[伴有或不伴有上腔静脉及主动脉根部脂肪垫的快速心房起搏犬的胶原空间分布]

Xiong Ri-Xin, Zhong Guo-Qiang, Song Hong-Xing, Zhang Jing-Chang, Ling Yun

Department of Cardiology, First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China.

Zhonghua Xin Xue Guan Bing Za Zhi. 2010 Feb;38(2):171-4.

OBJECTIVE

To observe the collagen spatial distribution, collagen volume fraction (CVF) and Cx40, Cx43mRNA expressions in rapid atrial pacing dogs post vagal denervation by removing fat pad located between the medial superior vena cava and aortic root (SVC-Ao fat pad).

METHODS

Twenty-four dogs were randomly divided into unpaced sham operation group (S group, n = 8), Keeping SVC-Ao fat pad group (K group, n = 8) and Removing SVC-Ao fat pad group (R group, SVC-Ao fat pad was removed by surgical excision before pacing, n = 8). K and R groups were paced for six weeks. Six weeks later, all dogs were sacrificed, left atrium (LA), right atrium (RA), left atrial appendage (LAA), right atrial appendage (RAA) and atrial septum (AS) were collected and stained with HE or Masson Trichrome or frozen in liquid nitrogen for quantifying the expression of Cx40, Cx43 mRNA by Real-time quantitative Reverse Transcription Polymerase Chain Reaction (RT-PCR).

RESULTS

Spatial distribution of collagen fibers as well as CVF between S and R group were similar (all P > 0.05). CVF was significantly higher in K group compared to R group, especially at LAA and AS locations (all P < 0.05). Cx40mRNA expression in K group was significantly decreased in LA, RA, and significantly increased in LAA, RAA and AS compared those in S group (all P < 0.05), significantly lower in LA and RA while significantly higher in LAA and RAA compared to R group (all P < 0.05). Cx43mRNA expression in K group was significantly reduced in LA, RA, LAA and RAA while significantly increased in AS compared to S group (all P < 0.05), significantly higher in LA, RA, RAA and AS while significantly lower in LAA compared to R group.

CONCLUSION

Pacing induced collagen remodeling and modulation on Cx40mRNA and Cx43 mRNA expressions could be partially attenuated by removing SVC-Ao fat pad suggesting vagal denervation plays a key role in the initiation and preservation of atrial fibrillation.

目的

通过去除位于上腔静脉内侧与主动脉根部之间的脂肪垫（SVC-Ao脂肪垫）来观察迷走神经切断术后快速心房起搏犬的胶原空间分布、胶原体积分数（CVF）以及Cx40、Cx43mRNA表达。

方法

将24只犬随机分为未起搏假手术组（S组，n = 8）、保留SVC-Ao脂肪垫组（K组，n = 8）和去除SVC-Ao脂肪垫组（R组，起搏前通过手术切除SVC-Ao脂肪垫，n = 8）。K组和R组进行六周的起搏。六周后，处死所有犬，收集左心房（LA）、右心房（RA）、左心耳（LAA）、右心耳（RAA）和房间隔（AS），进行HE或Masson三色染色，或液氮冷冻，通过实时定量逆转录聚合酶链反应（RT-PCR）定量Cx40、Cx43 mRNA的表达。

结果

S组和R组之间胶原纤维的空间分布以及CVF相似（均P > 0.05）。与R组相比，K组的CVF显著更高，尤其是在LAA和AS部位（均P < 0.05）。与S组相比，K组LA、RA中的Cx40mRNA表达显著降低，LAA、RAA和AS中的显著升高（均P < 0.05），与R组相比，LA和RA中显著更低，而LAA和RAA中显著更高（均P < 0.05）。与S组相比，K组LA、RA、LAA和RAA中的Cx43mRNA表达显著降低，而AS中显著升高（均P < 0.05），与R组相比，LA、RA、RAA和AS中显著更高，而LAA中显著更低。