title: Interaction of 4-aminopyridine with [3H]phencyclidine receptors in rat brain homogenates.
abstract: The effect of 4-aminopyridine and its analogs on the specific binding of [3H]phencyclidine was investigated in rat brain homogenates. 4-Aminopyridine (4-AP) and 3,4-diaminopyridine displaced [3H]phencyclidine binding, while 3-aminopyridine was without effect. The concentrations of 4-AP required for inhibition of binding increased with increasing the ligand concentration, and the resultant Dixon plots indicated a competitive type of interaction. However, 4-AP also accelerated the dissociation rate of the ligand-receptor complex, suggesting that the effect of 4-AP on phencyclidine receptors in the brain might not be purely competitive.
mesh_terms: D015761:4-Aminopyridine; D000077770:Amifampridine; D000631:Aminopyridines / Q000494:pharmacology*; D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000187:drug effects*; D007473:Ion Channels / Q000187:drug effects; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D017981:Receptors, Neurotransmitter / Q000187:drug effects*; D017478:Receptors, Phencyclidine; D013570:Synaptic Membranes / Q000187:drug effects
chemical_list: D000631:Aminopyridines; D007473:Ion Channels; D017981:Receptors, Neurotransmitter; D017478:Receptors, Phencyclidine; C031283:3-aminopyridine; D015761:4-Aminopyridine; D000077770:Amifampridine