Analysis of the different cell fractions present within the unstressed heart.

<p>Fluorescence microscopy of intact murine cardiomyocytes (<b>A</b>) and non-cardiomyocytes (<b>B</b>) extracted from the murine heart. Red = CD45⁺ cells (fluorescence microscopy). Blue = nuclear stain with DAPI. <b>C</b>: Representative flow cytometry plot of non-cardiomyocytes. Black = CD45⁺ cells (lower right), light grey = endothelial cells (CD31⁺, upper left) and dark grey = CD31⁻ CD45⁻ (lower left). <b>D</b>: Representative Ter-119/CD45 plot of non-cardiomyocytes to derive the ratio of erythrocytes to leukocytes in myocardial tissue. Assuming a ratio of erythrocytes/leukocytes in peripheral blood to be 1000∶1, contamination of blood derived leukocytes was calculated to be <0.2% (n = 5).