative stress parameters were measured and pancreatic tissue sections were stained with eosin-haematoxylene. Data were analysed by nonparametric statistics. The results revealed that nicotine induced prediabetes condition with subsequent damage to pancreatic islets in rats. Nicotine also caused oxidative stress in pancreatic tissue as evidenced by increased nitric oxide and malondialdehyde level and decreased superoxide dismutase, catalase and reduced glutathione level. Compared to vitamin B12 supplementation, folic acid blunted the nicotine-induced toxicity in pancreatic islets with higher efficacy. Further, folic acid and vitamin B12 in combination were able to confer significant protection on pancreatic islets against nicotine induced toxicity. These results suggest that supplementation of folic acid and vitamin B12 in combination may be a possible strategy of detoxification against nicotine-induced toxicity in pancreatic islets of the rat.

Simultaneous multiplexed quantification of nicotine and its metabolites using surface enhanced Raman scattering.

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Alharbi, Omar; Xu, Yun; Goodacre, Royston

2014-10-07

The detection and quantification of xenobiotics and their metabolites in man is important for drug dosing, therapy and for substance abuse monitoring where longer-lived metabolic products from illicit materials can be assayed after the drug of abuse has been cleared from the system. Raman spectroscopy offers unique specificity for molecular characterization and this usually weak signal can be significantly enhanced using surface enhanced Raman scattering (SERS). We report here the novel development of SERS with chemometrics for the simultaneous analysis of the drug nicotine and its major xenometabolites cotinine and trans-3'-hydroxycotinine. Initial experiments optimized the SERS conditions and we found that when these three determinands were analysed individually that the maximum SERS signals were found at three different pH. These were pH 3 for nicotine and pH 10 and 11 for cotinine and trans-3'-hydroxycotinine, respectively. Tertiary mixtures containing nicotine, cotinine and trans-3'-hydroxycotinine were generated in the concentration range 10(-7)-10(-5) M and SERS spectra were collected at all three pH values. Chemometric analysis using kernel-partial least squares (K-PLS) and artificial neural networks (ANNs) were conducted and these models were validated using bootstrap resampling. All three analytes were accurately quantified with typical root mean squared error of prediction on the test set data being 5-9%; nicotine was most accurately predicted followed by cotinine and then trans-3'-hydroxycotinine. We believe that SERS is a powerful approach for the simultaneous analysis of multiple determinands without recourse to lengthy chromatography, as demonstrated here for the xenobiotic nicotine and its two major xenometabolites.

Effects of Nicotine Metabolites on Nicotine Withdrawal Behaviors in Mice.

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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.

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

Stimulation of Alpha7 Nicotinic Acetylcholine Receptor Attenuates Nicotine-Induced Upregulation of MMP, MCP-1, and RANTES through Modulating ERK1/2/AP-1 Signaling Pathway in RAW264.7 and MOVAS Cells

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Liping Liu

2017-01-01

Full Text Available Vagus nerve stimulation through alpha7 nicotine acetylcholine receptors (α7-nAChR signaling had been demonstrated attenuation of inflammation. This study aimed to determine whether PNU-282987, a selective α7-nAChR agonist, affected activities of matrix metalloproteinase (MMP and inflammatory cytokines in nicotine-treatment RAW264.7 and MOVAS cells and to assess the underlying molecular mechanisms. RAW264.7 and MOVAS cells were treated with nicotine at different concentrations (0, 1, 10, and 100 ng/ml for 0–120 min. Nicotine markedly stimulated the phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2 and c-Jun in RAW264.7 cells. Pretreatment with U0126 significantly suppressed phosphorylation of ERK1/2 and further attenuated nicotine-induced activation of c-Jun and upregulation of MMP-2, MMP-9, monocyte chemotactic protein- (MCP- 1, and regulated upon activation normal T cell expressed and secreted (RANTES. Similarly, nicotine treatment also increased phosphorylation of c-Jun and expressions of MMP-2, MMP-9, MCP-1, and RANTES in MOVAS cells. When cells were pretreated with PNU-282987, nicotine-induced activations of ERK1/2 and c-Jun in RAW264.7 cells and c-Jun in MOVAS cells were effectively inhibited. Furthermore, nicotine-induced secretions of MMP-2, MMP-9, MCP-1, and RANTES were remarkably downregulated. Treatment with α7-nAChR agonist inhibits nicotine-induced upregulation of MMP and inflammatory cytokines through modulating ERK1/2/AP-1 signaling in RAW264.7 cells and AP-1 in MOVAS cells, providing a new therapeutic for abdominal aortic aneurysm.

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

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

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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.

Roselle supplementation prevents nicotine-induced vascular endothelial dysfunction and remodelling in rats.

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Si, Lislivia Yiang-Nee; Kamisah, Yusof; Ramalingam, Anand; Lim, Yi Cheng; Budin, Siti Balkis; Zainalabidin, Satirah

2017-07-01

Vascular endothelial dysfunction (VED) plays an important role in the initiation of cardiovascular diseases. Roselle, enriched with antioxidants, demonstrates high potential in alleviating hypertension. This study was undertaken to investigate the effects of roselle supplementation of VED and remodelling in a rodent model with prolonged nicotine administration. Male Sprague-Dawley rats (n = 6 per group) were administered with 0.6 mg/kg nicotine for 28 days to induce VED. The rats were given either aqueous roselle (100 mg/kg) or normal saline orally 30 min prior to nicotine injection daily. One additional group of rats served as control. Thoracic aorta was isolated from rats to measure vascular reactivity, vascular remodelling and oxidative stress. Roselle significantly lowered aortic sensitivity to phenylephrine-induced vasoconstriction (Endo-(+) C max = 234.5 ± 3.9%, Endo-(-) C max = 247.6 ± 5.2%) compared with untreated nicotine group (Endo-(+) C max = 264.5 ± 6.9%, Endo-(-) C max = 276.5 ± 6.8%). Roselle also improved aortic response to endothelium-dependent vasodilator, acetylcholine (Endo-(+) R max = 73.2 ± 2.1%, Endo-(-) R max = 26.2 ± 0.8%) compared to nicotine group (Endo-(+) R max = 57.8 ± 1.7%, Endo-(-) R max = 20.9 ± 0.8%). In addition, roselle prevented an increase in intimal media thickness and elastic lamellae proliferation to preserve vascular architecture. Moreover, we also observed a significantly lowered degree of oxidative stress in parallel with increased antioxidant enzymes in aortic tissues of the roselle-treated group. This study demonstrated that roselle prevents VED and remodelling, and as such it has high nutraceutical value as supplement to prevent cardiovascular diseases.

Type I and II positive allosteric modulators differentially modulate agonist-induced up-regulation of α7 nicotinic acetylcholine receptors

DEFF Research Database (Denmark)

Thomsen, Morten Skøtt; Mikkelsen, Jens D

2012-01-01

Long-term treatment with nicotine or selective α7 nicotinic acetylcholine receptor (nAChR) agonists increases the number of α7 nAChRs and this up-regulation may be involved in the mechanism underlying the sustained procognitive effect of these compounds. Here, we investigate the influence of type I...... expressing human α7 nAChR, whereas the type I PAMs AVL-3288 or NS1738 do not. Contrarily, neither type I nor II PAMs affect 10 μM nicotine-induced receptor up-regulation, suggesting that nicotine and A-582941 induce up-regulation through different mechanisms. We further show in vivo that 3 mg/kg PNU-120596...... is involved in A-582941-induced up-regulation. Our results are the first to show an in vivo difference between type I and II α7 nAChR PAMs, and demonstrate an agonist-dependent effect of type II PAMs occurring on a much longer time scale than previously appreciated. Furthermore, our data suggest that nicotine...

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

Neuronal effects of nicotine during auditory selective attention.

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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.

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.

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.

Nicotine disrupts safety learning by enhancing fear associated with a safety cue via the dorsal hippocampus.

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Connor, David A; Kutlu, Munir G; Gould, Thomas J

2017-07-01

Learned safety, a learning process in which a cue becomes associated with the absence of threat, is disrupted in individuals with post-traumatic stress disorder (PTSD). A bi-directional relationship exists between smoking and PTSD and one potential explanation is that nicotine-associated changes in cognition facilitate PTSD emotional dysregulation by disrupting safety associations. Therefore, we investigated whether nicotine would disrupt learned safety by enhancing fear associated with a safety cue. In the present study, C57BL/6 mice were administered acute or chronic nicotine and trained over three days in a differential backward trace conditioning paradigm consisting of five trials of a forward conditioned stimulus (CS)+ (Light) co-terminating with a footshock unconditioned stimulus followed by a backward CS- (Tone) presented 20 s after cessation of the unconditioned stimulus. Summation testing found that acute nicotine disrupted learned safety, but chronic nicotine had no effect. Another group of animals administered acute nicotine showed fear when presented with the backward CS (Light) alone, indicating the formation of a maladaptive fear association with the backward CS. Finally, we investigated the brain regions involved by administering nicotine directly into the dorsal hippocampus, ventral hippocampus, and prelimbic cortex. Infusion of nicotine into the dorsal hippocampus disrupted safety learning.

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.

Reciprocal activation of α5-nAChR and STAT3 in nicotine-induced human lung cancer cell proliferation.

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Zhang, Yao; Jia, Yanfei; Li, Ping; Li, Huanjie; Xiao, Dongjie; Wang, Yunshan; Ma, Xiaoli

2017-07-20

Cigarette smoking is the top environmental risk factor for lung cancer. Nicotine, the addictive component of cigarettes, induces lung cancer cell proliferation, invasion and migration via the activation of nicotinic acetylcholine receptors (nAChRs). Genome-wide association studies (GWAS) show that CHRNA5 gene encoding α5-nAChR is especially relevant to lung cancer. However, the mechanism of this subunit in lung cancer is not clear. In the present study, we demonstrate that the expression of α5-nAChR is correlated with phosphorylated STAT3 (pSTAT3) expression, smoking history and lower survival of non-small cell lung cancer (NSCLC) samples. Nicotine increased the levels of α5-nAChR mRNA and protein in NSCLC cell lines and activated the JAK2/STAT3 signaling cascade. Nicotine-induced activation of JAK2/STAT3 signaling was inhibited by the silencing of α5-nAChR. Characterization of the CHRNA5 promoter revealed four STAT3-response elements. ChIP assays confirmed that the CHRNA5 promoter contains STAT3 binding sites. By silencing STAT3 expression, nicotine-induced upregulation of α5-nAChR was suppressed. Downregulation of α5-nAChR and/or STAT3 expression inhibited nicotine-induced lung cancer cell proliferation. These results suggest that there is a feedback loop between α5-nAChR and STAT3 that contributes to the nicotine-induced tumor cell proliferation, which indicates that α5-nAChR is an important therapeutic target involved in tobacco-associated lung carcinogenesis. Copyright © 2017 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

Nicotine Withdrawal Induces Neural Deficits in Reward Processing.

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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

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)

Propionyl-L-Carnitine Enhances Wound Healing and Counteracts Microvascular Endothelial Cell Dysfunction.

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Maria Giovanna Scioli

Full Text Available Impaired wound healing represents a high cost for health care systems. Endothelial dysfunction characterizes dermal microangiopathy and contributes to delayed wound healing and chronic ulcers. Endothelial dysfunction impairs cutaneous microvascular blood flow by inducing an imbalance between vasorelaxation and vasoconstriction as a consequence of reduced nitric oxide (NO production and the increase of oxidative stress and inflammation. Propionyl-L-carnitine (PLC is a natural derivative of carnitine that has been reported to ameliorate post-ischemic blood flow recovery.We investigated the effects of PLC in rat skin flap and cutaneous wound healing. A daily oral PLC treatment improved skin flap viability and associated with reactive oxygen species (ROS reduction, inducible nitric oxide synthase (iNOS and NO up-regulation, accelerated wound healing and increased capillary density, likely favoring dermal angiogenesis by up-regulation for iNOS, vascular endothelial growth factor (VEGF, placental growth factor (PlGF and reduction of NADPH-oxidase 4 (Nox4 expression. In serum-deprived human dermal microvascular endothelial cell cultures, PLC ameliorated endothelial dysfunction by increasing iNOS, PlGF, VEGF receptors 1 and 2 expression and NO level. In addition, PLC counteracted serum deprivation-induced impairment of mitochondrial β-oxidation, Nox4 and cellular adhesion molecule (CAM expression, ROS generation and leukocyte adhesion. Moreover, dermal microvascular endothelial cell dysfunction was prevented by Nox4 inhibition. Interestingly, inhibition of β-oxidation counteracted the beneficial effects of PLC on oxidative stress and endothelial dysfunction.PLC treatment improved rat skin flap viability, accelerated wound healing and dermal angiogenesis. The beneficial effects of PLC likely derived from improvement of mitochondrial β-oxidation and reduction of Nox4-mediated oxidative stress and endothelial dysfunction. Antioxidant therapy and

Nitric oxide synthase inhibition ameliorates nicotine-induced sperm function decline in male rats

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Ibukun P. Oyeyipo

2015-09-01

Conclusion: Taken together, the present data indicate the abilities of l-NAME to ameliorate nicotine-induced spermatotoxic effects in male rats via a mechanism dependent on the circulating testosterone level.

Tamoxifen counteracts estradiol induced effects on striatal and hypophyseal dopamine receptors

International Nuclear Information System (INIS)

Ferretti, C.; Blengio, M.; Ghi, P.; Racca, S.; Genazzani, E.; Portaleone, P.

1988-01-01

We investigated the ability of Tamoxifen (TAM), an antiestrogen drug, to counteract the modification induced by estrogens on dopamine (DA) receptors on striatum and on adenohypophysis of ovex female rats. Subacute treatment with 17β-estradiol (E 2 ) at both low (0.1 μg/kg) and high (20 μg/kg) doses confirmed its ability to increase the number of striatal 3 H-Spiperone ( 3 H-SPI) binding sites in a dose dependent manner. By contrast in the pituitary, only high doses of estrogen were effective in reducing the number of DA receptors. We treated ovex female rats for 15 days with TAM alone or associated with E 2 , to see if these estrogenic effects could be suppressed by an antiestrogenic drug. TAM did not affect the number of striatal DA receptors, but significantly increased the adenohypophy-seal DA binding sites, without varying their affinity. No changes were observed in pituitary and striatal DA receptor density, even when TAM was injected in association with estradiol. In conclusions: TAM is able to counteract the effects estrogens have on DA receptors. However there is some evidence that it could influence the pituitary DA systems independently of it antiestrogenic activity

The effects of erdosteine, N-acetylcysteine, and vitamin E on nicotine-induced apoptosis of pulmonary cells

International Nuclear Information System (INIS)

Demiralay, Rezan; Guersan, Nesrin; Erdem, Havva

2006-01-01

This study was conducted to investigate the frequency of apoptosis in the pulmonary epithelial cells of rats after intratraperitoneal nicotine injection, in order to examine the role of inflammatory markers [myeloperoxidase (MPO) and tumor necrosis factor-alpha (TNF-α)] in nicotine-induced lung damage, and to determine the protective effects of three known antioxidant agents [N-acetylcysteine (NAC), erdosteine, and vitamin E] on the lung toxicity of nicotine in the lungs. Female Wistar rats were divided into seven groups, each composed of nine rats: two negative control groups, two positive control groups, one erdosteine-treated group (500 mg/kg), one NAC-treated group (500 mg/kg), and one vitamin E-treated group (500 mg/kg). Nicotine was injected intraperitoneally at a dosage of 0.6 mg/kg for 21 days. Following nicotine injection, the antioxidants were administered orally, treatment was continued until the rats were killed. Lung tissue samples were stained with hematoxylin-eosin (H and E) for histopathological assessments. The apoptosis level in the lung bronchiolar and alveolar epithelium was determined by using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) method. Cytoplasmic TNF-α in the bronchiolar and alveolar epithelial cells and the lung MPO activity were evaluated immunohistochemically. The protective effect of vitamin E on lung histology was stronger than that of erdosteine or NAC. Treatment with erdosteine, NAC, and vitamin E significantly reduced the rate of nicotine-induced pulmonary epithelial cell apoptosis, and there were no significant differences in apoptosis among the three antioxidants groups. Erdosteine, NAC, and vitamin E significantly reduced the increases in TNF-α staining and lung MPO activity. The effects of erdosteine on the increases in the local TNF-α level and lung MPO activity were weaker than that of NAC or vitamin E. This findings suggest that erdosteine and NAC can be as effective as vitamin

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.

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

Science.gov (United States)

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

Benfotiamine counteracts smoking-induced vascular dysfunction in healthy smokers.

Science.gov (United States)

Stirban, Alin; Nandrean, Simona; Kirana, Stanley; Götting, Christian; Veresiu, Ioan Andrei; Tschoepe, Diethelm

2012-01-01

Background. Smoking induces endothelial dysfunction (ED) mainly by exacerbating oxidative stress (OS) and inflammation. Benfotiamine, a thiamine prodrug with high bioavailability, prevents nicotine-induced vascular dysfunction in rats. It remained unknown whether this effect also occurs in humans. Methods. Therefore, 20 healthy volunteers (mean age: 38 years) were investigated twice, 7-10 days apart in a randomized, cross-over, and investigator-blinded design. Vascular function was assessed by flow-mediated vasodilatation (FMD) of the brachial artery and by measurements of the soluble vascular cell adhesion molecule (sVCAM)-1. Investigations were performed after an overnight fast as well as 20 minutes after one cigarette smoking. On another day, the same procedure was applied following a 3-day oral therapy with benfotiamine (1050 mg/day). Ten patients were randomized to start with smoking alone, and ten started with benfotiamine. Results. Results are expressed as (mean ± SEM). Smoking acutely induced a decrease in FMD by 50% ((∗∗)P benfotiamine treatment to 25%(∗§) ((∗)P benfotiamine. The endothelium-independent vasodilatation remained unaltered between days. Conclusion. In healthy volunteers, smoking blunts vascular function mirrored by a decrease in FMD and an increase in sVCAM-1. Short-term treatment with benfotiamine significantly reduces these effects, showing protective vascular properties.

Striatal increase of neurotrophic factors as a mechanism of nicotine protection in experimental parkinsonism.

Science.gov (United States)

Maggio, R; Riva, M; Vaglini, F; Fornai, F; Racagni, G; Corsini, G U

1997-01-01

The repeated finding of an apparent protective effect of cigarette smoking on the risk of Parkinson's disease is one of the few consistent results in the epidemiology of this disorder. Among the innumerous substances that originate from tobacco smoke, nicotine is by far the most widely studied, and the most likely candidate for a protective effect against neuronal degeneration in Parkinson's disease. Nicotine is a natural alkaloid that has considerable stimulatory effects on the central nervous system (CNS). Its effects on the CNS are mediated by the activation of neuronal heteromeric acetylcholine-gated ion channel receptors (nAChR, also termed nicotinic acetylcholine receptors). In the present study, we describe the neuroprotective effects of (-)nicotine in two animal models of parkinsonism: the diethyldithiocarbamate (DDC)-induced enhancement of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxicity in mice, and the methamphetamine-induced neurotoxicity in rats and mice. In parallel experiments, we found that (-)nicotine induces the basic fibroblast growth factor (FGF-2) and the brain-derived neurotrophic factor (BDNF) in rat striatum. As FGF-2 and BDNF have been reported to be neuroprotective for dopaminergic cells, our data indicate that the increase in neurotrophic factors is a possible mechanism by which (-)nicotine protects from experimental parkinsonisms. Moreover, they suggest that nAChR agonists could be of potential benefit in the progression of Parkinson's disease.

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.

Nicotine induced CpG methylation of Pax6 binding motif in StAR promoter reduces the gene expression and cortisol production

International Nuclear Information System (INIS)

Wang, Tingting; Chen, Man; Liu, Lian; Cheng, Huaiyan; Yan, You-E; Feng, Ying-Hong; Wang, Hui

2011-01-01

Steroidogenic acute regulatory protein (StAR) mediates the rate-limiting step in the synthesis of steroid hormones, essential to fetal development. We have reported that the StAR expression in fetal adrenal is inhibited in a rat model of nicotine-induced intrauterine growth retardation (IUGR). Here using primary human fetal adrenal cortex (pHFAC) cells and a human fetal adrenal cell line NCI-H295A, we show that nicotine inhibits StAR expression and cortisol production in a dose- and time-dependent manner, and prolongs the inhibitory effect on cells proliferating over 5 passages after termination of nicotine treatment. Methylation detection within the StAR promoter region uncovers a single site CpG methylation at nt -377 that is sensitive to nicotine treatment. Nicotine-induced alterations in frequency of this point methylation correlates well with the levels of StAR expression, suggesting an important role of the single site in regulating StAR expression. Further studies using bioinformatics analysis and siRNA approach reveal that the single CpG site is part of the Pax6 binding motif (CGCCTGA) in the StAR promoter. The luciferase activity assays validate that Pax6 increases StAR gene expression by binding to the glucagon G3-like motif (CGCCTGA) and methylation of this site blocks Pax6 binding and thus suppresses StAR expression. These data identify a nicotine-sensitive CpG site at the Pax6 binding motif in the StAR promoter that may play a central role in regulating StAR expression. The results suggest an epigenetic mechanism that may explain how nicotine contributes to onset of adult diseases or disorders such as metabolic syndrome via fetal programming. -- Highlights: ► Nicotine-induced StAR inhibition in two human adrenal cell models. ► Nicotine-induced single CpG site methylation in StAR promoter. ► Persistent StAR inhibition and single CpG methylation after nicotine termination. ► Single CpG methylation located at Pax6 binding motif regulates St

Nicotine promotes initiation and progression of KRAS-induced pancreatic cancer via Gata6-dependent dedifferentiation of acinar cells in mice.

Science.gov (United States)

Hermann, Patrick C; Sancho, Patricia; Cañamero, Marta; Martinelli, Paola; Madriles, Francesc; Michl, Patrick; Gress, Thomas; de Pascual, Ricardo; Gandia, Luis; Guerra, Carmen; Barbacid, Mariano; Wagner, Martin; Vieira, Catarina R; Aicher, Alexandra; Real, Francisco X; Sainz, Bruno; Heeschen, Christopher

2014-11-01

Although smoking is a leading risk factor for pancreatic ductal adenocarcinoma (PDAC), little is known about the mechanisms by which smoking promotes initiation or progression of PDAC. We studied the effects of nicotine administration on pancreatic cancer development in Kras(+/LSLG12Vgeo);Elas-tTA/tetO-Cre (Ela-KRAS) mice, Kras(+/LSLG12D);Trp53+/LSLR172H;Pdx-1-Cre (KPC) mice (which express constitutively active forms of KRAS), and C57/B6 mice. Mice were given nicotine for up to 86 weeks to produce blood levels comparable with those of intermediate smokers. Pancreatic tissues were collected and analyzed by immunohistochemistry and reverse transcriptase polymerase chain reaction; cells were isolated and assayed for colony and sphere formation and gene expression. The effects of nicotine were also evaluated in primary pancreatic acinar cells isolated from wild-type, nAChR7a(-/-), Trp53(-/-), and Gata6(-/-);Trp53(-/-) mice. We also analyzed primary PDAC cells that overexpressed GATA6 from lentiviral expression vectors. Administration of nicotine accelerated transformation of pancreatic cells and tumor formation in Ela-KRAS and KPC mice. Nicotine induced dedifferentiation of acinar cells by activating AKT-ERK-MYC signaling; this led to inhibition of Gata6 promoter activity, loss of GATA6 protein, and subsequent loss of acinar differentiation and hyperactivation of oncogenic KRAS. Nicotine also promoted aggressiveness of established tumors as well as the epithelial-mesenchymal transition, increasing numbers of circulating cancer cells and their dissemination to the liver, compared with mice not exposed to nicotine. Nicotine induced pancreatic cells to acquire gene expression patterns and functional characteristics of cancer stem cells. These effects were markedly attenuated in K-Ras(+/LSL-G12D);Trp53(+/LSLR172H);Pdx-1-Cre mice given metformin. Metformin prevented nicotine-induced pancreatic carcinogenesis and tumor growth by up-regulating GATA6 and promoting

Effects of mecamylamine (a nicotinic receptor antagonist on harman induced-amnesia in an inhibitory avoidance test

Directory of Open Access Journals (Sweden)

Mohammad Nasehi

2011-10-01

Full Text Available Introduction: β-carbolines alkaloids suchv as harmane have been found in common plant-derived foodstuffs (wheat, rice, corn, barley, grape and mushrooms. These alkaloids have many cognitive effects including alteration short and long term memory. In the present study, the effect of intra-CA1 injection of the nicotinic receptor antagonist mecamylamine on amnesia induced by harmane was examined in mice. Materials and Methods: Mice were bilaterally implanted with chronic cannulae in the CA1 regions of the dorsal hippocampus. One week after cannulae implantation, mice were trained in a step-down type inhibitory avoidance task, and were tested 24 h after training to measure step-down latency as a scale of memory. Results: Pre-training or post-training systemic injection of harmane induced amnesia. Pre-testing intra-dorsal hippocampus administration of the high dose of nicotinic receptor antagonist, mecamylamine (4 µg/mice also induced amnesia. On the other hand, pre-test intra-CA1 injection of ineffective doses of mecamylamine (0.5, 1 and 2 µg/mice fully restored harmane induced amnesia. Conclusion: The present finding in this study indicated that a complex interaction exists between nicotinic receptor of dorsal hippocampus and amnesia induced by Harmane.

Nicotine and caffeine modulate haloperidol-induced changes in postsynaptic density transcripts expression: Translational insights in psychosis therapy and treatment resistance.

Science.gov (United States)

de Bartolomeis, Andrea; Iasevoli, Felice; Marmo, Federica; Buonaguro, Elisabetta Filomena; Avvisati, Livia; Latte, Gianmarco; Tomasetti, Carmine

2018-04-01

Caffeine and nicotine are widely used by schizophrenia patients and may worsen psychosis and affect antipsychotic therapies. However, they have also been accounted as augmentation strategies in treatment-resistant schizophrenia. Despite both substances are known to modulate dopamine and glutamate transmission, little is known about the molecular changes induced by these compounds in association to antipsychotics, mostly at the level of the postsynaptic density (PSD), a site of dopamine-glutamate interplay. Here we investigated whether caffeine and nicotine, alone or combined with haloperidol, elicited significant changes in the levels of both transcripts and proteins of the PSD members Homer1 and Arc, which have been implicated in synaptic plasticity, schizophrenia pathophysiology, and antipsychotics molecular action. Homer1a mRNA expression was significantly reduced by caffeine and nicotine, alone or combined with haloperidol, compared to haloperidol. Haloperidol induced significantly higher Arc mRNA levels than both caffeine and caffeine plus haloperidol in the striatum. Arc mRNA expression was significantly higher by nicotine plus haloperidol vs. haloperidol in the cortex, while in striatum gene expression by nicotine was significantly lower than that by both haloperidol and nicotine plus haloperidol. Both Homer1a and Arc protein levels were significantly increased by caffeine, nicotine, and nicotine plus haloperidol. Homer1b mRNA expression was significantly increased by nicotine and nicotine plus haloperidol, while protein levels were unaffected. Locomotor activity was not significantly affected by caffeine, while it was reduced by nicotine. These data indicate that both caffeine and nicotine trigger relevant molecular changes in PSD sites when given in association with haloperidol. Copyright © 2018 Elsevier B.V. and ECNP. All rights reserved.

Effect of IR Laser on Myoblasts: Prospects of Application for Counteracting Microgravity-Induced Muscle Atrophy

Science.gov (United States)

Monici, Monica; Cialdai, Francesca; Romano, Giovanni; Corsetto, Paola Antonia; Rizzo, Angela Maria; Caselli, Anna; Ranaldi, Francesco

2013-02-01

Microgravity-induced muscle atrophy is a problem of utmost importance for the impact it may have on the health and performance of astronauts. Therefore, appropriate countermeasures are needed to prevent disuse atrophy and favour muscle recovery. Muscle atrophy is characterized by loss of muscle mass and strength, and a shift in substrate utilization from fat to glucose, that leads to a reduced metabolic efficiency and enhanced fatigability. Laser therapy is already used in physical medicine and rehabilitation to accelerate muscle recovery and in sports medicine to prevent damages produced by metabolic disturbances and inflammatory reactions after heavy exercise. The aim of the research we present was to get insights on possible benefits deriving from the application of an advanced infrared laser system to counteract deficits of muscle energy metabolism and stimulate the recovery of the hypotrophic tissue. The source used was a Multiwave Locked System (MLS) laser, which combines continuous and pulsed emissions at 808 nm and 905 nm, respectively. We studied the effect of MLS treatment on morphology and energy metabolism of C2C12 cells, a widely accepted myoblast model, previously exposed to microgravity conditions modelled by a Random Positioning Machine. The MLS laser treatment was able to restore basal levels of serine/threonine protein phosphatase activity and to counteract cytoskeletal alterations and increase in glycolytic enzymes activity that occurred following the exposure to modelled microgravity. In conclusion, the results provide interesting insights for the application of infrared laser in the treatment of muscle atrophy.

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

Science.gov (United States)

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.

