Effects of electroacupuncture on pain sensation in a rat model of hyperalgesia with nicotine dependence

Tobacco smoking is considered to be one of the main risk factors in the development of chronic pain.Long-term chronic exposure to nicotine and other forms of tobacco have been shown to be associated with an increased incidence of pain.Studies have shown that acupuncture can help smokers to reduce their desire to smoke,reduce their withdrawal symptoms,and avoid a relapse after treatment.However,little has been reported about the effects of acupuncture on pain sensitivity caused by long-term smoking.Models of hyperalgesia were established in rats exposed to nicotine for 6 weeks.After 6 weeks of continuous nicotine exposure,electroacupuncture at bilateral acupoints Zusanli(ST36)and Taichong(LR3)was performed 20 minutes per day for 6 days at a continuous wave with a frequency of 2 Hz and a stimulus intensity of 1 m A.The results revealed that electroacupuncture treatment increased the mechanical response threshold of hind paw of nicotine-dependent rats with hyperalgesia and up-regulated the protein expression of pain-related factorsμ-opioid receptor,β-endorphin and glutamic acid decarboxylase 65 in the spinal cord and midbrain periaqueductal gray and the protein expression of glutamic acid decarboxylase 67 in the spinal cord.These findings suggest that electroacupuncture treatment has positive analgesic effects on pain sensitivity caused by long-term chronic nicotine exposure.One possible mechanism for the improved analgesia is that electroacupuncture increases the expression of painrelated factors in the spinal cord and midbrain periaqueductal gray.This study was approved by Institutional Animal Care and Use Committee(IACUC)of the University of Miami(#18-167)on December 12,2018.

Dental Implant Patients Grouped by the Brinkman Index: Their Attitude toward Smoking, Nicotine Dependence, and Knowledge of Peri-Implantitis

Purpose: This study investigated the attitude of patients, grouped by the Brinkman index, towards smoking by using the Kano Test for Social Nicotine Dependence (KTSND) and their knowledge of peri-implantitis. Methods: The participants were 3093 new patients who visited the Tokyo Medical and Dental University Hospital from January 2012 to December 2013 for an oral implant. The methodology included a questionnaire about sex, age, smoking status, daily average number of cigarettes, years of smoking, knowledge of peri-implantitis, and the KTSND. The patients were grouped according to their smoking status by calculating their Brinkman index (over 200 or not): current smokers with the possibility of nicotine dependence (BI(+)CS), current smokers with no possibility of nicotine dependence (BI(-)CS), ex-smokers (ES), and non-smokers (NS). The Brinkman index is obtained by multiplying one’s daily average number of cigarettes by the number of years they have been smoking. Results: Data were collected from 2182 respondents (response rate = 71%). The KTSND scores of BI(+)CS (16.89 ± 4.26) were significantly higher than the scores of ES (11.99 ± 4.52) and NS (11.53 ± 5.01). In current smokers, there were no significant differences between BI(+)CS and BI(-)CS. The patients replied “I don’t know” about peri-implantitis most often in all groups;however, there were no significant differences between the groups. Discussion: BI(+)CS were more dependent on nicotine in social situations than the other groups were. In Japan, a Brinkman index over 200 is required for a nicotine-dependence management fee to be instituted for health insurance treatment. This is a major concern for young smokers, who may be excluded from treatment because their years of smoking are substantially less. Results revealed that there were no significant differences between BI(+)CS and BI(-)CS. Therefore, it was suggested that the Brinkman index did not sufficiently group the participants.

Nicotine Addiction Models and Evaluation of Animal Behavior

Nicotine is one of the most widely concerning components of cigarette smoke.Long-term intake of nicotine can lead to nicotine dependence that affects higher brain functions,which may involve anxiety,learning and memory impairments,and abnormal decision-making.To facilitate analyzing the molecular mechanisms of nicotine dependence,it is common to establish rodent nicotine dependence models to better understand the physiological changes.This paper summarizes and evaluates the application of animal behavior evaluation experiments in nicotine-dependent animal models,in order to provide a reliable reference for researchers to establish rodent nicotine-dependent models for evaluation.

Association of nicotinic acetylcholine receptor subunit alpha-4 polymorphisms with smoking behaviors in Chinese male smokers

Background it has been reported that the nicotinic acetylcholine receptor subunit a4 gene （CHRNA4） might be associated with smoking behaviors in the previous studies. Up to now, there are few reports on the relationship between CHRNA4 and smoking initiation, in this study, we tried to explore the role of two polymorphisms in CHRNA4 （rs1044396 and rs1044397） in smoking initiation and nicotine dependence in Chinese male smokers. Methods Nine hundred and sixty-six Chinese male lifetime nonsmokers and smokers were assessed by the Fagerstr6m test for nicotine dependence （FTND）, smoking quantity （SQ） and the heaviness of smoking index （HSI）.

Association between 5-hydroxytryptamine transporter gene-linked polymorphic region and smoking behavior in Chinese males

Background Tobacco use is the major risk factor for numerous health problems. However, only 5% of smokers can successfully quit without therapy owing to the highly addictive properties of nicotine. The serotoninergic system may be involved in smoking behavior because nicotine increases brain serotonin secretion, nicotine withdrawal decreases serotonin levels, and a selective serotonin reuptake inhibitor antagonizes the response to nicotine withdrawal. Serotonin transporter （5-HTT） is the most important protein, as it adjusts the serotonin concentration in the synaptic cleft. There is a polymorphism in the upstream regulatory region of the 5-HTT gene, named 5-hydroxytryptamine transporter gene-linked polymorphic region （5-HTTLPR）. Compared with the L allele, the S allele of the polymorphism is associated with decreased transcription efficiency of the 5-HTT gene. In this study, we investigated the relationship between this gene polymorphism and smoking behavior in Chinese males. Methods Polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） was performed to find 5-HTTLPR gene polymorphisms in 144 smokers and 135 age-matched healthy non-smokers. A questionnaire was completed in all recruited subjects. Results The proportion of L/L （15.3% vs 5.2%） and S/L （50.0% vs 33.3%） genotypes was significantly higher in the smokers than that in the non-smokers （X^2=21.9; P 〈0.01）. The odds ratio （OR） adjusted by age, education, effects of family members and friends who smoke, and alcohol intake was 2.9 （95%CI 1.78-4.80）. In smokers, the number of cigarettes/day （L/L vs S/L vs S/S： 28±12 vs 20±8 vs 16±6, X^2=18.5, P 〈0.01）, smoking index （L/L vs S/L vs S/S： 561±446 vs 393±341 vs 237±201, X^2=12.5, P 〈0.01） and score on the Fagerstrom test for nicotine dependence （FTND） （L/L vs S/L vs S/S： 7.8±1.6 vs 6.2±2.5 vs 3.5±2.1, X2=48.3, P 〈0.01） were significantly higher in smokers with an L/L or S/L genotype than that in the smokers with the S/S genotype. There were no significant differences in the proportion of starting smoking before 20 years old （P=0.219） and those who succeeded in quitting smoking for more than 1 month （P=-0.456） between individuals with different 5-HTTLPR genotypes in smokers. Conclusions 5-HTTLPR polymorphism may be associated with susceptibility to cigarette smoking in Chinese males. The proportion of the L/L and S/L genotype in smokers was higher than that in non-smokers. In smokers, the level of nicotine dependence and resultant cigarettes consumption may be much higher in individuals with an L/L or S/L genotype than those with the S/S genotype.