Angiotensin-(1-7) prevents atrial fibrosis and atrial fibrillation in long-term atrial tachycardia dogs

作者：Liu, Enzhao; Yang, Shengrong; Xu, Zhao; Li, Jian; Yang, Wansong; Li, Guangping^*

来源：Regulatory Peptides, 2010, 162(1-3): 73-78.

DOI：10.1016/j.regpep.2009.12.020

• Atrial fibrillation
• Remodeling
• Fibrosis
• Angiotensin-(1-7)

Renin-angiotensin system (RAS) is activated in the fibrillating atria. Angiotensin-(1-7) [Ang-(1 -7)] counterbalances the actions of angiotensin (Ang II). To investigate the effects of Ang-(1-7) on the long-term atrial tachycardia-induced atrial fibrosis and atrial fibrillation (AF) vulnerability, eighteen dogs were assigned to sham group, paced group, or paced + Ang-(1-7) group, 6 dogs in each group. Rapid atrial pacing at 500 bpm was maintained for 14 days, but dogs in the sham group were instrumented without pacing. During the pacing, Ang-( 1-7) (6 mu g.kg(-1).h(-1)) was given intravenously. After pacing, atrial mRNA expression of ERK1/ERK2 and atrial fibrosis were assessed, the inducibility and duration of AF were measured. Compared with sham, ERK1/ERK2 mRNA expression was increased in the paced group (P<0.05). Atrial tissue from the paced dogs showed a large amount of interstitial fibrosis, and the inducible rate of AF was increased at various BCLs in paced dogs (P<0.01). Compared with the paced group, Ang-(1-7) prevented the increase of ERK1/ERK2 mRNA expression (P<0.01 and P<0.05, respectively), and attenuated the interstitial fibrosis (P<0.01). Inducibility and duration of AF were reduced by Ang-( 1-7) at various BCLs. In conclusion, Ang-( 1-7) reduced AF vulnerability in chronic paced atria, and antifibrotic actions contributed to its preventive effects on AF.

• 出版日期2010-6-8
• 单位天津医科大学