Nicotine-induced retardation of chondrogenesis through down-regulation of IGF-1 signaling pathway to inhibit matrix synthesis of growth plate chondrocytes in fetal rats

International Nuclear Information System (INIS)

Deng, Yu; Cao, Hong; Cu, Fenglong; Xu, Dan; Lei, Youying; Tan, Yang; Magdalou, Jacques; Wang, Hui; Chen, Liaobin

2013-01-01

Previous studies have confirmed that maternal tobacco smoking causes intrauterine growth retardation (IUGR) and skeletal growth retardation. Among a multitude of chemicals associated with cigarette smoking, nicotine is one of the leading candidates for causing low birth weights. However, the possible mechanism of delayed chondrogenesis by prenatal nicotine exposure remains unclear. We investigated the effects of nicotine on fetal growth plate chondrocytes in vivo and in vitro. Rats were given 2.0 mg/kg·d of nicotine subcutaneously from gestational days 11 to 20. Prenatal nicotine exposure increased the levels of fetal blood corticosterone and resulted in fetal skeletal growth retardation. Moreover, nicotine exposure induced the inhibition of matrix synthesis and down-regulation of insulin-like growth factor 1 (IGF-1) signaling in fetal growth plates. The effects of nicotine on growth plates were studied in vitro by exposing fetal growth plate chondrocytes to 0, 1, 10, or 100 μM of nicotine for 10 days. Nicotine inhibited matrix synthesis and down-regulated IGF-1 signaling in chondrocytes in a concentration-dependent manner. These results suggest that prenatal nicotine exposure induces delayed chondrogenesis and that the mechanism may involve the down-regulation of IGF-1 signaling and the inhibition of matrix synthesis by growth plate chondrocytes. The present study aids in the characterization of delayed chondrogenesis caused by prenatal nicotine exposure, which might suggest a candidate mechanism for intrauterine origins of osteoporosis and osteoarthritis. - Highlights: ► Prenatal nicotine-exposure could induce delayed chondrogenesis in fetal rats. ► Nicotine inhibits matrix synthesis of fetal growth plate chondrocytes. ► Nicotine inhibits IGF-1 signaling pathway in fetal growth plate chondrocytes

Nicotine-induced retardation of chondrogenesis through down-regulation of IGF-1 signaling pathway to inhibit matrix synthesis of growth plate chondrocytes in fetal rats

Energy Technology Data Exchange (ETDEWEB)

Deng, Yu; Cao, Hong; Cu, Fenglong [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Xu, Dan [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China); Lei, Youying [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Tan, Yang [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Magdalou, Jacques [UMR 7561 CNRS-Nancy Université, Faculté de Médicine, Vandoeuvre-lès-Nancy (France); Wang, Hui [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China); Chen, Liaobin, E-mail: lbchen@whu.edu.cn [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China)

2013-05-15

Previous studies have confirmed that maternal tobacco smoking causes intrauterine growth retardation (IUGR) and skeletal growth retardation. Among a multitude of chemicals associated with cigarette smoking, nicotine is one of the leading candidates for causing low birth weights. However, the possible mechanism of delayed chondrogenesis by prenatal nicotine exposure remains unclear. We investigated the effects of nicotine on fetal growth plate chondrocytes in vivo and in vitro. Rats were given 2.0 mg/kg·d of nicotine subcutaneously from gestational days 11 to 20. Prenatal nicotine exposure increased the levels of fetal blood corticosterone and resulted in fetal skeletal growth retardation. Moreover, nicotine exposure induced the inhibition of matrix synthesis and down-regulation of insulin-like growth factor 1 (IGF-1) signaling in fetal growth plates. The effects of nicotine on growth plates were studied in vitro by exposing fetal growth plate chondrocytes to 0, 1, 10, or 100 μM of nicotine for 10 days. Nicotine inhibited matrix synthesis and down-regulated IGF-1 signaling in chondrocytes in a concentration-dependent manner. These results suggest that prenatal nicotine exposure induces delayed chondrogenesis and that the mechanism may involve the down-regulation of IGF-1 signaling and the inhibition of matrix synthesis by growth plate chondrocytes. The present study aids in the characterization of delayed chondrogenesis caused by prenatal nicotine exposure, which might suggest a candidate mechanism for intrauterine origins of osteoporosis and osteoarthritis. - Highlights: ► Prenatal nicotine-exposure could induce delayed chondrogenesis in fetal rats. ► Nicotine inhibits matrix synthesis of fetal growth plate chondrocytes. ► Nicotine inhibits IGF-1 signaling pathway in fetal growth plate chondrocytes.

Alpha-Tocopherol Counteracts the Cytotoxicity Induced by Ochratoxin A in Primary Porcine Fibroblasts

DEFF Research Database (Denmark)

Fusi, Elenora; Rebucci, Raffaella; Pecorini, Chiara

2010-01-01

The aims of the current study were to determine the half-lethal concentration of ochratoxin A (OTA) as well as the levels of lactate dehydrogenase release and DNA fragmentation induced by OTA in primary porcine fibroblasts, and to examine the role of α-tocopherol in counteracting its toxicity....... Cells showed a dose-, time- and origin-dependent (ear vs. embryo) sensitivity to ochratoxin A. Pre-incubation for 3 h with 1 nM α-tocopherol significantly (P tocopherol...

Blockade of nicotine sensitization by methanol extracts of Glycyrrhizae radix mediated via antagonism of accumbal oxidative stress.

Science.gov (United States)

Zhao, Zheng Lin; Kim, Sang Chan; Liu, Hong Feng; Wu, Yi Yan; Li, Li Bo; Wang, Yu Hua; Jiao, Yu; Fan, Yu; Lee, Chul Won; Lee, Bong Hyeo; Cho, Il Je; Yang, Chae Ha; Zhao, Rong Jie

2017-11-16

We previously reported that a methanol extract of Glycyrrhizae radix (MEGR) blocked methamphetamine-induced locomotor sensitization and conditioned place preference in rats. In the present study, the effects of MEGR on repeated nicotine-induced locomotor sensitization and enhanced extracellular dopamine (DA) release in the nucleus accumbens (Nacc) were evaluated. Male Sprague-Dawley rats received repeated administrations of nicotine (0.4 mg/kg, subcutaneous) or saline twice a day for 7 d and were challenged with nicotine 4 d after the last daily dosing. During the 4-d withdrawal period, the rats were treated once a day with MEGR (60 or 180 mg/kg/d). Extracellular DA levels were measured by in vivo microdialysis, the malondialdehyde levels and the activities of superoxide dismutase and catalase in the Nacc were biochemically evaluated, and the expression of antioxidant proteins was confirmed by Western blot assays. All data were assessed with analysis of variance tests followed by post-hoc comparison tests and p values nicotine-induced locomotor sensitization was dose-dependently attenuated by MEGR, and 180 mg/kg/d MEGR significantly inhibited augmented accumbal DA release induced by a direct local challenge of nicotine. Moreover, 180 mg/kg/d MEGR reversed increases in malondialdehyde production, decreases in superoxide dismutase and catalase activities, and the reduced expression of nuclear factor erythroid 2-related factor 2 and heme oxygenase 1 in the nicotine-sensitized Nacc. These results suggest that MEGR inhibited nicotine-induced locomotion and dopaminergic sensitization via antioxidant action.

Tamoxifen counteracts estradiol induced effects on striatal and hypophyseal dopamine receptors

Energy Technology Data Exchange (ETDEWEB)

Ferretti, C.; Blengio, M.; Ghi, P.; Racca, S.; Genazzani, E.; Portaleone, P.

1988-01-01

We investigated the ability of Tamoxifen (TAM), an antiestrogen drug, to counteract the modification induced by estrogens on dopamine (DA) receptors on striatum and on adenohypophysis of ovex female rats. Subacute treatment with 17..beta..-estradiol (E/sub 2/) at both low (0.1 ..mu..g/kg) and high (20 ..mu..g/kg) doses confirmed its ability to increase the number of striatal /sup 3/H-Spiperone (/sup 3/H-SPI) binding sites in a dose dependent manner. By contrast in the pituitary, only high doses of estrogen were effective in reducing the number of DA receptors. We treated ovex female rats for 15 days with TAM alone or associated with E/sub 2/, to see if these estrogenic effects could be suppressed by an antiestrogenic drug. TAM did not affect the number of striatal DA receptors, but significantly increased the adenohypophy-seal DA binding sites, without varying their affinity. No changes were observed in pituitary and striatal DA receptor density, even when TAM was injected in association with estradiol. In conclusions: TAM is able to counteract the effects estrogens have on DA receptors. However there is some evidence that it could influence the pituitary DA systems independently of it antiestrogenic activity.

Benfotiamine Counteracts Smoking-Induced Vascular Dysfunction in Healthy Smokers

Directory of Open Access Journals (Sweden)

Alin Stirban

2012-01-01

Full Text Available Background. Smoking induces endothelial dysfunction (ED mainly by exacerbating oxidative stress (OS and inflammation. Benfotiamine, a thiamine prodrug with high bioavailability, prevents nicotine-induced vascular dysfunction in rats. It remained unknown whether this effect also occurs in humans. Methods. Therefore, 20 healthy volunteers (mean age: 38 years were investigated twice, 7–10 days apart in a randomized, cross-over, and investigator-blinded design. Vascular function was assessed by flow-mediated vasodilatation (FMD of the brachial artery and by measurements of the soluble vascular cell adhesion molecule (sVCAM-1. Investigations were performed after an overnight fast as well as 20 minutes after one cigarette smoking. On another day, the same procedure was applied following a 3-day oral therapy with benfotiamine (1050 mg/day. Ten patients were randomized to start with smoking alone, and ten started with benfotiamine. Results. Results are expressed as (mean ± SEM. Smoking acutely induced a decrease in FMD by 50% (∗∗P<0.001 versus baseline an effect significantly reduced by benfotiamine treatment to 25%∗§ (∗P<0.05 versus baseline, §P<0.05 versus smoking alone. Smoking-induced elevation in sVCAM-1 was also prevented by benfotiamine. The endothelium-independent vasodilatation remained unaltered between days. Conclusion. In healthy volunteers, smoking blunts vascular function mirrored by a decrease in FMD and an increase in sVCAM-1. Short-term treatment with benfotiamine significantly reduces these effects, showing protective vascular properties.

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...

Phenobarbital increases monkey in vivo nicotine disposition and induces liver and brain CYP2B6 protein

Science.gov (United States)

Lee, Anna M; Miksys, Sharon; Tyndale, Rachel F

2006-01-01

CYP2B6 is a drug-metabolizing enzyme expressed in the liver and brain that can metabolize bupropion (Zyban®, a smoking cessation drug), activate tobacco-smoke nitrosamines, and inactivate nicotine. Hepatic CYP2B6 is induced by phenobarbital and induction may affect in vivo nicotine disposition, while brain CYP2B6 induction may affect local levels of centrally acting substrates. We investigated the effect of chronic phenobarbital treatment on induction of in vivo nicotine disposition and CYP2B6 expression in the liver and brain of African Green (Vervet) monkeys. Monkeys were split into two groups (n=6 each) and given oral saccharin daily for 22 days; one group was supplemented with 20 mg kg−1 phenobarbital. Monkeys were given a 0.1 mg kg−1 nicotine dose subcutaneously before and after treatment. Phenobarbital treatment resulted in a significant, 56%, decrease (P=0.04) in the maximum nicotine plasma concentration and a 46% decrease (P=0.003) in the area under the concentration–time curve. Phenobarbital also increased hepatic CYP2B6 protein expression. In monkey brain, significant induction (Pphenobarbital treatment in monkeys resulted in increased in vivo nicotine disposition, and induced hepatic and brain CYP2B6 protein levels and cellular expression. This induction may alter the metabolism of CYP2B6 substrates including peripherally acting drugs such as cyclophosphamide and centrally acting drugs such as bupropion, ecstasy and phencyclidine. PMID:16751792

A one-year monitoring of nicotine use in sport: frontier between potential performance enhancement and addiction issues.

Science.gov (United States)

Marclay, François; Grata, Elia; Perrenoud, Laurent; Saugy, Martial

2011-12-10

Tobacco consumption is a global epidemic responsible for a vast burden of disease. With pharmacological properties sought-after by consumers and responsible for addiction issues, nicotine is the main reason of this phenomenon. Accordingly, smokeless tobacco products are of growing popularity in sport owing to potential performance enhancing properties and absence of adverse effects on the respiratory system. Nevertheless, nicotine does not appear on the 2011 World Anti-Doping Agency (WADA) Prohibited List or Monitoring Program by lack of a comprehensive large-scale prevalence survey. Thus, this work describes a one-year monitoring study on urine specimens from professional athletes of different disciplines covering 2010 and 2011. A method for the detection and quantification of nicotine, its major metabolites (cotinine, trans-3-hydroxycotinine, nicotine-N'-oxide and cotinine-N-oxide) and minor tobacco alkaloids (anabasine, anatabine and nornicotine) was developed, relying on ultra-high pressure liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-TQ-MS/MS). A simple and fast dilute-and-shoot sample treatment was performed, followed by hydrophilic interaction chromatography-tandem mass spectrometry (HILIC-MS/MS) operated in positive electrospray ionization (ESI) mode with multiple reaction monitoring (MRM) data acquisition. After method validation, assessing the prevalence of nicotine consumption in sport involved analysis of 2185 urine samples, accounting for 43 different sports. Concentrations distribution of major nicotine metabolites, minor nicotine metabolites and tobacco alkaloids ranged from 10 (LLOQ) to 32,223, 6670 and 538 ng/mL, respectively. Compounds of interest were detected in trace levels in 23.0% of urine specimens, with concentration levels corresponding to an exposure within the last three days for 18.3% of samples. Likewise, hypothesizing conservative concentration limits for active nicotine consumption prior and/or during

Agmatine protects rat liver from nicotine-induced hepatic damage via antioxidative, antiapoptotic, and antifibrotic pathways.

Science.gov (United States)

El-Sherbeeny, Nagla A; Nader, Manar A; Attia, Ghalia M; Ateyya, Hayam

2016-12-01

Tobacco smoking with its various forms is a global problem with proved hazardous effects to human health. The present work was planned to study the defending role of agmatine (AGM) on hepatic oxidative stress and damage induced by nicotine in rats. Thirty-two rats divided into four groups were employed: control group, nicotine-only group, AGM group, and AGM-nicotine group. Measurements of serum hepatic biochemical markers, lipid profile, and vascular cell adhesion molecule-1 were done. In addition, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) activity, and nitrate/nitrite (NOx) levels were estimated in the liver homogenates. Immunohistochemistry for Bax and transforming growth factor beta (TGF-β1) and histopathology of the liver were also included. Data of the study demonstrated that nicotine administration exhibited marked liver deterioration, an increase in liver enzymes, changes in lipid profile, and an elevation in MDA with a decline in levels of SOD, GSH, and NOx (nitrate/nitrite). Also, levels of proapoptotic Bax and profibrotic TGF-β1 showed marked elevation in the liver. AGM treatment to rats in nicotine-only group ameliorated all the previous changes. These findings indicate that AGM could successfully overcome the nicotine-evoked hepatic oxidative stress and tissue injury, apoptosis, and fibrosis.

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 stimulates urokinase-type plasminogen activator receptor expression and cell invasiveness through mitogen-activated protein kinase and reactive oxygen species signaling in ECV304 endothelial cells

Energy Technology Data Exchange (ETDEWEB)

Khoi, Pham Ngoc; Park, Jung Sun; Kim, Nam Ho; Jung, Young Do, E-mail: ydjung@chonnam.ac.kr

2012-03-01

Urokinase-type plasminogen activator receptor (uPAR) expression is elevated during inflammation, tissue remodeling and in many human cancers. This study investigated the effect of nicotine, a major alkaloid in tobacco, on uPAR expression and cell invasiveness in ECV304 endothelial cells. Nicotine stimulated uPAR expression in a dose-dependent manner and activated extracellular signal-regulated kinases-1/2 (Erk-1/2), c-Jun amino-terminal kinase (JNK) and p38 mitogen activated protein kinase (MAPK). Specific inhibitors of MEK-1 (PD98059) and JNK (SP600125) inhibited the nicotine-induced uPAR expression, while the p38 MAPK inhibitor SB203580 did not. Expression vectors encoding dominant negative MEK-1 (pMCL-K97M) and JNK (TAM67) also prevented nicotine-induced uPAR promoter activity. The intracellular hydrogen peroxide (H{sub 2}O{sub 2}) content was increased by nicotine treatment. The antioxidant N-acetylcysteine prevented nicotine-activated production of reactive oxygen species (ROS) and uPAR expression. Furthermore, exogenous H{sub 2}O{sub 2} increased uPAR mRNA expression. Deleted and site-directed mutagenesis demonstrated the involvement of the binding sites of transcription factor nuclear factor-kappaB (NF-κB) and activator protein (AP)-1 in the nicotine-induced uPAR expression. Studies with expression vectors encoding mutated NF-κB signaling molecules and AP-1 decoy confirmed that NF-κB and AP-1 were essential for the nicotine-stimulated uPAR expression. MAPK (Erk-1/2 and JNK) and ROS functioned as upstream signaling molecules in the activation of AP-1 and NF-κB, respectively. In addition, ECV304 endothelial cells treated with nicotine displayed markedly enhanced invasiveness, which was partially abrogated by uPAR neutralizing antibodies. The data indicate that nicotine induces uPAR expression via the MAPK/AP-1 and ROS/NF-κB signaling pathways and, in turn, stimulates invasiveness in human ECV304 endothelial cells. -- Highlights: ► Endothelial cells

Nicotine stimulates urokinase-type plasminogen activator receptor expression and cell invasiveness through mitogen-activated protein kinase and reactive oxygen species signaling in ECV304 endothelial cells

International Nuclear Information System (INIS)

Khoi, Pham Ngoc; Park, Jung Sun; Kim, Nam Ho; Jung, Young Do

2012-01-01

Urokinase-type plasminogen activator receptor (uPAR) expression is elevated during inflammation, tissue remodeling and in many human cancers. This study investigated the effect of nicotine, a major alkaloid in tobacco, on uPAR expression and cell invasiveness in ECV304 endothelial cells. Nicotine stimulated uPAR expression in a dose-dependent manner and activated extracellular signal-regulated kinases-1/2 (Erk-1/2), c-Jun amino-terminal kinase (JNK) and p38 mitogen activated protein kinase (MAPK). Specific inhibitors of MEK-1 (PD98059) and JNK (SP600125) inhibited the nicotine-induced uPAR expression, while the p38 MAPK inhibitor SB203580 did not. Expression vectors encoding dominant negative MEK-1 (pMCL-K97M) and JNK (TAM67) also prevented nicotine-induced uPAR promoter activity. The intracellular hydrogen peroxide (H 2 O 2 ) content was increased by nicotine treatment. The antioxidant N-acetylcysteine prevented nicotine-activated production of reactive oxygen species (ROS) and uPAR expression. Furthermore, exogenous H 2 O 2 increased uPAR mRNA expression. Deleted and site-directed mutagenesis demonstrated the involvement of the binding sites of transcription factor nuclear factor-kappaB (NF-κB) and activator protein (AP)-1 in the nicotine-induced uPAR expression. Studies with expression vectors encoding mutated NF-κB signaling molecules and AP-1 decoy confirmed that NF-κB and AP-1 were essential for the nicotine-stimulated uPAR expression. MAPK (Erk-1/2 and JNK) and ROS functioned as upstream signaling molecules in the activation of AP-1 and NF-κB, respectively. In addition, ECV304 endothelial cells treated with nicotine displayed markedly enhanced invasiveness, which was partially abrogated by uPAR neutralizing antibodies. The data indicate that nicotine induces uPAR expression via the MAPK/AP-1 and ROS/NF-κB signaling pathways and, in turn, stimulates invasiveness in human ECV304 endothelial cells. -- Highlights: ► Endothelial cells treated with nicotine

Nicotine induced CpG methylation of Pax6 binding motif in StAR promoter reduces the gene expression and cortisol production

Energy Technology Data Exchange (ETDEWEB)

Wang, Tingting [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, Maryland (United States); Chen, Man; Liu, Lian [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Cheng, Huaiyan [Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, Maryland (United States); Yan, You-E [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Feng, Ying-Hong, E-mail: yhfeng@usuhs.edu [Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, Maryland (United States); Wang, Hui, E-mail: wanghui19@whu.edu.cn [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China)

2011-12-15

Steroidogenic acute regulatory protein (StAR) mediates the rate-limiting step in the synthesis of steroid hormones, essential to fetal development. We have reported that the StAR expression in fetal adrenal is inhibited in a rat model of nicotine-induced intrauterine growth retardation (IUGR). Here using primary human fetal adrenal cortex (pHFAC) cells and a human fetal adrenal cell line NCI-H295A, we show that nicotine inhibits StAR expression and cortisol production in a dose- and time-dependent manner, and prolongs the inhibitory effect on cells proliferating over 5 passages after termination of nicotine treatment. Methylation detection within the StAR promoter region uncovers a single site CpG methylation at nt -377 that is sensitive to nicotine treatment. Nicotine-induced alterations in frequency of this point methylation correlates well with the levels of StAR expression, suggesting an important role of the single site in regulating StAR expression. Further studies using bioinformatics analysis and siRNA approach reveal that the single CpG site is part of the Pax6 binding motif (CGCCTGA) in the StAR promoter. The luciferase activity assays validate that Pax6 increases StAR gene expression by binding to the glucagon G3-like motif (CGCCTGA) and methylation of this site blocks Pax6 binding and thus suppresses StAR expression. These data identify a nicotine-sensitive CpG site at the Pax6 binding motif in the StAR promoter that may play a central role in regulating StAR expression. The results suggest an epigenetic mechanism that may explain how nicotine contributes to onset of adult diseases or disorders such as metabolic syndrome via fetal programming. -- Highlights: Black-Right-Pointing-Pointer Nicotine-induced StAR inhibition in two human adrenal cell models. Black-Right-Pointing-Pointer Nicotine-induced single CpG site methylation in StAR promoter. Black-Right-Pointing-Pointer Persistent StAR inhibition and single CpG methylation after nicotine termination

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.

Activation of the cholinergic anti-inflammatory pathway by nicotine ameliorates lipopolysaccharide-induced preeclampsia-like symptoms in pregnant rats.

Science.gov (United States)

Liu, Yuanyuan; Yang, Jinying; Bao, Junjie; Li, Xiaolan; Ye, Aihua; Zhang, Guozheng; Liu, Huishu

2017-01-01

Preeclampsia (PE) exerts a more intense systemic inflammatory response than normal pregnancy. Recently, the role of the cholinergic anti-inflammatory pathway (CAP) in regulating inflammation has been extensively studied. The aim of this study was to investigate the effect of nicotine, a selective cholinergic agonist, on lipopolysaccharide (LPS)-induced preeclampsia-like symptoms in pregnant rats and to determine the molecular mechanism underlying it. Rats were administered LPS (1.0 μg/kg) via tail vein injection on gestational day 14 to induce preeclampsia-like symptoms. Nicotine (1.0 mg/kg/d) and α-bungarotoxin (1.0 μg/kg/d) were injected subcutaneously into the rats from gestational day 14-19. Clinical symptoms were recorded. Serum and placentas were collected to determine cytokine levels using Luminex. The mRNA and protein expression levels of α7 nicotinic acetylcholine receptor (α7nAChR) were determined using Real time-PCR and Western blot analysis. Immunohistochemistry was performed to determine the level of activation of nuclear factor-κB (NF-κB) in placentas. Nicotine significantly ameliorated LPS-induced preeclampsia-like symptoms in pregnant rats (P preeclampsia (P preeclampsia rats. Our findings suggest that the activation of α7nAChR by nicotine attenuates preeclampsia-like symptoms, and this protective effect is likely the result of the inhibition of inflammation via the NF-κB p65 pathway. Copyright © 2016 Elsevier Ltd. All rights reserved.

Counteracting effect of threat on reward enhancements during working memory.

Science.gov (United States)

Choi, Jong Moon; Padmala, Srikanth; Pessoa, Luiz

2015-01-01

Cognitive performance has been shown to be enhanced when performance-based rewards are at stake. On the other hand, task-irrelevant threat processing has been shown to have detrimental effects during several cognitive tasks. Crucially, the impact of reward and threat on cognition has been studied largely independently of one another. Hence, our understanding of how reward and threat simultaneously contribute to performance is incomplete. To fill in this gap, the present study investigated how reward and threat interact with one another during a cognitive task. We found that threat of shock counteracted the beneficial effect of reward during a working memory task. Furthermore, individual differences in self-reported reward-sensitivity and anxiety were linked to the extent to which reward and threat interacted during behaviour. Together, the current findings contribute to a limited but growing literature unravelling how positive and negative information processing jointly influence cognition.

Nicotine improves obesity and hepatic steatosis and ER stress in diet-induced obese male rats.

Science.gov (United States)

Seoane-Collazo, Patricia; Martínez de Morentin, Pablo B; Fernø, Johan; Diéguez, Carlos; Nogueiras, Rubén; López, Miguel

2014-05-01

Nicotine, the main addictive component of tobacco, promotes body weight reduction in humans and rodents. Recent evidence has suggested that nicotine acts in the central nervous system to modulate energy balance. Specifically, nicotine modulates hypothalamic AMP-activated protein kinase to decrease feeding and to increase brown adipose tissue thermogenesis through the sympathetic nervous system, leading to weight loss. Of note, most of this evidence has been obtained in animal models fed with normal diet or low-fat diet (LFD). However, its effectiveness in obese models remains elusive. Because obesity causes resistance towards many factors involved in energy homeostasis, the aim of this study has been to compare the effect of nicotine in a diet-induced obese (DIO) model, namely rats fed a high-fat diet, with rats fed a LFD. Our data show that chronic peripheral nicotine treatment reduced body weight by decreasing food intake and increasing brown adipose tissue thermogenesis in both LFD and DIO rats. This overall negative energy balance was associated to decreased activation of hypothalamic AMP-activated protein kinase in both models. Furthermore, nicotine improved serum lipid profile, decreased insulin serum levels, as well as reduced steatosis, inflammation, and endoplasmic reticulum stress in the liver of DIO rats but not in LFD rats. Overall, this evidence suggests that nicotine diminishes body weight and improves metabolic disorders linked to DIO and might offer a clear-cut strategy to develop new therapeutic approaches against obesity and its metabolic complications.

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

Inhibition of PaCaMKII-E isoform in the dorsal unpaired median neurosecretory cells of cockroach reduces nicotine- and clothianidin-induced currents.

Science.gov (United States)

List, Olivier; Calas-List, Delphine; Taillebois, Emiliane; Juchaux, Marjorie; Heuland, Emilie; Thany, Steeve H

2014-08-01

Cellular responses to Ca(2+) require intermediary proteins such as calcium/calmodulin-dependent protein kinase II (CaMKII), which transduces the signal into downstream effects. We recently demonstrated that the cockroach genome encodes five different CaMKII isoforms, and only PaCaMKII-E isoform is specifically expressed in the dorsal unpaired median neurosecretory cells. In the present study, using antisense oligonucleotides, we demonstrated that PaCaMKII-E isoform inhibition reduced nicotine-induced currents through α-bungarotoxin-sensitive and -insensitive nicotinic acetylcholine receptor subtypes. Specifically, PaCaMKII-E isoform is sufficient to repress nicotinic current amplitudes as a result of its depression by antisense oligonucleotides. Similar results were found using the neonicotinoid insecticide clothianidin, which acted as a full agonist of dorsal unpaired median neuron nicotinic acetylcholine receptors. Clothianidin current amplitudes are strongly reduced under bath application of PaCaMKII-E antisense oligonucleotides but no significant results are found with α-bungarotoxin co-applied, demonstrating that CaMKII-E isoform affects nicotine currents through α-bungarotoxin-sensitive and -insensitive receptor subtypes whereas clothianidin currents are reduced via α-bungarotoxin-insensitive receptors. In addition, we found that intracellular calcium increase induced by nicotine and clothianidin were reduced by PaCaMKII-E antisense oligonucleotides, demonstrating that intracellular calcium increase induced by nicotine and clothianidin are affected by PaCaMKII-E inhibition. Cellular responses to Ca(2+) require intermediary proteins such as calcium/calmodulin-dependent protein kinase II (CaMKII). We recently demonstrated that the cockroach genome encodes five different CaMKII isoforms and only PaCaMKII-E isoform was specifically expressed in the dorsal unpaired median neurosecretory cells. Here we show that specific inhibition of PaCaMKII-E isoform is

Endogenous fatty acid ethanolamides suppress nicotine-induced activation of mesolimbic dopamine neurons through nuclear receptors.

Science.gov (United States)

Melis, Miriam; Pillolla, Giuliano; Luchicchi, Antonio; Muntoni, Anna Lisa; Yasar, Sevil; Goldberg, Steven R; Pistis, Marco

2008-12-17

Nicotine stimulates the activity of mesolimbic dopamine neurons, which is believed to mediate the rewarding and addictive properties of tobacco use. Accumulating evidence suggests that the endocannabinoid system might play a major role in neuronal mechanisms underlying the rewarding properties of drugs of abuse, including nicotine. Here, we investigated the modulation of nicotine effects by the endocannabinoid system on dopamine neurons in the ventral tegmental area with electrophysiological techniques in vivo and in vitro. We discovered that pharmacological inhibition of fatty acid amide hydrolase (FAAH), the enzyme that catabolizes fatty acid ethanolamides, among which the endocannabinoid anandamide (AEA) is the best known, suppressed nicotine-induced excitation of dopamine cells. Importantly, this effect was mimicked by the administration of the FAAH substrates oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), but not methanandamide, the hydrolysis resistant analog of AEA. OEA and PEA are naturally occurring lipid signaling molecules structurally related to AEA, but devoid of affinity for cannabinoid receptors. They blocked the effects of nicotine by activation of the peroxisome proliferator-activated receptor-alpha (PPAR-alpha), a nuclear receptor transcription factor involved in several aspects of lipid metabolism and energy balance. Activation of PPAR-alpha triggered a nongenomic stimulation of tyrosine kinases, which might lead to phosphorylation and negative regulation of neuronal nicotinic acetylcholine receptors. These data indicate for the first time that the anorexic lipids OEA and PEA possess neuromodulatory properties as endogenous ligands of PPAR-alpha in the brain and provide a potential new target for the treatment of nicotine addiction.

Prenatal alcohol exposure increases postnatal acceptability of nicotine odor and taste in adolescent rats.

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Nicole M Mantella

Full Text Available Human studies indicate that alcohol exposure during gestation not only increases the chance for later alcohol abuse, but also nicotine dependence. The flavor attributes of both alcohol and nicotine can be important determinants of their initial acceptance and they both share the component chemosensory qualities of an aversive odor, bitter taste and oral irritation. There is a growing body of evidence demonstrating epigenetic chemosensory mechanisms through which fetal alcohol exposure increases adolescent alcohol acceptance, in part, by decreasing the aversion to alcohol's bitter and oral irritation qualities, as well as its odor. Given that alcohol and nicotine have noteworthy chemosensory qualities in common, we investigated whether fetal exposure to alcohol increased the acceptability of nicotine's odor and taste in adolescent rats. Study rats were alcohol-exposed during fetal development via the dams' liquid diet. Control animals received ad lib access to an iso-caloric, iso-nutritive diet throughout gestation. Odorant-induced innate behavioral responses to nicotine odor (Experiment 1 or orosensory-mediated responses to nicotine solutions (Experiment 2 were obtained, using whole-body plethysmography and brief access lick tests, respectively. Compared to controls, rats exposed to fetal alcohol showed an enhanced nicotine odor response that was paralleled by increased oral acceptability of nicotine. Given the common aversive component qualities imbued in the flavor profiles of both drugs, our findings demonstrate that like postnatal alcohol avidity, fetal alcohol exposure also influences nicotine acceptance, at a minimum, by decreasing the aversion of both its smell and taste. Moreover, they highlight potential chemosensory-based mechanism(s by which fetal alcohol exposure increases the later initial risk for nicotine use, thereby contributing to the co-morbid expression with enhanced alcohol avidity. Where common chemosensory mechanisms are

Prenatal alcohol exposure increases postnatal acceptability of nicotine odor and taste in adolescent rats.

