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Effects of cross-fostering on anticontractile function of aortic perivascular adipose tissue (PVAT) from hypertensive and normotensive rats

Grant number: 16/22674-1
Support type:Scholarships in Brazil - Scientific Initiation
Effective date (Start): February 01, 2017
Effective date (End): January 31, 2018
Field of knowledge:Biological Sciences - Physiology - Physiology of Organs and Systems
Principal researcher:Luciana Venturini Rossoni
Grantee:Thais Guedes Felisbino
Home Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Hypertension is considered a huge public health problem for its high prevalence, lower control rates and for being an important risk factor for other cardiovascular diseases. It is characterized for high arterial systolic and/ or diastolic pressures, as well as metabolic adjustments associated to functional and/or structural alterations in essential organs like: heart, brain, kidneys and blood vessels. Functional and structural vascular adjustments are observed on patients and hypertension models. The endothelial dysfunction is one of the vascular dysfunction observed, which compromises the regulation of vascular tone through the unbalance between vasodilators and vasoconstrictors endothelium-derived factors. Recently, it has also been given attention to the perivascular adipose tissue (PVAT) role in the control of vascular tone. It has been demonstrated that, in physiological conditions, PVAT has an anti-contractile function through the release of endothelium-dependent and -independent factors. However, hypertensive animals exhibit a reduction and/or loss of this anti-contractile function of PVAT. It is important to better understanding the factors involved in the genesis of hypertension as a strategy to reduce the incidence of this disease. It is well known that genetic factors, smoking, physic inactivity and bad eating behavior can predispose to hypertenion development. New researches are evaluating breast milk and microbiota as risk factors for hypertension. One of the methods which can be used for this analysis is cross-fostering, the exchange of normotensive and hypertensive litters, evaluating if modifications in post-natal environment have influence on this disease. 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 levels. It's interesting to observe that pups of obese rats have higher blood pressure levels and loss of PVAT anti-contractile effect when compared with control animals. This impairment of PVAT anti-contractile function was associated to decrease in NO bioavailability and to the release of a non-identified contractile factor derived from PVAT. In addition, female SHR that were fed with high salt diet during pregnancy and lactation predisposed the litter to cardiovascular diseases development. In this context, the aim of the present study is to evaluate if there is maternal influence on first weeks of life on the anti-contractile ability and structure of PVAT in cross-fostered SHR and Wistar (normotensive) rats. (AU)