Multiple nicotinic acetylcholine receptor alpha-subunits are expressed in the arterial system of the rat.
Neuronal nicotinic acetylcholine receptors (nAChRs) are hetero- and homopentamers built up by nine different alpha-subunits and three different beta-subunits. The subtype composition within the receptor determines ligand specificity, affinity and cation permeability. In this study we focused on the distribution of the ligand binding alpha-subunits in the rat arterial system by means of RT-PCR and immunohistochemistry. Subtypes alpha3, alpha5, alpha7 and alpha10 were found to be expressed by endothelial cells, suggesting that they are equipped both with calcium-preferring (alpha7 homopentamers) and monovalent cation-preferring (heteropentamers containing alpha3- and alpha5-subunits) nAChR channels. All alpha-subtypes except alpha9 were expressed by vascular smooth muscle cells with a highly specific distribution pattern along the vascular tree. While every alpha-subunit except alpha9 was detected in the thoracic aorta, intrapulmonary arterial branches contained only alpha7 immunoreactivity, and other vascular beds held intermediate positions with respect to the extent of alpha-subunit expression. Current knowledge does not allow to correlate these distribution patterns to specific functions, but it can be anticipated that at least some components of nAChR-mediated signalling in the arterial wall are highly specific for individual arteries.
Brüggmann
Dörthe
D
Institute for Anatomy and Cell Biology, Justus-Liebig-University, Aulweg 123, 35385 Giessen, Germany. Wolfgang.Kummer@anatomie.med.uni-giessen.de
Lips
Katrin S
KS
Pfeil
Uwe
U
Haberberger
Rainer V
RV
Kummer
Wolfgang
W
D000818:Animals; D001011:Aorta / Q000737:chemistry / Q000378:metabolism; D001012:Aorta, Abdominal / Q000737:chemistry / Q000378:metabolism; D001013:Aorta, Thoracic / Q000737:chemistry / Q000378:metabolism; D001158:Arteries / Q000737:chemistry / Q000378:metabolism*; D015870:Gene Expression; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D012313:RNA / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011978:Receptors, Nicotinic / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D020033:Protein Isoforms; D021122:Protein Subunits; D011978:Receptors, Nicotinic; D012313:RNA