Characterization of Recruited Macrophages in Atria by Flow Cytometry: New Tool for Insights into Atrial Inflammation Processes

Abstract

Background: Clinical studies with hsCRP or IL-6 have demonstrated that inflammation is closely associated with substrates for atrial fibrillation. Therefore, we analyzed the characteristics of macrophages in atria, which dominate the innate responses of inflammation, using flow cytometry with specific antibodies. Methods: Using ddy mice atria of 7 weeks and 5–6 months old, we determined the characteristics of the macrophages by flow cytometry, where cells were collected by the filtration with 20 µm filter after isolation and homogenization of atria and spleens. Results: In the spleen, CD11c-positive cells were about 25% of macrophages in young and old mice. This ratio was similar in the atria of young mice. In contrast, CD11c-positive macrophages were increased up to approximately 50% in the atria of old mice. Conclusions: Flow cytometric analyses could be applied to atrial samples to determine the characteristics of inflammation by characterizing recruited immunocytes.