Science.gov (United States)

Mantella, Nicole M; Youngentob, Steven L

2014-01-01

Human studies indicate that alcohol exposure during gestation not only increases the chance for later alcohol abuse, but also nicotine dependence. The flavor attributes of both alcohol and nicotine can be important determinants of their initial acceptance and they both share the component chemosensory qualities of an aversive odor, bitter taste and oral irritation. There is a growing body of evidence demonstrating epigenetic chemosensory mechanisms through which fetal alcohol exposure increases adolescent alcohol acceptance, in part, by decreasing the aversion to alcohol's bitter and oral irritation qualities, as well as its odor. Given that alcohol and nicotine have noteworthy chemosensory qualities in common, we investigated whether fetal exposure to alcohol increased the acceptability of nicotine's odor and taste in adolescent rats. Study rats were alcohol-exposed during fetal development via the dams' liquid diet. Control animals received ad lib access to an iso-caloric, iso-nutritive diet throughout gestation. Odorant-induced innate behavioral responses to nicotine odor (Experiment 1) or orosensory-mediated responses to nicotine solutions (Experiment 2) were obtained, using whole-body plethysmography and brief access lick tests, respectively. Compared to controls, rats exposed to fetal alcohol showed an enhanced nicotine odor response that was paralleled by increased oral acceptability of nicotine. Given the common aversive component qualities imbued in the flavor profiles of both drugs, our findings demonstrate that like postnatal alcohol avidity, fetal alcohol exposure also influences nicotine acceptance, at a minimum, by decreasing the aversion of both its smell and taste. Moreover, they highlight potential chemosensory-based mechanism(s) by which fetal alcohol exposure increases the later initial risk for nicotine use, thereby contributing to the co-morbid expression with enhanced alcohol avidity. Where common chemosensory mechanisms are at play, our

Hippocampal nicotinic receptors have a modulatory role for ethanol and MDMA interaction in memory retrieval.

Science.gov (United States)

Rostami, Maryam; Rezayof, Ameneh; Alijanpour, Sakineh; Sharifi, Khadijeh Alsadat

2017-08-15

The aim of the current study was to examine the effect of dorsal hippocampal nicotinic acetylcholine receptors (nAChRs) activation on the functional interaction between ethanol and 3,4-methylenedioxy-N-methylamphetamine (MDMA or ecstasy) in memory retrieval. The dorsal hippocampal CA1 regions of adult male NMRI mice were bilaterally cannulated and memory retrieval was measured in a step-down type passive avoidance apparatus. Post-training or pre-test systemic administration of ethanol (1g/kg, i.p.) induced amnesia. Pre-test administration of ethanol reversed pre-training ethanol-induced amnesia, suggesting ethanol state-dependent learning. Pre-test intra-CA1 microinjection of different doses of MDMA (0.25-1µg/mouse) with an ineffective dose of ethanol (0.25g/kg, i.p.) also induced amnesia. Interestingly, pre-test intra-CA1 microinjection of MDMA (0.25-1µg/mouse) potentiated ethanol state-dependent learning. On the other hand, the activation of the dorsal hippocampal nAChRs by pre-test microinjection of nicotine (0.1-1µg/mouse, intra-CA1) improved amnesia induced by the co-administration of MDMD and ethanol. It is important to note that intra-CA1 microinjection of the same doses of MDMA or nicotine could not affect memory formation by itself. Pre-test intra-CA1 microinjection of nicotine (0.3-0.9µg/mouse) could not reverse amnesia induced by pre-training administration of ethanol while this treatment enhanced MDMA response on ethanol state-dependent learning. Thus, it can be concluded that there may be functional interactions among ethanol, MDMA and nicotine via the dorsal hippocampal nicotinic acetylcholine receptor mechanism in memory retrieval and drug state-dependent learning. Copyright © 2017 Elsevier B.V. All rights reserved.

Complex osteoclastogenic inductive effects of nicotine over hydroxyapatite.

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Costa-Rodrigues, Joao; Rocha, Isabel; Fernandes, Maria H

2018-02-01

Cigarette smoke is associated to pathological weakening of bone tissue, being considered an important playmaker in conditions such as osteoporosis and periodontal bone loss. In addition, it is also associated with an increased risk of failure in bone regeneration strategies. The present work aimed to characterize the effects of nicotine on human osteoclastogenesis over a hydroxyapatite substrate. Osteoclast precursors were maintained in the absence or presence of the osteoclastogenesis enhancers M-CSF and RANKL, and were further treated with nicotine levels representative of the concentrations observed in the plasma and saliva of smokers. It was observed that nicotine at low concentrations elicit an increase in osteoclast differentiation, but only in the presence of M-CSF and RANKL it was also able to significantly increase the resorbing ability of osteoclasts. A slight downregulation of NFkB pathway and an increase in the production of TNF-α and, particularly PGE2, were involved in the observed effects of nicotine. At high concentrations, nicotine revealed cytotoxic effects, causing a decrease in cell density. In conclusion, nicotine at levels found in the plasma of the smokers, has the ability to act directly on osteoclast precursors, inducing its osteoclastogenic differentiation. The stimulatory behavior appears to be dependent on the stage of osteoclastic differentiation of the precursor cells, which means, in the absence of M-CSF and RANKL, it only favors the initial stages of osteoclast differentiation, while in the presence of the growth factors, a significant increase in their resorbing ability is also achieved. © 2017 Wiley Periodicals, Inc.

Prefrontal gamma-aminobutyric acid type A receptor insertion controls cue-induced relapse to nicotine seeking.

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Lubbers, Bart R; van Mourik, Yvar; Schetters, Dustin; Smit, August B; De Vries, Taco J; Spijker, Sabine

2014-11-01

Current smoking cessation therapies offer limited success, as relapse rates remain high. Nicotine, which is the major component of tobacco smoke, is thought to be primarily responsible for the addictive properties of tobacco. However, little is known about the molecular mechanisms underlying nicotine relapse, hampering development of more effective therapies. The objective of this study was to elucidate the role of medial prefrontal cortex (mPFC) glutamatergic and gamma-aminobutyric acid (GABA)ergic receptors in controlling relapse to nicotine seeking. Using an intravenous self-administration model, we studied glutamate and gamma-aminobutyric acid receptor regulation in the synaptic membrane fraction of the rat mPFC following extinction and cue-induced relapse to nicotine seeking. Subsequently, we locally intervened at the level of GABAergic signaling by using a mimetic peptide of the GABA receptor associated protein-interacting domain of GABA type A (GABAA) receptor subunit γ2 (TAT-GABAγ2) and muscimol, a GABAA receptor agonist. Alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid and N-methyl-D-aspartate receptors were not regulated after the 30-min relapse test. However, GABAA receptor subunits α1 and γ2 were upregulated, and interference with GABAA receptor insertion in the cell membrane using the TAT-GABAγ2 peptide in the dorsal mPFC, but not the ventral mPFC, significantly increased responding during relapse. Increasing GABAA transmission with muscimol in the dorsal and ventral mPFC attenuated relapse. These data indicate that cue-induced relapse entails a GABAergic plasticity mechanism that limits nicotine seeking by restoring inhibitory control in the dorsal mPFC. GABAA receptor-mediated neurotransmission in the dorsal mPFC constitutes a possible future therapeutic target for maintaining smoking abstinence. Copyright © 2014 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Nicotine-induced activation of caudate and anterior cingulate cortex in response to errors in schizophrenia.

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Moran, Lauren V; Stoeckel, Luke E; Wang, Kristina; Caine, Carolyn E; Villafuerte, Rosemond; Calderon, Vanessa; Baker, Justin T; Ongur, Dost; Janes, Amy C; Evins, A Eden; Pizzagalli, Diego A

2018-03-01

Nicotine improves attention and processing speed in individuals with schizophrenia. Few studies have investigated the effects of nicotine on cognitive control. Prior functional magnetic resonance imaging (fMRI) research demonstrates blunted activation of dorsal anterior cingulate cortex (dACC) and rostral anterior cingulate cortex (rACC) in response to error and decreased post-error slowing in schizophrenia. Participants with schizophrenia (n = 13) and healthy controls (n = 12) participated in a randomized, placebo-controlled, crossover study of the effects of transdermal nicotine on cognitive control. For each drug condition, participants underwent fMRI while performing the stop signal task where participants attempt to inhibit prepotent responses to "go (motor activation)" signals when an occasional "stop (motor inhibition)" signal appears. Error processing was evaluated by comparing "stop error" trials (failed response inhibition) to "go" trials. Resting-state fMRI data were collected prior to the task. Participants with schizophrenia had increased nicotine-induced activation of right caudate in response to errors compared to controls (DRUG × GROUP effect: p corrected  state functional connectivity analysis, relative to controls, participants with schizophrenia had significantly decreased connectivity between the right caudate and dACC/bilateral dorsolateral prefrontal cortices. In sum, we replicated prior findings of decreased post-error slowing in schizophrenia and found that nicotine was associated with more adaptive (i.e., increased) post-error reaction time (RT). This proof-of-concept pilot study suggests a role for nicotinic agents in targeting cognitive control deficits in schizophrenia.

Dietary spices protect against hydrogen peroxide-induced DNA damage and inhibit nicotine-induced cancer cell migration.

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Jayakumar, R; Kanthimathi, M S

2012-10-01

Spices are rich sources of antioxidants due to the presence of phenols and flavonoids. In this study, the DNA protecting activity and inhibition of nicotine-induced cancer cell migration of 9 spices were analysed. Murine fibroblasts (3T3-L1) and human breast cancer (MCF-7) cells were pre-treated with spice extracts and then exposed to H₂O₂ and nicotine. The comet assay was used to analyse the DNA damage. Among the 9 spices, ginger, at 50 μg/ml protected against 68% of DNA damage in 3T3-L1 cells. Caraway, cumin and fennel showed statistically significant (pspices reduced this migration. Pepper, long pepper and ginger exhibited a high rate of inhibition of cell migration. The results of this study prove that spices protect DNA and inhibit cancer cell migration. Copyright © 2012 Elsevier Ltd. All rights reserved.

Regular nicotine intake increased tooth movement velocity, osteoclastogenesis and orthodontically induced dental root resorptions in a rat model

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Kirschneck, Christian; Maurer, Michael; Wolf, Michael; Reicheneder, Claudia; Proff, Peter

2017-01-01

Orthodontic forces have been reported to significantly increase nicotine-induced periodontal bone loss. At present, however, it is unknown, which further (side) effects can be expected during orthodontic treatment at a nicotine exposure corresponding to that of an average European smoker. 63 male Fischer344 rats were randomized in three consecutive experiments of 21 animals each (A/B/C) to 3 experimental groups (7 rats, 1/2/3): (A) cone-beam-computed tomography (CBCT); (B) histology/serology; (C) reverse-transcription quantitative real-time polymerase chain reaction (RT-qPCR)/cotinine serology—(1) control; (2) orthodontic tooth movement (OTM) of the first and second upper left molar (NiTi closed coil spring, 0.25 N); (3) OTM with 1.89 mg·kg−1 per day s.c. of L(−)-nicotine. After 14 days of OTM, serum cotinine and IL-6 concentration as well as orthodontically induced inflammatory root resorption (OIIRR), osteoclast activity (histology), orthodontic tooth movement velocity (CBCT, within 14 and 28 days of OTM) and relative gene expression of known inflammatory and osteoclast markers were quantified in the dental-periodontal tissue (RT–qPCR). Animals exposed to nicotine showed significantly heightened serum cotinine and IL-6 levels corresponding to those of regular European smokers. Both the extent of root resorption, osteoclast activity, orthodontic tooth movement and gene expression of inflammatory and osteoclast markers were significantly increased compared to controls with and without OTM under the influence of nicotine. We conclude that apart from increased periodontal bone loss, a progression of dental root resorption and accelerated orthodontic tooth movement are to be anticipated during orthodontic therapy, if nicotine consumption is present. Thus patients should be informed about these risks and the necessity of nicotine abstinence during treatment. PMID:28960194

Chronic Underactivity of Medial Frontal Cortical β2-Containing Nicotinic Receptors Increases Clozapine-Induced Working Memory Impairment in Female Rats

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Levin, Edward D.; Perkins, Abigail; Brotherton, Terrell; Qazi, Melissa; Berez, Chantal; Montalvo-Ortiz, Janitza; Davis, Kasey; Williams, Paul; Christopher, N. Channelle

2009-01-01

Nicotinic receptor decreases in the frontal cortex and hippocampus are important mediators of cognitive impairment in both schizophrenia and Alzheimer's disease. Drug treatments for these diseases should take into account the impacts of compromised brain function on drug response. This study investigated the impact of compromised nicotinic receptor activity in the frontal cortex in rats on memory function. Since both Alzheimer's disease and schizophrenia can involve psychosis, antipsychotic drugs are often given. The impacts of antipsychotic drugs on cognitive function have been found to be quite variable. It is the hypothesis of this and previous studies that the cognitive effects of antispychotic drugs on cognitive function depend on the integrity of brain systems involved in cognition. Previously in studies of the hippocampus, we found that chronic inhibition of β2-containing nicotinic receptors with dihydro-β-erythrodine (DHβE) impaired working memory and that this effect was attenuated by the antipsychotic drug clozapine. In contrast, chronic hippocampal α7 nicotinic receptor blockade with methyllycaconitine (MLA) potentiated the clozapine-induced memory impairment which is seen in rats without compromised nicotinic receptor activity. The current study determined medial frontal cortical α7 and β2-containing nicotinic receptor involvement in memory and the interactions with antipsychotic drug therapy with clozapine. Chronic DHβE and MLA infusion effects and interactions with systemic clozapine were assessed in female rats tested for memory on the radial-arm maze. Antipsychotic drug interactions with chronic systemic nicotine were investigated because nicotinic procognitive treatment has been proposed. The same local infusion DHβE dose that impaired memory with hippocampal infusion did not impair memory when infused in the medial frontal cortex. Frontal DHβE infusion potentiated clozapine-induced memory impairment, whereas previously the memory

Chronic underactivity of medial frontal cortical beta2-containing nicotinic receptors increases clozapine-induced working memory impairment in female rats.

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Levin, Edward D; Perkins, Abigail; Brotherton, Terrell; Qazi, Melissa; Berez, Chantal; Montalvo-Ortiz, Janitza; Davis, Kasey; Williams, Paul; Christopher, N Channelle

2009-03-17

Nicotinic receptor decreases in the frontal cortex and hippocampus are important mediators of cognitive impairment in both schizophrenia and Alzheimer's disease. Drug treatments for these diseases should take into account the impacts of compromised brain function on drug response. This study investigated the impact of compromised nicotinic receptor activity in the frontal cortex in rats on memory function. Since both Alzheimer's disease and schizophrenia can involve psychosis, antipsychotic drugs are often given. The impacts of antipsychotic drugs on cognitive function have been found to be quite variable. It is the hypothesis of this and previous studies that the cognitive effects of antispychotic drugs on cognitive function depend on the integrity of brain systems involved in cognition. Previously in studies of the hippocampus, we found that chronic inhibition of beta2-containing nicotinic receptors with dihydro-beta-erythrodine (DHbetaE) impaired working memory and that this effect was attenuated by the antipsychotic drug clozapine. In contrast, chronic hippocampal alpha7 nicotinic receptor blockade with methyllycaconitine (MLA) potentiated the clozapine-induced memory impairment which is seen in rats without compromised nicotinic receptor activity. The current study determined medial frontal cortical alpha7 and beta2-containing nicotinic receptor involvement in memory and the interactions with antipsychotic drug therapy with clozapine. Chronic DHbetaE and MLA infusion effects and interactions with systemic clozapine were assessed in female rats tested for memory on the radial-arm maze. Antipsychotic drug interactions with chronic systemic nicotine were investigated because nicotinic procognitive treatment has been proposed. The same local infusion DHbetaE dose that impaired memory with hippocampal infusion did not impair memory when infused in the medial frontal cortex. Frontal DHbetaE infusion potentiated clozapine-induced memory impairment, whereas previously

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.

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.

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.

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.

Developmental hippocampal neuroplasticity in a model of nicotine replacement therapy during pregnancy and breastfeeding.

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Ian Mahar

Full Text Available The influence of developmental nicotine exposure on the brain represents an important health topic in light of the popularity of nicotine replacement therapy (NRT as a smoking cessation method during pregnancy.In this study, we used a model of NRT during pregnancy and breastfeeding to explore the consequences of chronic developmental nicotine exposure on cerebral neuroplasticity in the offspring. We focused on two dynamic lifelong phenomena in the dentate gyrus (DG of the hippocampus that are highly sensitive to the environment: granule cell neurogenesis and long-term potentiation (LTP.Pregnant rats were implanted with osmotic mini-pumps delivering either nicotine or saline solutions. Plasma nicotine and metabolite levels were measured in dams and offspring. Corticosterone levels, DG neurogenesis (cell proliferation, survival and differentiation and glutamatergic electrophysiological activity were measured in pups.Juvenile (P15 and adolescent (P41 offspring exposed to nicotine throughout prenatal and postnatal development displayed no significant alteration in DG neurogenesis compared to control offspring. However, NRT-like nicotine exposure significantly increased LTP in the DG of juvenile offspring as measured in vitro from hippocampal slices, suggesting that the mechanisms underlying nicotine-induced LTP enhancement previously described in adult rats are already functional in pups.These results indicate that synaptic plasticity is disrupted in offspring breastfed by dams passively exposed to nicotine in an NRT-like fashion.

Electronic cigarettes induce DNA strand breaks and cell death independently of nicotine in cell lines.

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Yu, Vicky; Rahimy, Mehran; Korrapati, Avinaash; Xuan, Yinan; Zou, Angela E; Krishnan, Aswini R; Tsui, Tzuhan; Aguilera, Joseph A; Advani, Sunil; Crotty Alexander, Laura E; Brumund, Kevin T; Wang-Rodriguez, Jessica; Ongkeko, Weg M

2016-01-01

Evaluate the cytotoxicity and genotoxicity of short- and long-term e-cigarette vapor exposure on a panel of normal epithelial and head and neck squamous cell carcinoma (HNSCC) cell lines. HaCaT, UMSCC10B, and HN30 were treated with nicotine-containing and nicotine-free vapor extract from two popular e-cigarette brands for periods ranging from 48 h to 8 weeks. Cytotoxicity was assessed using Annexin V flow cytometric analysis, trypan blue exclusion, and clonogenic assays. Genotoxicity in the form of DNA strand breaks was quantified using the neutral comet assay and γ-H2AX immunostaining. E-cigarette-exposed cells showed significantly reduced cell viability and clonogenic survival, along with increased rates of apoptosis and necrosis, regardless of e-cigarette vapor nicotine content. They also exhibited significantly increased comet tail length and accumulation of γ-H2AX foci, demonstrating increased DNA strand breaks. E-cigarette vapor, both with and without nicotine, is cytotoxic to epithelial cell lines and is a DNA strand break-inducing agent. Further assessment of the potential carcinogenic effects of e-cigarette vapor is urgently needed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Validation of the human odor span task: effects of nicotine.

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MacQueen, David A; Drobes, David J

2017-10-01

Amongst non-smokers, nicotine generally enhances performance on tasks of attention, with limited effect on working memory. In contrast, nicotine has been shown to produce robust enhancements of working memory in non-humans. To address this gap, the present study investigated the effects of nicotine on the performance of non-smokers on a cognitive battery which included a working memory task reverse-translated from use with rodents (the odor span task, OST). Nicotine has been reported to enhance OST performance in rats and the present study assessed whether this effect generalizes to human performance. Thirty non-smokers were tested on three occasions after consuming either placebo, 2 mg, or 4 mg nicotine gum. On each occasion, participants completed a battery of clinical and experimental tasks of working memory and attention. Nicotine was associated with dose-dependent enhancements in sustained attention, as evidenced by increased hit accuracy on the rapid visual information processing (RVIP) task. However, nicotine failed to produce main effects on OST performance or on alternative measures of working memory (digit span, spatial span, letter-number sequencing, 2-back) or attention (digits forward, 0-back). Interestingly, enhancement of RVIP performance occurred concomitant to significant reductions in self-reported attention/concentration. Human OST performance was significantly related to N-back performance, and as in rodents, OST accuracy declined with increasing memory load. Given the similarity of human and rodent OST performance under baseline conditions and the strong association between OST and visual 0-back accuracy, the OST may be particular useful in the study of conditions characterized by inattention.

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

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

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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.

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

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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....

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.

Moringa oleifera phytochemicals protect the brain against experimental nicotine-induced neurobehavioral disturbances and cerebellar degeneration.

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Omotoso, Gabriel Olaiya; Gbadamosi, Ismail Temitayo; Olajide, Olayemi Joseph; Dada-Habeeb, Shakirat Opeyemi; Arogundade, Tolulope Timothy; Yawson, Emmanuel Olusola

2018-03-01

Nicotine is a neuro-stimulant that has been implicated in the pathophysiology of many brain diseases. The need to prevent or alleviate the resulting dysfunction is therefore paramount, which has also given way to the use of medicinal plants in the management of brain conditions. This study was designed to determine the histomorphological and neurobehavioural changes in the cerebellum of Wistar rats following nicotine insult and how such injuries respond to Moringa intervention. Twenty-four adult male Wistar rats were divided into 4 groups. Group A and B were orally treated with normal saline and Moringa oleifera respectively for twenty-eight days; Group C was treated with nicotine while group D was treated orally with Moringa oleifera and intraperitoneally with nicotine for twenty-eight days. Animals were subjected to the open field test on the last day of treatment. 24 h after last day treatment, the animals were anesthetized and perfusion fixation was carried out. The cerebellum was excised and post-fixed in 4% paraformaldehyde and thereafter put through routine histological procedures. Results revealed cytoarchitectural distortion and extreme chromatolysis in neuronal cells of the cerebellar cortical layers in the nicotine-treated group. The Purkinje cells of the cerebellum of animals in this group were degenerated. There were also reduced locomotor activities in the group. Moringa was able to prevent the chromatolysis, distortion of the cerebellar cortical cells and neurobehavioural deficit. Our result suggests that Moringa oleifera could prevent nicotine-induced cerebellar injury in Wistar rats, with the possibility of ameliorating the clinical features presented in associated cerebellar pathology. Copyright © 2018 Elsevier B.V. All rights reserved.

Nicotine-induced Disturbances of Meiotic Maturation in Cultured Mouse Oocytes: Alterations of Spindle Integrity and Chromosome Alignment

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Zenzes Maria

2004-09-01

Full Text Available Abstract We investigated whether nicotine exposure in vitro of mouse oocytes affects spindle and chromosome function during meiotic maturation (M-I and M-II. Oocytes in germinal vesicle (GV stage were cultured in nicotine for 8 h or for 16 h, to assess effects in M-I and in metaphase II (M-II. The latter culture setting used the three protocols: 8 h nicotine then 8 h medium (8N + 8M; 16 h nicotine (16N; 8 h medium then 8 h nicotine (8M + 8N. Non-toxic concentrations of nicotine at 1.0, 2.5, 5.0 and 10.0 mmol/L were used. Spindle-chromosome configurations were analyzed with wide-field optical sectioning microscopy. In 8 h cultures, nicotine exposure resulted in dose-related increased proportions of M-I oocytes with defective spindle-chromosome configurations. A dose-related delayed entry into anaphase I was also detected. In 16 h cultures, nicotine exposure for the first 8 h (8N + 8M, or for 16 h (16N, resulted in dose- and time-related increased proportions of oocytes arrested in M-I (10 mmol/L; 8 h: 53.2%, controls 9.6%; 16 h: 87.6%, controls 8.5%. Defects in M-I spindles and chromosomes caused M-I arrest leading to dose-related decreased proportions of oocytes that reached metaphase-II (10 mmol/L 8 h: 46.8%, controls 90.4%;16 h: 12.4%, controls 91.5%. A delayed anaphase-I affected the normal timing of M-II, leading to abnormal oocytes with dispersed chromosomes, or with double spindles and no polar body. Nicotine exposure during the second 8 h (8M + 8N resulted in dose-related, increased proportions of M-II oocytes with defective spindles and chromosomes (10 mmol/L: 42.9%, controls 2.0%. Nicotine has no adverse effects on GV break down, but induces spindle and chromosome defects compromising oocyte meiotic maturation and development.

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

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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

Effects of BMS-902483, an α7 nicotinic acetylcholine receptor partial agonist, on cognition and sensory gating in relation to receptor occupancy in rodents.

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Pieschl, Rick L; Miller, Regina; Jones, Kelli M; Post-Munson, Debra J; Chen, Ping; Newberry, Kimberly; Benitex, Yulia; Molski, Thaddeus; Morgan, Daniel; McDonald, Ivar M; Macor, John E; Olson, Richard E; Asaka, Yukiko; Digavalli, Siva; Easton, Amy; Herrington, James; Westphal, Ryan S; Lodge, Nicholas J; Zaczek, Robert; Bristow, Linda J; Li, Yu-Wen

2017-07-15

The α7 nicotinic acetylcholine receptor is thought to play an important role in human cognition. Here we describe the in vivo effects of BMS-902483, a selective potent α7 nicotinic acetylcholine receptor partial agonist, in relationship to α7 nicotinic acetylcholine receptor occupancy. BMS-902483 has low nanomolar affinity for rat and human α7 nicotinic acetylcholine receptors and elicits currents in cells expressing human or rat α7 nicotinic acetylcholine receptors that are about 60% of the maximal acetylcholine response. BMS-902483 improved 24h novel object recognition memory in mice with a minimal effective dose (MED) of 0.1mg/kg and reversed MK-801-induced deficits in a rat attentional set-shifting model of executive function with an MED of 3mg/kg. Enhancement of novel object recognition was blocked by the silent α7 nicotinic acetylcholine receptor agonist, NS6740, demonstrating that activity of BMS-902483 was mediated by α7 nicotinic acetylcholine receptors. BMS-902483 also reversed ketamine-induced deficits in auditory gating in rats, and enhanced ex vivo hippocampal long-term potentiation examined 24h after dosing in mice. Results from an ex vivo brain homogenate binding assay showed that α7 receptor occupancy ranged from 64% (novel object recognition) to ~90% (set shift and gating) at the MED for behavioral and sensory processing effects of BMS-902483. Copyright © 2017 Elsevier B.V. All rights reserved.

Modulation of Intestinal Barrier and Bacterial Endotoxin Production Contributes to the Beneficial Effect of Nicotinic Acid on Alcohol-Induced Endotoxemia and Hepatic Inflammation in Rats

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Wei Zhong

2015-10-01

Full Text Available Alcohol consumption causes nicotinic acid deficiency. The present study was undertaken to determine whether dietary nicotinic acid supplementation provides beneficial effects on alcohol-induced endotoxin signaling and the possible mechanisms at the gut-liver axis. Male Sprague-Dawley rats were pair-fed the Lieber-DeCarli liquid diets containing ethanol or isocaloric maltose dextrin for eight weeks, with or without dietary supplementation with 750 mg/liter nicotinic acid. Chronic alcohol feeding elevated the plasma endotoxin level and activated hepatic endotoxin signaling cascade, which were attenuated by nicotinic acid supplementation. Alcohol consumption remarkably decreased the mRNA levels of claudin-1, claudin-5, and ZO-1 in the distal intestine, whereas nicotinic acid significantly up-regulated these genes. The concentrations of endotoxin, ethanol, and acetaldehyde in the intestinal contents were increased by alcohol exposure, and niacin supplementation reduced the intestinal endotoxin and acetaldehyde levels. Nicotinic acid supplementation upregulated the intestinal genes involved in aldehyde detoxification via transcriptional regulation. These results demonstrate that modulation of the intestinal barrier function and bacterial endotoxin production accounts for the inhibitory effects of nicotinic acid on alcohol-induced endotoxemia and hepatic inflammation.

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

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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.

Nicotinic acid- and monomethyl fumarate-induced flushing involves GPR109A expressed by keratinocytes and COX-2-dependent prostanoid formation in mice

NARCIS (Netherlands)

Hanson, Julien; Gille, Andreas; Zwykiel, Sabrina; Lukasova, Martina; Clausen, Björn E.; Ahmed, Kashan; Tunaru, Sorin; Wirth, Angela; Offermanns, Stefan

2010-01-01

The antidyslipidemic drug nicotinic acid and the antipsoriatic drug monomethyl fumarate induce cutaneous flushing through activation of G protein-coupled receptor 109A (GPR109A). Flushing is a troublesome side effect of nicotinic acid, but may be a direct reflection of the wanted effects of

Waterpipe tobacco products: nicotine labelling versus nicotine delivery.

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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.

Nucleosome Repositioning: A Novel Mechanism for Nicotine- and Cocaine-Induced Epigenetic Changes.

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Amber N Brown

Full Text Available Drugs of abuse modify behavior by altering gene expression in the brain. Gene expression can be regulated by changes in DNA methylation as well as by histone modifications, which alter chromatin structure, DNA compaction and DNA accessibility. In order to better understand the molecular mechanisms directing drug-induced changes in chromatin structure, we examined DNA-nucleosome interactions within promoter regions of 858 genes in human neuroblastoma cells (SH-SY5Y exposed to nicotine or cocaine. Widespread, drug- and time-resolved repositioning of nucleosomes was identified at the transcription start site and promoter region of multiple genes. Nicotine and cocaine produced unique and shared changes in terms of the numbers and types of genes affected, as well as repositioning of nucleosomes at sites which could increase or decrease the probability of gene expression based on DNA accessibility. Half of the drug-induced nucleosome positions approximated a theoretical model of nucleosome occupancy based on physical and chemical characteristics of the DNA sequence, whereas the basal or drug naïve positions were generally DNA sequence independent. Thus we suggest that nucleosome repositioning represents an initial dynamic genome-wide alteration of the transcriptional landscape preceding more selective downstream transcriptional reprogramming, which ultimately characterizes the cell- and tissue-specific responses to drugs of abuse.

Design, formulation and evaluation of nicotine chewing gum

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Abolfazl Aslani

2012-01-01

Conclusion: 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.

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...

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

Enhanced Chromatographic Determination of Nicotine in Human Plasma: Applied to Human Volunteers.

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Ayoub, Bassam M; Mohamady, Samy; Hendy, Moataz S; Elmazar, Mohamed M

2015-12-01

Development of enhanced UPLC-UV method for determination of nicotine in human plasma was achieved on a Symmetry(®) C18 column (100 mm × 2.1 mm, 2.2 μm) applying isocratic elution based on Methanol: Acetonitrile: Phosphate Buffer (pH: 2.7) with the ratio (20:30:50, v/v/v) as a mobile phase. The ultraviolet detector was operated at 260 nm. The mobile phase was pumped through the column at a flow rate of 0.2 mL min(-1). The column temperature was adjusted to 50ºC and the injection volume was 2 μL. Quinine was selected as an internal standard (IS) due to its structure similarity to nicotine having basic pyridine ring to optimize the liquid liquid extraction procedure using diethyl ether coupled with vacuum evaporation at 40°C. Validation parameters for nicotine were found to be acceptable over the concentration range of 2.5-50 ng ml(-1). The application of the proposed method on four healthy human volunteers was approved by the ethical committee. The study was carried out under fasting conditions and the concerned subjects were informed about the objectives and possible risks involved in the study. The proposed method proved to be simple and fast which is a major advantage to analyze large number of samples per day using the accelerated vacuum evaporation technique. The method showed satisfactory data for all the parameters tested within the limits for bioanalytical assays. The lower limit of quantification (LLOQ) permits the application of the method for further pharmacological and clinical studies.

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

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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.

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.

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

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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.

Protective Effect of Vitamin E on Nicotine Induced Reproductive ...

African Journals Online (AJOL)

The current study assessed the protective role of vitamin E in alleviating the detrimental effect of nicotine on reproductive functions in male rats. Twenty four male albino rats were divided into four groups of six rats. Control group was treated orally with 1.1 ml/kg body weight normal saline, nicotine treated group received 1.0 ...

