Connexin37 is the major connexin expressed in the media of caudal artery.
OBJECTIVE
To determine the connexins (Cxs) involved in intercellular coupling within vascular muscle, the present study has quantified mRNA and protein expression for Cx37, Cx40, Cx43, and Cx45 in the caudal artery (CA) and thoracic aorta (ThA) of the rat.


RESULTS
Real-time polymerase chain reaction and immunohistochemistry identified Cx37 as the most abundantly expressed Cx in the CA, with fine punctate staining observed in the media. Conversely, mRNA for Cx43 was 40-fold greater in the ThA than in the CA, with punctate staining in the endothelium and media of the ThA but confined to the endothelium in the CA. Western blotting confirmed the differences in the relative amounts of Cx43 between the 2 vessels. For both arteries, Cx45 was expressed to a lesser degree in the media but not in the endothelium, whereas Cx40 was found only in the endothelium. Cx37, Cx40, and Cx43 were expressed in the endothelium of both vessels, although the density of Cx40 plaques was significantly greater in the CA.


CONCLUSIONS
The demonstration of Cx37 as the dominant Cx in the media of the CA highlights the potential heterogeneity in Cx involvement in vascular smooth muscle.
Rummery
Nicole M
NM
Division of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, Australia. nicole.rummery@anu.edu.au
Hickey
Haruyo
H
McGurk
Gordon
G
Hill
Caryl E
CE
D000818:Animals; D000906:Antibodies / Q000378:metabolism; D001013:Aorta, Thoracic / Q000737:chemistry / Q000378:metabolism; D001158:Arteries / Q000378:metabolism*; D015153:Blotting, Western; D018031:Connexin 43 / Q000096:biosynthesis; D017630:Connexins / Q000096:biosynthesis* / Q000276:immunology; D004730:Endothelium, Vascular / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D007150:Immunohistochemistry; D009131:Muscle, Smooth, Vascular / Q000737:chemistry* / Q000378:metabolism*; D051381:Rats; D012445:Sacrococcygeal Region / Q000098:blood supply; D017540:Tunica Media / Q000737:chemistry / Q000378:metabolism*; D000097003:Gap Junction alpha-5 Protein; D000097006:Gap Junction alpha-4 Protein
D000906:Antibodies; D018031:Connexin 43; D017630:Connexins; D000097003:Gap Junction alpha-5 Protein; D000097006:Gap Junction alpha-4 Protein; C082920:connexin 45