Fig. 8. Substance P (SP) treatments markedly improved cardiac function by reducing the infarct size and fibrosis after permanent ligation of the left anterior descending (LAD) artery. (A) Triphenyltetrazolium chloride (TTC) staining at 8 weeks post-LAD ligation was performed to examine the infarct area. (B, C) The fibrotic area in the cardiac tissue was examined by Masson trichrome (MTC) staining and was quantitatively evaluated. (D) Representative immunostaining images for α-SMA+ vasculature in the infarct zone. EP: epicardium, M: myocardium. Scale bar: 100m. Quantitative analysis of vessel density (E), and ratio of α-SMA+ vessels to the total number of vessels (F) in the infarct, peri-infarct, and contralateral zones at 8 weeks post-LAD ligation. n = 6 per group. The data shown reflect the mean SD. *p<0.05, **p<0.01, ***p<0.001.