Protective effect of Urtica dioica L against nicotine-induced damage on sperm parameters, testosterone and testis tissue in mice.

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Jalili, Cyrus; Salahshoor, Mohammad Reza; Naseri, Ali

2014-06-01

Nicotine consumption can decrease fertility drive in males by inducing oxidative stress and DNA damage. Urtica dioica L (U.dioica) is a multipurpose herb in traditional medicine for which some anti-oxidative and anti-inflammatory properties have been identified. The main goal is to investigate whether the U.dioica could inhibit nicotine adverse effects on sperm cells viability, count, motility, and testis histology and testosterone hormone. In this study, hydro-alcoholic extract of U.dioica was prepared and various doses of U.dioica (0, 10, 20, and 50 mg/kg) and U.dioica plus nicotine (0, 10, 20, and 50 mg/kg) were administered intraperitoneally to 56 male mice for 28 consequent days. These mice were randomly assigned to 8 groups (n=7) and sperm parameters (sperm cells viability, count, motility, and morphology), testis and prostate weight, testis histology and testosterone hormone were analyzed and compared. The results indicated that nicotine administration (0.5 mg/kg) significantly decreased testosterone level, count and motility of sperm cells, and testis weight compared to control group (p=0.00). However, increasing the dose of U.dioica significantly boosted motility, count, normal morphology of sperm cells, seminiferous tubules diameter, and testosterone in all groups compared to control (p=0.00) and testis weight in 20 and 50 mg/kg doses in comparison with control group (p=0.00). It seems that U.dioica hydro-alcoholic extract administration could increase the quality of spermatozoa and inhibits nicotine-induced adverse effects on sperm parameters.

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.

Unraveling the concentration-dependent metabolic response of Pseudomonas sp. HF-1 to nicotine stress by ¹H NMR-based metabolomics.

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Ye, Yangfang; Wang, Xin; Zhang, Limin; Lu, Zhenmei; Yan, Xiaojun

2012-07-01

Nicotine can cause oxidative damage to organisms; however, some bacteria, for example Pseudomonas sp. HF-1, are resistant to such oxidative stress. In the present study, we analyzed the concentration-dependent metabolic response of Pseudomonas sp. HF-1 to nicotine stress using ¹H NMR spectroscopy coupled with multivariate data analysis. We found that the dominant metabolites in Pseudomonas sp. HF-1 were eight aliphatic organic acids, six amino acids, three sugars and 11 nucleotides. After 18 h of cultivation, 1 g/L nicotine caused significant elevation of sugar (glucose, trehalose and maltose), succinate and nucleic acid metabolites (cytidine, 5'-CMP, guanine 2',3'-cyclic phosphate and adenosine 2',3'-cyclic phosphate), but decrease of glutamate, putrescine, pyrimidine, 2-propanol, diethyl ether and acetamide levels. Similar metabolomic changes were induced by 2 g/L nicotine, except that no significant change in trehalose, 5'-UMP levels and diethyl ether were found. However, 3 g/L nicotine led to a significant elevation in the two sugars (trehalose and maltose) levels and decrease in the levels of glutamate, putrescine, pyrimidine and 2-propanol. Our findings indicated that nicotine resulted in the enhanced nucleotide biosynthesis, decreased glucose catabolism, elevated succinate accumulation, severe disturbance in osmoregulation and complex antioxidant strategy. And a further increase of nicotine level was a critical threshold value that triggered the change of metabolic flow in Pseudomonas sp. HF-1. These findings revealed the comprehensive insights into the metabolic response of nicotine-degrading bacteria to nicotine-induced oxidative toxicity.

Platelet activation, adhesion, inflammation, and aggregation potential are altered in the presence of electronic cigarette extracts of variable nicotine concentrations.

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Hom, Sarah; Chen, Li; Wang, Tony; Ghebrehiwet, Berhane; Yin, Wei; Rubenstein, David A

2016-11-01

Tobacco smoke extracts prepared from both mainstream and sidestream smoking have been associated with heightened platelet activation, aggregation, adhesion, and inflammation. Conversely, it has been shown that pure nicotine inhibits similar platelet functions. In this work, we 1) evaluated the effects of e-cigarette extracts on platelet activities and 2) elucidated the differences between the nicotine-dependent and non-nicotine dependent (e.g. fine particulate matter or toxic compounds) effects of tobacco and e-cigarette products on platelet activities. To accomplish these goals, platelets from healthy volunteers (n = 50) were exposed to tobacco smoke extracts, e-cigarette vapor extracts, and pure nicotine and changes in platelet activation, adhesion, aggregation, and inflammation were evaluated, using optical aggregation, flow cytometry, and ELISA methods. Interestingly, the exposure of platelets to e-vapor extracts induced a significant up-regulation in the expression of the pro-inflammatory gC1qR and cC1qR and induced a marked increase in the deposition of C3b as compared with traditional tobacco smoke extracts. Similarly, platelet activation, as measured by a prothrombinase based assay, and platelet aggregation were also significantly enhanced after exposure to e-vapor extracts. Finally, platelet adhesion potential toward fibrinogen, von Willebrand factor, and other platelets was also enhanced after exposure to e-cigarette vapor extracts. In the presence of pure nicotine, platelet functions were observed to be inhibited, which further suggests that other constituents of tobacco smoke and electronic vapor can antagonize platelet functions, however, the presence of nicotine in extracts somewhat perpetuated the platelet functional changes in a dose-dependent manner.

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

Nicotine facilitates memory consolidation in perceptual learning.

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Beer, Anton L; Vartak, Devavrat; Greenlee, Mark W

2013-01-01

Perceptual learning is a special type of non-declarative learning that involves experience-dependent plasticity in sensory cortices. The cholinergic system is known to modulate declarative learning. In particular, reduced levels or efficacy of the neurotransmitter acetylcholine were found to facilitate declarative memory consolidation. However, little is known about the role of the cholinergic system in memory consolidation of non-declarative learning. Here we compared two groups of non-smoking men who learned a visual texture discrimination task (TDT). One group received chewing tobacco containing nicotine for 1 h directly following the TDT training. The other group received a similar tasting control substance without nicotine. Electroencephalographic recordings during substance consumption showed reduced alpha activity and P300 latencies in the nicotine group compared to the control group. When re-tested on the TDT the following day, both groups responded more accurately and more rapidly than during training. These improvements were specific to the retinal location and orientation of the texture elements of the TDT suggesting that learning involved early visual cortex. A group comparison showed that learning effects were more pronounced in the nicotine group than in the control group. These findings suggest that oral consumption of nicotine enhances the efficacy of nicotinic acetylcholine receptors. Our findings further suggest that enhanced efficacy of the cholinergic system facilitates memory consolidation in perceptual learning (and possibly other types of non-declarative learning). In that regard acetylcholine seems to affect consolidation processes in perceptual learning in a different manner than in declarative learning. Alternatively, our findings might reflect dose-dependent cholinergic modulation of memory consolidation. This article is part of a Special Issue entitled 'Cognitive Enhancers'. Copyright © 2012 Elsevier Ltd. All rights reserved.

Motoneuron axon pathfinding errors in zebrafish: Differential effects related to concentration and timing of nicotine exposure

International Nuclear Information System (INIS)

Menelaou, Evdokia; Paul, Latoya T.; Perera, Surangi N.; Svoboda, Kurt R.

2015-01-01

Nicotine exposure during embryonic stages of development can affect many neurodevelopmental processes. In the developing zebrafish, exposure to nicotine was reported to cause axonal pathfinding errors in the later born secondary motoneurons (SMNs). These alterations in SMN axon morphology coincided with muscle degeneration at high nicotine concentrations (15–30 μM). Previous work showed that the paralytic mutant zebrafish known as sofa potato exhibited nicotine-induced effects onto SMN axons at these high concentrations but in the absence of any muscle deficits, indicating that pathfinding errors could occur independent of muscle effects. In this study, we used varying concentrations of nicotine at different developmental windows of exposure to specifically isolate its effects onto subpopulations of motoneuron axons. We found that nicotine exposure can affect SMN axon morphology in a dose-dependent manner. At low concentrations of nicotine, SMN axons exhibited pathfinding errors, in the absence of any nicotine-induced muscle abnormalities. Moreover, the nicotine exposure paradigms used affected the 3 subpopulations of SMN axons differently, but the dorsal projecting SMN axons were primarily affected. We then identified morphologically distinct pathfinding errors that best described the nicotine-induced effects on dorsal projecting SMN axons. To test whether SMN pathfinding was potentially influenced by alterations in the early born primary motoneuron (PMN), we performed dual labeling studies, where both PMN and SMN axons were simultaneously labeled with antibodies. We show that only a subset of the SMN axon pathfinding errors coincided with abnormal PMN axonal targeting in nicotine-exposed zebrafish. We conclude that nicotine exposure can exert differential effects depending on the levels of nicotine and developmental exposure window. - Highlights: • Embryonic nicotine exposure can specifically affect secondary motoneuron axons in a dose-dependent manner. �

Motoneuron axon pathfinding errors in zebrafish: Differential effects related to concentration and timing of nicotine exposure

Energy Technology Data Exchange (ETDEWEB)

Menelaou, Evdokia; Paul, Latoya T. [Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803 (United States); Perera, Surangi N. [Joseph J. Zilber School of Public Health, University of Wisconsin — Milwaukee, Milwaukee, WI 53205 (United States); Svoboda, Kurt R., E-mail: svobodak@uwm.edu [Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803 (United States); Joseph J. Zilber School of Public Health, University of Wisconsin — Milwaukee, Milwaukee, WI 53205 (United States)

2015-04-01

Nicotine exposure during embryonic stages of development can affect many neurodevelopmental processes. In the developing zebrafish, exposure to nicotine was reported to cause axonal pathfinding errors in the later born secondary motoneurons (SMNs). These alterations in SMN axon morphology coincided with muscle degeneration at high nicotine concentrations (15–30 μM). Previous work showed that the paralytic mutant zebrafish known as sofa potato exhibited nicotine-induced effects onto SMN axons at these high concentrations but in the absence of any muscle deficits, indicating that pathfinding errors could occur independent of muscle effects. In this study, we used varying concentrations of nicotine at different developmental windows of exposure to specifically isolate its effects onto subpopulations of motoneuron axons. We found that nicotine exposure can affect SMN axon morphology in a dose-dependent manner. At low concentrations of nicotine, SMN axons exhibited pathfinding errors, in the absence of any nicotine-induced muscle abnormalities. Moreover, the nicotine exposure paradigms used affected the 3 subpopulations of SMN axons differently, but the dorsal projecting SMN axons were primarily affected. We then identified morphologically distinct pathfinding errors that best described the nicotine-induced effects on dorsal projecting SMN axons. To test whether SMN pathfinding was potentially influenced by alterations in the early born primary motoneuron (PMN), we performed dual labeling studies, where both PMN and SMN axons were simultaneously labeled with antibodies. We show that only a subset of the SMN axon pathfinding errors coincided with abnormal PMN axonal targeting in nicotine-exposed zebrafish. We conclude that nicotine exposure can exert differential effects depending on the levels of nicotine and developmental exposure window. - Highlights: • Embryonic nicotine exposure can specifically affect secondary motoneuron axons in a dose-dependent manner. �

Nicotine Impairs Macrophage Control of Mycobacterium tuberculosis.

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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.

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

Inside-out neuropharmacology of nicotinic drugs.

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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.

Adrenergic Component of Nicotine Antinociception in Rats | Ibironke ...

African Journals Online (AJOL)

African Journal of Biomedical Research ... Abstract. It has been widely established that nicotine , the active pharmacological agent in tobacco has antinociceptive effects , but the mechanism of this activity is yet to be fully ... These findings suggest the involvement of the adrenergic system in nicotine induced antinociception .

Comparative cytotoxicity study of nicotine and cotinine on MRC-5 cell line

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Ana-Maria Vlasceanu

2018-04-01

Full Text Available Nicotine has several health hazards regarding carcinogenic potential. It also imparts increased risk for respiratory, cardiovascular, and gastrointestinal disorders. Several mechanisms have been proposed for the carcinogenic potential, including effects on cell proliferation, inducing oxidative stress, DNA mutation, or inhibition of apoptosis. The cotinine metabolite is generally thought to have effects similar to nicotine in some experimental systems. The purpose of this study was to assess the nicotine and cotinine cytotoxicity on MRC-5 lung fibroblasts. The pulmonary fibroblasts were treated with various concentrations of nicotine or cotinine (in the range 1 µM – 2 mM for 24 or 48 h and analyzed for cell viability by MTT test. The results indicated that high nicotine concentrations (2 mM induced marked cell death (about 50% in MRC-5 cell line. Cotinine showed lower toxicity than nicotine on the MRC-5 cells. In contrast to nicotine treatment, cells treated with cotinine continued to proliferate after the 48h incubation period.

Fetal and neonatal exposure to nicotine leads to augmented hepatic and circulating triglycerides in adult male offspring due to increased expression of fatty acid synthase

International Nuclear Information System (INIS)

Ma, Noelle; Nicholson, Catherine J.; Wong, Michael; Holloway, Alison C.; Hardy, Daniel B.

2014-01-01

While nicotine replacement therapy is assumed to be a safer alternative to smoking during pregnancy, the long-term consequences for the offspring remain elusive. Animal studies now suggest that maternal nicotine exposure during perinatal life leads to a wide range of adverse outcomes for the offspring including increased adiposity. The focus of this study was to investigate if nicotine exposure during pregnancy and lactation leads to alterations in hepatic triglyceride synthesis. Female Wistar rats were randomly assigned to receive daily subcutaneous injections of saline (vehicle) or nicotine bitartrate (1 mg/kg/day) for two weeks prior to mating until weaning. At postnatal day 180 (PND 180), nicotine exposed offspring exhibited significantly elevated levels of circulating and hepatic triglycerides in the male offspring. This was concomitant with increased expression of fatty acid synthase (FAS), the critical hepatic enzyme in de novo triglyceride synthesis. Given that FAS is regulated by the nuclear receptor Liver X receptor (LXRα), we measured LXRα expression in both control and nicotine-exposed offspring. Nicotine exposure during pregnancy and lactation led to an increase in hepatic LXRα protein expression and enriched binding to the putative LXRE element on the FAS promoter in PND 180 male offspring. This was also associated with significantly enhanced acetylation of histone H3 [K9,14] surrounding the FAS promoter, a hallmark of chromatin activation. Collectively, these findings suggest that nicotine exposure during pregnancy and lactation leads to an increase in circulating and hepatic triglycerides long-term via changes in the transcriptional and epigenetic regulation of the hepatic lipogenic pathway. - Highlights: • Our data reveals the links nicotine exposure in utero and long-term hypertriglyceridemia. • It is due to nicotine-induced augmented expression of hepatic FAS and LXRα activity. • Moreover, this involves nicotine-induced enhanced

Fetal and neonatal exposure to nicotine leads to augmented hepatic and circulating triglycerides in adult male offspring due to increased expression of fatty acid synthase

Energy Technology Data Exchange (ETDEWEB)

Ma, Noelle [Department of Physiology and Pharmacology, The University of Western Ontario (Canada); Department of Obstetrics and Gynecology, The University of Western Ontario (Canada); The Lawson Health Research Institute, The University of Western Ontario (Canada); Nicholson, Catherine J. [Department of Obstetrics and Gynecology, McMaster University (Canada); Wong, Michael [Department of Physiology and Pharmacology, The University of Western Ontario (Canada); Department of Obstetrics and Gynecology, The University of Western Ontario (Canada); The Lawson Health Research Institute, The University of Western Ontario (Canada); Holloway, Alison C. [Department of Obstetrics and Gynecology, McMaster University (Canada); Hardy, Daniel B., E-mail: Daniel.Hardy@schulich.uwo.ca [Department of Physiology and Pharmacology, The University of Western Ontario (Canada); Department of Obstetrics and Gynecology, The University of Western Ontario (Canada); The Children' s Health Research Institute, The University of Western Ontario (Canada); The Lawson Health Research Institute, The University of Western Ontario (Canada)

2014-02-15

While nicotine replacement therapy is assumed to be a safer alternative to smoking during pregnancy, the long-term consequences for the offspring remain elusive. Animal studies now suggest that maternal nicotine exposure during perinatal life leads to a wide range of adverse outcomes for the offspring including increased adiposity. The focus of this study was to investigate if nicotine exposure during pregnancy and lactation leads to alterations in hepatic triglyceride synthesis. Female Wistar rats were randomly assigned to receive daily subcutaneous injections of saline (vehicle) or nicotine bitartrate (1 mg/kg/day) for two weeks prior to mating until weaning. At postnatal day 180 (PND 180), nicotine exposed offspring exhibited significantly elevated levels of circulating and hepatic triglycerides in the male offspring. This was concomitant with increased expression of fatty acid synthase (FAS), the critical hepatic enzyme in de novo triglyceride synthesis. Given that FAS is regulated by the nuclear receptor Liver X receptor (LXRα), we measured LXRα expression in both control and nicotine-exposed offspring. Nicotine exposure during pregnancy and lactation led to an increase in hepatic LXRα protein expression and enriched binding to the putative LXRE element on the FAS promoter in PND 180 male offspring. This was also associated with significantly enhanced acetylation of histone H3 [K9,14] surrounding the FAS promoter, a hallmark of chromatin activation. Collectively, these findings suggest that nicotine exposure during pregnancy and lactation leads to an increase in circulating and hepatic triglycerides long-term via changes in the transcriptional and epigenetic regulation of the hepatic lipogenic pathway. - Highlights: • Our data reveals the links nicotine exposure in utero and long-term hypertriglyceridemia. • It is due to nicotine-induced augmented expression of hepatic FAS and LXRα activity. • Moreover, this involves nicotine-induced enhanced

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.

Nicotinic α7 and α4β2 agonists enhance the formation and retrieval of recognition memory: Potential mechanisms for cognitive performance enhancement in neurological and psychiatric disorders.

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McLean, Samantha L; Grayson, Ben; Marsh, Samuel; Zarroug, Samah H O; Harte, Michael K; Neill, Jo C

2016-04-01

Cholinergic dysfunction has been shown to be central to the pathophysiology of Alzheimer's disease and has also been postulated to contribute to cognitive dysfunction observed in various psychiatric disorders, including schizophrenia. Deficits are found across a number of cognitive domains and in spite of several attempts to develop new therapies, these remain an unmet clinical need. In the current study we investigated the efficacy of donepezil, risperidone and selective nicotinic α7 and α4β2 receptor agonists to reverse a delay-induced deficit in recognition memory. Adult female Hooded Lister rats received drug treatments and were tested in the novel object recognition (NOR) task following a 6h inter-trial interval (ITI). In all treatment groups, there was no preference for the left or right identical objects in the acquisition trial. Risperidone failed to enhance recognition memory in this paradigm whereas donepezil was effective such that rats discriminated between the novel and familiar object in the retention trial following a 6h ITI. Although a narrow dose range of PNU-282987 and RJR-2403 was tested, only one dose of each increased recognition memory, the highest dose of PNU-282987 (10mg/kg) and the lowest dose of RJR-2403 (0.1mg/kg), indicative of enhanced cognitive performance. Interestingly, these compounds were also efficacious when administered either before the acquisition or the retention trial of the task, suggesting an important role for nicotinic receptor subtypes in the formation and retrieval of recognition memory. Copyright © 2016. Published by Elsevier B.V.

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

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.

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.

Inhibition of nicotine-DNA adduct formation by polyphenolic compounds in vitro

International Nuclear Information System (INIS)

Cheng Yan; Wang Haifang; Sun Hongfang; Li Hongli

2004-01-01

Nicotine[3-(1-methyl-2-pyrrolidinyl)-pyridine], a major alkaloid in tobacco products, has proven to be a potential genotoxic compound. Some polyphenolic compounds can suppress the DNA adduction, and hence act as the potential inhibitors of carcinogenesis. In this study, the inhibitory effects of three polyphenolic compounds, curcumin (diferuloylmethane), resveratrol (trans-3, 5, 4-trihydroxystilbene) and tea polyphenols, on the nicotine-DNA adduction have been investigated in vitro using radiolabelled nicotine and liquid scintillation counting (LSC) technique. Also, the inhibition mechanism of these chemopreventive agents in regard to the activity of the biotransformation enzymes, including cytochrome P450 (CYP450), cytochrome b 5 (CYb 5 ) and glutathione S-transferase (GST), has been studied. The results demonstrated that these three polyphenols induced marked dose-dependent decrease in nicotine-DNA adducts as compared with the controls. The elimination rate of adducts reached above 46% at the highest dose for all the three agents with 51.6% for resveratrol. Correspondingly, three polyphenols all suppressed CYP450 and CYb 5 , whereas curcumin and resveratrol induced GST. The authors may arrive at a point that the three polyphenols are beneficial to prevent the nicotine adduct formation, and thus may be used to block the potential carcinogenesis induced by nicotine. (authors)

alpha(7) Nicotinic acetylcholine receptor activation prevents behavioral and molecular changes induced by repeated phencyclidine treatment

DEFF Research Database (Denmark)

Thomsen, Morten Skøtt; Christensen, Ditte Z; Hansen, Henrik H

2009-01-01

in a modified Y-maze test. Polymorphisms in the alpha(7) nicotinic acetylcholine receptor (nAChR) gene have been linked to schizophrenia. Here we demonstrate that acute administration of the selective alpha(7) nAChR partial agonist SSR180711 dose-dependently reversed the behavioral impairment induced by PCP...

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.

Cystoid Macular Edema Induced by Low Doses of Nicotinic Acid

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Daniela Domanico

2013-01-01

Full Text Available Cystoid macular edema (CME is a condition that involves the macula, causing painless vision loss. In this paper, we report a case of niacin-induced bilateral cystoid macular edema (CME in a middle-age woman taking low dose of niacin (18 mg of nicotinic acid. Optical coherence tomography (OCT showed retinal thickening and cystoid spaces in both eyes, whereas fluorescein angiography (FA; HRA 2, Heidelberg Engineering revealed the absence of fluorescein leakage also in later phases. Four weeks after discontinuation of therapy there were a complete disappearance of macular edema at funduscopic examination and an improvement of visual acuity in both eyes. Furthermore OCT showed a normal retinal profile in both eyes. In our opinion considering the wide availability of niacin, medical monitoring and periodical examination should be considered during niacin administration. To our knowledge, this is the first report in the literature that described the very low-dose niacin-induced bilateral niacin maculopathy.

Enriched environment palliates nicotine-induced addiction and associated neurobehavioral deficits in rats.

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Nawaz, Amber; Batool, Zehra; Ahmed, Saara; Tabassum, Saiqa; Khaliq, Saima; Mehdi, Bushra Jabeen; Sajid, Irfan; Ahmad, Shoaib; Saleem, Sadia; Naqvi, Fizza; Naqvi, Faizan; Haider, Saida

2017-11-01

This study was designed to investigate the role of enriched environment in preventing and/or reducing the neurobehavioral deficits produced after nicotine administration in albino Wistar rats. Equal numbers of rat in two groups were either placed in social environment (control group) or social along with physically enriched environment for four weeks before the administration of nicotine. Exposure to different environmental conditions was followed by the intraperitoneal injection of nicotine at the dose of 0.6 mg/kg for seven consecutive days during which addictive behavior was monitored using conditioned placed preference paradigm. Behavioral responses to locomotor activity, anxiety and retention of short term memory were investigated in control and nicotine injected groups exposed to different environments. Results of this study showed that the rats pre-exposed to physical along with social enrichment exhibited a decrease in drug seeking behavior, hyper locomotion, anxiogenic effects along with improvement of working memory as compared to control and nicotine injected groups that were kept in social environment alone. This behavioral study suggests that the exposure to physical enrichment along with socialization in young age can later reduce the chances of compulsive dependence on nicotine and related neurobehavioral deficits.

Double dissociation of working memory and attentional processes in smokers and non-smokers with and without nicotine.

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Grundey, Jessica; Amu, Rosa; Ambrus, Géza Gergely; Batsikadze, Georgi; Paulus, Walter; Nitsche, Michael A

2015-07-01

Nicotine has been shown to affect cortical excitability measured using transcranial magnetic stimulation in smoking and non-smoking subjects in different ways. In tobacco-deprived smokers, administration of nicotine restores compromised cortical facilitation while in non-smokers, it enhances cortical inhibition. As cortical excitability and activity are closely linked to cognitive processes, we aimed to explore whether nicotine-induced physiological alterations in non-smokers and smokers are associated with cognitive changes. Specifically, we assessed the impact of nicotine on working memory performance (n-back letter task) and on attentional processes (Stroop interference test) in healthy smokers and non-smokers. Both tasks have been shown to rely on prefrontal areas, and nicotinic receptors are relevantly involved in prefrontal function. Sixteen smoking and 16 non-smoking subjects participated in the 3-back letter task and 21 smoking and 21 non-smoking subjects in the Stroop test after the respective application of placebo or nicotine patches. The results show that working memory and attentional processes are compromised in nicotine-deprived smokers compared to non-smoking individuals. After administration of nicotine, working memory performance in smokers improved, while non-smoking subjects displayed decreased accuracy with increased number of errors. The effects have been shown to be more apparent for working memory performance than attentional processes. In summary, cognitive functions can be restored by nicotine in deprived smokers, whereas non-smokers do not gain additional benefit. The respective changes are in accordance with related effects of nicotine on cortical excitability in both groups.

Involvement of Cholinergic and Adrenergic Receptors in Pathogenesis and Inflammatory Response Induced by Alpha-Neurotoxin Bot III of Scorpion Venom.

Science.gov (United States)

Nakib, Imene; Martin-Eauclaire, Marie-France; Laraba-Djebari, Fatima

2016-10-01

Bot III neurotoxin is the most lethal α neurotoxin purified from Buthus occitanus tunetanus scorpion venom. This toxin binds to the voltage-gated sodium channel of excitable cells and blocks its inactivation, inducing an increased release of neurotransmitters (acetylcholine and catecholamines). This study aims to elucidate the involvement of cholinergic and adrenergic receptors in pathogenesis and inflammatory response triggered by this toxin. Injection of Bot III to animals induces an increase of peroxidase activities, an imbalance of oxidative status, tissue damages in lung parenchyma, and myocardium correlated with metabolic disorders. The pretreatment with nicotine (nicotinic receptor agonist) or atropine (muscarinic receptor antagonist) protected the animals from almost all disorders caused by Bot III toxin, especially the immunological alterations. Bisoprolol administration (selective β1 adrenergic receptor antagonist) was also efficient in the protection of animals, mainly on tissue damage. Propranolol (non-selective adrenergic receptor antagonist) showed less effect. These results suggest that both cholinergic and adrenergic receptors are activated in the cardiopulmonary manifestations induced by Bot III. Indeed, the muscarinic receptor appears to be more involved than the nicotinic one, and the β1 adrenergic receptor seems to dominate the β2 receptor. These results showed also that the activation of nicotinic receptor leads to a significant protection of animals against Bot III toxin effect. These findings supply a supplementary data leading to better understanding of the mechanism triggered by scorpionic neurotoxins and suggest the use of drugs targeting these receptors, especially the nicotinic one in order to counteract the inflammatory response observed in scorpion envenomation.

Characterizing the Genetic Basis for Nicotine Induced Cancer Development: A Transcriptome Sequencing Study.

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Jasmin H Bavarva

Full Text Available Nicotine is a known risk factor for cancer development and has been shown to alter gene expression in cells and tissue upon exposure. We used Illumina® Next Generation Sequencing (NGS technology to gain unbiased biological insight into the transcriptome of normal epithelial cells (MCF-10A to nicotine exposure. We generated expression data from 54,699 transcripts using triplicates of control and nicotine stressed cells. As a result, we identified 138 differentially expressed transcripts, including 39 uncharacterized genes. Additionally, 173 transcripts that are primarily associated with DNA replication, recombination, and repair showed evidence for alternative splicing. We discovered the greatest nicotine stress response by HPCAL4 (up-regulated by 4.71 fold and NPAS3 (down-regulated by -2.73 fold; both are genes that have not been previously implicated in nicotine exposure but are linked to cancer. We also discovered significant down-regulation (-2.3 fold and alternative splicing of NEAT1 (lncRNA that may have an important, yet undiscovered regulatory role. Gene ontology analysis revealed nicotine exposure influenced genes involved in cellular and metabolic processes. This study reveals previously unknown consequences of nicotine stress on the transcriptome of normal breast epithelial cells and provides insight into the underlying biological influence of nicotine on normal cells, marking the foundation for future studies.

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

Directory of Open Access Journals (Sweden)

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

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

Directory of Open Access Journals (Sweden)

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.

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

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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.

Examination of the effects of varenicline, bupropion, lorcaserin, or naltrexone on responding for conditioned reinforcement in nicotine-exposed rats.

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Guy, Elizabeth G; Fisher, Daniel C; Higgins, Guy A; Fletcher, Paul J

2014-12-01

Smoking tobacco remains one of the leading causes of preventable deaths in North America. Nicotine reinforces smoking behavior, in part, by enhancing the reinforcing properties of reward-related stimuli, or conditioned stimuli (CSs), associated with tobacco intake. To investigate how pharmaceutical interventions may affect this property of nicotine, we examined the effect of four US Food and Drug Administration (FDA) approved drugs on the ability of nicotine to enhance operant responding for a CS as a conditioned reinforcer. Thirsty rats were exposed to 13 Pavlovian sessions where a CS was paired with water delivery. Nicotine (0.4 mg/kg) injections were administered before each Pavlovian session. Then, in separate groups of rats, the effects of varenicline (1 mg/kg), bupropion (10 and 30 mg/kg), lorcaserin (0.6 mg/kg), and naltrexone (2 mg/kg), and their interaction with nicotine on responding for conditioned reinforcement were examined. Varenicline and lorcaserin each reduced nicotine-enhanced responding for conditioned reinforcement, whereas naltrexone had a modest effect of reducing response enhancements by nicotine. In contrast, bupropion enhanced the effect of nicotine on this measure. The results of these studies may inform how pharmaceutical interventions can affect smoking cessation attempts and relapse through diverse mechanisms, either substituting for, or interacting with, the reinforcement-enhancing properties of nicotine.

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.

NSs protein of Schmallenberg virus counteracts the antiviral response of the cell by inhibiting its transcriptional machinery.

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Barry, Gerald; Varela, Mariana; Ratinier, Maxime; Blomström, Anne-Lie; Caporale, Marco; Seehusen, Frauke; Hahn, Kerstin; Schnettler, Esther; Baumgärtner, Wolfgang; Kohl, Alain; Palmarini, Massimo

2014-08-01

Bunyaviruses have evolved a variety of strategies to counteract the antiviral defence systems of mammalian cells. Here we show that the NSs protein of Schmallenberg virus (SBV) induces the degradation of the RPB1 subunit of RNA polymerase II and consequently inhibits global cellular protein synthesis and the antiviral response. In addition, we show that the SBV NSs protein enhances apoptosis in vitro and possibly in vivo, suggesting that this protein could be involved in SBV pathogenesis in different ways. © 2014 The Authors.

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.

Green tea (-)-epigallocatechin-3-gallate counteracts daytime overeating induced by high-fat diet in mice.

