Effect of chronic treatment with apocynin in the left ventricular hypertrophic response in spontaneously hypertensive rats (SHR)

• Grant number: 11/19859-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2011
• End date: November 30, 2012
• Field of knowledge: Biological Sciences - Pharmacology - Cardiorenal Pharmacology
• Principal Investigator: Cristina Antoniali Silva
• Grantee: Mariana Silva de Lima
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

Chronic treatment with NADPH oxidase inhibitors reduces blood pressure in SHR. As the main source of superoxide anion in the aorta, the activity of this enzyme is associated with decreased NO bioavailability and uncoupling of eNOS. Rats that developed cardiac hypertrophy had a higher myocardial expression of p22phox and p67phox subunits of NADPH oxidase. This study will test the hypothesis that apocynin (NADPH oxidase inhibitor) reduces left ventricular hypertrophy in SHR. For this, normotensive Wistar and SHR will be treated with apocynin (30 mg/kg/day orally) from the fourth to the tenth week of life. During the treatment, the systolic blood pressure of the animals will be verified by tail plethysmography. In treated animals, in vivo experiments will be conducted to assess possible changes in the baseline blood pressure (mean systolic and diastolic) and heart rate. In the in vitro experiments, the changes in ventricular hypertrophy will be evaluated in histological sections stained with hematoxylin and eosin (HE) and picrosirius (Sirius Red) to specifically assess possible changes in collagen.(AU)