RTN4R and Myocardial fibrosis: Meanwhile, the results of masson staining showed that the myocardial tissue of sham group mice had scattered distribution or striated collagen fibers and intact myocardial fibers; while the myocardial fibers in the CLP group were broken in the center of the myocardial tissue, with thickened collagen fibers and increased deposition; surprisingly, the degree of myocardial fibrosis in the NG-R1 pretreated CLP group was moderated and approached that of the sham group (Figures 2G,H).