Sensitivity of neuronal nicotinic acetylcholine receptors to the opiate antagonists naltrexone and naloxone: receptor blockade and up-regulation

In HEK293 cells stably expressing α4β2 nAChRs, naltrexone, but not naloxone, blocked α4β2 nAChRs via an open-channel blocking mechanism. In primary hippocampal cultures, naltrexone inhibited α7 nAChRs up-regulated by nicotine, and in organotypic hippocampal cultures naltrexone caused a time-dependent up-regulation of functional α7 nAChRs that was detected after removal of the drug. These results indicate that naltrexone could be used as a smoking cessation aid.