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1.
Int Ophthalmol ; 44(1): 199, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38662017

RESUMO

PURPOSE: To explore whether differences in choroidal thickness arise from nicotine consumption in healthy young individuals, specifically comparing the effects of nicotine gum to electronic cigarette (vaping), while maintaining a consistent 4 mg nicotine dosage. METHODS: In a randomized double-blinded prospective cross-sectional study, 20 healthy participants (mean age ± standard deviation: 23 ± 2.36 years) were randomly assigned to either the nicotine gum or vaping group. Choroidal thickness (ChT) measurements were conducted using optical coherence tomography (OCT) (Topcon 3D OCT-1 Maestro System) at baseline, 30, and 60 min after ingesting 4 mg of nicotine, with ChT measurements taken from five different horizontal areas. RESULTS: Neither the nicotine delivery method (gum or vaping) demonstrated a statistically significant impact on ChT mean scores among subjects in the five measured areas at baseline, 30, and 60 min (p > 0.05). However, significant differences were observed in ChT mean scores within subjects across the five areas (F (1.83, 72) = 36.43, p < 0.001), regardless of other study factors such as group, time, and visit (p > 0.05). A statistically significant interaction was identified between the factors of area and time concerning participants' ChT mean scores when stratified by the type of smoking (tobacco, vaping, and dual) (p = 0.003). CONCLUSION: The results of this study revealed that nicotine, up to particular concentration of 4 mg, does not have a statistically significant vasoconstrictive effect on choroidal thickness, regardless of the delivery method, within the examined group. These findings offer valuable insights into the relationship between nicotine intake and choroidal dynamics in young adults.


Assuntos
Corioide , Sistemas Eletrônicos de Liberação de Nicotina , Nicotina , Tomografia de Coerência Óptica , Humanos , Corioide/patologia , Corioide/diagnóstico por imagem , Corioide/efeitos dos fármacos , Masculino , Método Duplo-Cego , Feminino , Tomografia de Coerência Óptica/métodos , Estudos Prospectivos , Estudos Transversais , Adulto Jovem , Adulto , Nicotina/administração & dosagem , Nicotina/efeitos adversos , Abandono do Hábito de Fumar/métodos , Dispositivos para o Abandono do Uso de Tabaco , Goma de Mascar de Nicotina
3.
N Engl J Med ; 390(7): 601-610, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38354139

RESUMO

BACKGROUND: Electronic nicotine-delivery systems - also called e-cigarettes - are used by some tobacco smokers to assist with quitting. Evidence regarding the efficacy and safety of these systems is needed. METHODS: In this open-label, controlled trial, we randomly assigned adults who were smoking at least five tobacco cigarettes per day and who wanted to set a quit date to an intervention group, which received free e-cigarettes and e-liquids, standard-of-care smoking-cessation counseling, and optional (not free) nicotine-replacement therapy, or to a control group, which received standard counseling and a voucher, which they could use for any purpose, including nicotine-replacement therapy. The primary outcome was biochemically validated, continuous abstinence from smoking at 6 months. Secondary outcomes included participant-reported abstinence from tobacco and from any nicotine (including smoking, e-cigarettes, and nicotine-replacement therapy) at 6 months, respiratory symptoms, and serious adverse events. RESULTS: A total of 1246 participants underwent randomization; 622 participants were assigned to the intervention group, and 624 to the control group. The percentage of participants with validated continuous abstinence from tobacco smoking was 28.9% in the intervention group and 16.3% in the control group (relative risk, 1.77; 95% confidence interval, 1.43 to 2.20). The percentage of participants who abstained from smoking in the 7 days before the 6-month visit was 59.6% in the intervention group and 38.5% in the control group, but the percentage who abstained from any nicotine use was 20.1% in the intervention group and 33.7% in the control group. Serious adverse events occurred in 25 participants (4.0%) in the intervention group and in 31 (5.0%) in the control group; adverse events occurred in 272 participants (43.7%) and 229 participants (36.7%), respectively. CONCLUSIONS: The addition of e-cigarettes to standard smoking-cessation counseling resulted in greater abstinence from tobacco use among smokers than smoking-cessation counseling alone. (Funded by the Swiss National Science Foundation and others; ESTxENDS ClinicalTrials.gov number, NCT03589989.).