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Li, Hongyu; Kek, Huiling Calvina; Lim, Joy; Gelling, Richard Wayne; Han, Weiping

2016-12-01

High-fat diet (HFD) induces overeating and obesity. Green tea (-)-epigallocatechin-3-gallate (EGCG) reduces HFD-induced body weight and body fat gain mainly through increased lipid metabolism and fat oxidation. However, little is known about its effect on HFD-induced alterations in feeding behavior. Three diet groups of wildtype C57B/6j male mice at 5 months old were fed on normal chow diet, 1 week of HFD (60% of energy) and 3 months of HFD (diet-induced obesity (DIO)) prior to EGCG supplement in respective diet. EGCG had no effect on feeding behavior in normal chow diet group. Increased daytime feeding induced by HFD was selectively corrected by EGCG treatment in HFD groups, including reversed food intake, feeding frequency and meal size in HFD + EGCG group, and reduced food intake and feeding frequency in DIO + EGCG group. Moreover, EGCG treatment altered diurnally oscillating expression pattern of key appetite-regulating genes, including AGRP, POMC, and CART, and key circadian genes Clock and Bmal1 in hypothalamus of DIO mice, indicating its central effect on feeding regulation. Our study demonstrates that EGCG supplement specifically counteracts daytime overeating induced by HFD in mice, suggesting its central role in regulating feeding behavior and energy homeostasis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nicotine induces cell proliferation in association with cyclin D1 up-regulation and inhibits cell differentiation in association with p53 regulation in a murine pre-osteoblastic cell line

International Nuclear Information System (INIS)

Sato, Tsuyoshi; Abe, Takahiro; Nakamoto, Norimichi; Tomaru, Yasuhisa; Koshikiya, Noboru; Nojima, Junya; Kokabu, Shoichiro; Sakata, Yasuaki; Kobayashi, Akio; Yoda, Tetsuya

2008-01-01

Recent studies have suggested that nicotine critically affects bone metabolism. Many studies have examined the effects of nicotine on proliferation and differentiation, but the underlying molecular mechanisms remain unclear. We examined cell cycle regulators involved in the proliferation and differentiation of MC3T3-E1 cells. Nicotine induced cell proliferation in association with p53 down-regulation and cyclin D1 up-regulation. In differentiated cells, nicotine reduced alkaline phosphatase activity and mineralized nodule formation in dose-dependent manners. Furthermore, p53 expression was sustained in nicotine-treated cells during differentiation. These findings indicate that nicotine promotes the cell cycle and inhibits differentiation in association with p53 regulation in pre-osteoblastic cells

Nicotinic receptor-associated modulation of stimulatory and inhibitory neurotransmitters in NNK-induced adenocarcinoma of the lungs and pancreas

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Al-Wadei, Hussein A. N.; Schuller, Hildegard M.

2012-01-01

Small airway-derived pulmonary adenocarcinoma (PAC) and pancreatic ductal adenocarcinoma (PDAC) are among the most common human cancers and smoking is a risk factor for both. Emerging research has identified cAMP signaling stimulated by the stress neurotransmitters adrenaline and noradrenaline as important stimulators of several adenocarcinomas, including PAC and PDAC. The nicotine-derived nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a potent mutagen and the most powerful tobacco carcinogen. NNK is also an agonist for nicotinic acetylcholine receptors (nAChRs). Using hamster models of NNK-induced PAC and PDAC, we have tested the hypothesis that in analogy to chronic effects of nicotine in the brain, NNK may modulate the α7- and α4β2nAChRs, causing an increase in stress neurotransmitters and decrease in the inhibitory neurotransmitter γ-aminobutyric acid (GABA). In support of our hypothesis, immunoassays showed a significant increase in serum adrenaline/noradrenaline and increased intracellular cAMP in the cellular fraction of blood of NNK treated hamsters. Western blots were done with cells harvested by laser capture microcopy from control small airway epithelia, alveolar epithelia, pancreatic islet and pancreatic duct epithelia and from NNK-induced PACs and PDACs. The GABA synthesizing enzyme glutamate decarboxylase 65 (GAD65) and GABA were suppressed in NNK-induced PACs and PDACs whereas protein expression of the α7nAChR, α4nAChR as well as p-CREB and p-ERK1/2 were upregulated. These findings suggest, for the first time, that NNK-induced alterations in regulatory nAChRs may contribute to the development of smoking-associated PAC and PDAC by disturbing the balance between cancer stimulating and inhibiting neurotransmitters. PMID:19274673

Role of green tea on nicotine toxicity on liver and lung of mice ...

African Journals Online (AJOL)

DR_Mohsen

2012-01-26

Jan 26, 2012 ... Nicotine is the more abundant component in cigarette smoking. The natural diet contains a variety ... morphometrical methods and study the protective effect of green tea against toxicity of nicotine. Four groups of the male ... nicotine exposure induced oxidative stress and causes histopathological changes ...

Chronic electronic cigarette exposure in mice induces features of COPD in a nicotine-dependent manner.

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Garcia-Arcos, Itsaso; Geraghty, Patrick; Baumlin, Nathalie; Campos, Michael; Dabo, Abdoulaye Jules; Jundi, Bakr; Cummins, Neville; Eden, Edward; Grosche, Astrid; Salathe, Matthias; Foronjy, Robert

2016-12-01

The use of electronic (e)-cigarettes is increasing rapidly, but their lung health effects are not established. Clinical studies examining the potential long-term impact of e-cigarette use on lung health will take decades. To address this gap in knowledge, this study investigated the effects of exposure to aerosolised nicotine-free and nicotine-containing e-cigarette fluid on mouse lungs and normal human airway epithelial cells. Mice were exposed to aerosolised phosphate-buffered saline, nicotine-free or nicotine-containing e-cigarette solution, 1-hour daily for 4 months. Normal human bronchial epithelial (NHBE) cells cultured at an air-liquid interface were exposed to e-cigarette vapours or nicotine solutions using a Vitrocell smoke exposure robot. Inhalation of nicotine-containing e-cigarettes increased airway hyper-reactivity, distal airspace enlargement, mucin production, cytokine and protease expression. Exposure to nicotine-free e-cigarettes did not affect these lung parameters. NHBE cells exposed to nicotine-containing e-cigarette vapour showed impaired ciliary beat frequency, airway surface liquid volume, cystic fibrosis transmembrane regulator and ATP-stimulated K+ ion conductance and decreased expression of FOXJ1 and KCNMA1. Exposure of NHBE cells to nicotine for 5 days increased interleukin (IL)-6 and IL-8 secretion. Exposure to inhaled nicotine-containing e-cigarette fluids triggered effects normally associated with the development of COPD including cytokine expression, airway hyper-reactivity and lung tissue destruction. These effects were nicotine-dependent both in the mouse lung and in human airway cells, suggesting that inhaled nicotine contributes to airway and lung disease in addition to its addictive properties. Thus, these findings highlight the potential dangers of nicotine inhalation during e-cigarette use. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Malaysian adolescent students' needs for enhancing thinking skills, counteracting risk factors and demonstrating academic resilience

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Kuldas, Seffetullah; Hashim, Shahabuddin; Ismail, Hairul Nizam

2015-01-01

The adolescence period of life comes along with changes and challenges in terms of physical and cognitive development. In this hectic period, many adolescents may suffer more from various risk factors such as low socioeconomic status, substance abuse, sexual abuse and teenage pregnancy. Findings indicate that such disadvantaged backgrounds of Malaysian adolescent students lead to failure or underachievement in their academic performance. This narrative review scrutinises how some of these students are able to demonstrate academic resilience, which is satisfactory performance in cognitive or academic tasks in spite of their disadvantaged backgrounds. The review stresses the need for developing a caregiving relationship model for at-risk adolescent students in Malaysia. Such a model would allow educators to meet the students' needs for enhancing thinking skills, counteracting risk factors and demonstrating academic resilience. PMID:25663734

Nilotinib Enhances Tumor Angiogenesis and Counteracts VEGFR2 Blockade in an Orthotopic Breast Cancer Xenograft Model with Desmoplastic Response

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Sara Zafarnia

2017-11-01

Full Text Available Vascular endothelial growth factor (VEGF/VEGF receptor (VEGFR-targeted therapies predominantly affect nascent, immature tumor vessels. Since platelet-derived growth factor receptor (PDGFR blockade inhibits vessel maturation and thus increases the amount of immature tumor vessels, we evaluated whether the combined PDGFR inhibition by nilotinib and VEGFR2 blockade by DC101 has synergistic therapy effects in a desmoplastic breast cancer xenograft model. In this context, besides immunohistological evaluation, molecular ultrasound imaging with BR55, the clinically used VEGFR2-targeted microbubbles, was applied to monitor VEGFR2-positive vessels noninvasively and to assess the therapy effects on tumor angiogenesis. DC101 treatment alone inhibited tumor angiogenesis, resulting in lower tumor growth and in significantly lower vessel density than in the control group after 14 days of therapy. In contrast, nilotinib inhibited vessel maturation but enhanced VEGFR2 expression, leading to markedly increased tumor volumes and a significantly higher vessel density. The combination of both drugs led to an almost similar tumor growth as in the DC101 treatment group, but VEGFR2 expression and microvessel density were higher and comparable to the controls. Further analyses revealed significantly higher levels of tumor cell–derived VEGF in nilotinib-treated tumors. In line with this, nilotinib, especially in low doses, induced an upregulation of VEGF and IL-6 mRNA in the tumor cells in vitro, thus providing an explanation for the enhanced angiogenesis observed in nilotinib-treated tumors in vivo. These findings suggest that nilotinib inhibits vessel maturation but counteracts the effects of antiangiogenic co-therapy by enhancing VEGF expression by the tumor cells and stimulating tumor angiogenesis.

Nicotine at clinically relevant concentrations affects atrial inward rectifier potassium current sensitive to acetylcholine.

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Bébarová, Markéta; Matejovič, Peter; Švecová, Olga; Kula, Roman; Šimurdová, Milena; Šimurda, Jiří

2017-05-01

Nicotine abuse is associated with variety of diseases including arrhythmias, most often atrial fibrillation (AF). Altered inward rectifier potassium currents including acetylcholine-sensitive current I K(Ach) are known to be related to AF pathogenesis. Since relevant data are missing, we aimed to investigate I K(Ach) changes at clinically relevant concentrations of nicotine. Experiments were performed by the whole cell patch clamp technique at 23 ± 1 °C on isolated rat atrial myocytes. Nicotine was applied at following concentrations: 4, 40 and 400 nM; ethanol at 20 mM (∼0.09%). Nicotine at 40 and 400 nM significantly activated constitutively active component of I K(Ach) with the maximum effect at 40 nM (an increase by ∼100%); similar effect was observed at -110 and -50 mV. Changes at 4 nM nicotine were negligible on average. Coapplication of 40 nM nicotine and 20 mM ethanol (which is also known to activate this current) did not show cumulative effect. In the case of acetylcholine-induced component of I K(Ach) , a dual effect of nicotine and its correlation with the current magnitude in control were apparent: the current was increased by nicotine in the cells showing small current in control and vice versa. The effect of 40 and 400 nM nicotine on acetylcholine-induced component of I K(Ach) was significantly different at -110 and -50 mV. We conclude that nicotine at clinically relevant concentrations significantly increased constitutively active component of I K(Ach) and showed a dual effect on its acetylcholine-induced component, similarly as ethanol. Synchronous application of nicotine and ethanol did not cause additive effect.

The effects of nicotine exposure during Pavlovian conditioning in rats on several measures of incentive motivation for a conditioned stimulus paired with water.

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Guy, Elizabeth Glenn; Fletcher, Paul J

2014-06-01

Nicotine enhances approach toward and operant responding for conditioned stimuli (CSs), but the effect of exposure during different phases of Pavlovian incentive learning on these measures remains to be determined. These studies examined the effects of administering nicotine early, late or throughout Pavlovian conditioning trials on discriminated approach behavior, nicotine-enhanced responding for conditioned reinforcement, extinction, and the reinstatement of responding for conditioned reinforcement. We also tested the effect of nicotine on approach to a lever-CS in a Pavlovian autoshaping procedure and for this CS to serve as a conditioned reinforcer. Thirsty rats were exposed to 13 conditioning sessions where a light/tone CS was paired with the delivery of water. Nicotine was administered either prior to the first or last seven sessions, or throughout the entire conditioning procedure. Responding for conditioned reinforcement, extinction, and the reinstatement of responding by the stimulus and nicotine were compared across exposure groups. Separately, the effects of nicotine on conditioned approach toward a lever-CS during autoshaping, and responding for that CS as a conditioned reinforcer, were examined. Nicotine exposure was necessary for nicotine-enhanced responding for conditioned reinforcement and the ability for nicotine and the stimulus to additively reinstate responding on the reinforced lever. Nicotine increased contacts with a lever-CS during autoshaping, and removal of nicotine abolished this effect. Prior nicotine exposure was necessary for nicotine-enhanced responding reinforced by the lever. Enhancements in the motivating properties of CSs by nicotine occur independently from duration and timing effects of nicotine exposure during conditioning.

Gene expression signatures affected by ethanol and/or nicotine in normal human normal oral keratinocytes (NHOKs

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Jeffrey J. Kim

2014-12-01

Full Text Available It has been reported that nicotine/alcohol alters epigenetic control and leads to abrogated DNA methylation and histone modifications, which could subsequently perturb transcriptional regulation critically important in cellular transformation. The aim of this study is to determine the molecular mechanisms of nicotine/alcohol-induced epigenetic alterations and their mechanistic roles in transcriptional regulation in human adult stem cells. We hypothesized that nicotine/alcohol induces deregulation of epigenetic machinery and leads to epigenetic alterations, which subsequently affect transcriptional regulation in oral epithelial stem cells. As an initiating step we have profiled transcriptomic alterations induced by the combinatory administration of EtOH and nicotine in primary normal human oral keratinocytes. Here we provide detailed experimental methods, analysis and information associated with our data deposited into Gene Expression Omnibus (GEO under GSE57634. Our data provide comprehensive transcriptomic map describing molecular changes induced by EtOH and nicotine on normal human oral keratinocytes.

A point mutation in the hair cell nicotinic cholinergic receptor prolongs cochlear inhibition and enhances noise protection.

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Julian Taranda

2009-01-01

Full Text Available The transduction of sound in the auditory periphery, the cochlea, is inhibited by efferent cholinergic neurons projecting from the brainstem and synapsing directly on mechanosensory hair cells. One fundamental question in auditory neuroscience is what role(s this feedback plays in our ability to hear. In the present study, we have engineered a genetically modified mouse model in which the magnitude and duration of efferent cholinergic effects are increased, and we assess the consequences of this manipulation on cochlear function. We generated the Chrna9L9'T line of knockin mice with a threonine for leucine change (L9'T at position 9' of the second transmembrane domain of the alpha9 nicotinic cholinergic subunit, rendering alpha9-containing receptors that were hypersensitive to acetylcholine and had slower desensitization kinetics. The Chrna9L9'T allele produced a 3-fold prolongation of efferent synaptic currents in vitro. In vivo, Chrna9L9'T mice had baseline elevation of cochlear thresholds and efferent-mediated inhibition of cochlear responses was dramatically enhanced and lengthened: both effects were reversed by strychnine blockade of the alpha9alpha10 hair cell nicotinic receptor. Importantly, relative to their wild-type littermates, Chrna9(L9'T/L9'T mice showed less permanent hearing loss following exposure to intense noise. Thus, a point mutation designed to alter alpha9alpha10 receptor gating has provided an animal model in which not only is efferent inhibition more powerful, but also one in which sound-induced hearing loss can be restrained, indicating the ability of efferent feedback to ameliorate sound trauma.

Nicotine aversion: Neurobiological mechanisms and relevance to tobacco dependence vulnerability

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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

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.

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.

Nicotine Lozenges

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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 ...

Withdrawal from Chronic Nicotine Administration Impairs Contextual Fear Conditioning in C57BL/6 Mice

OpenAIRE

Davis, Jennifer A.; James, John R.; Siegel, Steven J.; Gould, Thomas J.

2005-01-01

The effects of acute nicotine administration (0.09 mg/kg nicotine), chronic nicotine administration (6.3 mg/kg/d nicotine for 14 d), and withdrawal from chronic nicotine administration on fear conditioning in C57BL/6 mice were examined. Mice were trained using two coterminating conditioned stimulus (30 s; 85 dB white noise)– unconditioned stimulus (2 s; 0.57 mA foot shock) pairings and tested 24 h later for contextual and cued fear conditioning. Acute nicotine administration enhanced contextu...

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.

Neural and behavioural changes in male periadolescent mice after prolonged nicotine-MDMA treatment.

Science.gov (United States)

Adeniyi, Philip A; Ishola, Azeez O; Laoye, Babafemi J; Olatunji, Babawale P; Bankole, Oluwamolakun O; Shallie, Philemon D; Ogundele, Olalekan M

2016-02-01

The interaction between MDMA and Nicotine affects multiple brain centres and neurotransmitter systems (serotonin, dopamine and glutamate) involved in motor coordination and cognition. In this study, we have elucidated the effect of prolonged (10 days) MDMA, Nicotine and a combined Nicotine-MDMA treatment on motor-cognitive neural functions. In addition, we have shown the correlation between the observed behavioural change and neural structural changes induced by these treatments in BALB/c mice. We observed that MDMA (2 mg/Kg body weight; subcutaneous) induced a decline in motor function, while Nicotine (2 mg/Kg body weight; subcutaneous) improved motor function in male periadolescent mice. In combined treatment, Nicotine reduced the motor function decline observed in MDMA treatment, thus no significant change in motor function for the combined treatment versus the control. Nicotine or MDMA treatment reduced memory function and altered hippocampal structure. Similarly, a combined Nicotine-MDMA treatment reduced memory function when compared with the control. Ultimately, the metabolic and structural changes in these neural systems were seen to vary for the various forms of treatment. It is noteworthy to mention that a combined treatment increased the rate of lipid peroxidation in brain tissue.

Nicotine, but not mecamylamine, enhances antidepressant-like effects of citalopram and reboxetine in the mouse forced swim and tail suspension tests

DEFF Research Database (Denmark)

Andreasen T., Jesper; Redrobe, John P

2009-01-01

and 10mg/kg citalopram and 3 and 10mg/kg reboxetine in the mTST. No concomitant locomotor stimulation was observed at the tested dose combinations. Mecamylamine was effective on its own in some tests, but did not augment the effects of citalopram or reboxetine at the doses tested. The data show...... activity and facilitates serotonin and noradrenaline release. Thus, we hypothesise that nicotine may enhance the behavioural effects of serotonin (e.g., citalopram) and/or noradrenaline (e.g., reboxetine) reuptake inhibitors. Here, we tested if nicotine enhanced the activity of citalopram or reboxetine...... in the mouse forced swim test (mFST) and the mouse tail suspension test (mTST). The potential for mecamylamine to augment antidepressant drug action was also investigated. Sub-threshold and threshold doses of citalopram (3 and 10mg/kg) or reboxetine (3, 10 and 20mg/kg) were tested alone and in combination...

Effect of hydroalcoholic extract of Lavandula officinalis on nicotine-induced convulsion in mice.

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Arzi, A; Ahamehe, M; Sarahroodi, S

2011-06-01

Epilepsy an important CNS (central nervous system) problem that about 1% of world's population suffer of it. The aim of study was to evaluate of anticonvulsant effect of hydroalcoholic extract of Lavandula officinalis. In this study, anticonvulsant activity of the hydroalcoholic extract of Lavandula officinalis (L. officinalis) was studied against chemoconvulsant-induced seizures in male mice. Lavandula officinalis (100, 200, 400, 600 and 800 mg kg(-1)), diazepam (0.15 mg kg(-1)) and normal saline (10 mL kg(-1)) were injected intraperitoneally, respectively in different groups of mice, 30 min before nicotine (5 mg kg(-) i.p.). The onset time intensity and duration of convulsions and the percentage of death were recorded. Also the time-response (0, 15, 30, 45, 60 min before nicotine injection) for most effective dose of plant extract (600 mg kg(-1)) was investigated. The results showed that hydroalcoholic extract of Lavandula officinalis had anticonvulsant effect. The most effective dose of plant extract was 600 mg kg(-1). In time-response study for the most effective dose of extract (600 mg kg(-1)), the onset, duration and intensity of convulsion significantly (p Lavandula.

The brain activations for both cue-induced gaming urge and smoking craving among subjects comorbid with Internet gaming addiction and nicotine dependence.

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Ko, Chih-Hung; Liu, Gin-Chung; Yen, Ju-Yu; Yen, Cheng-Fang; Chen, Cheng-Sheng; Lin, Wei-Chen

2013-04-01

Internet gaming addiction (IGA) has been classified as an addictive disorder in the proposed DSM 5 draft. However, whether its underlying addiction mechanism is similar to other substance use disorders has not been confirmed. The present functional magnetic resonance images study is aimed at evaluating the brain correlates of cue-induced gaming urge or smoking craving in subjects with both IGA and nicotine dependence to make a simultaneous comparison of cue induced brain reactivity for gaming and smoking. For this purpose, 16 subjects with both IGA and nicotine dependence (comorbid group) and 16 controls were recruited from the community. All subjects were made to undergo 3-T fMRIs scans while viewing images associated with online games, smoking, and neutral images, which were arranged according to an event-related design. The resultant image data was analyzed with full factorial and conjunction analysis of SPM5. The results demonstrate that anterior cingulate, and parahippocampus activates higher for both cue-induced gaming urge and smoking craving among the comorbid group in comparison to the control group. The conjunction analysis demonstrates that bilateral parahippocampal gyrus activates to a greater degree for both gaming urge and smoking craving among the comorbid group in comparison to the control group. Accordingly, the study demonstrates that both IGA and nicotine dependence share similar mechanisms of cue-induced reactivity over the fronto-limbic network, particularly for the parahippocampus. The results support that the context representation provided by the parahippocampus is a key mechanism for not only cue-induced smoking craving, but also for cue-induced gaming urge. Copyright © 2012 Elsevier Ltd. All rights reserved.

A new IRAK-M-mediated mechanism implicated in the anti-inflammatory effect of nicotine via α7 nicotinic receptors in human macrophages.

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Maria C Maldifassi

Full Text Available Nicotine stimulation of α7 nicotinic acetylcholine receptor (α7 nAChR powerfully inhibits pro-inflammatory cytokine production in lipopolysaccharide (LPS-stimulated macrophages and in experimental models of endotoxemia. A signaling pathway downstream from the α7 nAChRs, which involves the collaboration of JAK2/STAT3 and NF-κB to interfere with signaling by Toll-like receptors (TLRs, has been implicated in this anti-inflammatory effect of nicotine. Here, we identifiy an alternative mechanism involving interleukin-1 receptor-associated kinase M (IRAK-M, a negative regulator of innate TLR-mediated immune responses. Our data show that nicotine up-regulates IRAK-M expression at the mRNA and protein level in human macrophages, and that this effect is secondary to α7 nAChR activation. By using selective inhibitors of different signaling molecules downstream from the receptor, we provide evidence that activation of STAT3, via either JAK2 and/or PI3K, through a single (JAK2/PI3K/STAT3 or two convergent cascades (JAK2/STAT3 and PI3K/STAT3, is necessary for nicotine-induced IRAK-M expression. Moreover, down-regulation of this expression by small interfering RNAs specific to the IRAK-M gene significantly reverses the anti-inflammatory effect of nicotine on LPS-induced TNF-α production. Interestingly, macrophages pre-exposed to nicotine exhibit higher IRAK-M levels and reduced TNF-α response to an additional LPS challenge, a behavior reminiscent of the 'endotoxin tolerant' phenotype identified in monocytes either pre-exposed to LPS or from immunocompromised septic patients. Since nicotine is a major component of tobacco smoke and increased IRAK-M expression has been considered one of the molecular determinants for the induction of the tolerant phenotype, our findings showing IRAK-M overexpression could partially explain the known influence of smoking on the onset and progression of inflammatory and infectious diseases.

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

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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.

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

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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.

Moderation of Nicotine Effects on Covert Orienting of Attention Tasks by Poor Placebo Performance and Cue Validity

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Gilbert, David G.; Rzetelny, Adam; Rabinovich, Norka E.

2016-01-01

Introduction and Rationale Given baseline-dependent effects of nicotine on other forms of attention, there is reason to believe that inconsistent findings for the effects of nicotine on attentional orienting may be partly due to individual differences in baseline (abstinence state) functioning. Individuals with low baseline attention may benefit more from nicotine replacement. Method The effects of nicotine as a function of baseline performance (bottom, middle, and top third of mean reaction times during placebo) were assessed in 52 habitual abstinent smokers (26 females/26 males) utilizing an arrow-cued covert orienting of attention task. Results Compared to a placebo patch, a 14 mg nicotine patch produced faster overall reaction times (RTs). In addition, individuals with slower RTs during the placebo condition benefitted more from nicotine on cued trials than did those who had shorter (faster) RTs during placebo. Nicotine also enhanced the validity effect (shorter RTs to validly vs. invalidly cued targets), but this nicotine benefit did not differ as a function of overall placebo-baseline performance. Conclusions These findings support the view that nicotine enhances cued spatial attentional orienting in individuals who have slower RTs during placebo (nicotine-free) conditions; however, baseline-dependent effects may not generalize to all aspects of spatial attention. These findings are consistent with findings indicating that nicotine’s effects vary as a function of task parameters rather than simple RT speeding or cognitive enhancement. PMID:27461547

Chronic nicotine differentially alters spontaneous recovery of contextual fear in male and female mice.

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Tumolo, Jessica M; Kutlu, Munir Gunes; Gould, Thomas J

2018-04-02

Post-traumatic stress disorder (PTSD) is a devastating disorder with symptoms such as flashbacks, hyperarousal, and avoidance of reminders of the traumatic event. Exposure therapy, which attempts to extinguish fear responses, is a commonly used treatment for PTSD but relapse following successful exposure therapy is a frequent problem. In rodents, spontaneous recovery (SR), where extinguished fear responses resurface following extinction treatment, is used as a model of fear relapse. Previous studies from our lab showed that chronic nicotine impaired fear extinction and acute nicotine enhanced SR of contextual fear in adult male mice. In addition, we showed that acute nicotine's effects were specific to SR as acute nicotine did not affect recall of contextual fear conditioning in the absence of extinction. However, effects of chronic nicotine administration on SR are not known. Therefore, in the present study, we investigated if chronic nicotine administration altered SR or recall of contextual fear in adult male and female C57BL/6J mice. Our results showed that chronic nicotine significantly enhanced SR in female mice and significantly decreased SR in males. Chronic nicotine had no effect on recall of contextual fear in males or females. Female sham mice also had significantly less baseline SR than male sham mice. Overall, these results demonstrate sex differences in SR of fear memories and that chronic nicotine modulates these effects on SR but nicotine does not alter recall of contextual fear. Copyright © 2018 Elsevier B.V. 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

Global actions of nicotine on the striatal microcircuit.

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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.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Caffeine attenuates scopolamine-induced memory impairment in humans.

Science.gov (United States)

Riedel, W; Hogervorst, E; Leboux, R; Verhey, F; van Praag, H; Jolles, J

1995-11-01

Caffeine consumption can be beneficial for cognitive functioning. Although caffeine is widely recognized as a mild CNS stimulant drug, the most important consequence of its adenosine antagonism is cholinergic stimulation, which might lead to improvement of higher cognitive functions, particularly memory. In this study, the scopolamine model of amnesia was used to test the cholinergic effects of caffeine, administered as three cups of coffee. Subjects were 16 healthy volunteers who received 250 mg caffeine and 2 mg nicotine separately, in a placebo-controlled double-blind cross-over design. Compared to placebo, nicotine attenuated the scopolamine-induced impairment of storage in short-term memory and attenuated the scopolamine-induced slowing of speed of short-term memory scanning. Nicotine also attenuated the scopolamine-induced slowing of reaction time in a response competition task. Caffeine attenuated the scopolamine-induced impairment of free recall from short- and long-term memory, quality and speed of retrieval from long-term memory in a word learning task, and other cognitive and non-cognitive measures, such as perceptual sensitivity in visual search, reading speed, and rate of finger-tapping. On the basis of these results it was concluded that caffeine possesses cholinergic cognition enhancing properties. Caffeine could be used as a control drug in studies using the scopolamine paradigm and possibly also in other experimental studies of cognitive enhancers, as the effects of a newly developed cognition enhancing drug should at least be superior to the effects of three cups of coffee.

Grazing management can counteract the impacts of climate change-induced sea level rise on salt marsh-dependent waterbirds

DEFF Research Database (Denmark)

Clausen, Kevin Kuhlmann; Stjernholm, Michael; Clausen, Preben

2013-01-01

with these changes. In addition, we quantify the areal extent of inadequate salt marsh management in four EU Special Protection Areas for Birds, and demonstrate concurrent population dynamics in four species relying on managed habitats. We conclude by investigating potential compensation for climate change......1) Climate change–induced rises in sea level threaten to drastically reduce the areal extent of important salt marsh habitats for large numbers of waterfowl and waders. Furthermore, recent changes in management practice have rendered existent salt marshes unfavourable to many birds, as lack...... (around 1 cow per hectare) is an important initiative to counteract the accelerating climate change–induced habitat loss in near-coastal areas across the globe, and to secure priority salt marsh habitats that support internationally important populations of breeding, wintering and staging waterfowl...

Enhancement of arachidonic acid signaling pathway by nicotinic acid receptor HM74A

International Nuclear Information System (INIS)

Tang, Yuting; Zhou, Lubing; Gunnet, Joseph W.; Wines, Pamela G.; Cryan, Ellen V.; Demarest, Keith T.

