Rat arteries contain multiple nicotinic acetylcholine receptor alpha-subunits

We investigated the occurrence and distribution of the ligand-binding alpha-subunits of nicotinic acetylcholine receptors in the rat arterial system in situ by means of RT-PCR and immunohistochemistry. Except the alpha9-subunit, all other mammalian non-muscular alpha-subunits were expressed in the arterial wall--either in endothelial or in smooth muscle cells--suggesting it as a direct target of nicotine and endogenous acetylcholine. The distribution pattern of alpha-subunits found in smooth muscle cells varied considerably among the individual elastic, muscular and intraparenchymal arteries investigated, suggesting that non-neuronal cholinergic signalling via nicotinic receptors in the vascular wall includes components that are highly specific for individual arteries.