6-nitrodopamine receptor modulation in the rat and mouse isolated atria

• Grant number: 24/17989-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2025
• End date: April 30, 2026
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Gilberto de Nucci
• Grantee: Theodora Cristina Cruz de Assis
• Host Institution: Faculdade de Ciências Médicas (FCM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Dopamine (DA), noradrenaline, and adrenaline are known for their sympathomimetic roles. In the heart, the right isolated rat atrium has greater expression of beta-1 adrenoceptors compared to the left atrium of the same animal, making it a source of chronotropism study. 6-nitrodopamine (6-ND) emerges as the main new catecholamine responsible for the positive chronotropic and inotropic effects in the atrium. The hypothesis of adenylyl cyclase (AC) regulation by 6-ND, along with the identification of membrane proteins that positively regulate AC as potential 6-ND receptors in cardiac muscle cells, highlights the relevance of studying them. Despite its importance in positive chronotropic and inotropic effects, 6-ND receptor modulation still lacks sufficient studies. In this sense, the main objective is to understand the regulation and the modulation of 6-ND receptors in isolated rat and mouse right atrium. This will be done, after the due approval of the Animal Ethics Committee of UNICAMP (CEUA), through organ bath-based experiments evaluating chronotropism in isolated atria from adult male Wistar rats and mutant mice with Cap2 inhibition.