抄録
The effect of piperidine and related alicyclic amines on central nicotinic and muscarinic cholinoceptors was investigated by measuring specific binding of [3H] nicotine and [3H] cismethyldioxolane (CD) in rat cerebral cortical membranes. Piperidine, pyrrolidine, 4-hydroxypiperidine and piperazine at concentrations of 1μM-30 mM completed dosedependently with [3H] nicotine and [3H] CD for the binding sites. Among these compounds, piperidine was the most potent competitor of brain [3H] nicotine binding sites. Piperidine and pyrrolidine showed a greater affinity for [3H] nicotine binding sites in the rat cerebral cortex than of [3H] CD binding sites. In contrast, 4-hydroxypiperidine and piperazine displayed approximately 10 times greater affinity for [3H] CD binding sites. Pipecolic acid had little effect on these cholinoceptor agonist binding sites. The inhibitory effect of brain [3H] nicotine binding by piperidine did not differ between brain regions or during development. In addition, there was little difference in the piperidine-induced inhibition of brain [3H] nicotine binding between species such as rat, mouse, guinea-pig and rabbit. Thus, the present study demonstrates a high affinity of piperidine for nicotinic cholinoceptors in the mammalian brain.
