Effects of cross-fostering on mechanical and structural adjustments of mesenteric resistance arteries from hypertensive and normotensive rats

• Grant number: 16/18828-3
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): November 01, 2016
• Effective date (End): October 31, 2017
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal researcher: Luciana Venturini Rossoni
• Grantee: Flávia Midori Ishikawa
• Home Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Hypertension is characterized by persistent and elevated values of blood pressure (BP). Among the cardiovascular diseases, hypertension is a major cause of mortality in Brazil (~ 30%) and is associated with functional and/ or structural changes in the cardiovascular system. It is known that hypertension is a disease characterized by increased peripheral vascular resistance which is often associated with vascular remodeling. Also, the resistance arteries (RA), either in patients with essential hypertension as well as in spontaneously hypertensive rats (SHR), have structural and mechanical alterations characterized as inward eutrophic remodeling, with a consequent increase of wall/lumen ratio, followed by increased vascular stiffness. Together these adjustments contribute to the maintenance of high BP levels.Studies indicate breast milk and the microbiota as risk factors for hypertension. The relationship between the development of hypertension and the postnatal environment is still not clear, and some studies describe that the cross-fostering reduces the severity or delay the development of hypertension in SHR, and suggest that modulation of renin-angiotensin system and reactive oxygen species as possible targets, mainly at renal system. However, there are few studies on the effects of cross-fostering in cardiovascular parameters of SHR and, specially, at the RA adjustments, which have a key role in the control of peripheral vascular resistance and thus in BP regulation. There is only one study that evaluates the effect of cross-fostering between normotensive and New Zealand genetically hypertensive rats (GH), a genetic model of hypertension which is not sensitive to salt, in structural parameters of mesenteric resistance arteries (MRA). The authors observed a reduction of the wall / lumen ratio in MRA of hypertensive rats suckled by normotensive mothers compared to GH animals.Within this context, this project aims to evaluate the maternal breastfeeding influence in the first weeks of life on the development of hypertension and remodeling (structural and mechanical changes) in MRA of SHR and normotensive (Wistar) rats who suffered postnatal cross-fostering, in line to better understand the genesis and development of hypertension and thus enabling new approaches to its control.