Fig. 3. Cardiac remodeling. Left anterior descending coronary artery was ligated, and infarct size was determined after 12 h using 1% triphenyltetrazolium chloride staining ( A , upper panel ). Viable myocardium is stained brick-stone red , whereas freshly infarcted myocardium is stained salmon pink . Note the black ties on the two basal transverse heart sections. A mean infarct size of 35 ± 5% was obtained (see also table 1). Six weeks after ligation, necrosis was replaced by scar tissue, and compensatory hypertrophy developed ( A , lower panel ). Chronic infarct is stained bright white . Transcript levels of remodeling markers ( B ): atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), α- and β-myosin heavy chains (α- and β-MHC), α-skeletal-actin (α-skl-actin). Western blot analysis of remodeling markers ( C ): ANP, BNP, α- and β-MHC, α-skl-actin. Alpha-tubulin and total actin (pan-actin) were used as loading controls. Remod = postinfarct remodeled hearts; sham = sham-operated hearts. Data are given as mean ± SD (n = 5 in each group). * P < 0.05 versus sham.