[The influence of persistent rapid atrial pacing on the levels of connexin 43 and type III collagen in pulmonary vein and atrium in a canine model].
OBJECTIVE
To investigate the influence of persistent rapid atrial pacing on the levels of connexin 43 (Cx43) and type III collagen in pulmonary vein and atrium in a canine model.


METHODS
Sixteen mongrel dogs were divided into rapid atrial pacing (RAP) group (n = 8) and normal control group (n = 8) randomly. In the RAP group, atrial pacing was performed with a rate of 400 bpm for 10 weeks to establish atrial fibrillation model. The tissues of left superior pulmonary vein (LSPV), left atrial free wall (LAFW) and right atrial appendage (RAA) were collected from each dogs. The levels of Cx43 and type III collagen were measured in each tissue.


RESULTS
Ten weeks later, persistent atrial fibrillation was induced in all dogs in RAP group. The level of Cx43 in RAP group was higher than that in normal control group (LSPV: 3370.91 +/- 275.11 vs 1405.82 +/- 90.38, P < 0.05; LAFW: 2448.68 +/- 272.10 vs 1467.12 +/- 147.93, P < 0.05, RAA: 2331.96 +/- 199.61 vs 1288.27 +/- 216.22, P < 0.05). The level of Cx43 in LSPV was higher than that in LAFW and RAA in RAP group, whereas the difference between LAFW and RAA was not significant in RAP group. The quantities of type III collagen in RAP group were higher than those in normal control group (LSPV: 3301.97 +/- 309.70 vs 1404.56 +/- 178.02, P < 0.05; LAFW: 2477.86 +/- 190.43 vs 1479.20 +/- 187.17, P < 0.05; RAA: 2045.92 +/- 139.43 vs 1417.07 +/- 139.43, P < 0.05). The quantities of type III collagen in LSPV was higher than those in LAFW and RAA in RAP group.


CONCLUSIONS
Persistent rapid atrial pacing could increase the levels of Cx43 and type III collagen in pulmonary vein and atrium in a canine model of atrial fibrillation. The levels of Cx43 and type III collagen in pulmonary vein were higher than those in atrium. This findings indicated that pulmonary vein may be a crucial regions in maintaining atrial fibrillation.
Wang
Jian
J
Emergency Center, Beijing Anzhen Hospital, Beijing 100029, China.
Liu
Xing-peng
XP
Liu
Xiao-qing
XQ
Long
De-yong
DY
Dong
Jian-zeng
JZ
Ma
Chang-sheng
CS
D000818:Animals; D001281:Atrial Fibrillation / Q000378:metabolism / Q000503:physiopathology*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D024061:Collagen Type III / Q000097:blood*; D018031:Connexin 43 / Q000097:blood*; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D008297:Male; D011667:Pulmonary Veins / Q000378:metabolism / Q000503:physiopathology*
D024061:Collagen Type III; D018031:Connexin 43