Aromatic analogs of arcaine inhibit MK-801 binding to the NMDA receptor

Aromatic analogs of arcaine were shown to have inhibitory effects on the binding of the channel blocking drug [3H]MK-801 to the NMDA receptor complex. The most potent compound of the series was an N,N′-bis(propyl)guanidinium which inhibited [3H]MK-801 binding with an IC50 of 0.58 μM and an IC50 of 12.17 μM upon addition of 100 μM spermidine. The increase in IC50 upon addition of spermidine suggests competitive antagonism between the inhibitor and spermidine at the arcaine-sensitive polyamine site of the NMDA receptor complex.