Effects of sympathomimetic agent on remodeling of connexin 43 in atrium of isolated heart with rapid atrial pacing
10.3969/j.issn.1000-4718.2017.02.004
- VernacularTitle:拟交感效应对快速起搏离体心脏心房缝隙连接蛋白43重构的影响
- Author:
Chenglin SHU
;
Yan HE
;
Zhiyu ZENG
;
Tao HE
;
Jinyi LI
;
Weiqiang HUANG
;
Jian XU
;
Yanqun HUANG
- Keywords:
Sympathetic nerves;
Connexin 43;
Atrial fibrillation;
Oxidative stress;
Autophagy
- From:
Chinese Journal of Pathophysiology
2017;33(2):215-220
- CountryChina
- Language:Chinese
-
Abstract:
AIM:To investigate the changes of connexin 43 (Cx43) via establishing a model of sympathomi-metic atrial fibrillation ( AF) .METHODS:The mongrels ( n=15) were randomly divided into control group , rapid atrial pacing (RAP) group and isoprenaline (ISO) perfusion+RAP group (ISO+RAP group).All mongrels’ hearts were taken out rapidly by median sternotomy to establish the cardiac model with Langendorff perfusion in vitro.The atrial effective re-fractory period ( AERP) and AF inducability were tested .The expression and distribution of tyrosine hydroxylase ( TH) were analyzed by immunohistochemistry .Total protein level of Cx 43 and phosphorylation of Cx 43 were determined by West-ern blot.The distribution of Cx43 were also observed by immunofluorescence staining .The cell apoptosis was analyzed by TUNEL staining.The generation of reactive oxygen species ( ROS) in the mitochondria was measured by fluorescence spec-trophotometry .RESULTS:No significant change of AERP was found between control group and RAP group , while that in ISO+RAP group was significantly decreased (P<0.05) and induced AF.Compared with control group, the expression of TH, apoptotic index and the generation of ROS increased gradually (P<0.05), while the content of Cx43 decreased grad-ually both in the total protein and the phosphorylation levels in RAP group and ISO +RAP group (P<0.05).The fluores-cence intensity of Cx43 was also attenuated and Cx43 were lateralized apparently in RAP group , while Cx43 were character-ized as punctate distribution in ISO +RAP group.CONCLUSION:Sympathetic nerves may activate autophagosome at in-tercalated discs and trigger cell apoptosis , resulting in remodeling and downregulation of Cx 43 via oxidative stress , thus having effects on mediating and maintaining AF .