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Abandono do Hábito de Fumar , Adulto , Humanos , Nicotina/administração & dosagem , Nicotina/efeitos adversos , Abandono do Hábito de Fumar/métodos , Dispositivos para o Abandono do Uso de Tabaco/efeitos adversos
4.
Cogn Affect Behav Neurosci ; 24(2): 351-367, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38253774

RESUMO

The rapid serial visual presentation (RSVP) task and continuous performance tasks (CPT) are used to assess attentional impairments in patients with psychiatric and neurological conditions. This study developed a novel touchscreen task for rats based on the structure of a human RSVP task and used pharmacological manipulations to investigate their effects on different performance measures. Normal animals were trained to respond to a target image and withhold responding to distractor images presented within a continuous sequence. In a second version of the task, a false-alarm image was included, so performance could be assessed relative to two types of nontarget distractors. The effects of acute administration of stimulant and nonstimulant treatments for ADHD (amphetamine and atomoxetine) were tested in both tasks. Methylphenidate, ketamine, and nicotine were tested in the first task only. Amphetamine made animals more impulsive and decreased overall accuracy but increased accuracy when the target was presented early in the image sequence. Atomoxetine improved accuracy overall with a specific reduction in false-alarm responses and a shift in the attentional curve reflecting improved accuracy for targets later in the image sequence. However, atomoxetine also slowed responding and increased omissions. Ketamine, nicotine, and methylphenidate had no specific effects at the doses tested. These results suggest that stimulant versus nonstimulant treatments have different effects on attention and impulsive behaviour in this rat version of an RSVP task. These results also suggest that RSVP-like tasks have the potential to be used to study attention in rodents.


Assuntos
Anfetamina , Cloridrato de Atomoxetina , Atenção , Estimulantes do Sistema Nervoso Central , Ketamina , Metilfenidato , Nicotina , Animais , Estimulantes do Sistema Nervoso Central/farmacologia , Estimulantes do Sistema Nervoso Central/administração & dosagem , Cloridrato de Atomoxetina/farmacologia , Cloridrato de Atomoxetina/administração & dosagem , Atenção/efeitos dos fármacos , Atenção/fisiologia , Masculino , Ratos , Metilfenidato/farmacologia , Metilfenidato/administração & dosagem , Nicotina/farmacologia , Nicotina/administração & dosagem , Anfetamina/farmacologia , Anfetamina/administração & dosagem , Ketamina/farmacologia , Ketamina/administração & dosagem , Estimulação Luminosa/métodos , Inibidores da Captação Adrenérgica/farmacologia , Inibidores da Captação Adrenérgica/administração & dosagem , Aprendizagem Seriada/efeitos dos fármacos , Aprendizagem Seriada/fisiologia , Tempo de Reação/efeitos dos fármacos , Tempo de Reação/fisiologia , Percepção Visual/efeitos dos fármacos , Percepção Visual/fisiologia , Ratos Sprague-Dawley
5.
Braz. j. oral sci ; 22: e231137, Jan.-Dec. 2023. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1523140

RESUMO

The purpose of this in vitro study was to analyze the influence of nicotine on the extracellular polysaccharides in Fusobacterium nucleatum biofilm. Methods: F. nucleatum (ATCC 10953) biofilms supplemented with different concentrations of nicotine (0, 0.5, 1, 2, 4, and 8 mg/mL) were grown in two different BHI broth conditions [no sucrose and 1% sucrose]. Extracellular polysaccharides assay, pH measurements, and a spectrophotometric assay were performed. Data were submitted for ANOVA and Tukey honestly significant difference analyses (HSD) tests (α =.05). Results: Extracellular polysaccharides synthesis was influenced by an interaction between nicotine concentrations and growth medium solution containing sucrose (P<.05). The pH values declined in the sucrose-exposed biofilm were greater than in the group exposed only to nicotine (P<.05). The biofilm exposed to sucrose and nicotine had a higher total biofilm growth (P<.05) than the nicotine-treated biofilm without sucrose. Conclusions: Regardless of sucrose exposure, biofilms exposed to different nicotine concentrations influenced the amount of extracellular polysaccharides


Assuntos
Humanos , Polissacarídeos Bacterianos/síntese química , Fusobacterium nucleatum/crescimento & desenvolvimento , Biofilmes/crescimento & desenvolvimento , Nicotina/farmacologia , Doenças Periodontais/microbiologia , Espectrofotometria , Sacarose/administração & dosagem , Meios de Cultura , Cárie Dentária/microbiologia , Nicotina/administração & dosagem
6.
Clin Sci (Lond) ; 136(12): 973-987, 2022 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-35678315

