Masson's trichrome staining on whole heart slides. Blue, fibrillar collagen; red, myocardium. Collagen fibrosis was seen in myocardial-infarcted areas in I/R-2m and MI-2m groups. In the no ischemic/remote area, collagen fibrosis was significantly increased in Ab-4m, Ab + I/R, and Ab + I/R + DeAb hearts.