Fig 1: NAMPT IHC staining images of rat hearts subjected to IRI and treated with ALT-100 or saline. Panels A–B and C–D display cardiac sections (10X) illustrating Masson’s Trichrome staining (A & C) and anti-NAMPT IHC staining (B & D), respectively. Panels A & B are from a control heart treated with saline, while panels C & D are from an ALT-100-treated rat heart at 4 weeks post-IRI. The numbered boxes on the IHC images indicate areas from distinct zones selected for 40X magnification: the remote non-infarct area (“1”), the peri-infarct zone (“2”), and the fibrotic infarct region (“3”). Panels B1–B3 and D1–D3 are magnified microphotographs (40X) from the corresponding boxed areas on panels B and D, respectively. The brown staining represents NAMPT expression in the cardiac tissues. No discernible difference in the distribution patterns of NAMPT expression was qualitatively observed between the heart treated with ALT-100 and the saline control. The intensity of positive anti-NAMPT staining is lower in the cardiac section from the rat treated with ALT-100 compared to that in the saline control.