RESUMO

Cigarette smoking remains the leading modifiable risk factor for cardiopulmonary diseases; however, the effects of nicotine alone on cardiopulmonary function remain largely unknown. Previously, we have shown that chronic nicotine vapor inhalation in mice leads to the development of pulmonary hypertension (PH) with right ventricular (RV) remodeling. The present study aims to further examine the cardiopulmonary effects of nicotine and the role of the α7 nicotinic acetylcholine receptor (α7-nAChR), which is widely expressed in the cardiovascular system. Wild-type (WT) and α7-nAChR knockout (α7-nAChR-/-) mice were exposed to room air (control) or nicotine vapor daily for 12 weeks. Consistent with our previous study, echocardiography and RV catheterization reveal that male WT mice developed increased RV systolic pressure with RV hypertrophy and dilatation following 12-week nicotine vapor exposure; in contrast, these changes were not observed in male α7-nAChR-/- mice. In addition, chronic nicotine inhalation failed to induce PH and RV remodeling in female mice regardless of genotype. The effects of nicotine on the vasculature were further examined in male mice. Our results show that chronic nicotine inhalation led to impaired acetylcholine-mediated vasodilatory response in both thoracic aortas and pulmonary arteries, and these effects were accompanied by altered endothelial nitric oxide synthase phosphorylation (enhanced inhibitory phosphorylation at threonine 495) and reduced plasma nitrite levels in WT but not α7-nAChR-/- mice. Finally, RNA sequencing revealed up-regulation of multiple inflammatory pathways in thoracic aortas from WT but not α7-nAChR-/- mice. We conclude that the α7-nAChR mediates chronic nicotine inhalation-induced PH, RV remodeling and vascular dysfunction.


Assuntos
Nicotina , Receptor Nicotínico de Acetilcolina alfa7 , Acetilcolina/metabolismo , Administração por Inalação , Animais , Aorta Torácica/efeitos dos fármacos , Feminino , Masculino , Camundongos , Nicotina/administração & dosagem , Artéria Pulmonar/efeitos dos fármacos , Regulação para Cima , Vasodilatação/efeitos dos fármacos , Receptor Nicotínico de Acetilcolina alfa7/genética , Receptor Nicotínico de Acetilcolina alfa7/metabolismo
7.
Eur J Pharmacol ; 928: 175088, 2022 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-35690082

RESUMO

Tobacco use disorder is a worldwide health problem for which available medications show limited efficacy. Nicotine is the psychoactive component of tobacco responsible for its addictive liability. Similar to other addictive drugs, nicotine enhances mesolimbic dopamine transmission. Inhibition of the fatty acid amide hydrolase (FAAH), the enzyme responsible for the degradation of the endocannabinoid anandamide (AEA), palmitoylethanolamide (PEA) and oleoylethanolamide (OEA), reduces nicotine-enhanced dopamine transmission and acquisition of nicotine self-administration in rats. Down-regulation of dopamine transmission by antagonists or partial agonists of the dopamine D3 receptor (DRD3) also reduced nicotine self-administration and conditioned place preference. Based on these premises, we evaluated the effect of ARN15381, a multitarget compound showing FAAH inhibition and DRD3 partial agonist activity in the low nanomolar range, on nicotine self-administration in rats. Pretreatment with ARN15381 dose dependently decreased self-administration of a nicotine dose at the top of the nicotine dose/response (D/R) curve, while it did not affect self-administration of a nicotine dose laying on the descending limb of the D/R curve. Conversely, pretreatment with the selective FAAH inhibitor URB597 and the DRD3 partial agonist CJB090 failed to modify nicotine self-administration independent of the nicotine dose self-administered. Our data indicates that the concomitant FAAH inhibition and DRD3 partial agonism produced by ARN15381 is key to the observed reduction of nicotine self-administration, demonstrating that a multitarget approach may hold clinical importance for the treatment of tobacco use disorder.


Assuntos
Amidoidrolases , Nicotina , Tabagismo , Amidoidrolases/antagonistas & inibidores , Animais , Dopamina/metabolismo , Endocanabinoides , Masculino , Nicotina/administração & dosagem , Nicotina/efeitos adversos , Ratos , Autoadministração , Tabagismo/tratamento farmacológico
8.
Biomed Res Int ; 2022: 5782228, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35237688

RESUMO

OBJECTIVE: To assess the knowledge, practice, attitude, and preparedness of dental professionals in prescribing nicotine replacement therapy (NRT). Methodology. A prevalidated voluntary web-based questionnaire was generated as a link through Google Drive and was sent to 117 dental professionals in North India using Whatsapp, Messenger, and Instagram social media platforms. A total of 94 responses were received and out of which 76 responses were analyzed (18 forms were excluded due to incomplete or duplicate responses). Frequency analysis was done using SPSS software version 21. RESULT: The participation rate was found to be 80.3%. More than half of the study population were familiar with the term NRT (77.6%) and its uses (67.1%), but approximately less than half of the total study subjects knew the duration (32.9%), cost (27.6%), dosage (25%), and contraindications (36.8%) of the NRT. Approximately 56.6% of the study participants showed a positive attitude towards helping patients to quit smoking through tobacco cessation counseling. Nearly one-fourth of the study population, i.e., 27.6%, were confident in explaining the negative impacts of tobacco, while 22.4% knew about the tobacco cessation protocol. Among the participants, only 27.6% reported that they practice NRT and out of which approximately less than 20% of the study participants were prescribing correct dose of NRT. CONCLUSION: Though study subjects had an ample knowledge regarding NRT use in tobacco cessation, it does not reflect their current attitude and preparedness. Thus, there is a need for continuing education to further train dental professionals for prescribing NRT.


