Fig. 2

a Heart sections underwent Masson’s trichrome staining (magnification 400 X) to distinguish myocardial tissue (red) from fibrotic tissue (blue). In the normal group, the size of the myocardial cells was normal, and the muscle fibers were regular and no significant pathological changes were observed. In the model group, the cardiomyocytes were looser and the collagen fibers were significantly thickened and exhibited a net-like shape, and were infiltrated with a small amount of inflammatory cells. In the treatment group, the arrangement of myocardial cells was ordered, but there were still fibrotic changes compared with the normal group. b MMP-2 immunohistochemical staining of the infarct zone (400×). c MMP-9 immunohistochemical staining of the infarct zone (400×). d IHS of MMP-2 and MMP-9. Note: * P < 0.05 vs. the normal group; ^# P < 0.05 indicates the comparison of pre- and post-RDN between the model group and the treatment group