Effects of losartan on the concentration of the Renin-Angiotensin System components in bone and gingival tissues of rats with experimentally induced periodontal disease

• Grant number: 21/00654-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2021
• End date: April 30, 2022
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Carlos Ferreira dos Santos
• Grantee: John Willer Pimentel Barrozo
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil
• Associated research grant: 15/03965-2 - Role of the renin-angiotensin system in different oral inflammatory models: an experimental interdisciplinary and clinical approach, AP.TEM

Abstract

Periontal disease (PD) comprises a group of lesions that affect periodontal tissues of protection (gingivitis) and support (periodontitis) that may lead to tooth loss. Interactions between microbial pathogens and various systems play a critical role in the development and progression of PD through the release of many inflammatory and immunologic mediators. Recent experiments of our laboratory showed that the expression of mRNA for all the renin-angiotensin system (RAS) components is found in the mandibular and gingival tissue of rats and that treatment with losartan suppressed various cytokines whose expression was increased in PD. The hypothesis of the present study is that in PD higher concentrations of Ang II are found and treatment with losartan favour the formation of Ang 1-7. Thus, the aim of the present project is to investigate the presence of peptides involved in the cascade of the RAS in rats with PD treated or not with losartan. In order to test this hypothesis, the model of silk ligature around the lower first molar will be used and rats will be divided into four groups of ten animals each. Group 1 will not have PD induced and will not take losartan. Group 2 will have PD induced and will be treated with water for 14 days. Group 3 will have PD induced and will be treated with losartan (50 mg/kg/day) for 14 days and the beginning of treatment will be the same day of PD induction. Group 4 will have PD induced and will be treated with losartan (50 mg/kg/day) for 14 days and the beginning of treatment will be 30 days before the PD induction (treatment will be continued after PD induction). Mandibular and gingival tissue, as well as blood, will be homogenized for measurements of peptides of RAS cascade through mass spectrometry.