Molecular expression and histological changes in non-ischemic myocardium in sham and MI mice. Upper: The mRNA levels of ANP, BNP, and collagens type I and III in the non-ischemic myocardium of MI (n = 5) and sham (n = 5) groups by real-time RT-PCR to assess the molecular aspects of myocardial hypertrophy and fibrosis. ANP, BNP, and collagens type I and III were all significantly up-regulated in MI myocardium compared with sham myocardium. * p < 0.05 vs. sham. Lower: Myocardial fibrosis in the remote non-ischemic myocardium after MI. Histological assessment of remote non-ischemic myocardium with H&E (left column; A and C) and Masson’s Trichrome staining (right column; B and D. Collagen stains as blue color) in sham (A, B) and MI (C, D) hearts. In MI hearts, there is an increase deposition of collagen in the interstitial space (arrows) in the remote non-ischemic myocardium suggesting the development of myocardial fibrosis. Magnification bar = 100 μm.