Assuntos
Atitude do Pessoal de Saúde , Relações Dentista-Paciente , Conhecimentos, Atitudes e Prática em Saúde , Abandono do Hábito de Fumar/métodos , Prevenção do Hábito de Fumar/métodos , Adulto , Humanos , Índia , Nicotina/administração & dosagem , Papel do Médico , Atenção Primária à Saúde , Dispositivos para o Abandono do Uso de Tabaco/estatística & dados numéricos
9.
Sci Rep ; 12(1): 1091, 2022 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-35058535

RESUMO

Physiologically based pharmacokinetic (PBPK) modeling can be a useful tool for characterizing nicotine pharmacokinetics (PK) from use of tobacco products. We expand a previously published PBPK model to simulate a nicotine PK profile, following single or multiple use of various tobacco products [cigarettes, smokeless tobacco, and electronic nicotine delivery systems, or a nicotine inhaler (NICOTROL)] The uptake route in the model was designed to allow for three uptake compartments: buccal cavity (BC), upper respiratory tract (URT) (conducting and transitional airways) and lower respiratory tract (alveolar region). Within each region, the model includes product-specific descriptions of the flux of nicotine into plasma, as well as the flux of nicotine from the BC and URT to the gastrointestinal tract. These descriptions are based on regional deposition and diffusion models of nicotine into plasma, which depends on the product type. Regional deposition flux combined with regional differences in physiological parameters (e.g., blood perfusion ratio and tissue thickness) play a key role in the product-specific PK profile of nicotine. The current model describes the slower flux of nicotine into plasma across the BC and URT, as well as the rapid flux known to occur in the alveolar region. Overall, the addition of the BC and respiratory tract compartments to the nicotine model provided simulation results that are comparable to the nicotine time-course plasma concentrations reported from clinical studies for the four product categories simulated.


Assuntos
Nicotina/administração & dosagem , Nicotina/farmacocinética , Uso de Tabaco/fisiopatologia , Fumar Cigarros , Biologia Computacional/métodos , Simulação por Computador , Sistemas Eletrônicos de Liberação de Nicotina , Humanos , Modelos Biológicos , Produtos do Tabaco/efeitos adversos , Uso de Tabaco/efeitos adversos , Tabaco sem Fumaça
10.
Psico USF ; 27(1): 157-167, jan.-mar. 2022. tab, graf
Artigo em Português | LILACS, Index Psicologia - Periódicos | ID: biblio-1376039

RESUMO

Estudos mostram que o tabagismo é responsável por afetar algumas funções cognitivas. No entanto, a nicotina é apenas um dos componentes existentes no cigarro e existem evidências de que pode servir como agente neuroprotetivo e causar melhoras em algumas funções cognitivas. O objetivo desta pesquisa foi investigar como a nicotina interage com algumas funções cognitivas. Um ensaio clínico piloto com administração de gomas de nicotina contendo 2-mg ou 4-mg, ou gomas placebo contendo a mesma textura, sabor e aparência, foi realizado. Quarenta e dois participantes participaram da pesquisa e os resultados indicaram que a relação entre nicotina e o desempenho na tarefa Go/No-Go podem ser bidirecionais. Os resultados indicaram que participantes do grupo que utilizaram 4-mg de nicotina apresentaram menor desempenho, enquanto os participantes que fizeram uso de 2-mg de nicotina tiveram melhor desempenho do que os demais. Esta pesquisa tem aplicações biopsicossociais e podem ajudar na compreensão da relação entre tabagismo e nicotina, além de contribuir para estratégias que possam ajudar no abandono do cigarro ou na melhora de condições que afetem a cognição (AU).


Past findings in the literature indicated that smoking could affect given cognitive functions. However, nicotine is only one of the components in cigarettes and there is evidence that it may act as a neuroprotective agent and improve some cognitive functions. The purpose of this research was to investigate how nicotine interacts with certain cognitive functions. We conducted a pilot clinical trial using nicotine gum containing 2-mg or 4-mg, or placebo gum with the same texture, flavor, and appearance. Forty-two healthy nonsmokers were enrolled in this research. Our findings indicated that the relationship between nicotine and performance on the Go/No-Go task might be opposite. The results showed that participants in the 4-mg group performed worse, while participants who used 2-mg of nicotine performed better than the others. This research supports biopsychosocial applications and can help interpret the relationship between smoking and nicotine, and contribute to strategies that may support smoking cessation, or improve conditions that affect cognition (AU).


