Association between cerebrospinal fluid dopamine concentrations and catechol-O-methyltransferase gene polymorphisms in forensic autopsy cases of methamphetamine abusers

- Catecholamine concentrations were measured in the cerebrospinal fluid (CSF) of drug abusers.
- The COMT polymorphisms, rs4633 and rs4680 were identified among drug abusers.
- COMT polymorphisms correlated with CSF dopamine (DA) concentrations in methamphetamine abusers.
- COMT polymorphisms did not correlate with CSF DA concentrations in fatal psychotropic cases.
- COMT polymorphisms were not associated with Adr or Nad concentrations in the CSF of drug abusers.

Methamphetamine (MA) is an illicit psychostimulant that stimulates the release of catecholamines from sympathetic nerve terminals and is widely abused worldwide. Since catechol-O-methyltransferase (COMT) metabolizes catecholamines and mediates adrenergic, noradrenergic, and dopaminergic signaling responses, we investigated the effects of the COMT polymorphisms rs4633 and rs4680 on cerebrospinal fluid (CSF) catecholamine concentrations in autopsies of subjects who died of drug intoxication. 28 MA abusers and 22 fatal psychotropic drug intoxication cases were evaluated. No correlations were identified between rs4633 or rs4680 polymorphisms and CSF concentrations of adrenaline (Adr), noradrenaline (Nad), or dopamine (DA) in fatal psychotropic cases. However, among MA abusers, DA concentrations in the CSF were significantly higher in those with the T allele (CT and TT) of rs4633 than in CC genotype carriers (p = 0.004). Moreover, among MA abusers, DA concentrations were significantly higher in those with the A allele (GA and AA) of rs4680 than in GG genotype carriers (p = 0.017). In subsequent haplotype analyses of MA abusers, a strong correlation was identified between two COMT haplotypes and CSF DA concentrations (p = 0.002). However, the CSF concentrations of Adr and Nad were not associated with COMT genotypes or haplotypes. The present results indicate that rs4633 and rs4680 polymorphisms influence CSF DA concentrations and MA toxicity in MA abusers.