| Title : Novel adamantane derivatives act as blockers of open ligand-gated channels and as anticonvulsants - Antonov_1995_Mol.Pharmacol_47_558 |
| Author(s) : Antonov SM , Johnson JW , Lukomskaya NY , Potapyeva NN , Gmiro VE , Magazanik LG |
| Ref : Molecular Pharmacology , 47 :558 , 1995 |
| Abstract : We examined the influence of the molecular structure of four novel adamantane derivatives on their ability to block the channels of nicotinic acetylcholine (ACh) and N-methyl-D-aspartate (NMDA) receptors. The structure of the drugs is Ad-CH2-N+H2-(CH2)5-R, where Ad is adamantane and R was varied from ammonium (IEM-1754) to tert-butyldimethylammonium (IEM-1857) radical. The compounds induced double-exponential decays of postsynaptic currents in frog muscles and flickering of NMDA-activated channels, suggesting that each drug acts as a fast open-channel blocker at both types of receptors. The equilibrium dissociation constants (Kd) of the drugs for ACh-activated channels at -80 mV were similar, whereas the Kd values for NMDA-activated channels at -80 mV were 2-10 times lower. Several observations suggested that occupation of either type of channel by these compounds inhibited channel closure; the time constant (tau) of the slow component of the decay of postsynaptic currents in the presence of each compound was greater than the control tau, the IC50 of IEM-1754 for inhibition of NMDA-activated whole-cell currents was > 20 times larger than its Kd for the open channel, and a transient increase in NMDA-activated whole-cell currents was observed after washout of IEM-1754. Thus, these drugs appear to act on nicotinic ACh and NMDA receptors via similar mechanisms, although the voltage dependence of block suggested that the drugs bind at a more superficial site in the ACh-activated channel. All compounds also potently prevented NMDA-induced convulsions in mice. The ED50 of IEM-1754 was 4 times lower than the ED50 of MK-801. |
| ESTHER : Antonov_1995_Mol.Pharmacol_47_558 |
| PubMedSearch : Antonov_1995_Mol.Pharmacol_47_558 |
| PubMedID: 7535380 |
Antonov SM, Johnson JW, Lukomskaya NY, Potapyeva NN, Gmiro VE, Magazanik LG (1995)
Novel adamantane derivatives act as blockers of open ligand-gated channels and as anticonvulsants
Molecular Pharmacology
47 :558
Antonov SM, Johnson JW, Lukomskaya NY, Potapyeva NN, Gmiro VE, Magazanik LG (1995)
Molecular Pharmacology
47 :558