Estudios demuestran que el tabaquismo es responsable de afectar a algunas funciones cognitivas. Sin embargo, la nicotina es solo uno de los componentes de los cigarrillos, y existen evidencias de que la nicotina puede actuar como un agente neuroprotector y mejorar algunas funciones cognitivas. El objetivo de este estudio fue investigar cómo la nicotina interactúa con algunas funciones cognitivas. Se realizó un ensayo clínico piloto con la administración de chicles de nicotina de 2 mg o 4 mg, o chicles de placebo con la misma textura, sabor y apariencia. Cuarenta y dos participantes participaron en la investigación y los resultados indicaron que la relación entre la nicotina y el rendimiento en la tarea Go/No-go puede ser bidireccional. Los resultados indicaron que los participantes del grupo de 4 mg obtuvieron un menor rendimiento en las variables del Go/No-Go, mientras que los participantes que utilizaron 2 mg de nicotina obtuvieron un mejor rendimiento que los demás. Esta investigación respalda las aplicaciones biopsicosociales y puede ayudar a interpretar la relación entre el tabaquismo y la nicotina, además de contribuir a las estrategias que pueden ayudar a dejar de fumar o mejorar las condiciones que afectan la cognición (AU).


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Função Executiva , Goma de Mascar de Nicotina , Nicotina/administração & dosagem , Placebos/administração & dosagem , Tabagismo/psicologia , Distribuição de Qui-Quadrado , Projetos Piloto , Método Duplo-Cego , Análise de Variância
11.
Neuropharmacology ; 202: 108845, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34678376

RESUMO

Nicotine enhances the rewarding effects of other environmental stimuli; this reward-enhancement encourages and maintains nicotine consumption. Nicotine use precedes other psychostimulant use, but receiving a stimulant prescription also predicts future smoking. Previously, no study has investigated effects of drug exposure order in reward-enhancement, nor with nicotine and d-amphetamine. Thus, we aimed to investigate how drug exposure order impacted the reward-enhancing effects of nicotine and d-amphetamine, alone and in combination. We used 20 male and 20 female Sprague-Dawley rats. Enhancement was investigated within-subjects by examining responding maintained by a visual stimulus reinforcer following a pre-session injection of either d-amphetamine (Sal, 0.1, 0.3, or 0.6 mg/kg) or nicotine (Sal, 0.03, 0.06, 0.1, 0.3 mg/kg). Twenty rats (10 M, 10 F) completed enhancement testing with nicotine before d-amphetamine. The other 20 rats (10 M, 10 F) completed testing with d-amphetamine before nicotine. Following these phases, rats were then given two pre-session injections: one of d-amphetamine (Sal, 0.1, 0.3, or 0.6 mg/kg) and another of nicotine (Sal, 0.03, 0.06, 0.1, or 0.3 mg/kg). Experiencing amphetamine before nicotine increased reward-enhancing effects of nicotine. Females exhibited greater effects of d-amphetamine on reward-enhancement, with no effect of exposure order. During the interaction phase, receiving nicotine before amphetamine enhanced the interaction between nicotine and d-amphetamine for females whereas amphetamine before nicotine heightened this interaction for males. From this, prior and current amphetamine use, in addition to sex, should be considered when treating nicotine dependency and when examining factors driving poly-substance use involving nicotine and d-amphetamine. Keywords: Adderall, ADHD, Dexedrine, operant, smoking, polysubstance use.


Assuntos
Dextroanfetamina/administração & dosagem , Dextroanfetamina/efeitos adversos , Nicotina/administração & dosagem , Nicotina/efeitos adversos , Reforço Psicológico , Recompensa , Caracteres Sexuais , Animais , Condicionamento Operante , Combinação de Medicamentos , Feminino , Humanos , Masculino , Ratos Sprague-Dawley , Transtornos Relacionados ao Uso de Substâncias
12.
Behav Brain Res ; 416: 113574, 2022 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-34499942

