RESUMO
Myocardial infarction (MI) and pulmonary artery hypertension (PAH) are two prevalent cardiovascular diseases. In both conditions, oxidative stress is associated with a worse prognosis. Pterostilbene (PTE), an antioxidant compound, has been studied as a possible therapy for cardiovascular diseases. This study aims to evaluate the effect of PTE on oxidative stress in the hearts of animals with myocardial infarction and in the lungs of animals with PAH. Male Wistar rats were used in both models. In the MI model, the experimental groups were sham, MI, and MI+PTE. In PAH model, the experimental groups were control, PAH, and PAH+PTE. Animals were exposed to MI through surgical ligation of the left coronary artery, or to PAH, by administration of monocrotaline (60 mg/kg). Seven days after undergoing cardiac injury, the MI+PTE animals were treated with PTE (100 mg/kg day) for 8 days. After this, the heart was collected for molecular analysis. The PAH+PTE animals were treated with PTE (100 mg/kg day) for 14 days, beginning 7 days after PAH induction. After this, the lungs were collected for biochemical evaluation. We found that PTE administration attenuated the decrease in ejection fraction and improved LV end-systolic volume in infarcted animals. In the PAH model, PTE improved pulmonary artery flow and decreased ROS levels in the lung. PTE administration promoted protective effects in terms of oxidative stress in two experimental models of cardiac diseases: MI and PAH. PTE also improved cardiac function in infarcted rats and pulmonary artery flow in animals with PAH.
RESUMO
BACKGROUND: Pulmonary arterial hypertension is a disease characterized by increased pulmonary vascular resistance and redox imbalance, leading to failure of right ventricle. Trapidil has been described to improve the redox balance and cardiac conditions. HYPOTHESIS: Trapidil can improve the redox balance and contribute to functional improvements of the RV in PAH. METHODS AND RESULTS: Male, 5week-old Wistar rats were divided into four groups: Control, Controlâ¯+â¯Trapidil, Monocrotaline and Monocrotalineâ¯+â¯Trapidil. PAH was induced by an intraperitoneal injection of monocrotaline 60â¯mg/kg at day 0. Treatment started at day 7 (5 or 8â¯mg/kg/day) until day 14, when animals were euthanized after echocardiography and catheterism. Right ventricular systolic pressure and pressure/time derivatives were increased in monocrotaline animals. The increased right ventricular diameters in monocrotaline groups were reduced with trapidil. Monocrotaline groups showed higher lipid peroxidation and glutathione peroxidase activity. Trapidil reduced NADPH oxidases activities and increased the reduced glutathiones/total glutathiones ratio. Protein expression of phospholamban in RV was diminished in monocrotaline groups, whereas expression of RyR and SERCA was enhanced in the groups treated with trapidil. CONCLUSION: Our data suggest that trapidil induces an improvement in RV remodeling in PAH model, mitigating the progression of the disease.