Cardiac tissue structure.

(A) Representative photomicrographs of immunohistochemical staining of smooth muscle actin, wheat germ agglutinin, and Dapi in myocardial tissue sections. Five different heart tissues per group were stained. Approximately 10–15 high-power fields per area from a minimum 3 slides per heart were analyzed to obtain the average regional cross sectional area and regional myocyte nuclear density. 100 cardiomyocytes per heart were evaluated. (B) Quantification of cross-sectional area in the peri-infarct and D. in the remote zone respectively. (C,E) Measurement of the total number of cell nuclei per field evaluated in both above-mentioned regions. (F) Representative photomicrographs of immunohistochemical staining of α-sarcomeric actin, Ki67 and Dapi, in the peri-infarct zone and (I) in the remote area. (G–H) Quantification of proliferating cardiomyocytes per total number of cardiomyocytes per field and of proliferating cardiomyocytes per total nuclei per field respectively. (J–K) Same quantification as in G–H but in the remote area. Arrows point to Ki67+/asa+ cells. (Scale bars 50 µm). Data are mean±SEM. ¶ p<0.05 control vs. MI+CSp, * p<0.05 vs. sham.