RESUMO

The habenula is an epithalamic structure through which descending connections go from the telencephalon to the brainstem, putting it in a key location to provide feedback control over the ascending projections from the brainstem to the telencephalon. The medial habenula has a high concentration of nicotinic receptors. We assessed the role of medial habenular nicotinic receptors for nicotine self-administration (SA) in female young adult Sprague-Dawley rats. The rats had bilateral chronic infusion cannulae placed into the medial habenula nucleus. Each cannula was connected to a slow delivery osmotic minipump to chronically infuse mecamylamine (100 µg/side/day) or vehicle for four consecutive weeks. The rats were tested for nicotine SA for the first two weeks of mecamylamine infusion. Then, they had one week of enforced abstinence, during which they had no access to the nicotine SA. Finally, they had one week of resumed nicotine SA access. There was a significantly differential mecamylamine effects in animals with lower and higher pretreatment baseline nicotine SA. Rats with lower baseline nicotine SA levels showed a nearly significant mecamylamine-induced reduction in SA while those with higher baseline levels of SA showed a significant mecamylamine-induced increase in nicotine SA. This study determined that medial habenular nicotinic receptors are important for nicotine reinforcement. Baseline level of performance makes a crucial difference for the involvement of habenular mechanisms in nicotine reinforcement with nicotinic activation being important for maintaining nicotine self-administration for those with lower levels of baseline self-administration and the opposite effect with subjects with higher levels of baseline self-administration.


Assuntos
Habenula/efeitos dos fármacos , Mecamilamina/farmacologia , Nicotina/farmacologia , Receptores Nicotínicos/metabolismo , Autoadministração , Animais , Feminino , Habenula/fisiologia , Infusões Intraventriculares , Nicotina/administração & dosagem , Ratos , Ratos Sprague-Dawley , Reforço Psicológico
13.
Nat Commun ; 12(1): 6945, 2021 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-34836948

RESUMO

Long-term exposure to nicotine alters brain circuits and induces profound changes in decision-making strategies, affecting behaviors both related and unrelated to drug seeking and consumption. Using an intracranial self-stimulation reward-based foraging task, we investigated in mice the impact of chronic nicotine on midbrain dopamine neuron activity and its consequence on the trade-off between exploitation and exploration. Model-based and archetypal analysis revealed substantial inter-individual variability in decision-making strategies, with mice passively exposed to nicotine shifting toward a more exploitative profile compared to non-exposed animals. We then mimicked the effect of chronic nicotine on the tonic activity of dopamine neurons using optogenetics, and found that photo-stimulated mice adopted a behavioral phenotype similar to that of mice exposed to chronic nicotine. Our results reveal a key role of tonic midbrain dopamine in the exploration/exploitation trade-off and highlight a potential mechanism by which nicotine affects the exploration/exploitation balance and decision-making.


Assuntos
Comportamento Exploratório/efeitos dos fármacos , Mesencéfalo/efeitos dos fármacos , Nicotina/efeitos adversos , Animais , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Dopamina/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Comportamento Exploratório/fisiologia , Masculino , Mesencéfalo/citologia , Mesencéfalo/metabolismo , Camundongos , Modelos Animais , Nicotina/administração & dosagem , Optogenética , Preconceito , Recompensa , Autoadministração , Técnicas Estereotáxicas
14.
Int J Neuropsychopharmacol ; 24(12): 979-987, 2021 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-34622270

RESUMO

BACKGROUND: The present study utilized the methylazoxymethanol (MAM) neurodevelopmental rodent model of schizophrenia (SCZ) to evaluate the hypothesis that individuals with SCZ smoke in an attempt to "self-medicate" their symptoms through nicotine (NIC) intake. METHODS: To explore this question, we examined the effects of acute and chronic administration of NIC in 2 established behavioral tests known to be disrupted in the MAM model: prepulse inhibition of startle and novel object recognition. Additionally, we assessed the effects of acute and chronic NIC on 2 indices of the pathophysiology of SCZ modeled by MAM, elevated dopamine neuron population activity in the ventral tegmental area and neuronal activity in the ventral hippocampus, using in vivo electrophysiological recordings. RESULTS: Our findings demonstrated that both acute and chronic administration of NIC significantly improved deficits in prepulse inhibition of startle and novel object recognition among MAM rats and normalized elevated ventral tegmental area and ventral hippocampal neuronal activity in these animals. CONCLUSION: Together, these findings of NIC-induced improvement of deficits lend support for a "self-medication" hypothesis behind increased cigarette smoking in SCZ and illustrate the potential utility of nicotinic modulation in future pharmacotherapies for certain SCZ symptoms.