2006-01-01

HM74A is a G protein-coupled receptor for nicotinic acid (niacin), which has been used clinically to treat dyslipidemia for decades. The molecular mechanisms whereby niacin exerts its pleiotropic effects on lipid metabolism remain largely unknown. In addition, the most common side effect in niacin therapy is skin flushing that is caused by prostaglandin release, suggesting that the phospholipase A 2 (PLA 2 )/arachidonic acid (AA) pathway is involved. Various eicosanoids have been shown to activate peroxisome-proliferator activated receptors (PPAR) that play a diverse array of roles in lipid metabolism. To further elucidate the potential roles of HM74A in mediating the therapeutic effects and/or side effects of niacin, we sought to explore the signaling events upon HM74A activation. Here we demonstrated that HM74A synergistically enhanced UTP- and bradykinin-mediated AA release in a pertussis toxin-sensitive manner in A431 cells. Activation of HM74A also led to Ca 2+ -mobilization and enhanced bradykinin-promoted Ca 2+ -mobilization through Gi protein. While HM74A increased ERK1/2 activation by the bradykinin receptor, it had no effects on UTP-promoted ERK1/2 activation.Furthermore, UTP- and bradykinin-mediated AA release was significantly decreased in the presence of both MAPK kinase inhibitor PD 098059 and PKC inhibitor GF 109203X. However, the synergistic effects of HM74A were not dramatically affected by co-treatment with both inhibitors, indicating the cross-talk occurred at the receptor level. Finally, stimulation of A431 cells transiently transfected with PPRE-luciferase with AA significantly induced luciferase activity, mimicking the effects of PPARγ agonist rosiglitazone, suggesting that alteration of AA signaling pathway can regulate gene expression via endogenous PPARs

Enhancement of arachidonic acid signaling pathway by nicotinic acid receptor HM74A

Energy Technology Data Exchange (ETDEWEB)

Tang, Yuting [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Zhou, Lubing [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Gunnet, Joseph W [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Wines, Pamela G [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Cryan, Ellen V [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Demarest, Keith T [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States)

2006-06-23

HM74A is a G protein-coupled receptor for nicotinic acid (niacin), which has been used clinically to treat dyslipidemia for decades. The molecular mechanisms whereby niacin exerts its pleiotropic effects on lipid metabolism remain largely unknown. In addition, the most common side effect in niacin therapy is skin flushing that is caused by prostaglandin release, suggesting that the phospholipase A{sub 2} (PLA{sub 2})/arachidonic acid (AA) pathway is involved. Various eicosanoids have been shown to activate peroxisome-proliferator activated receptors (PPAR) that play a diverse array of roles in lipid metabolism. To further elucidate the potential roles of HM74A in mediating the therapeutic effects and/or side effects of niacin, we sought to explore the signaling events upon HM74A activation. Here we demonstrated that HM74A synergistically enhanced UTP- and bradykinin-mediated AA release in a pertussis toxin-sensitive manner in A431 cells. Activation of HM74A also led to Ca{sup 2+}-mobilization and enhanced bradykinin-promoted Ca{sup 2+}-mobilization through Gi protein. While HM74A increased ERK1/2 activation by the bradykinin receptor, it had no effects on UTP-promoted ERK1/2 activation.Furthermore, UTP- and bradykinin-mediated AA release was significantly decreased in the presence of both MAPK kinase inhibitor PD 098059 and PKC inhibitor GF 109203X. However, the synergistic effects of HM74A were not dramatically affected by co-treatment with both inhibitors, indicating the cross-talk occurred at the receptor level. Finally, stimulation of A431 cells transiently transfected with PPRE-luciferase with AA significantly induced luciferase activity, mimicking the effects of PPAR{gamma} agonist rosiglitazone, suggesting that alteration of AA signaling pathway can regulate gene expression via endogenous PPARs.

Methamphetamine and 3,4-methylenedioxymethamphetamine interact with central nicotinic receptors and induce their up-regulation

International Nuclear Information System (INIS)

Garcia-Rates, Sara; Camarasa, Jordi; Escubedo, Elena; Pubill, David

2007-01-01

Previous work from our group indicated that α7 nicotinic acetylcholine receptors (α7 nAChR) potentially play a role in methamphetamine (METH) and 3,4-methylenedioxymethamphetamine (MDMA) neurotoxicity. The aims of the present study were two-fold: (1) to demonstrate the interaction of METH and MDMA with homomeric α7 nAChR ([ 3 H]methyllycaconitine binding) and other heteromeric subtypes ([ 3 H]epibatidine binding); and (2) to show the effects of amphetamine derivative pretreatment on the density of binding sites. METH and MDMA displaced [ 3 H]methyllycaconitine and [ 3 H]epibatidine binding in membranes from NGF-differentiated PC 12 cells and mouse brain, with K i values in the micromolar range, MDMA revealing a greater affinity than METH. In addition, METH and MDMA induced a time- and concentration-dependent increase in [ 3 H]methyllycaconitine and [ 3 H]epibatidine binding; which had already been apparent after 6 h of pretreatment, and which peaked in differentiated PC 12 cells after 48 h. The highest increases were found in [ 3 H]epibatidine binding, with MDMA inducing higher increases than METH. Treatment with METH and MDMA increased B max of high-affinity sites for both radioligands without affecting K d . The heightened binding was inhibited by pretreatment with cycloheximide, suggesting the participation of newly synthesised proteins while inhibition of protein trafficking to plasma membrane did not block up-regulation. The effects of protein kinase and cyclophilin inhibitors on such up-regulation were explored, revealing a rapid, differential and complex regulation, similar to that described for nicotinic ligands. All of these results demonstrate that METH and MDMA have affinity for, and can interact with, nAChR, inducing their up-regulation, specially when higher doses are used. Such effects may have a role in METH- and MDMA-induced neurotoxicity, cholinergic neurotransmission, and in processes related to addiction and dependence

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

Science.gov (United States)

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.

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

The selectively bred high alcohol sensitivity (HAS) and low alcohol sensitivity (LAS) rats differ in sensitivity to nicotine.

Science.gov (United States)

de Fiebre, NancyEllen C; Dawson, Ralph; de Fiebre, Christopher M

2002-06-01

Studies in rodents selectively bred to differ in alcohol sensitivity have suggested that nicotine and ethanol sensitivities may cosegregate during selective breeding. This suggests that ethanol and nicotine sensitivities may in part be genetically correlated. Male and female high alcohol sensitivity (HAS), control alcohol sensitivity, and low alcohol sensitivity (LAS) rats were tested for nicotine-induced alterations in locomotor activity, body temperature, and seizure activity. Plasma and brain levels of nicotine and its primary metabolite, cotinine, were measured in these animals, as was the binding of [3H]cytisine, [3H]epibatidine, and [125I]alpha-bungarotoxin in eight brain regions. Both replicate HAS lines were more sensitive to nicotine-induced locomotor activity depression than the replicate LAS lines. No consistent HAS/LAS differences were seen on other measures of nicotine sensitivity; however, females were more susceptible to nicotine-induced seizures than males. No HAS/LAS differences in nicotine or cotinine levels were seen, nor were differences seen in the binding of nicotinic ligands. Females had higher levels of plasma cotinine and brain nicotine than males but had lower brain cotinine levels than males. Sensitivity to a specific action of nicotine cosegregates during selective breeding for differential sensitivity to a specific action of ethanol. The differential sensitivity of the HAS/LAS rats is due to differences in central nervous system sensitivity and not to pharmacokinetic differences. The differential central nervous system sensitivity cannot be explained by differences in the numbers of nicotinic receptors labeled in ligand-binding experiments. The apparent genetic correlation between ethanol and nicotine sensitivities suggests that common genes modulate, in part, the actions of both ethanol and nicotine and may explain the frequent coabuse of these agents.

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.

Design, formulation and evaluation of nicotine chewing gum.

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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.

A model for evolution and regulation of nicotine biosynthesis regulon in tobacco.

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Kajikawa, Masataka; Sierro, Nicolas; Hashimoto, Takashi; Shoji, Tsubasa

2017-06-03

In tobacco, the defense alkaloid nicotine is produced in roots and accumulates mainly in leaves. Signaling mediated by jasmonates (JAs) induces the formation of nicotine via a series of structural genes that constitute a regulon and are coordinated by JA-responsive transcription factors of the ethylene response factor (ERF) family. Early steps in the pyrrolidine and pyridine biosynthesis pathways likely arose through duplication of the polyamine and nicotinamide adenine dinucleotide (NAD) biosynthetic pathways, respectively, followed by recruitment of duplicated primary metabolic genes into the nicotine biosynthesis regulon. Transcriptional regulation of nicotine biosynthesis by ERF and cooperatively-acting MYC2 transcription factors is implied by the frequency of cognate cis-regulatory elements for these factors in the promoter regions of the downstream structural genes. Indeed, a mutant tobacco with low nicotine content was found to have a large chromosomal deletion in a cluster of closely related ERF genes at the nicotine-controlling NICOTINE2 (NIC2) locus.

Prenatal nicotinic exposure suppresses fetal adrenal steroidogenesis via steroidogenic factor 1 (SF-1) deacetylation

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Yan, You-e [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan (China); Liu, Lian [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan (China); Department of Pharmacology, Medical School of Yangtze University, Jingzhou 434000 (China); Wang, Jian-fei; Liu, Fang; Li, Xiao-hai; Qin, Hai-quan [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan (China); Wang, Hui, E-mail: wanghui19@whu.edu.cn [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan (China); Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan 430071 (China)

2014-06-15

This study aimed to investigate the suppressive effect of nicotine on fetal adrenal steroidogenesis and to explore the potential role of epigenetic modification of steroidogenic factor-1 (SF-1) transcriptional activity in this process. Nicotine was intragastrically administered to pregnant rats and NCI-H295A cells were treated with nicotine or trichostatin A (TSA). The pathomorphology of fetal adrenals, steroid hormone levels, the expression of SF-1 and its target genes, and histone deacetylase (HDAC) mRNA were analyzed. Histone modification and DNA methylation of the SF-1 promoter region were assessed using chromatin immunoprecipitation (ChIP) and bisulfite sequencing PCR. The interaction between SF1 and its target genes was observed. Prenatal nicotinic exposure decreased fetal body weight, increased the IUGR rate and caused detrimental changes in fetal adrenal. In addition, the levels of corticosterone, the expression of SF-1 and its target genes were decreased while HDAC2 expression was enhanced. Nicotine treatment decreased histone H3K9 and H3K14 acetylation levels while there was no effect on the methylation frequency on the SF-1 promoter region. Furthermore, in nicotine-treated NCI-H295A cells, lower levels of steroidogenic synthesis, lower expression of SF-1 and its target genes were observed while the expression of HDACs was enhanced. The interaction between SF1 and StAR decreased with nicotine treatment. Nicotine treatment decreased histone H3K9 and H3K14 acetylation levels, and addition of TSA reversed the inhibition of nicotine-mediated SF-1 and its partial target genes. Thus, nicotine-mediated reduction of SF-1 expression resulted in an inhibitory effect on the expression of its target genes and steroid production via histone deacetylation. - Highlights: • Prenatal nicotine-exposed suppresses fetal adrenal steroidogenesis. • Nicotine-supressed fetal adrenal steroidogenesis is related to SF-1 deacetylation. • Prenatal nicotinic exposure decreased

Prenatal nicotinic exposure suppresses fetal adrenal steroidogenesis via steroidogenic factor 1 (SF-1) deacetylation

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Yan, You-e; Liu, Lian; Wang, Jian-fei; Liu, Fang; Li, Xiao-hai; Qin, Hai-quan; Wang, Hui

2014-01-01

This study aimed to investigate the suppressive effect of nicotine on fetal adrenal steroidogenesis and to explore the potential role of epigenetic modification of steroidogenic factor-1 (SF-1) transcriptional activity in this process. Nicotine was intragastrically administered to pregnant rats and NCI-H295A cells were treated with nicotine or trichostatin A (TSA). The pathomorphology of fetal adrenals, steroid hormone levels, the expression of SF-1 and its target genes, and histone deacetylase (HDAC) mRNA were analyzed. Histone modification and DNA methylation of the SF-1 promoter region were assessed using chromatin immunoprecipitation (ChIP) and bisulfite sequencing PCR. The interaction between SF1 and its target genes was observed. Prenatal nicotinic exposure decreased fetal body weight, increased the IUGR rate and caused detrimental changes in fetal adrenal. In addition, the levels of corticosterone, the expression of SF-1 and its target genes were decreased while HDAC2 expression was enhanced. Nicotine treatment decreased histone H3K9 and H3K14 acetylation levels while there was no effect on the methylation frequency on the SF-1 promoter region. Furthermore, in nicotine-treated NCI-H295A cells, lower levels of steroidogenic synthesis, lower expression of SF-1 and its target genes were observed while the expression of HDACs was enhanced. The interaction between SF1 and StAR decreased with nicotine treatment. Nicotine treatment decreased histone H3K9 and H3K14 acetylation levels, and addition of TSA reversed the inhibition of nicotine-mediated SF-1 and its partial target genes. Thus, nicotine-mediated reduction of SF-1 expression resulted in an inhibitory effect on the expression of its target genes and steroid production via histone deacetylation. - Highlights: • Prenatal nicotine-exposed suppresses fetal adrenal steroidogenesis. • Nicotine-supressed fetal adrenal steroidogenesis is related to SF-1 deacetylation. • Prenatal nicotinic exposure decreased

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.

The Effect of Nicotine Administration on Physical and Psychological Signs of Withdrawal Syndrome Induced by Single or Frequent Doses of Morphine in Rats

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Mohammad Allahtavakoli

2012-07-01

Full Text Available Introduction. Morphine addiction and morphine withdrawal syndrome are the two main problems of today’s human society. The present study has investigated the effects of nicotine on the strength of physical and psychological dependency in single and repeated doses morphine administrated rats. Materials and methods. Male Wistar rats were subjected to morphine consumption with single or frequent dose protocols. In the single dose protocol, rats received only one dose of morphine and 24hrs later they also received one dose of nicotine 30 min prior to injection of naloxone. In the repeated dose protocol, rats received incremental doses of morphine for 7 days and 24hr after the last dose (the 8th day were given naloxone. However, the nicotine regimen of this group was injected 15 min before the morphine injection, for 4 days, from the 4th to the 7th day. Five minutes after naloxone injection, each rat′s behavior was captured for 30 min, and then physical and psychological signs of withdrawal syndrome were recorded. Data were analyzed by ANOVA followed by Tukey tests and p<0.05 was considered as significant difference. Findings. Results showed that the injection of frequent and single doses of morphine lead to morphine dependency. In single dose protocol, nicotine consumption attenuated the signs of withdrawal syndrome, especially weight of excrement and total withdrawal score. In frequent dose protocol, in addition to these effects, nicotine induced weight loss and place aversion. Conclusion. The inhibitory effects of nicotine on signs of withdrawal syndrome may involve a dopaminergic portion of the central nervous system and is mediated by central nicotinic receptors. There is also a cross-dependence between nicotine and morphine.

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 replacement therapy

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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 ...

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.

Effect of wheel-running during abstinence on subsequent nicotine-seeking in rats

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Sanchez, Victoria; Moore, Catherine F; Brunzell, Darlene H; Lynch, Wendy J

2013-01-01

Rationale Exercise appears to be a promising non-pharmacological treatment for nicotine addiction that may be useful for the vulnerable adolescent population. Objectives To determine if wheel running, an animal model of aerobic exercise, during an abstinence period would decrease subsequent nicotine-seeking in rats that had extended access to nicotine self-administration during adolescence. Methods Male adolescent rats (n = 55) were trained to self-administer saline or nicotine infusions (5 or 10 μg/kg) under a fixed ratio 1 schedule with a maximum of 20 infusions/day beginning on postnatal day 30. After 5 days, access was extended to 23-hr/day with unlimited infusions for a total of 10 days. After the last self-administration session, rats were moved to polycarbonate cages for a 10-day abstinence period where they either had access to a locked or unlocked running wheel for 2-hr/day. Nicotine-seeking was examined following the 10th day of abstinence under a within-session extinction/cue-induced reinstatement paradigm. Results Intake was higher at the 10 μg/kg dose as compared to the 5 μg/kg dose; however, intake did not differ within doses prior to wheel assignment. Compared to saline controls, rats that self-administered nicotine at either dose showed a significant increase in drug-seeking during extinction, and consistent with our hypothesis, exercise during abstinence attenuated this effect. Nicotine led to modest, but significant levels of cue-induced reinstatement; however, in this adolescent-onset model, levels were variable and not affected by exercise. Conclusions Exercise may effectively reduce relapse vulnerability for adolescent-onset nicotine addiction. PMID:23371488

Toxic potential of the emerging contaminant nicotine to the aquatic ecosystem.

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Oropesa, Ana Lourdes; Floro, António Miguel; Palma, Patrícia

2017-07-01

Nicotine is a "life-style compound" widely consumed by human populations and, consequently, often found in surface waters. This fact presents a concern for possible effects in the aquatic ecosystems. The objective of this study was to assess the potential lethal and sublethal toxicity of nicotine in aquatic organisms from different trophic levels (Vibrio fischeri, Pseudokirchneriella subcapitata, Thamnocephalus platyurus, and Daphnia magna). The bioassays were performed by exposing the organisms to concentrations of nicotine in a range of 0.5-1000 μg/L. Results showed that nicotine, at tested concentration, was not acutely toxic to V. fischeri and T. platyurus. On the contrary, this substance exhibited toxicity to P. subcapitata and Daphnia magna. Thus, concentrations of nicotine of 100 and 200 μg/L promoted an inhibition in the growth of P. subcapitata. In addition, a concentration of 100 μg/L nicotine acted on the reproduction of the crustacean D. magna, by decreasing the number of juveniles produced by female. On the other hand, the results showed that concentrations equal to or greater than 10 μg/L induced the production of daphnids male offspring, which may indicate that nicotine is a weak juvenoid compound of the D. magna endocrine system. Furthermore, the result showed that concentrations tested of this chemical have the capacity to revert the effect of fenoxycarb, a strong juvenoid chemical insecticide. The results of the study revealed that nicotine can induce several changes in some of the most important key groups of the aquatic compartment, which can compromise, in a short time, the balance of aquatic ecosystem. Finally, a preliminary environmental risk assessment of this stimulant was performed from the highest measured concentration in surface water and the no observable effect concentration value in the most sensitive species, i.e., D. magna. This process revealed that nicotine can produce an important risk to aquatic organisms.

Nature gives us strength: exposure to nature counteracts ego-depletion.

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Chow, Jason T; Lau, Shun

2015-01-01

Previous research rarely investigated the role of physical environment in counteracting ego-depletion. In the present research, we hypothesized that exposure to natural environment counteracts ego-depletion. Three experiments were conducted to test this hypothesis. In Experiment 1, initially depleted participants who viewed pictures of nature scenes showed greater persistence on a subsequent anagram task than those who were given a rest period. Experiment 2 expanded upon this finding by showing that natural environment enhanced logical reasoning performance after ego-depleting task. Experiment 3 adopted a two- (depletion vs. no-depletion) -by-two (nature exposure vs. urban exposure) factorial design. We found that nature exposure moderated the effect of depletion on anagram task performance. Taken together, the present studies offer a viable and novel strategy to mitigate the negative impacts of ego-depletion.

Adolescent chronic variable social stress influences exploratory behavior and nicotine responses in male, but not female, BALB/cJ mice.

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Caruso, M J; Reiss, D E; Caulfield, J I; Thomas, J L; Baker, A N; Cavigelli, S A; Kamens, H M

2018-04-01

Anxiety disorders and nicotine use are significant contributors to global morbidity and mortality as independent and comorbid diseases. Early-life stress, potentially via stress-induced hypothalamic-pituitary-adrenal axis (HPA) dysregulation, can exacerbate both. However, little is known about the factors that predispose individuals to the development of both anxiety disorders and nicotine use. Here, we examined the relationship between anxiety-like behaviors and nicotine responses following adolescent stress. Adolescent male and female BALB/cJ mice were exposed to either chronic variable social stress (CVSS) or control conditions. CVSS consisted of repeated cycles of social isolation and social reorganization. In adulthood, anxiety-like behavior and social avoidance were measured using the elevated plus-maze (EPM) and social approach-avoidance test, respectively. Nicotine responses were assessed with acute effects on body temperature, corticosterone production, locomotor activity, and voluntary oral nicotine consumption. Adolescent stress had sex-dependent effects on nicotine responses and exploratory behavior, but did not affect anxiety-like behavior or social avoidance in males or females. Adult CVSS males exhibited less exploratory behavior, as indicated by reduced exploratory locomotion in the EPM and social approach-avoidance test, compared to controls. Adolescent stress did not affect nicotine-induced hypothermia in either sex, but CVSS males exhibited augmented nicotine-induced locomotion during late adolescence and voluntarily consumed less nicotine during adulthood. Stress effects on male nicotine-induced locomotion were associated with individual differences in exploratory locomotion in the EPM and social approach-avoidance test. Relative to controls, adult CVSS males and females also exhibited reduced corticosterone levels at baseline and adult male CVSS mice exhibited increased corticosterone levels following an acute nicotine injection. Results

Uncoupling nicotine mediated motoneuron axonal pathfinding errors and muscle degeneration in zebrafish

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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.

Hippocampal changes produced by overexpression of the human CHRNA5/A3/B4 gene cluster may underlie cognitive deficits rescued by nicotine in transgenic mice.

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Molas, Susanna; Gener, Thomas; Güell, Jofre; Martín, Mairena; Ballesteros-Yáñez, Inmaculada; Sanchez-Vives, Maria V; Dierssen, Mara

2014-11-11

Addiction involves long-lasting maladaptive changes including development of disruptive drug-stimuli associations. Nicotine-induced neuroplasticity underlies the development of tobacco addiction but also, in regions such as the hippocampus, the ability of this drug to enhance cognitive capabilities. Here, we propose that the genetic locus of susceptibility to nicotine addiction, the CHRNA5/A3/B4 gene cluster, encoding the α5, α3 and β4 subunits of the nicotinic acetylcholine receptors (nAChRs), may influence nicotine-induced neuroadaptations. We have used transgenic mice overexpressing the human cluster (TgCHRNA5/A3/B4) to investigate hippocampal structure and function in genetically susceptible individuals. TgCHRNA5/A3/B4 mice presented a marked reduction in the dendrite complexity of CA1 hippocampal pyramidal neurons along with an increased dendritic spine density. In addition, TgCHRNA5/A3/B4 exhibited increased VGLUT1/VGAT ratio in the CA1 region, suggesting an excitatory/inhibitory imbalance. These hippocampal alterations were accompanied by a significant impairment in short-term novelty recognition memory. Interestingly, chronic infusion of nicotine (3.25 mg/kg/d for 7 d) was able to rescue the reduced dendritic complexity, the excitatory/inhibitory imbalance and the cognitive impairment in TgCHRNA5/A3/B4. Our results suggest that chronic nicotine treatment may represent a compensatory strategy in individuals with altered expression of the CHRNA5/A3/B4 region.

Vitamin D Counteracts Mycobacterium tuberculosis-Induced Cathelicidin Downregulation in Dendritic Cells and Allows Th1 Differentiation and IFNγ Secretion.

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Rode, Anna K O; Kongsbak, Martin; Hansen, Marie M; Lopez, Daniel Villalba; Levring, Trine B; Woetmann, Anders; Ødum, Niels; Bonefeld, Charlotte M; Geisler, Carsten

2017-01-01

Tuberculosis (TB) presents a serious health problem with approximately one-third of the world's population infected with Mycobacterium tuberculosis in a latent state. Experience from the pre-antibiotic era and more recent clinical studies have established a beneficial role of sunlight and vitamin D in patients with TB. At the same time, experimental data have shown that Th1 cells through production of IFNγ are crucial for cathelicidin release by macrophages, bacterial killing, and containment of M. tuberculosis in granulomas. Paradoxically, vitamin D has repeatedly been ascribed an immune-suppressive function inhibiting Th1 differentiation and production of IFNγ in T cells. The aim of this study was to investigate this apparent paradox. We studied naïve human CD4 + T cells activated either with CD3 and CD28 antibodies or with allogeneic dendritic cells (DC) stimulated with heat-killed M. tuberculosis (HKMT) or purified toll-like receptor (TLR) ligands. We show that vitamin D does not block differentiation of human CD4 + T cells to Th1 cells and that interleukin (IL)-12 partially counteracts vitamin D-mediated inhibition of IFNγ production promoting production of equal amounts of IFNγ in Th1 cells in the presence of vitamin D as in T cells activated in the absence of vitamin D and IL-12. Furthermore, we show that HKMT and TLR2 ligands strongly downregulate cathelicidin expression in DC and that vitamin D counteracts this by upregulating cathelicidin expression. In conclusion, we demonstrate that vitamin D counteracts M. tuberculosis -induced cathelicidin downregulation and allows Th1 differentiation and IFNγ secretion.

Vitamin D Counteracts Mycobacterium tuberculosis-Induced Cathelicidin Downregulation in Dendritic Cells and Allows Th1 Differentiation and IFNγ Secretion

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Anna K. O. Rode

2017-05-01

Full Text Available Tuberculosis (TB presents a serious health problem with approximately one-third of the world’s population infected with Mycobacterium tuberculosis in a latent state. Experience from the pre-antibiotic era and more recent clinical studies have established a beneficial role of sunlight and vitamin D in patients with TB. At the same time, experimental data have shown that Th1 cells through production of IFNγ are crucial for cathelicidin release by macrophages, bacterial killing, and containment of M. tuberculosis in granulomas. Paradoxically, vitamin D has repeatedly been ascribed an immune-suppressive function inhibiting Th1 differentiation and production of IFNγ in T cells. The aim of this study was to investigate this apparent paradox. We studied naïve human CD4+ T cells activated either with CD3 and CD28 antibodies or with allogeneic dendritic cells (DC stimulated with heat-killed M. tuberculosis (HKMT or purified toll-like receptor (TLR ligands. We show that vitamin D does not block differentiation of human CD4+ T cells to Th1 cells and that interleukin (IL-12 partially counteracts vitamin D-mediated inhibition of IFNγ production promoting production of equal amounts of IFNγ in Th1 cells in the presence of vitamin D as in T cells activated in the absence of vitamin D and IL-12. Furthermore, we show that HKMT and TLR2 ligands strongly downregulate cathelicidin expression in DC and that vitamin D counteracts this by upregulating cathelicidin expression. In conclusion, we demonstrate that vitamin D counteracts M. tuberculosis-induced cathelicidin downregulation and allows Th1 differentiation and IFNγ secretion.

Effects of nicotine gum on psychomotor performance in smokers and non-smokers.

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Hindmarch, I; Kerr, J S; Sherwood, N

1990-01-01

Two experiments were conducted to investigate the effects of nicotine on human performance. In the first study six smokers, who had been allowed to smoke normally prior to testing, completed a battery of psychometric tests (choice reaction time, memory scanning, tracking and flicker fusion threshold) at set points over 4 h after chewing 0, 2, or 4 mg nicotine polacrilex gum. A second study followed a similar design, but used five non-smoker volunteers who were required to chew only the 0 or 2 mg nicotine gum. Blood nicotine levels following the gum were measured in all subjects. The results indicate that additional nicotine improved both the speed and accuracy of motor activity among the smokers, but did not enhance central cognitive processes. No drug effects were found in the non-smoker study.

Gc-protein-derived macrophage activating factor counteracts the neuronal damage induced by oxaliplatin.

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Morucci, Gabriele; Branca, Jacopo J V; Gulisano, Massimo; Ruggiero, Marco; Paternostro, Ferdinando; Pacini, Alessandra; Di Cesare Mannelli, Lorenzo; Pacini, Stefania

2015-02-01

Oxaliplatin-based regimens are effective in metastasized advanced cancers. However, a major limitation to their widespread use is represented by neurotoxicity that leads to peripheral neuropathy. In this study we evaluated the roles of a proven immunotherapeutic agent [Gc-protein-derived macrophage activating factor (GcMAF)] in preventing or decreasing oxaliplatin-induced neuronal damage and in modulating microglia activation following oxaliplatin-induced damage. The effects of oxaliplatin and of a commercially available formula of GcMAF [oleic acid-GcMAF (OA-GcMAF)] were studied in human neurons (SH-SY5Y cells) and in human microglial cells (C13NJ). Cell density, morphology and viability, as well as production of cAMP and expression of vascular endothelial growth factor (VEGF), markers of neuron regeneration [neuromodulin or growth associated protein-43 (Gap-43)] and markers of microglia activation [ionized calcium binding adaptor molecule 1 (Iba1) and B7-2], were determined. OA-GcMAF reverted the damage inflicted by oxaliplatin on human neurons and preserved their viability. The neuroprotective effect was accompanied by increased intracellular cAMP production, as well as by increased expression of VEGF and neuromodulin. OA-GcMAF did not revert the effects of oxaliplatin on microglial cell viability. However, it increased microglial activation following oxaliplatin-induced damage, resulting in an increased expression of the markers Iba1 and B7-2 without any concomitant increase in cell number. When neurons and microglial cells were co-cultured, the presence of OA-GcMAF significantly counteracted the toxic effects of oxaliplatin. Our results demonstrate that OA-GcMAF, already used in the immunotherapy of advanced cancers, may significantly contribute to neutralizing the neurotoxicity induced by oxaliplatin, at the same time possibly concurring to an integrated anticancer effect. The association between these two powerful anticancer molecules would probably produce

Tyrosine receptor kinase B receptor activation reverses the impairing effects of acute nicotine on contextual fear extinction.

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Kutlu, Munir Gunes; Cole, Robert D; Connor, David A; Natwora, Brendan; Gould, Thomas J

2018-03-01

Anxiety and stress disorders have been linked to deficits in fear extinction. Our laboratory and others have demonstrated that acute nicotine impairs contextual fear extinction, suggesting that nicotine exposure may have negative effects on anxiety and stress disorder symptomatology. However, the neurobiological mechanisms underlying the acute nicotine-induced impairment of contextual fear extinction are unknown. Therefore, based on the previous studies showing that brain-derived neurotrophic factor is central for fear extinction learning and acute nicotine dysregulates brain-derived neurotrophic factor signaling, we hypothesized that the nicotine-induced impairment of contextual fear extinction may involve changes in tyrosine receptor kinase B signaling. To test this hypothesis, we systemically, intraperitoneally, injected C57BL/6J mice sub-threshold doses (2.5 and 4.0 mg/kg) of 7,8-dihydroxyflavone, a small-molecule tyrosine receptor kinase B agonist that fully mimics the effects of brain-derived neurotrophic factor, or vehicle an hour before each contextual fear extinction session. Mice also received injections, intraperitoneally, of acute nicotine (0.18 mg/kg) or saline 2-4 min before extinction sessions. While the animals that received only 7,8-dihydroxyflavone did not show any changes in contextual fear extinction, 4.0 mg/kg of 7,8-dihydroxyflavone ameliorated the extinction deficits in mice administered acute nicotine. Overall, these results suggest that acute nicotine-induced impairment of context extinction may be related to a disrupted brain-derived neurotrophic factor signaling.

Analogues of neuroactive polyamine wasp toxins that lack inner basic sites exhibit enhanced antagonism toward a muscle-type mammalian nicotinic acetylcholine receptor

DEFF Research Database (Denmark)

Stromgaard, K; Brierley, M J; Andersen, K

1999-01-01

noncompetitively antagonized the nicotinic acetylcholine receptor (nAChR) in a concentration-, time-, and voltage-dependent manner. The amplitudes of acetylcholine-induced currents were compared at their peaks and at the end of a 1 s application in the presence or absence of the analogues. Most of the analogues...

Cortical cholinergic deficiency enhances amphetamine-induced dopamine release in the accumbens but not striatum.

