Binding differences between nicotine and alpha-bungarotoxin in the rat brain.
Radioreceptor assay (RAA) results in rat brain with 3H-nicotine were compared with those obtained using 125I-alpha-Bungarotoxin (BTX). Scatchard analysis showed that the 3H-nicotine binding site had an average Kd and Bmax of 5.31 nM and 0.047 p moles/mg protein, respectively, and that the corresponding 125I-alpha-BTX binding site values were 0.092 nM and 0.044 p moles/mg protein. Cotinine, which is a nicotine metabolite and has a nicotine-like effect in vivo, inhibited 3H-nicotine binding but did not inhibit 125I-alpha-BTX binding. This result suggests that 3H-nicotine is a more useful ligand than 125I-alpha-BTX for investigating the pharmacological action of nicotine in the brain.
Nukina
I
I
Ogawa
N
N
Takayama
H
H
Ota
Z
Z
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002038:Bungarotoxins / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D018377:Neurotransmitter Agents / Q000378:metabolism; D009538:Nicotine / Q000378:metabolism*; D011869:Radioligand Assay; D051381:Rats; D011919:Rats, Inbred Strains; D011978:Receptors, Nicotinic / Q000378:metabolism*; D013570:Synaptic Membranes / Q000378:metabolism
D002038:Bungarotoxins; D018377:Neurotransmitter Agents; D011978:Receptors, Nicotinic; D009538:Nicotine