N-Methyl-D-Aspartate Receptor 2B Gene(GRIN2B) Polymorphism In Chronic Ketamine Users

Part One Profiling the socio-demographic and drug use characteristics of Ketamine usersBackground Ketamine,as a non-competitive antagonist of the N-methyl-D-aspirate(NMDA)glutamate receptor,was introduced into China in 1990 s and has become one of the most commonly abused drugs among young people.Contents This study analyzed the socio-demographic and drug use characteristics of ketamine users in Guangdong,in order to provide a profile of ketamine users.Then take appropriate measures to prevent ketamine from further being used.Method A case report form(CRF)was used to collect information about socio-demographic data and drug use characteristics of ketamine users.Results The information of 376 ketamine users were collected.For socio-demographic characteristics,92.0% of ketamine users were male and 8.0% were female.The avarage age of ketamine users was 26.3±4.8 years old(15-44 years old)and 73.4% of them were 21 years old to 30 years old.53.7% of the ketamine subjects were never married.The avarage education years of ketamine users was 10.6±2.7 years.73.1% of the ketamine users were employed,most of them were self-employed workers(30.0%)and followed by enterprises(13.0%).For drug use characteristics,the avarage age of first ketamine use was 19.8±4.8 yesrs old(11-44 years old)and 63.6% of the subjects were under 20 years old.The duration of ketamine use was 6.8±3.2 years and the average daily dose of ketamine was 3.1±2.4g.73.7% of ketamine users had taken other substances,including MDMA(33.8%),methamphetamine(14.6%),codeine(8.8%)and marijuana(8.5%).Conclusions The results suggested that ketamine users point to a trend of young males who mainly focus on low education level.Most of the ketamine users were singles and were employed.Ketamine users were young at first use and the average daily dose was large.Besides,most ketamine users used multi-substance.Therefore,efforts to raise young people awareness of the harms of ketamine are urgently needed.Part Two N-Methyl-D-Aspartate Receptor 2B(GRIN2B)gene polymorphism in chronic ketamine usersBackground Previous studies indicated that NMDA receptor gene(GRIN)polymorphisms are involved in addiction.However,there was no study analysing GRIN polymorphisms in ketamine users.Contents This study examined the allelic variants of the N-Methyl-D-Aspartate Receptor 2B gene(GRIN2B)in chronic ketamine users in Chinese population and analysis the association between GRIN2 B gene polymorphism and ketamine-induced clinical symptoms which include psychotic,depressive and anxiety symptoms.The relationship between the polymorphisms and ketamine use conditions was also examined.Methods Four single nucleotide polymorphisms(SNPs)of GRIN2 B,rs1805502,rs7301328,rs890 and rs1806201 were examined using a real-time PCR with the Taq Man? assay system.Clinical symptoms in ketamine users were assessed using the Positive and Negative Syndrome Scale(PANSS),Beck Depression Inventory(BDI)and the Beck Anxiety Inventory(BAI).Results 242 ketamine users and 80 control subjects were enrolled.The genotype distribution of 4 SNPs had no significant difference between ketamine users and control subjects(p>0.05).The A allele frequency of rs890 in ketamine users was higher than that in the controls(p=0.047,OR=5.366,95%CI=1.023-28.156).The allele frequency of the other three SNPs(rs1805502,rs7301328 and rs890)were not significantly different between ketamine users and control subjects(p>0.05).The age of first ketamine use was significantly different among the three genotypic groups of rs1806201(F=3.772,p=0.024,eta=0.175),and subjects of genotype TT had earlier onset of ketamine use than subjects of genotype TC(p=0.010).The other three SNPs has no relationship to ketamine use conditions(p>0.05).There was no difference in PANSS scores in different genotype of the four GRIN2 B gene polymorphisms in ketamine users(p>0.05).Conclusion Ketamine users have higher A allele frequency in rs890,it suggest that GRIN2 B gene polymorphism may play a role in vulnerability in ketamine use.;there was a significant relationship between rs1806201 gene polymorphism and eailier onset age of ketamine use,TT genotype of rs1806201 had earlier onset of ketamine use than TC genotype;there was no significant association between symptom measures and GRIN2 B gene polymorphism.