Abstract:

 To investigate expressions of angiotensin converting enzyme （ACE） and creactive protein （CRP）in dogs with chronic atrial fibrillation（AF）.  MethodsSixteen mongrel dogs were randomly divided into two groups: the pacing group(n=8) and the control group(n=8). High frequency pacing (500±20?ppm) was performed in the pacing group with a permanent pacemaker, while pacing was not performed in the control group. After pacing for 24 weeks, tissue samples were obtained from the left and right atria when dogs were killed. Levels of angiotensin converting enzyme(ACE), creactive protein（CRP） and angiotensin converting enzyme inhibitors(ACEI) in the atria were determined by immunohistochemistry.  ResultsCompared with the control group, expressions of ACE and CRP were significantly enhanced (P<0.01) in atrial tissues during AF, but expression of ACEI was obviously decreased (P<0.01).    ConclusionThere may be relations between the renin angiotensin system(RAS), inflammation and atrial fibrillation, and interruption of the renin angiotensin system (RAS) may inhibit the genesis and development of atrial fibrillation.

Key words: trial fibrillation;  Peptidyldipeptidase A;  C reactive protein