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Mattsson, Anna; Olson, Lars; Svensson, Torgny H; Schilström, Björn

2007-11-01

Cholinergic dysfunction has been implicated as a putative contributing factor in the pathogenesis of schizophrenia. Recently, we showed that cholinergic denervation of the neocortex in adult rats leads to a marked increase in the behavioral response to amphetamine. The main objective of this study was to investigate if the enhanced locomotor response to amphetamine seen after cortical cholinergic denervation was paralleled by an increased amphetamine-induced release of dopamine in the nucleus accumbens and/or striatum. The corticopetal cholinergic projections were lesioned by intraparenchymal infusion of 192 IgG-saporin into the nucleus basalis magnocellularis of adult rats. Amphetamine-induced dopamine release in the nucleus accumbens or striatum was monitored by in vivo microdialysis 2 to 3 weeks after lesioning. We found that cholinergic denervation of the rat neocortex leads to a significantly increased amphetamine-induced dopamine release in the nucleus accumbens. Interestingly, the cholinergic lesion did not affect amphetamine-induced release of dopamine in the striatum. The enhanced amphetamine-induced dopamine release in the nucleus accumbens in the cholinergically denervated rats could be reversed by administration of the muscarinic agonist oxotremorine, but not nicotine, prior to the amphetamine challenge, suggesting that loss of muscarinic receptor stimulation is likely to have caused the observed effect. The results suggest that abnormal responsiveness of dopamine neurons can be secondary to cortical cholinergic deficiency. This, in turn, might be of relevance for the pathophysiology of schizophrenia and provides a possible link between cholinergic disturbances and alteration of dopamine transmission.

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.

Low-energy electron-induced dissociation in gas-phase nicotine, pyridine, and methyl-pyrrolidine

Science.gov (United States)

Ryszka, Michal; Alizadeh, Elahe; Li, Zhou; Ptasińska, Sylwia

2017-09-01

Dissociative electron attachment to nicotine, pyridine, and N-methyl-pyrrolidine was studied in the gas phase in order to assess their stability with respect to low-energy electron interactions. Anion yield curves for different products at electron energies ranging from zero to 15 eV were measured, and the molecular fragmentation pathways were proposed. Nicotine does not form a stable parent anion or a dehydrogenated anion, contrary to other biological systems. However, we have observed complex dissociation pathways involving fragmentation at the pyrrolidine side accompanied by isomerization mechanisms. Combining structure optimization and enthalpy calculations, performed with the Gaussian09 package, with the comparison with a deuterium-labeled N-methyl-d3-pyrrolidine allowed for the determination of the fragmentation pathways. In contrast to nicotine and N-methylpyrrolidine, the dominant pathway in dissociative electron attachment to pyridine is the loss of hydrogen, leading to the formation of an [M—H]- anion. The presented results provide important new information about the stability of nicotine and its constituent parts and contribute to a better understanding of the fragmentation mechanisms and their effects on the biological environment.

The potential role of cotinine in the cognitive and neuroprotective actions of nicotine.

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Buccafusco, Jerry J; Terry, Alvin V

2003-05-16

Cotinine is a primary metabolite of nicotine that has been suggested in many studies in animals and in humans to exert measurable effects on aspects of on-going behavior or on cognitive function. Much of the interest in cotinine derives from its long pharmacological half-life (15-19 hours) relative to nicotine (2-3 hours). Despite decades of study focusing on nicotine as the predominant behaviorally active component of tobacco, there continue to be aspects of the pharmacology of the drug that have yet to be explained. For example, nicotine can evoke a protracted behavioral response, i.e., in great excess of the presence of the drug in the plasma. Also, there is often a striking differential between the potency for nicotine-induced behavioral responses in humans and animals, and its potency as a cholinergic agonist, neurochemically. One possibility that may explain one or more of these properties of nicotine is the presence of a long-lived bioactive metabolite or breakdown product of nicotine such as cotinine. Preliminary data in support of this hypothesis are consistent with the ability of cotinine to improve performance accuracy on delayed matching task by macaque monkeys, and in reversing apomorphine-induced deficits in prepulse inhibition of acoustic startle in rats. The drug also was shown to be as potent as nicotine in the ability to act as a cytoprotective agent in cells that express a neuronal cholinergic phenotype. This new appreciation for the role of cotinine in nicotine's actions, and as a pharmacological agent in its own right, particularly in aspects of cognitive function and for neuroprotection, ultimately may be applied towards the treatment of Alzheimer's disease and related disorders, and for various psychiatric syndromes.

‌‌The effect of nicotine administration on physical and psychological signs of withdrawal syndrome induced by single or frequent doses of morphine in rats

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Ali Shamsizadeh

2012-07-01

Full Text Available Introduction: Morphine addiction and morphine withdrawal syndrome are the two main problems of today’s human society. The present study has investigated the effects of nicotine on the strength of physical and psychological dependency in single and repeated doses morphine administrated rats. Methods: Male Wistar rats were subjected to morphine consumption with single or frequent dose protocols. In the single dose protocol, rats received only one dose of morphine and 24hrs later they also received one dose of nicotine 30 min prior to injection of naloxone. In the repeated dose protocol, rats received incremental doses of morphine for 7 days and 24hr after the last dose (the 8th day were given naloxone. However, the nicotine regimen of this group was injected 15 min before the morphine injection, for 4 days, from the 4th to the 7th day. Five minutes after naloxone injection, each rat′s behavior was captured for 30 min, and then physical and psychological signs of withdrawal syndrome were recorded. Data were analyzed by ANOVA followed by Tukey tests and p<0.05 was considered as significant difference. Results: Results showed that the injection of frequent and single doses of morphine lead to morphine dependency. In single dose protocol, nicotine consumption attenuated the signs of withdrawal syndrome, especially weight of excrement and total withdrawal score. In frequent dose protocol, in addition to these effects, nicotine induced weight loss and place aversion. Discussion: The inhibitory effects of nicotine on signs of withdrawal syndrome may involve a dopaminergic portion of the central nervous system and is mediated by central nicotinic receptors. There is also a cross-dependence between nicotine and morphine.

MDM2 Antagonists Counteract Drug-Induced DNA Damage

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Anna E. Vilgelm

2017-10-01

Full Text Available Antagonists of MDM2-p53 interaction are emerging anti-cancer drugs utilized in clinical trials for malignancies that rarely mutate p53, including melanoma. We discovered that MDM2-p53 antagonists protect DNA from drug-induced damage in melanoma cells and patient-derived xenografts. Among the tested DNA damaging drugs were various inhibitors of Aurora and Polo-like mitotic kinases, as well as traditional chemotherapy. Mitotic kinase inhibition causes mitotic slippage, DNA re-replication, and polyploidy. Here we show that re-replication of the polyploid genome generates replicative stress which leads to DNA damage. MDM2-p53 antagonists relieve replicative stress via the p53-dependent activation of p21 which inhibits DNA replication. Loss of p21 promoted drug-induced DNA damage in melanoma cells and enhanced anti-tumor activity of therapy combining MDM2 antagonist with mitotic kinase inhibitor in mice. In summary, MDM2 antagonists may reduce DNA damaging effects of anti-cancer drugs if they are administered together, while targeting p21 can improve the efficacy of such combinations.

Counteracting the Influence of Peer Smoking on YouTube

OpenAIRE

Romer, Daniel; Jamieson, Patrick E.; Jamieson, Kathleen Hall; Jones, Christopher; Sherr, Susan

2017-01-01

YouTube, a popular online site for user-generated content, is emerging as a powerful source of peer modeling of smoking. Previous research suggests that in counteracting such influence, health messages may inadvertently increase the perceived prevalence of drug use (a descriptive norm) without reducing its acceptability (injunctive norm). This research tested the ability of health messages to reduce the social acceptability of peer smoking on YouTube despite enhancing its perceived prevalence...

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

FOXM1 upregulation is an early event in human squamous cell carcinoma and it is enhanced by nicotine during malignant transformation.

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Emilios Gemenetzidis

Full Text Available Cancer associated with smoking and drinking remains a serious health problem worldwide. The survival of patients is very poor due to the lack of effective early biomarkers. FOXM1 overexpression is linked to the majority of human cancers but its mechanism remains unclear in head and neck squamous cell carcinoma (HNSCC.FOXM1 mRNA and protein expressions were investigated in four independent cohorts (total 75 patients consisting of normal, premalignant and HNSCC tissues and cells using quantitative PCR (qPCR, expression microarray, immunohistochemistry and immunocytochemistry. Effect of putative oral carcinogens on FOXM1 transcriptional activity was dose-dependently assayed and confirmed using a FOXM1-specific luciferase reporter system, qPCR, immunoblotting and short-hairpin RNA interference. Genome-wide single nucleotide polymorphism (SNP array was used to 'trace' the genomic instability signature pattern in 8 clonal lines of FOXM1-induced malignant human oral keratinocytes. Furthermore, acute FOXM1 upregulation in primary oral keratinocytes directly induced genomic instability. We have shown for the first time that overexpression of FOXM1 precedes HNSCC malignancy. Screening putative carcinogens in human oral keratinocytes surprisingly showed that nicotine, which is not perceived to be a human carcinogen, directly induced FOXM1 mRNA, protein stabilisation and transcriptional activity at concentrations relevant to tobacco chewers. Importantly, nicotine also augmented FOXM1-induced transformation of human oral keratinocytes. A centrosomal protein CEP55 and a DNA helicase/putative stem cell marker HELLS, both located within a consensus loci (10q23, were found to be novel targets of FOXM1 and their expression correlated tightly with HNSCC progression.This study cautions the potential co-carcinogenic effect of nicotine in tobacco replacement therapies. We hypothesise that aberrant upregulation of FOXM1 may be inducing genomic instability through a

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.

Performance effects of nicotine during selective attention, divided attention, and simple stimulus detection: an fMRI study.

Science.gov (United States)

Hahn, Britta; Ross, Thomas J; Wolkenberg, Frank A; Shakleya, Diaa M; Huestis, Marilyn A; Stein, Elliot A

2009-09-01

Attention-enhancing effects of nicotine appear to depend on the nature of the attentional function. Underlying neuroanatomical mechanisms, too, may vary depending on the function modulated. This functional magnetic resonance imaging study recorded blood oxygen level-dependent (BOLD) activity in minimally deprived smokers during tasks of simple stimulus detection, selective attention, or divided attention after single-blind application of a transdermal nicotine (21 mg) or placebo patch. Smokers' performance in the placebo condition was unimpaired as compared with matched nonsmokers. Nicotine reduced reaction time (RT) in the stimulus detection and selective attention but not divided attention condition. Across all task conditions, nicotine reduced activation in frontal, temporal, thalamic, and visual regions and enhanced deactivation in so-called "default" regions. Thalamic effects correlated with RT reduction selectively during stimulus detection. An interaction with task condition was observed in middle and superior frontal gyri, where nicotine reduced activation only during stimulus detection. A visuomotor control experiment provided evidence against nonspecific effects of nicotine. In conclusion, although prefrontal activity partly displayed differential modulation by nicotine, most BOLD effects were identical across tasks, despite differential performance effects, suggesting that common neuronal mechanisms can selectively benefit different attentional functions. Overall, the effects of nicotine may be explained by increased functional efficiency and downregulated task-independent "default" functions.

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).

Nicotine protects kidney from renal ischemia/reperfusion injury through the cholinergic anti-inflammatory pathway.

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Claude Sadis

Full Text Available Kidney ischemia/reperfusion injury (I/R is characterized by renal dysfunction and tubular damages resulting from an early activation of innate immunity. Recently, nicotine administration has been shown to be a powerful inhibitor of a variety of innate immune responses, including LPS-induced toxaemia. This cholinergic anti-inflammatory pathway acts via the alpha7 nicotinic acetylcholine receptor (alpha7nAChR. Herein, we tested the potential protective effect of nicotine administration in a mouse model of renal I/R injury induced by bilateral clamping of kidney arteries. Renal function, tubular damages and inflammatory response were compared between control animals and mice receiving nicotine at the time of ischemia. Nicotine pretreatment protected mice from renal dysfunction in a dose-dependent manner and through the alpha7nAChR, as attested by the absence of protection in alpha7nAChR-deficient mice. Additionally, nicotine significantly reduced tubular damages, prevented neutrophil infiltration and decreased productions of the CXC-chemokine KC, TNF-alpha and the proinflammatory high-mobility group box 1 protein. Reduced tubular damage in nicotine pre-treated mice was associated with a decrease in tubular cell apoptosis and proliferative response as attested by the reduction of caspase-3 and Ki67 positive cells, respectively. All together, these data highlight that nicotine exerts a protective anti-inflammatory effect during kidney I/R through the cholinergic alpha7nAChR pathway. In addition, this could provide an opportunity to overcome the effect of surgical cholinergic denervation during kidney transplantation.

Acidosis counteracts itch tachyphylaxis to consecutive pruritogen exposure dependent on acid-sensing ion channel 3.

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Jiang, Yi-Ming; Huang, Chen; Peng, Zhong; Han, Shao-Ling; Li, Wei-Guang; Zhu, Michael Xi; Xu, Tian-Le

2017-01-01

Tachyphylaxis of itch refers to a markedly reduced scratching response to consecutive exposures of a pruritogen, a process thought to protect against tissue damage by incessant scratching and to become disrupted in chronic itch. Here, we report that a strong stimulation of the Mas-related G-protein-coupled receptor C11 by its agonist, Ser-Leu-Ile-Gly-Arg-Leu-NH 2 (SL-NH 2 ) or bovine adrenal medulla 8-22 peptide, via subcutaneous injection in mice induces tachyphylaxis to the subsequent application of SL-NH 2 to the same site. Notably, co-application of acid and SL-NH 2 following the initial injection of the pruritogen alone counteracted itch tachyphylaxis by augmenting the scratching behaviors in wild-type but not in acid-sensing ion channel 3-null, animals. Using an activity-dependent silencing strategy, we identified that acid-sensing ion channel 3-mediated itch enhancement mainly occurred via the Mas-related G-protein-coupled receptor C11-responsive sensory neurons. Together, our results indicate that acid-sensing ion channel 3, activated by concomitant acid and certain pruritogens, constitute a novel signaling pathway that counteracts itch tachyphylaxis to successive pruritogenic stimulation, which likely contributes to chronic itch associated with tissue acidosis.

Effects of the Sazetidine-a Family of Compounds on the Body Temperature in Wildtype, Nicotinic Receptor B2(-/-) and a7(-/-) Mice

Science.gov (United States)

Nicotine elicits hypothermic responses in rodents. This effect appears to be related to nicotinic receptor desensitization because sazetidine-A, an a4B2 nicotinic receptor desensitizing agent, produces marked hypothermia and potentiates nicotine-induced hypothermia in mice. To de...

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...

Characterization of Surface-Enhanced Raman Scattering of Nicotine Utilizing Plasmonic Nanometals for the Applications of Medical and Chemical Sensing

Science.gov (United States)

Jackson, Ashley; Rigo, Maria; Seo, Jaetae; HU Team

2011-05-01

Raman spectroscopy has received a great deal of interest for its applications in biological sensing and cell imaging due to the ease with which it can be used to extract significant data from tissue and cells. This study has focused on the application of SERS for nicotine detection. Liquid nicotine was diluted and combined with Au nanoparticles (NPs). The nicotine-gold solution was analyzed by acquiring Raman spectra data using a Delta Nu Spectrometer. Absorption data shows the characteristic peak of Au NPs at ~528 nm while showing successful aggregation of the nicotine particles. Data taken from Raman spectra shows characteristic Raman shifts of nicotine at ~1030 cm-1 and ~1590 cm-1. Currently work is being done to optimize the SERS signal for nicotine in the 1590-1600 region using higher concentrations of nicotine and various sizes of Au NPs. This work at Hampton University was supported by the National Science Foundation (HRD-0734635 and HRD-063037).

Interaction between Harmane and Nicotinic in the Passive Avoidance Test

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M Piri

2011-01-01

Full Text Available Introduction & Objective: A number of β-carboline alkaloids such as harmane are naturally present in the human food chain. Furthermore, some plants which contain β-carboline have behavioral effects such as hallucination. In the present study, the effect of intra-dorsal hippocampus injection of nicotinic receptor agonist on memory impairment induced by harmane was examined in mice. Materials & Methods: This study was conducted at Shahid Beheshti University in 2009. Two hundred and forty mice were anesthetized with intra-peritoneal injection of ketamine hydrochloride, plus xylazine which afterwards were placed in a stereotaxic apparatus. Two cannuale were placed in the CA1 regions of the dorsal hippocampus. All animals were allowed to recover for a total week before beginning of the behavioral testing. After that, the animals were trained in a step-down type inhibitory avoidance task and tested 24 hours after training to measure step-down latency as a scale of memory. Results: Pre-training and post-training, intra-peritoneal injection of harmane impairs inhibitory avoidance memory, but pre-testing injection of harmane did not alter memory retrieval. Pre-testing administration of high dose of nicotine (0.5 µg/mice, intra-CA1 decreased memory retrieval. On the other hand, pre-test intra-CA1 injection of ineffective doses of nicotine (0.1 and 2.5 µg/mice fully reversed harmane induced impairment of memory. Conclusion: The present results indicated that complex interaction exists between nicotinic receptor of dorsal hippocampus and the impairment of inhibitory avoidance memory induced by harmane.

Anti-inflammatory effects of nicotine in obesity and ulcerative colitis

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Kirchgessner Annette

2011-08-01

Full Text Available Abstract Cigarette smoke is a major risk factor for a number of diseases including lung cancer and respiratory infections. Paradoxically, it also contains nicotine, an anti-inflammatory alkaloid. There is increasing evidence that smokers have a lower incidence of some inflammatory diseases, including ulcerative colitis, and the protective effect involves the activation of a cholinergic anti-inflammatory pathway that requires the α7 nicotinic acetylcholine receptor (α7nAChR on immune cells. Obesity is characterized by chronic low-grade inflammation, which contributes to insulin resistance. Nicotine significantly improves glucose homeostasis and insulin sensitivity in genetically obese and diet-induced obese mice, which is associated with suppressed adipose tissue inflammation. Inflammation that results in disruption of the epithelial barrier is a hallmark of inflammatory bowel disease, and nicotine is protective in ulcerative colitis. This article summarizes current evidence for the anti-inflammatory effects of nicotine in obesity and ulcerative colitis. Selective agonists for the α7nAChR could represent a promising pharmacological strategy for the treatment of inflammation in obesity and ulcerative colitis. Nevertheless, we should keep in mind that the anti-inflammatory effects of nicotine could be mediated via the expression of several nAChRs on a particular target cell.

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

Science.gov (United States)

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.

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

Wild tobacco genomes reveal the evolution of nicotine biosynthesis.

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Xu, Shuqing; Brockmöller, Thomas; Navarro-Quezada, Aura; Kuhl, Heiner; Gase, Klaus; Ling, Zhihao; Zhou, Wenwu; Kreitzer, Christoph; Stanke, Mario; Tang, Haibao; Lyons, Eric; Pandey, Priyanka; Pandey, Shree P; Timmermann, Bernd; Gaquerel, Emmanuel; Baldwin, Ian T

2017-06-06

Nicotine, the signature alkaloid of Nicotiana species responsible for the addictive properties of human tobacco smoking, functions as a defensive neurotoxin against attacking herbivores. However, the evolution of the genetic features that contributed to the assembly of the nicotine biosynthetic pathway remains unknown. We sequenced and assembled genomes of two wild tobaccos, Nicotiana attenuata (2.5 Gb) and Nicotiana obtusifolia (1.5 Gb), two ecological models for investigating adaptive traits in nature. We show that after the Solanaceae whole-genome triplication event, a repertoire of rapidly expanding transposable elements (TEs) bloated these Nicotiana genomes, promoted expression divergences among duplicated genes, and contributed to the evolution of herbivory-induced signaling and defenses, including nicotine biosynthesis. The biosynthetic machinery that allows for nicotine synthesis in the roots evolved from the stepwise duplications of two ancient primary metabolic pathways: the polyamine and nicotinamide adenine dinucleotide (NAD) pathways. In contrast to the duplication of the polyamine pathway that is shared among several solanaceous genera producing polyamine-derived tropane alkaloids, we found that lineage-specific duplications within the NAD pathway and the evolution of root-specific expression of the duplicated Solanaceae-specific ethylene response factor that activates the expression of all nicotine biosynthetic genes resulted in the innovative and efficient production of nicotine in the genus Nicotiana Transcription factor binding motifs derived from TEs may have contributed to the coexpression of nicotine biosynthetic pathway genes and coordinated the metabolic flux. Together, these results provide evidence that TEs and gene duplications facilitated the emergence of a key metabolic innovation relevant to plant fitness.

Prenatal nicotine exposure induces poor articular cartilage quality in female adult offspring fed a high-fat diet and the intrauterine programming mechanisms.

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Tie, Kai; Tan, Yang; Deng, Yu; Li, Jing; Ni, Qubo; Magdalou, Jacques; Chen, Liaobin; Wang, Hui

2016-04-01

Prenatal nicotine exposure (PNE) induces skeletal growth retardation and dyslipidemia in offspring displaying intrauterine growth retardation (IUGR). Cholesterol accumulation resulting from cholesterol efflux dysfunction may reduce the quality of articular cartilage through fetal programming. This study evaluated the quality of articular cartilage of female adult offspring fed a high-fat diet and explored the mechanisms using a rat IUGR model established by the administration of 2.0mg/kg/d of subcutaneous nicotine from gestational days 11-20. The results demonstrated an increased OARSI (Osteoarthritis Research Society International) score and total cholesterol content, decreased serum corticosterone, and increased IGF1 and dyslipidemia with catch-up growth in PNE adult offspring. Cartilage matrix, IGF1 and cholesterol efflux pathway expression were reduced in PNE fetuses and adult offspring. Therefore, PNE induced poor articular cartilage quality in female adult offspring fed a high-fat diet via a dual programming mechanism. Copyright © 2016 Elsevier Inc. All rights reserved.

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.

The 5-HT2C receptor agonist lorcaserin reduces nicotine self-administration, discrimination, and reinstatement: relationship to feeding behavior and impulse control.

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Higgins, Guy A; Silenieks, Leo B; Rossmann, Anne; Rizos, Zoe; Noble, Kevin; Soko, Ashlie D; Fletcher, Paul J

2012-04-01

Lorcaserin ((1R)-8-chloro-1-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine HCl) is a selective 5-HT(2C) receptor agonist with clinical efficacy in phase-III obesity trials. Based on evidence that this drug class also affects behaviors motivated by drug reinforcement, we compared the effect of lorcaserin on behavior maintained by food and nicotine reinforcement, as well as the stimulant and discriminative stimulus properties of nicotine in the rat. Acutely administered lorcaserin (0.3-3 mg/kg, subcutaneous (SC)) dose dependently reduced feeding induced by 22-h food deprivation or palatability. Effects up to 1 mg/kg were consistent with a specific effect on feeding motivation. Lorcaserin (0.6-1 mg/kg, SC) reduced operant responding for food on progressive and fixed ratio schedules of reinforcement. In this dose range lorcaserin also reversed the motor stimulant effect of nicotine, reduced intravenous self-administration of nicotine, and attenuated the nicotine cue in rats trained to discriminate nicotine from saline. Lorcaserin also reduced the reinstatement of nicotine-seeking behavior elicited by a compound cue comprising a nicotine prime and conditioned stimulus previously paired with nicotine reinforcement. Lorcaserin did not reinstate nicotine-seeking behavior or substitute for a nicotine cue. Finally, lorcaserin (0.3-1 mg/kg) reduced nicotine-induced increases in anticipatory responding, a measure of impulsive action, in rats performing the five-choice serial reaction time task. Importantly, these results indicate that lorcaserin, and likely other selective 5-HT(2C) receptor agonists, similarly affect both food- and nicotine-motivated behaviors, and nicotine-induced impulsivity. Collectively, these findings highlight a therapeutic potential for 5-HT(2C) agonists such as lorcaserin beyond obesity into addictive behaviors, such as nicotine dependence.

CNF1 Enhances Brain Energy Content and Counteracts Spontaneous Epileptiform Phenomena in Aged DBA/2J Mice.

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Sara Travaglione

Full Text Available Epilepsy, one of the most common conditions affecting the brain, is characterized by neuroplasticity and brain cell energy defects. In this work, we demonstrate the ability of the Escherichia coli protein toxin cytotoxic necrotizing factor 1 (CNF1 to counteract epileptiform phenomena in inbred DBA/2J mice, an animal model displaying genetic background with an high susceptibility to induced- and spontaneous seizures. Via modulation of the Rho GTPases, CNF1 regulates actin dynamics with a consequent increase in spine density and length in pyramidal neurons of rat visual cortex, and influences the mitochondrial homeostasis with remarkable changes in the mitochondrial network architecture. In addition, CNF1 improves cognitive performances and increases ATP brain content in mouse models of Rett syndrome and Alzheimer's disease. The results herein reported show that a single dose of CNF1 induces a remarkable amelioration of the seizure phenotype, with a significant augmentation in neuroplasticity markers and in cortex mitochondrial ATP content. This latter effect is accompanied by a decrease in the expression of mitochondrial fission proteins, suggesting a role of mitochondrial dynamics in the CNF1-induced beneficial effects on this epileptiform phenotype. Our results strongly support the crucial role of brain energy homeostasis in the pathogenesis of certain neurological diseases, and suggest that CNF1 could represent a putative new therapeutic tool for epilepsy.

PXR (NR1I2): splice variants in human tissues, including brain, and identification of neurosteroids and nicotine as PXR activators

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Lamba, Vishal; Yasuda, Kazuto; Lamba, Jatinder K.; Assem, Mahfoud; Davila, Julio; Strom, Stephen; Schuetz, Erin G.

2004-01-01

To gain insight on the expression of pregnane X receptor (PXR), we analyzed PXR.1 and PXR alternatively spliced transcripts in a panel of 36 human tissues. PXR.1 was expressed in many more tissues than previously determined, including human bone marrow and select regions of the human brain. In each of these tissues, we observed alternative splicing of various exons of PXR that generated multiple distinct PXR isoforms. The most abundant PXR alternative mRNA transcripts lacked 111 nucleotides, deleting 37 amino acids from the PXR LBD (PXR.2), or lacked 123 nt, deleting 41 amino acids from the PXR LBD (PXR.3). CYP3A4, a gene transcriptionally regulated by PXR, showed incomplete overlap with PXR in its tissue distribution. Quantitation of PXR mRNAs in human liver demonstrated that PXR.2 and PXR.3 represented 6.7% and 0.32% of total PXR mRNA transcripts. Brain expression of PXR prompted analysis of whether some brain acting chemicals were PXR ligands. The neurosteroids allopregnanolone and pregnanolone activated PXR and induced transcription of a CYP3A4-luciferase reporter. Nicotine, the psychoactive and addictive chemical in cigarettes, and a known inducer of brain CYP2B6, was an efficacious activator of PXR and inducer of CYP3A4 transcription. Because nicotine activation of PXR will enhance metabolism of nicotine to the non-psychoactive cotinine, these results provide one molecular mechanism for the development of tolerance to nicotine. Moreover, the identification of PXR in many human tissues, such as brain, and activation by tissue specific ligands (such as neurosteroids) suggests additional biological roles for this receptor in these tissues

PXR (NR1I2): splice variants in human tissues, including brain, and identification of neurosteroids and nicotine as PXR activators.

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Lamba, Vishal; Yasuda, Kazuto; Lamba, Jatinder K; Assem, Mahfoud; Davila, Julio; Strom, Stephen; Schuetz, Erin G

2004-09-15

To gain insight on the expression of pregnane X receptor (PXR), we analyzed PXR.1 and PXR alternatively spliced transcripts in a panel of 36 human tissues. PXR.1 was expressed in many more tissues than previously determined, including human bone marrow and select regions of the human brain. In each of these tissues, we observed alternative splicing of various exons of PXR that generated multiple distinct PXR isoforms. The most abundant PXR alternative mRNA transcripts lacked 111 nucleotides, deleting 37 amino acids from the PXR LBD (PXR.2), or lacked 123 nt, deleting 41 amino acids from the PXR LBD (PXR.3). CYP3A4, a gene transcriptionally regulated by PXR, showed incomplete overlap with PXR in its tissue distribution. Quantitation of PXR mRNAs in human liver demonstrated that PXR.2 and PXR.3 represented 6.7% and 0.32% of total PXR mRNA transcripts. Brain expression of PXR prompted analysis of whether some brain acting chemicals were PXR ligands. The neurosteroids allopregnanolone and pregnanolone activated PXR and induced transcription of a CYP3A4-luciferase reporter. Nicotine, the psychoactive and addictive chemical in cigarettes, and a known inducer of brain CYP2B6, was an efficacious activator of PXR and inducer of CYP3A4 transcription. Because nicotine activation of PXR will enhance metabolism of nicotine to the non-psychoactive cotinine, these results provide one molecular mechanism for the development of tolerance to nicotine. Moreover, the identification of PXR in many human tissues, such as brain, and activation by tissue specific ligands (such as neurosteroids) suggests additional biological roles for this receptor in these tissues.

Inducing rat brain CYP2D with nicotine increases the rate of codeine tolerance; predicting the rate of tolerance from acute analgesic response.

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McMillan, Douglas M; Tyndale, Rachel F

2017-12-01

Repeated opioid administration produces analgesic tolerance, which may lead to dose escalation. Brain CYP2D metabolizes codeine to morphine, a bioactivation step required for codeine analgesia. Higher brain, but not liver, CYP2D is found in smokers and nicotine induces rat brain, but not liver, CYP2D expression and activity. Nicotine induction of rat brain CYP2D increases acute codeine conversion to morphine, and analgesia, however the role of brain CYP2D on the effects of repeated codeine exposure and tolerance is unknown. Rats were pretreated with nicotine (brain CYP2D inducer; 1mg/kg subcutaneously) or vehicle (saline; 1ml/kg subcutaneously). Codeine (40-60mg/kg oral-gavage) or morphine (20-30mg/kg oral-gavage) was administered daily and analgesia was assessed daily using the tail-flick reflex assay. Nicotine (versus saline) pretreatment increased acute codeine analgesia (1.32-fold change in AUC 0-60 min ; pnicotine did not alter acute morphine analgesia (1.03-fold; p>0.8), or the rate of morphine tolerance (8.1%/day versus 7.6%; p>0.9). The rate of both codeine and morphine tolerance (loss in peak analgesia from day 1 to day 4) correlated with initial analgesic response on day 1 (R=0.97, p<001). Increasing brain CYP2D altered initial analgesia and subsequent rate of tolerance. Variation in an individual's initial response to analgesic (e.g. high initial dose, smoking) may affect the rate of tolerance, and thereby the risk for dose escalation and/or opioid dependence. Copyright © 2017 Elsevier Inc. All rights reserved.

Chronic agmatine treatment prevents behavioral manifestations of nicotine withdrawal in mice.

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Kotagale, Nandkishor R; Chopde, Chandrabhan T; Umekar, Milind J; Taksande, Brijesh G

2015-05-05

Smoking cessation exhibits an aversive withdrawal syndrome characterized by both increases in somatic signs and affective behaviors including anxiety and depression. In present study, abrupt withdrawal of daily nicotine injections (2mg/kg, s.c., four times daily, for 10 days) significantly increased somatic signs viz. rearing, grooming, jumping, genital licking, leg licking, head shakes with associated depression (increased immobility in forced swim test) as well as anxiety (decreased the number of entries and time spent in open arm in elevated plus maze) in nicotine dependent animals. The peak effect was observed at 24h time point of nicotine withdrawal. Repeated administration of agmatine (40-80µg/mouse, i.c.v.) before the first daily dose of nicotine from day 5 to 10 attenuated the elevated scores of somatic signs and abolished the depression and anxiety like behavior induced by nicotine withdrawal in dependent animals. However, in separate groups, its acute administration 30min before behavior analysis of nicotine withdrawal was ineffective. This result clearly shows the role of agmatine in development of nicotine dependence and its withdrawal. In extension to behavioral experiments, brain agmatine analyses, carried out at 24h time point of nicotine withdrawal demonstrated marked decrease in basal brain agmatine concentration as compared to control animals. Taken together, these data support the role of agmatine as common biological substrate for somatic signs and affective symptoms of nicotine withdrawal. This data may project therapies based on agmatine in anxiety, depression and mood changes associated with tobacco withdrawal. Copyright © 2015 Elsevier B.V. All rights reserved.

