Effects of the 1-amino-adamantanes at the MK-801-binding site of the NMDA-receptor-gated ion channel: a human postmortem brain study

Eur J Pharmacol. 1991 Apr 25;206(4):297-300. doi: 10.1016/0922-4106(91)90113-v.


Recent studies from our laboratory have provided evidence that the 1-amino-adamantane derivative memantine (1-amino-3,5-dimethyl-adamantane) binds to the MK-801-binding site of the N-methyl-D-aspartate (NMDA)-receptor-gated ion channel. This action has been suggested to account for the antiparkinsonian and antispastic activity of the drug. In the present investigation we have extended our work by testing a series of 1-amino-adamantanes, including amantadine (1-amino-adamantane) and memantine, for their ability to compete with [3H]MK-801 binding in membrane homogenates of postmortem human frontal cortex. The most potent substance (1-amino-3,5-diethyl-adamantane) had a Ki-value of 0.19 +/- 0.06 microM while the weakest substance (1-N-methyl-amino-adamantane) had a Ki-value of 21.72 +/- 1.63 microM. The Ki-value of amantadine was 10.50 +/- 6.10 microM. In agreement with our earlier investigation, the Ki-value of memantine was 0.54 +/- 0.23 microM. The results indicate that 1-amino-adamantanes, in general, may produce their pharmacological effects through an interaction with the NMDA-receptor-gated ion channel. The displacement of [3H]MK-801 binding thus may provide the basis to predict the antiparkinsonian and antispastic activity of novel substituted 1-amino-adamantanes and possibly of other drugs.

MeSH terms

  • Adamantane / analogs & derivatives*
  • Adamantane / pharmacology
  • Amantadine / metabolism
  • Amantadine / pharmacology
  • Binding Sites
  • Brain / metabolism*
  • Brain / ultrastructure
  • Dizocilpine Maleate / metabolism*
  • Humans
  • Ion Channel Gating / physiology
  • Ion Channels / metabolism
  • Kinetics
  • Memantine / metabolism
  • Memantine / pharmacology
  • Receptors, N-Methyl-D-Aspartate / metabolism*
  • Structure-Activity Relationship
  • Tritium


  • Ion Channels
  • Receptors, N-Methyl-D-Aspartate
  • Tritium
  • Dizocilpine Maleate
  • Amantadine
  • Adamantane
  • Memantine