Objectives: In this study, we used a proteomic approach to investigate the potential proteins regulated by ramipril in post-infarction left ventricular remodelling in the rabbit.
Methods and results: Myocardial infarction (MI) was induced in male New Zealand White rabbits (2.5-3 kg) by ligation of the left anterior descending coronary artery. Two months later, the rabbits were either left untreated (MI group) or were treated daily for one month with 0.1 mg/kg wt of ramipril (ramipril group), then sacrificed. One month of ramipril treatment resulted in a significant improvement in the LV ejection fraction (LVEF) and a decrease in hydroxyproline content. The protein profiles of LV tissue showed that ramipril caused upregulation of glutathione peroxidase, superoxide dismutase (SOD), and heart-type fatty acid binding-protein (h-FABP) and downregulation of HSP27 and cyclophilin A. Ramipril treatment caused an increase in catalase, glutathione peroxidase, and SOD activity in the LV tissue. Oxidized glutathione levels and the GSSG/GSH ratio in the heart tissue were lower in the ramipril group than in the MI group.
Conclusions: Ramipril increased antioxidative protein expression and enzyme activity, which could partly explain the role of ramipril in attenuating LV remodelling. In addition, the present study identifies several potential protein targets which may help to explain the mechanism by which ramipril exerts its effect in post-infarction LV remodelling in the rabbit.