Stereospecificity of 2-methylpiperidine binding to a nicotinic up-regulatory site in the rat brain P2 preparation.

(+/-)-2-Methylpiperidine has a high degree of specificity in enhancing the binding of (-)-[3H]nicotine in the rat brain P2 preparation. (-)- and (+)-2-Methylpiperidine have been resolved. The (+) but not the (-) isomer increased the binding of (-)-[3H]nicotine. The two isomers were equally effective in inhibiting the binding of (-)-[3H]nicotine in high concentrations. These data provide additional support for a stereospecific nicotinic up-regulatory site.