Human Bronchial Epithelial and Endothelial Cells Express α7 Nicotinic Acetylcholine Receptors

摘要: The epithelial or endothelial cells that line the human bronchi and aorta express nicotinic acetylcholine receptors (nAChRs) of α3 subtypes. We report here bronchial (BEC) aortic (AEC) also nAChR α7 subunit, which forms functional nAChRs. Polymerase chain reaction in situ hybridization experiments detected subunit mRNA cultured BEC AEC sections rat trachea. binding radiolabeled α-bungarotoxin revealed a few thousand sites per cell bovine AEC. Western blot immunohistochemistry demonstrated protein(s) recognized by anti-α7 antibodies. Whole-cell patch-clamp studies presence fast-desensitizing currents activated choline nicotine were blocked reversibly methyllycaconitine (1 nM) irreversibly (100 nM), consistent with expression In some cells, slowly decaying currents, confirming previous reports α3β4 Exposure to μM) for 3 days up-regulated nAChRs, as indicated increased number responding choline, both α-bungarotoxin, desensitizing are α-bungarotoxin–insensitive currents. nAChRs suggests toxic effects tobacco smoke could be mediated through these nicotine-sensitive receptors.