Assuntos
Acetato de Metilazoximetanol/análogos & derivados , Nicotina/administração & dosagem , Esquizofrenia/tratamento farmacológico , Animais , Modelos Animais de Doenças , Neurônios Dopaminérgicos/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Masculino , Inibição Pré-Pulso/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Automedicação , Área Tegmentar Ventral/efeitos dos fármacos
15.
Eur Rev Med Pharmacol Sci ; 25(19): 6057-6064, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34661266

RESUMO

Human and animal studies have conclusively shown that prenatal nicotine exposure alters fetal brain development and causes persistent impairment in the cognitive function of offspring. However, the mechanisms underlying the effect of prenatal nicotine exposure on cognitive function in offspring are still unclear. The objective of this review is to discuss the published studies on the mechanisms underlying the effects of prenatal nicotine exposure on cognitive impairment and discuss the potential mechanisms of action. The findings of the reviewed studies show that the main mechanisms involved are alteration in the composition of nicotinic acetylcholine receptor subunits, increase in surface expression of the glutamate receptor subunit GluR2, a reduction in neurogenesis, alteration of Akt and ERK1/2 activity, and mitochondrial dysfunction in the hippocampus and cortex. These pathways could shed light on future molecular markers and therapeutic targets for the prevention and treatment of cognitive dysfunction induced by prenatal nicotine exposure.


Assuntos
Disfunção Cognitiva/etiologia , Nicotina/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal/etiologia , Animais , Cognição/efeitos dos fármacos , Disfunção Cognitiva/fisiopatologia , Feminino , Desenvolvimento Fetal/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Humanos , Nicotina/administração & dosagem , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/patologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Receptores Nicotínicos/metabolismo
16.
Neurosci Lett ; 764: 136235, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34508846

RESUMO

The mechanisms involved in the maintenance of cigarette smoking and nicotine reward remain unclear. Immune response might play an important role in this context. Nicotine may induce both central and systemic inflammatory responses as well as changes in the regulation of brain-derived neurotrophic factor (BDNF). The conditioned place preference (CPP) is a method used for the evaluation of nicotine-induced reward, reproducing nicotine-seeking behavior in humans. So far, there are no studies investigating the relationship between neuroinflammation and nicotine-induced CPP. This study aimed to evaluate the levels of inflammatory mediators and neurotrophic factors in key areas of the central nervous system (CNS) of mice subject to nicotine-induced CPP. CPP was induced with an intraperitoneal administration of 0.5 mg/kg of nicotine in male Swiss mice, using an unbiased protocol. Control group received vehicle by the same route. The levels of cytokines, chemokines, and neurotrophic factors were measured using Enzyme-Linked Immunosorbent Assay (ELISA) in the brain after CPP test. As expected, nicotine induced place preference behavior. In parallel, we observed increased peripheral levels of IL-6 and IL-10 alongside increased hippocampal levels of NGF but decreased GDNF in mice treated with nicotine compared to controls. In the striatum, nicotine promoted decrease of IL-1ß, IL-10 and GDNF levels, while the levels of all the mediators were similar between groups in the pre-frontal cortex. Our results provide evidence on the role of cytokines and neurotrophic factors in nicotine-induced CPP in mice.


Assuntos
Condicionamento Psicológico/efeitos dos fármacos , Doenças Neuroinflamatórias/psicologia , Nicotina/administração & dosagem , Recompensa , Tabagismo/psicologia , Animais , Fator Neurotrófico Derivado do Encéfalo/análise , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Corpo Estriado/imunologia , Corpo Estriado/patologia , Modelos Animais de Doenças , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Hipocampo/imunologia , Hipocampo/patologia , Humanos , Injeções Intraperitoneais , Interleucina-10/análise , Interleucina-10/metabolismo , Interleucina-1beta/análise , Interleucina-1beta/metabolismo , Masculino , Camundongos , Doenças Neuroinflamatórias/imunologia , Doenças Neuroinflamatórias/patologia , Nicotina/efeitos adversos , Córtex Pré-Frontal/imunologia , Córtex Pré-Frontal/patologia , Tabagismo/imunologia , Tabagismo/patologia
17.
PLoS One ; 16(9): e0256730, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34495991

RESUMO

INTRODUCTION: Recently, electric cigarettes with liquid (e-liquid) were introduced as an alternative to tobacco smoking. They were promoted as possible cessation aids and were considered to be potentially less harmful than traditional tobacco-based cigarettes. However, there is little information on the toxicants present in e-liquids and their possible carcinogenic effects. METHODS: Western blot analysis was performed to identify the protein levels of cancer progression related signal transducers. Patient-derived brain tumor cells (CSC2) were injected into mouse brains and tumor growth was then observed by performing magnetic resonance imaging (MRI) and hematoxylin and eosin (H&E) staining of the whole brain. Immunohistochemistry (IHC) staining and Immunofluorescence staining were performed to study the expression of pEGFR and pERK. RESULTS: Western blotting revealed that e-liquids increased pEGFR and pERK expression in a dose dependent manner. Animal experiments revealed that the e-liquid treated group had accelerated tumor growth and poor prognosis compared to the vehicle group. Histological staining showed activation of pEGFR and pERK in the e-liquid treated group. CONCLUSION: Our study revealed that e-liquid activates pEGFR and pERK, leading to accelerated brain tumor growth and poor prognosis.


