Overexpression of PDGFA leads to an increase of collagen type III alpha 1 (COL3A1) and LOX proteins in an MI rat model, and it also has beneficial effects in terms of ventricular function, partly due to revascularization of the infarcted tissue and an increased ratio of collagen type III to collagen type I.57As collagen type I decreased in this study, and the changes in collagen III were not significant, our study suggests that the increase of PDGFA has protective effects in the aging atria, rather than detrimental effects stemming from increased levels of fibrosis. This evidence concerns the gene LOX and myocardial infarction.