Endothelial modulation of nitric oxide synthase by the no donor (RuBPY)

• Grant number: 16/25300-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2017
• End date: March 31, 2018
• Field of knowledge: Biological Sciences - Pharmacology - Cardiorenal Pharmacology
• Principal Investigator: Lusiane Maria Bendhack
• Grantee: Jessica Tamiris Romano
• Host Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The endothelial cells produce and release relaxing dependent endothelial factors (EDRFs) and contractile factors. The major EDRF is nitric oxide (NO) that is produced by endothelial nitric oxide synthase (eNOS). Uncoupled eNO produces oxygen reactive species (ROS). eNOS can be expressed as dimer (active enzyme) or monomer (inactive enzyme). NO donors can release NO in the endothelial cells and in the vascular smooth muscle cells (VSMC). The hypothesis of this study is that the NO donor (RuBPY) positively modulates eNOS activity, increasing NO production in normotensive rat vessels that do not present endothelial dysfunction. Therefore, this project aims to study the relaxation induced by RuBPY in intact endothelium rat aorta in order to evaluate the positive modulation of this compound on eNOS activity. In rat isolated aortas, we will study the vascular reactivity, flow citometry and Western Blot. The responses to RuBPY will be evaluated in the presence of eNOS inhibitor (L-NAME), its substrate (L-Arginine) and superoxide scavenger (Tiron). We will study the relaxation induced by acetylcholine and its modulation by RuBPY. By using flow citometry, we will measure the cytosolic NO concentration ([NO]c) in the human umbilical vein endothelial cells (HUVECs) by the NO sensitive dye DAF-2DA and the ROS production by DHE. By using Western Blot, we will verify if the enzyme eNOS is active (dimer) or if it is uncoupled and inactive (monomer). (AU)