High- and low-affinity binding of [3H]acetylcholine at nicotinic cholinergic receptors in rat brain.
There is both high-affinity and low-affinity nicotinic cholinergic binding of [3H]acetylcholine [( 3H]ACh) in rat brain membrane preparations. As determined by a filtration binding assay, [3H]ACh bound with Kd = 36.0 +/- 8.4 nM and Bmax = 19.4 +/- 4.5 fmol/mg protein or 3.3 +/- 0.7 fmol/mg tissue for high-affinity binding and Kd about 10(-7) to 10(-6) M and Bmax about 6-10 fmol/mg tissue or 40-60 fmol/mg protein for low-affinity binding. d-Tubocurarine (1 mM) inhibits high- as well as low-affinity binding, whereas 10 microM alpha-bungarotoxin does not compete at both binding sites. Substance P had no effect on the binding parameters of high-affinity nicotinic cholinergic binding.
Reulecke
M
M
Hucho
F
F
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry / Q000187:drug effects; D002038:Bungarotoxins / Q000494:pharmacology; D051381:Rats; D011978:Receptors, Nicotinic / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism; D013373:Substance P / Q000378:metabolism; D014403:Tubocurarine / Q000494:pharmacology
D002038:Bungarotoxins; D011978:Receptors, Nicotinic; D013373:Substance P; D000109:Acetylcholine; D014403:Tubocurarine