Calcium channel antagonists suppress cross-tolerance to the anxiogenic effects of D-amphetamine and nicotine in the mouse elevated plus maze test

Prog Neuropsychopharmacol Biol Psychiatry. 2008 Jan 1;32(1):54-61. doi: 10.1016/j.pnpbp.2007.07.006. Epub 2007 Jul 13.

Abstract

The purpose of the current experiments was to examine the anxiety-related effects of repeated amphetamine and nicotine administration using the mouse elevated plus maze (EPM). d-amphetamine was administered daily for 8 days (2 mg/kg, i.p.). On the 9th day, mice were challenged with amphetamine (2 mg/kg, i.p.) or nicotine (0.1 mg/kg, s.c.), and were tested 30 min after this last injection. Additionally, a distinct group of mice was pretreated with nicotine (0.1 mg/kg, s.c., 6 days). These mice were subjected to nicotine (0.1 mg/kg, s.c.) or amphetamine (2 mg/kg, i.p.) challenge on the seventh day to see if full crossover effects developed after the pretreatment of both psychostimulant drugs. Moreover, the L-type voltage-dependent calcium channel antagonists nimodipine (5 and 10 mg/kg, i.p.), flunarizine (5 and 10 mg/kg, i.p.), verapamil (5 and 10 mg/kg, i.p.) and diltiazem (5 and 10 mg/kg, i.p.) were injected prior to each injection of chronic d-amphetamine or nicotine. We observed cross-tolerance to the anxiogenic effects of d-amphetamine and nicotine that was blunted by a pretreatment with calcium channel blockers. Overall our findings imply that similar neural calcium-dependent mechanisms are involved in the anxiety-related responses to chronic amphetamine and nicotine injections. As anxiety seems to be an important factor for the development of psychostimulant dependence, the L-type VDCC antagonists can offer an interesting approach for the pharmacotherapy of addiction, including amphetamine and/or nicotine dependence.

MeSH terms

  • Analysis of Variance
  • Animals
  • Anti-Anxiety Agents / therapeutic use*
  • Anxiety / drug therapy*
  • Anxiety / physiopathology
  • Behavior, Animal / drug effects
  • Calcium Channel Blockers / pharmacology*
  • Dextroamphetamine / therapeutic use*
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Drug Interactions
  • Drug Tolerance
  • Male
  • Maze Learning / drug effects*
  • Mice
  • Nicotine / therapeutic use*
  • Time Factors

Substances

  • Anti-Anxiety Agents
  • Calcium Channel Blockers
  • Nicotine
  • Dextroamphetamine