Dopamine transporter genotype dependent effects of apomorphine on cold pain tolerance in healthy volunteers

PLoS One. 2013 May 21;8(5):e63808. doi: 10.1371/journal.pone.0063808. Print 2013.

Abstract

The aims of this study were to assess the effects of the dopamine agonist apomorphine on experimental pain models in healthy subjects and to explore the possible association between these effects and a common polymorphism within the dopamine transporter gene. Healthy volunteers (n = 105) participated in this randomized double-blind, placebo-controlled, cross-over trial. Heat pain threshold and intensity, cold pain threshold, and the response to tonic cold pain (latency, intensity, and tolerance) were evaluated before and for up to 120 min after the administration of 1.5 mg apomorphine/placebo. A polymorphism (3'-UTR 40-bp VNTR) within the dopamine transporter gene (SLC6A3) was investigated. Apomorphine had an effect only on tolerance to cold pain, which consisted of an initial decrease and a subsequent increase in tolerance. An association was found between the enhancing effect of apomorphine on pain tolerance (120 min after its administration) and the DAT-1 polymorphism. Subjects with two copies of the 10-allele demonstrated significantly greater tolerance prolongation than the 9-allele homozygote carriers and the heterozygote carriers (p = 0.007 and p = 0.003 in comparison to the placebo, respectively). In conclusion, apomorphine administration produced a decrease followed by a genetically associated increase in cold pain tolerance.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Alleles
  • Apomorphine / adverse effects
  • Apomorphine / pharmacology*
  • Cold Temperature*
  • Dopamine Plasma Membrane Transport Proteins / genetics*
  • Female
  • Genotype
  • Healthy Volunteers*
  • Humans
  • Male
  • Pain Threshold / drug effects*
  • Placebos
  • Polymorphism, Single Nucleotide / genetics
  • Young Adult

Substances

  • Dopamine Plasma Membrane Transport Proteins
  • Placebos
  • SLC6A3 protein, human
  • Apomorphine

Grants and funding

This study was funded by a grant from the Israeli Science Foundation (ISF) no 529-10. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.