Assuntos
Neoplasias Encefálicas/metabolismo , Carcinogênese/efeitos dos fármacos , Sistemas Eletrônicos de Liberação de Nicotina , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glioblastoma/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Nicotina/administração & dosagem , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Neoplasias Encefálicas/patologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Fumar Cigarros/metabolismo , Modelos Animais de Doenças , Receptores ErbB/metabolismo , Feminino , Glioblastoma/patologia , Xenoenxertos/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Neoplasias/métodos , Fosforilação/efeitos dos fármacos , Prognóstico , Propilenoglicol/administração & dosagem , Soluções , Solventes/administração & dosagem , Carga Tumoral/efeitos dos fármacos
18.
Neurosci Lett ; 763: 136152, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34384845

RESUMO

Lycium ruthenicum Murray is widely used in traditional Chinese medicine and is believed to have antimicrobial, antioxidant, and anti-fatigue effects. Anthocyanins are considered to be one of the main active components. The previous work by our research team found that the anthocyanins in Lycium ruthenicum extract (ALRM) produce a stable anti-anxiety effect. The mechanisms of action include reducing the level of corticotropin-releasing factor (CRF) as well as regulating extracellular signal-regulated kinase/mitogen activation, protein kinase (ERK/MAPK) pathways, and others, all of which are related to the mechanisms of nicotine addiction. To investigate the effects of ALRM on anxiety and craving behavior after nicotine withdrawal, the components of ALRM were analyzed using the UPLC-Orbitrap MS method. The effects of ALRM on anxiety behavior induced by nicotine withdrawal were investigated in mice using the elevated plus maze (EPM) and light-dark box (LDB) tests. The effects of ALRM on craving behavior after nicotine withdrawal were further investigated using the conditional place preference (CPP) test. The EPM and LDB tests demonstrated that ALRM could alleviate the anxiety behavior induced by nicotine withdrawal and reduce nicotine craving in mice. Based on the identified ALRM components, the network pharmacology method was used to predict the mechanism of ALRM alleviating anxiety after nicotine withdrawal in mice. It was speculated that ALRM was involved in the production and transmission of dopamine, choline, and other nervous system functions and exhibited a potential role in treating nicotine addiction.


Assuntos
Antocianinas/administração & dosagem , Ansiedade/tratamento farmacológico , Lycium/química , Nicotina/administração & dosagem , Síndrome de Abstinência a Substâncias/tratamento farmacológico , Animais , Antocianinas/isolamento & purificação , Ansiedade/diagnóstico , Ansiedade/psicologia , Fissura/efeitos dos fármacos , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Farmacologia em Rede , Síndrome de Abstinência a Substâncias/psicologia
20.
Sci Rep ; 11(1): 17393, 2021 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-34462474

RESUMO

In this study, we investigated whether intravenously self-administered nicotine with menthol and audiovisual cue modulates nicotine-metabolizing CYP2A6, oxidative stress modulators, and cytokines/chemokines in plasma extracellular vesicles (EVs) in rats. We assigned rats to self-administered nicotine with: (a) audiovisual cue (AV), (b) menthol, and (c) menthol and AV cue. We found increased levels of CD9 in plasma EVs after self-administered nicotine with menthol and AV cue. Moreover, expression of CYP2A6 in plasma EVs was significantly increased after self-administered nicotine in response to menthol and AV cue. However, despite an upward trend on SOD1 and catalase, increase was not found to be statistically significant, while total antioxidant capacity was found to be significantly increased in plasma and plasma EVs obtained after self-administered nicotine with menthol and AV cue. Among cytokine and chemokine profiling, we found a significant increase in the levels of MCP-1 after self-administered nicotine with menthol and AV cue and complete packaging of IL-1ß in EVs. Taken together, the study provides evidence that nicotine in response to menthol and AV cues can package altered levels of CYP2A6, and cytokines/chemokines in plasma EVs that may contribute to cell-cell communication, nicotine metabolism, and inflammation upon cigarette smoking.


Assuntos
Quimiocinas/sangue , Citocromo P-450 CYP2A6/metabolismo , Citocinas/sangue , Vesículas Extracelulares/metabolismo , Mentol/administração & dosagem , Nicotina/administração & dosagem , Animais , Antioxidantes/metabolismo , Feminino , Masculino , Nicotina/metabolismo , Ratos , Autoadministração , Tetraspanina 29/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/metabolismo
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