Figure 5. Infarct lymphangiogenesis effects on cardiac edema and infiltrating macrophages after MI.

(A) The left ventricle (LV) was separated from the right ventricle (RV) and septum and water content was assayed for each tissue piece by gravimetry. Wet-to-dry weight ratios for the right ventricle and septum (B) and the left ventricle including infarcted tissue (C) are presented for Flt4^fl/fl and Flt4^fl/fl; Cdh5-Cre^ERT2 animals (n = 8, 9). (D–I) Macrophages within the infarct zone were examined by immunohistochemical staining for CD68 (red) on day 3 (D and E), day 7 (F and G), and day 14 (H and I) after MI. Insets in D–I show the boxed region at higher magnification. (J and K) Quantification of the ratio of CD68⁺ area to infarct area at the 3-, 7-, and 14-day post-MI time points in the Flt4^fl/fl (J) and Flt4^fl/fl; Cdh5-Cre^ERT2 (K) animals. For the 3-day time point n = 6, 6; for the 7-day time point n = 4, 6; for the 14-day time point n = 5, 6. In D–I, “epi” denotes epicardial surface of the heart and “infarct” denotes infarct zone. Scale bars presented in H and I apply to D–I. Bar graphs represent mean ± SEM. Statistical comparisons were made with a 2-tailed t test.