Nicotine promotes rooting in leaf explants of in vitro raised seedlings of tomato, Lycopersicon esculentum Miller var. Pusa Ruby.

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Bamel, Kiran; Gupta, Rajendra; Gupta, Shrish C

2015-11-01

Nicotine promotes rooting in leaf explants of tomato (Lycopersicon esculentum Miller var. Pusa Ruby). Nicotine at 10(-9) to 10(-3) M concentrations was added to the MS basal medium. The optimum response (three-fold increase in rooting) was obtained at 10(-7) M nicotine-enriched MS medium. At the same level i.e. 10(-7) M Nicotine induced dramatic increase (11-fold) in the number of secondary roots per root. We have shown earlier that exogenous acetylcholine induces a similar response in tomato leaves. Since nicotine is an agonist of one of the two acetylcholine receptors in animals, its ability to simulate ACh action in a plant system suggests the presence of the same molecular mechanism operative in both, animal and plant cells. Copyright © 2015 Elsevier B.V. All rights reserved.

Electronic Nicotine Delivery Systems.

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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.

Impact of e-cigarette refill liquid with or without nicotine on liver function in adult rats.

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El Golli, Narges; Jrad-Lamine, Aicha; Neffati, Hajira; Rahali, Dalila; Dallagi, Yosra; Dkhili, Houssem; Ba, Nathalie; El May, Michele V; El Fazaa, Saloua

2016-07-01

This study was conducted to evaluate the effects of e-cigarette refill liquid administration alone or with nicotine on the antioxidant defense status, functional and histopathological changes in adult rat liver tissue. For this purpose, 32 rats were treated for 28 days as follows: control group was injected intra-peritoneally with physiological saline; e-cigarette 0% treated group received an intra-peritoneal injection of e-liquid without nicotine diluted in physiological saline, e-cigarette-treated group received an intra-peritoneal injection of e-liquid containing 0.5 mg of nicotine/kg of body weight/day diluted in physiological saline and nicotine-treated group received an intra-peritoneal injection of 0.5 mg of nicotine/kg of body weight/day diluted in physiological saline. In e-liquid without nicotine-exposed group, activities of the liver biomarkers aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and lactate dehydrogenase increase. Interestingly, oxidative stress indicators showed decreased total protein content, associated with a reduction in the antioxidant enzymes activities superoxide dismutase, catalase and glutathione-S-transferase, and an elevation in malondialdehyde content, highlighting the promotion of lipid peroxidation and oxidative stress. Histological studies identified inflammatory cells infiltration and cell death. Thus, e-liquid seems to promote oxidative tissue injuries, which in turn lead to the observed histopathological finding. In comparison, nicotine alone induced less oxidative stress and less histopathological disorders, whereas e-liquid with nicotine gave rise to more histopathological injuries. Thereby, e-liquid, per se, is able to induce hepatotoxicity and supplementation with nicotine worsens this state.

Pre-adolescent and adolescent mice are less sensitive to the effects of acute nicotine on extinction and spontaneous recovery.

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Kutlu, Munir Gunes; Zeid, Dana; Tumolo, Jessica M; Gould, Thomas J

2018-04-01

Adolescence is a period of high risk for the initiation of nicotine product usage and exposure to traumatic events. In parallel, nicotine exposure has been found to age-dependently modulate acquisition of contextual fear memories; however, it is unknown if adolescent nicotine exposure alters extinction of fear related memories. Age-related differences in sensitivity to the effects of nicotine on fear extinction could increase or decrease susceptibility to anxiety disorders. In this study, we examined the effects of acute nicotine administration on extinction and spontaneous recovery of contextual fear memories in pre-adolescent (PND 23), late adolescent (PND 38), and adult (PND 53) C57B6/J mice. Mice were first trained in a background contextual fear conditioning paradigm and given an intraperitoneal injection of one of four doses of nicotine (0.045, 0.09, 0.18, or 0.36mg/kg, freebase) prior to subsequent extinction or spontaneous recovery sessions. Results indicated that all acute nicotine doses impaired extinction of contextual fear in adult mice. Late adolescent mice exhibited impaired extinction of contextual fear only following higher doses of acute nicotine, and extinction of contextual fear was unaffected by acute nicotine exposure in pre-adolescent mice. Finally, acute nicotine exposure enhanced spontaneous recovery of fear memory, but only in adult mice. Overall, our results suggest that younger mice were less sensitive to nicotine's impairing effects on extinction of contextual fear and to nicotine's enhancing effects on spontaneous recovery of contextual fear memory. Copyright © 2017 Elsevier Inc. All rights reserved.

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

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

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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

The effects of acute nicotine on contextual safety discrimination.

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Kutlu, Munir G; Oliver, Chicora; Gould, Thomas J

2014-11-01

Anxiety disorders, such as post-traumatic stress disorder (PTSD), may be related to an inability to distinguish safe versus threatening environments and to extinguish fear memories. Given the high rate of cigarette smoking in patients with PTSD, as well as the recent finding that an acute dose of nicotine impairs extinction of contextual fear memory, we conducted a series of experiments to investigate the effect of acute nicotine in an animal model of contextual safety discrimination. Following saline or nicotine (at 0.0275, 0.045, 0.09 and 0.18 mg/kg) administration, C57BL/6J mice were trained in a contextual discrimination paradigm, in which the subjects received presentations of conditioned stimuli (CS) that co-terminated with a foot-shock in one context (context A (CXA)) and only CS presentations without foot-shock in a different context (context B (CXB)). Therefore, CXA was designated as the 'dangerous context', whereas CXB was designated as the 'safe context'. Our results suggested that saline-treated animals showed a strong discrimination between dangerous and safe contexts, while acute nicotine dose-dependently impaired contextual safety discrimination (Experiment 1). Furthermore, our results demonstrate that nicotine-induced impairment of contextual safety discrimination learning was not a result of increased generalized freezing (Experiment 2) or contingent on the common CS presentations in both contexts (Experiment 3). Finally, our results show that increasing the temporal gap between CXA and CXB during training abolished the impairing effects of nicotine (Experiment 4). The findings of this study may help link nicotine exposure to the safety learning deficits seen in anxiety disorder and PTSD patients. © The Author(s) 2014.

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.

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

Perinatal nicotine treatment induces transient increases in NACHO protein levels in the rat frontal cortex

DEFF Research Database (Denmark)

Wichern, Franziska; Jensen, Majbrit M; Christensen, Ditte Z

2017-01-01

The nicotinic acetylcholine receptor (nAChR) regulator chaperone (NACHO) was recently identified as an important regulator of nAChR maturation and surface expression. Here we show that NACHO levels decrease during early postnatal development in rats. This decrease occurs earlier and to a greater...... degree in the frontal cortex (FC) compared with the hippocampus (HIP). We further show that rats exposed to nicotine during pre- and postnatal development exhibit significantly higher NACHO levels in the FC at postnatal day (PND) 21, but not at PND60. Repeated exposure to nicotine selectively during...... a single exposure to a combination of nicotine and the type II α7 nAChR positive allosteric modulator (PAM) PNU-120596, but not the type I PAM AVL-3288. These findings suggest that exposure to nAChR agonism affects NACHO protein levels, and that this effect is more pronounced during pre- or early postnatal...

Nicotine-mediated suppression of the retinoic acid metabolizing enzyme CYP26A1 limits the oncogenic potential of breast cancer.

Science.gov (United States)

Osanai, Makoto; Lee, Gang-Hong

2011-06-01

Tobacco smoke influences cancer development in tissues that are not directly exposed, and epidemiological studies have indicated that smoking women might experience decreased risk of breast cancer as a result of antiestrogenic effects. However, it remains to be clarified whether nicotine, one of the major addictive and best-investigated constituents of tobacco smoke, has any effect on breast cancer. Our recent work demonstrated that the retinoic acid metabolizing enzyme CYP26A1 enhances oncogenic and cell survival properties of breast carcinoma cells, implying a role as an oncogene. Here, we present evidence that nicotine significantly suppresses constitutive expression of CYP26A1, and that cells treated with nicotine exhibit enhanced sensitivity to apoptosis. In addition, nicotine may inhibit anchorage independent growth, cellular invasiveness and motility. These data show that nicotine can limit CYP26A1-mediated oncogenic characteristics, and suggest mechanisms by which nicotine might inhibit breast cancer development. © 2011 Japanese Cancer Association.

Selection of a novel anti-nicotine vaccine: influence of antigen design on antibody function in mice.

Directory of Open Access Journals (Sweden)

David C Pryde

Full Text Available Anti-nicotine vaccines may aid smoking cessation via the induction of anti-nicotine antibodies (Ab which reduce nicotine entering the brain, and hence the associated reward. Ab function depends on both the quantity (titer and the quality (affinity of the Ab. Anti-nicotine vaccines tested previously in clinical studies had poor efficacy despite high Ab titer, and this may be due to inadequate function if Ab of low affinity were induced. In this study, we designed and synthesized a series of novel nicotine-like haptens which were all linked to diphtheria toxoid (DT as carrier, but which differed in the site of attachment of linker to nicotine, the nature of linker used, and the handle used to attach the hapten to DT. The resulting hapten conjugates were evaluated in a mouse model, using CpG (a TLR9 agonist and aluminum hydroxide (Al(OH3 as adjuvants, whereby Ab titers, affinity and function were evaluated using a radiolabeled nicotine challenge model. A series of additional linkers varying in length, rigidity and polarity were used with a single hapten to generate additional DT-conjugates, which were also tested in mice. Conjugates made with different haptens resulted in various titers of anti-nicotine Ab. Several haptens gave similarly high Ab titers, but among these, Ab affinity and hence function varied considerably. Linker also influenced Ab titer, affinity and function. These results demonstrate that immune responses induced in mice by nicotine-conjugate antigens are greatly influenced by hapten design including site of attachment of linker to nicotine, the nature of linker used, and the handle used to attach the hapten to DT. While both Ab titer and affinity contributed to function, affinity was more sensitive to antigen differences.

Activation of α7 nicotinic acetylcholine receptor decreases on-site mortality in crush syndrome through insulin signaling-Na/K-ATPase pathway

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Bo-Shi eFan

2016-03-01

Full Text Available On-site mortality in crush syndrome remains high due to lack of effective drugs based on definite diagnosis. Anisodamine is widely used in China for treatment of shock, and activation of α7 nicotinic acetylcholine receptor (α7nAChR mediates such antishock effect. The present work was designed to test whether activation of α7nAChR with anisodamine decreased mortality in crush syndrome shortly after decompression. Sprague-Dawley rats and C57BL/6 mice with crush syndrome were injected with anisodamine (20 mg/kg and 28 mg/kg respectively, i.p. 30 min before decompression. Survival time, serum potassium, insulin, and glucose levels were observed shortly after decompression. Involvement of α7nAChR was verified with methyllycaconitine (selective α7nAChR antagonist and PNU282987 (selective α7nAChR agonist, or in α7nAChR knockout mice. Effect of anisodamine was also appraised in C2C12 myotubes. Anisodamine reduced mortality and serum potassium and enhanced insulin sensitivity shortly after decompression in animals with crush syndrome, and PNU282987 exerted similar effects. Such effects were counteracted by methyllycaconitine or in α7nAChR knockout mice. Mortality and serum potassium in rats with hyperkalemia were also reduced by anisodamine. Phosphorylation of Na/K-ATPase was enhanced by anisodamine in C2C12 myotubes. Inhibition of tyrosine kinase on insulin receptor, phosphoinositide 3-kinase, mammalian target of rapamycin, signal transducer and activator of transcription 3, and Na/K-ATPase counteracted the effect of anisodamine on extracellular potassium. These findings demonstrated that activation of α7nAChR could decrease on-site mortality in crush syndrome, at least in part based on the decline of serum potassium through insulin signaling-Na/K-ATPase pathway.

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

Studies on the metabolism and bioactivation of (S)-nicotine and beta-nicotyrine

International Nuclear Information System (INIS)

Shigenaga, M.K.

1989-01-01

(S)-Nicotine has long been suspected of contributing to the chronic toxicities associated with the use of cigarettes and other tobacco products. The possibility that (S)-nicotine could contribute to these chronic toxicities by causing irreversible damage to cellular macromolecules has prompted studies aimed at characterizing the metabolic pathways of (S)-nicotine that form reactive metabolites which bind covalently. In order to study these processes, (S)-5- 3 H-nicotine was synthesized by catalytic tritiolysis of (S)-5-bromonicotine with carrier-free tritium gas, purified by HPLC and characterized by tritium NMR, diode array VV and HPLC chromatographic analysis. The metabolism of (S)-5- 3 H-nicotine by rabbit liver and lung microsomal enzymes produced reactive intermediates which bound covalently to microsomal macromolecules in a time, NADPH and cytochrome P-450 dependent manner. The results of studies employing rabbit lung microsomes and agents which inhibit or alter the expression of the cytochrome P-450 isozyme composition in this tissue indicated that the covalent binding of (S)-nicotine requires (S)-nicotine Δ 1',5' -iminium ion as an obligate intermediate and the catalytic activity of lung cytochrome P-450 isozyme-2. Investigations of the effects of (S)-nicotine and related tobacco alkaloids on the oxidation of the Parkinson's disease inducing agent MPTP by the mitochondrial enzyme MAO-B were prompted by the inverse correlation between cigarette smoking and Parkinson's disease. In the author studies (S)-nicotine A 1',5' -iminium bisperchlorate inhibited the MAOB catalyzed oxidation of MPTP by a linear-mixed type mechanism. Subsequent studies identified β-nicotyrine as a MAO-B catalyzed oxidation product of (S)-nicotine A 1',5' -iminium ion

Imidacloprid, a neonicotinoid insecticide, facilitates tyrosine hydroxylase transcription and phenylethanolamine N-methyltransferase mRNA expression to enhance catecholamine synthesis and its nicotine-evoked elevation in PC12D cells.

Science.gov (United States)

Kawahata, Ichiro; Yamakuni, Tohru

2018-02-01

Imidacloprid is a neonicotinoid insecticide acting as an agonist of nicotinic acetylcholine receptors (nAChRs) in the target insects. However, questions about the safety to mammals, including human have emerged. Overactivation of mammalian peripheral catecholaminergic systems leads to onset of tachycardia, hypertension, vomiting, etc., which have been observed in acutely imidacloprid-poisoned patients as well. Physiological activation of the nAChRs is known to drive catecholamine biosynthesis and secretion in mammalian adrenal chromaffin cells. Yet, the impacts of imidacloprid on the catecholaminergic function of the chromaffin cells remain to be evaluated. In this study using PC12D cells, a catecholaminergic cell line derived from the medulla chromaffin-cell tumors of rat adrenal gland, we examined whether imidacloprid itself could impact the catecholamine-synthesizing ability. Imidacloprid alone did facilitate tyrosine hydroxylase (TH) transcription via activation of α3β4 nAChR and the α7 subunit-comprising receptor. The insecticide showed the TH transcription-facilitating ability at the concentrations of 3 and 30 μM, at which acetylcholine is known to produce physiological responses, including catecholamine secretion through the nAChRs in adrenal chromaffin cells. The insecticide-facilitated TH transcription was also dependent on PKA- and RhoA-mediated signaling pathways. The insecticide coincidentally raised levels of TH and phenylethanolamine N-methyltransferase (PNMT) mRNA, and as a consequence, increased catecholamine production, although the efficacy of the neonicotinoid was lesser than that of nicotine, indicating its partial agonist-like action. Intriguingly, in cultured rat adrenal chromaffin cells, imidacloprid did increase levels of TH and PNMT protein. When the chromaffin cells were treated with nicotine in the presence of the insecticide, nicotine-elevated adrenaline production was enhanced due to facilitation of nicotine-increased TH and PNMT

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.

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.

4 acute nicotine induced pressor response is in part due

African Journals Online (AJOL)

DR. AMINU

increases in heart rate in both normal and in nicotine treated rats but the increases shows no significant differences. ... pre-eclampsia in pregnant women by reduction of production .... (Hilton, 1965) and events occurring in man stress ... during emotional stress in normotensive and ... mechanism contributing to ischemic left.

Nicotine, auditory sensory memory and attention in a human ketamine model of schizophrenia: moderating influence of a hallucinatory trait

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Verner eKnott

2012-09-01

Full Text Available Background: The procognitive actions of the nicotinic acetylcholine receptor (nAChR agonist nicotine are believed, in part, to motivate the excessive cigarette smoking in schizophrenia, a disorder associated with deficits in multiple cognitive domains, including low level auditory sensory processes and higher order attention-dependent operations. Objectives: As N-methyl-D-aspartate receptor (NMDAR hypofunction has been shown to contribute to these cognitive impairments, the primary aims of this healthy volunteer study were to: a to shed light on the separate and interactive roles of nAChR and NMDAR systems in the modulation of auditory sensory memory (and sustained attention, as indexed by the auditory event-related brain potential (ERP – mismatch negativity (MMN, and b to examine how these effects are moderated by a predisposition to auditory hallucinations/delusions (HD. Methods: In a randomized, double-blind, placebo controlled design involving a low intravenous dose of ketamine (.04 mg/kg and a 4 mg dose of nicotine gum, MMN and performance on a rapid visual information processing (RVIP task of sustained attention were examined in 24 healthy controls psychometrically stratified as being lower (L-HD, n = 12 or higher (H-HD for HD propensity. Results: Ketamine significantly slowed MMN, and reduced MMN in H-HD, with amplitude attenuation being blocked by the co-administration of nicotine. Nicotine significantly enhanced response speed (reaction time and accuracy (increased % hits and d΄ and reduced false alarms on the RIVIP, with improved performance accuracy being prevented when nicotine was administered with ketamine. Both % hits and d΄, as well as reaction time were poorer in H-HD (vs. L-HD and while hit rate and d΄ was increased by nicotine in H-HD, reaction time was slowed by ketamine in L-HD. Conclusions: Nicotine alleviated ketamine-induced sensory memory impairments and improved attention, particularly in individuals prone to HD.

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

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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.

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

Science.gov (United States)

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

Trace Amine-Associated Receptor 1 Modulates the Locomotor and Sensitization Effects of Nicotine

Science.gov (United States)

Sukhanov, Ilya; Dorofeikova, Mariia; Dolgorukova, Antonina; Dorotenko, Artem; Gainetdinov, Raul R.

2018-01-01

Trace amine-associated receptor 1 (TAAR1) has emerged as a promising target for addiction treatments because it affects dopamine transmission in the mesolimbic pathway. TAAR1 is involved in the effects of addictive drugs, such as amphetamines, cocaine and ethanol, but the impact of TAAR1 on the effects of nicotine, the psychoactive drug responsible for the development and maintenance of tobacco smoking, has not yet been studied. This study was performed to investigate the possible modulatory action of TAAR1 on the effects of nicotine on locomotor behaviors in rats and mice. Pretreatment with the TAAR1 agonist RO5263397 dose-dependently decreased nicotine-induced hyperlocomotion in rats habituated to locomotor boxes, prevented the development of nicotine sensitization and blocked hypermotility in nicotine-sensitized rats at the highest tested dose (10 mg/kg). The lack of TAAR1 failed to affect the effects of nicotine on the locomotion of mutant mice. Based on the results of the present study, TAAR1 activation attenuates the locomotion-stimulating effects of nicotine on rats. These results further support the previously proposed hypothesis that TAAR1 is a promising target for the prevention and treatment of drug addiction. Further studies aimed at analyzing the effects of TAAR1 agonists on animal models of nicotine addiction are warranted. PMID:29681856

Trace Amine-Associated Receptor 1 Modulates the Locomotor and Sensitization Effects of Nicotine

Directory of Open Access Journals (Sweden)

Ilya Sukhanov

2018-04-01

Full Text Available Trace amine-associated receptor 1 (TAAR1 has emerged as a promising target for addiction treatments because it affects dopamine transmission in the mesolimbic pathway. TAAR1 is involved in the effects of addictive drugs, such as amphetamines, cocaine and ethanol, but the impact of TAAR1 on the effects of nicotine, the psychoactive drug responsible for the development and maintenance of tobacco smoking, has not yet been studied. This study was performed to investigate the possible modulatory action of TAAR1 on the effects of nicotine on locomotor behaviors in rats and mice. Pretreatment with the TAAR1 agonist RO5263397 dose-dependently decreased nicotine-induced hyperlocomotion in rats habituated to locomotor boxes, prevented the development of nicotine sensitization and blocked hypermotility in nicotine-sensitized rats at the highest tested dose (10 mg/kg. The lack of TAAR1 failed to affect the effects of nicotine on the locomotion of mutant mice. Based on the results of the present study, TAAR1 activation attenuates the locomotion-stimulating effects of nicotine on rats. These results further support the previously proposed hypothesis that TAAR1 is a promising target for the prevention and treatment of drug addiction. Further studies aimed at analyzing the effects of TAAR1 agonists on animal models of nicotine addiction are warranted.

The effect of nicotine on reproduction and attachment of human gingival fibroblasts in vitro.

Science.gov (United States)

Peacock, M E; Sutherland, D E; Schuster, G S; Brennan, W A; O'Neal, R B; Strong, S L; Van Dyke, T E

1993-07-01

The ability of fibroblasts to reproduce and attach to teeth is of paramount importance in re-establishing the lost connective tissue attachment after periodontal therapy. This study examined the effect of nicotine, a major component of the particulate phase of tobacco smoke, on human gingival fibroblast (HGF) reproduction and attachment to tissue culture surfaces. Pooled HGF cultures made from explants of gingival biopsies were utilized between passages 5 and 10 and plated in 96-well plates at 1.0 x 10(4) cells per well. Cell numbers were determined using 3-(4,5-dimethylthiazol-2-y)-2,5-diphenyl tetrazolium bromide (MTT), which is a reflection of mitochondrial dehydrogenase activity. The concentrations of nicotine used were 0.025, 0.05, 0.1, 0.2, and 0.4 microM, the average serum concentration for a smoker being approximately 0.1 microM. The effect of continuous nicotine exposure on HGF reproduction was determined by incubating cell cultures and media containing nicotine for up to 48 hours. Residual toxicity was determined by preincubating cells with nicotine for 1 or 6 hours. HGF suspensions and increasing concentrations of nicotine were added together to determine the effect on attachment. Results showed an enhanced effect of nicotine on HGF attachment, with increasing numbers of cells attaching with increasing nicotine concentrations, compared to the control. Low concentrations of nicotine had a stimulatory effect on cell replication, while higher concentrations of nicotine appear to have no significant effect on HGF reproduction. The responses of cells to some concentrations of nicotine may persist after its removal.

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

Science.gov (United States)

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*

Science.gov (United States)

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

Opioid and nicotine receptors affect growth regulation of human lung cancer cell lines

International Nuclear Information System (INIS)

Maneckjee, R.; Minna, J.D.

1990-01-01

Using specific radioactively-labeled ligands, the authors find that lung cancer cell lines of diverse histologic types express multiple, high-affinity membrane receptors for μ, δ, and κ opioid agonists and for nicotine and α-bungarotoxin. These receptors are biologically active because cAMP levels decreased in lung cancer cells after opioid and nicotine application. Nicotine at concentrations found in the blood of smokers had no effect on in vitro lung cancer cell growth, whereas μ, δ, and κ opioid agonists at low concentrations inhibited lung cancer growth in vitro. They also found that lung cancer cells expressed various combinations of immunoreactive opioid peptides (β-endorphin, enkephalin, or dynorphin), suggesting the participation of opioids in a negative autocrine loop or tumor-suppressing system. Due to the almost universal exposure of patients with lung cancer to nicotine, they tested whether nicotine affected the response of lung cancer cell growth to opioids and found that nicotine at concentrations of 100-200 nM partially or totally reversed opioid-induced growth inhibition in 9/14 lung cancer cell lines. These in vitro results for lung cancer cells suggest that opioids could function as part of a tumor suppressor system and that nicotine can function to circumvent this system in the pathogenesis of lung cancer

Opioid and nicotine receptors affect growth regulation of human lung cancer cell lines

Energy Technology Data Exchange (ETDEWEB)

Maneckjee, R.; Minna, J.D. (National Cancer Institute-Navy Medical Oncology Branch, Bethesda, MD (USA) Uniformed Services Univ. of the Health Sciences, Bethesda, MD (USA))

1990-05-01

Using specific radioactively-labeled ligands, the authors find that lung cancer cell lines of diverse histologic types express multiple, high-affinity membrane receptors for {mu}, {delta}, and {kappa} opioid agonists and for nicotine and {alpha}-bungarotoxin. These receptors are biologically active because cAMP levels decreased in lung cancer cells after opioid and nicotine application. Nicotine at concentrations found in the blood of smokers had no effect on in vitro lung cancer cell growth, whereas {mu}, {delta}, and {kappa} opioid agonists at low concentrations inhibited lung cancer growth in vitro. They also found that lung cancer cells expressed various combinations of immunoreactive opioid peptides ({beta}-endorphin, enkephalin, or dynorphin), suggesting the participation of opioids in a negative autocrine loop or tumor-suppressing system. Due to the almost universal exposure of patients with lung cancer to nicotine, they tested whether nicotine affected the response of lung cancer cell growth to opioids and found that nicotine at concentrations of 100-200 nM partially or totally reversed opioid-induced growth inhibition in 9/14 lung cancer cell lines. These in vitro results for lung cancer cells suggest that opioids could function as part of a tumor suppressor system and that nicotine can function to circumvent this system in the pathogenesis of lung cancer.

The Use of gamma-Irradiation in Counteracting the Effect of Salinity for Cultivation of Barley and Pea Plants

International Nuclear Information System (INIS)

Aly, M.A.S.; Afifi, L.M.; Kamel, H.A.; Mostafa, I.Y.; Kord, M.A.

2000-01-01

The biochemical changes induced by salinity in two economic plants (Barley and Pea) and the probable counteraction of gamma irradiation for enhancement of growth were studied. The data obtained revealed that the reduction in pigments content due to salinity treatment was more pronounced in pea plants than barley. However, gamma irradiation caused a significant increase in pigment content of both plants. The interaction effect of salinity and radiation varied from an increase in case of barley to a reduction in peas. In both plants, soluble sugars content increased due to salinity and /or gamma-radiation. Moreover, total carbohydrates increased due to the combined treatment. A matched increase in free proline content was recorded with increase of salinity. While, gamma-irradiation showed a different trend. Protein and nucleic acids contents were proportionally decreased with increase of salinity levels, whereas gamma radiation induced an increase in both protein and nucleic acids content. A progressive reduction in the yield by increasing salinity was observed, while gamma-irradiation increased the yield of both plants. 14 CO 2 fixation was reduced by salinity treatment while gamma-radiation increased it. Contrary to 14 CO 2 fixation, salinity enhanced respiration, while radiation retarded it

Orbitofrontal participation in sign- and goal-tracking conditioned responses: Effects of nicotine.

Science.gov (United States)

Stringfield, Sierra J; Palmatier, Matthew I; Boettiger, Charlotte A; Robinson, Donita L

2017-04-01

Pavlovian conditioned stimuli can acquire incentive motivational properties, and this phenomenon can be measured in animals using Pavlovian conditioned approach behavior. Drugs of abuse can influence the expression of this behavior, and nicotine in particular exhibits incentive amplifying effects. Both conditioned approach behavior and drug abuse rely on overlapping corticolimbic circuitry. We hypothesize that the orbitofrontal cortex (OFC) regulates conditioned approach, and that one site of nicotine action is in the OFC where it reduces cortical output. To test this, we repeatedly exposed rats to 0.4 mg/kg nicotine (s.c.) during training and then pharmacologically inactivated the lateral OFC or performed in vivo electrophysiological recordings of lateral OFC neurons in the presence or absence of nicotine. In Experiment 1, animals were trained in a Pavlovian conditioning paradigm and behavior was evaluated after inactivation of the OFC by microinfusion of the GABA agonists baclofen and muscimol. In Experiment 2, we monitored phasic firing of OFC neurons during Pavlovian conditioning sessions. Nicotine reliably enhanced conditioned responding to the conditioned cue, and inactivation of the OFC reduced conditioned responding, especially the sign-tracking response. OFC neurons exhibited phasic excitations to cue presentation and during goal tracking, and nicotine acutely blunted this phasic neuronal firing. When nicotine was withheld, both conditioned responding and phasic firing in the OFC returned to the level of controls. These results suggest that the OFC is recruited for the expression of conditioned responses, and that nicotine acutely influences this behavior by reducing phasic firing in the OFC. Copyright © 2016 Elsevier Ltd. All rights reserved.

Toward a comprehensive long term nicotine policy.

Science.gov (United States)

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.

Intermittent hypercapnic hypoxia effects on the nicotinic acetylcholine receptors in the developing piglet hippocampus and brainstem.

Science.gov (United States)

Vivekanandarajah, Arunnjah; Aishah, Atqiya; Waters, Karen A; Machaalani, Rita

2017-05-01

This study investigated the effects of acute (1 day) vs repeated (4 days) exposure to intermittent hypercapnic hypoxia (IHH) on the immunohistochemical expression of α2, α3, α5, α7, α9 and β2 nicotinic acetylcholine receptor (nAChR) subunits in the developing piglet hippocampus and brainstem medulla, and how prior nicotine exposure alters the response to acute IHH. Five piglet groups included: 1day IHH (1D IHH, n=9), 4days IHH (4D IHH, n=8), controls exposed only to air cycles for 1day (1D Air, n=6) or 4days (4D Air, n=5), and pre-exposed to nicotine for 13days prior to 1day IHH (Nic+1D IHH, n=7). The exposure period alternated 6min of HH (8%O 2 , 7%CO 2 , balance N 2 ) and 6min of air over 48min, while controls were switched from air-to-air. Results showed that: 1. repeated IHH induces more changes in nAChR subunit expression than acute IHH in both the hippocampus and brainstem medulla, 2. In the hippocampus, α2 and β2 changed the most (increased) following IHH and the CA3, CA2 and DG were mostly affected. In the brainstem medulla, α2, α5, α9 and β2 were changed (decreased) in most nuclei with the hypoglossal and nucleus of the solitary tract being mostly affected. 3. Pre-exposure to nicotine enhanced the changes in the hippocampus but dampened those in the brainstem medulla. These findings indicate that the nAChRs (predominantly with the α2/β2 complex) are affected by IHH in critical hippocampal and brainstem nuclei during early brain development, and that pre-exposure to nicotine alters the pattern of susceptibility to IHH. Copyright © 2017 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

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.