Figure 2: Immunohistochemical Analysis Following Induction of Stress-Induced Takotsubo-Like Cardiomyopathy

Immunohistochemical analysis demonstrates progressive neutrophil and macrophage infiltration into myocardial tissue (day 0 to 14) following induction of stress-induced takotsubo-like cardiomyopathy. Representative examples of neutrophil (A) and macrophage (CD68-positive cells) (B) staining in mid-region rat myocardial tissue, original magnification ×400. Neutrophil (C) and macrophage (D) cell counts in the mid-region of saline injected (control) and isoprenaline injected rat hearts (day 0 to 14). Values represent mean counts ± SD in 24 fields of view from defined areas as described in the Methods section. The number of animals per group were as follows: control n = 7, day 1 n = 6, day 2 n = 6, day 3 n = 7, day 4 n = 6, day 5 n = 7, day 6 n = 6, day 7 n = 5, and day 14 n = 5 animals. Statistical difference in mean number of neutrophil and macrophage counts between control rats and those injected with isoprenaline were calculated with p values denoted above each time point bar. Values in bold indicate statistically significant differences compared with the control group.