Center of Experimental Morphology

Departamento de Anatomia - Faculdade de Medicina da Universidade do Porto

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Nutritional Deprivations in the Adult Rat Brain


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Research Area: Health Sciences
Status: In progress  
Project leaders:  
In cooperation with
  • Faculdade de Medicina - Universidade do Porto
 
Description:

OBJECTIVES

One of the main objectives is to investigate the actions of polyphenols in the central nervous system and several other organs. Green tea (GT) consumption is increasing worldwide due to its known health-promoting effects. In this line, we have previously demonstrated that GT very rich in epigallocatechin-3-gallate (EGCG) has powerful antioxidant action in the hippocampal formation of old animals as described in a PhD thesis defended in April. To verify if the other catechins of GT have a similar effect we have also used in the same experimental settings and methodologies a green tea extract (GTE) composed mainly of epicatechin and epicatechin-gallate.

The hippocampal formation is vulnerable to the degenerative events related to aging resulting in deleterious morphological modifications in several neuronal organelles and lipofuscin accumulation. Therefore, we intended to analyze the effects of prolonged consumption of the catechins in GTE on the morphologic alterations induced by aging in rat hippocampal CA3 pyramidal neurons and dentate granule cells. Using stereological methodology in electron micrographs of CA3 pyramids, the volumes of lipofuscin granules, mitochondria, lysosomes per neuron and number of pores in the nuclear membrane were quantified. Using Golgi-impregnated neurons we analyzed the dendritic arborizations of granule cells and quantified the number of dendritic spines.

We have also previously demonstrated that polyphenols present in red wine presented some improvement in oxidative stress-related events in brain as described in a PhD thesis defended this year. In a collaborative study we studied the effects of chronic red wine consumption on the expression of vascular endothelial growth factor, angiopoietin 1 and angiopoietin 2 and its receptors in rat erectile tissue.

MAIN ACHIEVEMENTS

Lipofuscin and lysosomal volume content were reduced by treatment with GTE when compared with age-matched controls to levels similar to those found in young controls. Furthermore, aging was associated with a significant increase in mitochondrial volume. Some beneficial alterations of the catechins were also described in the structure of dendritic arborizations and in the number of dendritic spines of granule cells. Our results demonstrate that the consumption of the catechins present in protected the HF from some of the age-associated morphological changes and the anti-oxidant and cell signaling-regulating properties of green tea polyphenols are likely to be involved. These results were presented in the V Young European Scientist Meeting in Porto, Portugal in a poster presentation and a manuscript is being written.

Concerning the red wine study it was found in animals that consumed chronically this beverage that there was a reduction of VEGF and VEGFR2 expression in smooth muscle and endothelial cells of the corpus cavernosum. However, there was an increase of angipoietins/tie2 expression accompanied by a decresase in the expression of the receptors VEGFR2 and Tie2. Taken together, these results suggest that the anitoxidants present in red wine are capable to activate some mechanisms for the maintenance of the vessels of the corpus cavernosum.

PUBLICATIONS IN PEER REVIEW JOURNALS

Neves DR, Tomada IM, Assunção MM, Marques FA, Almeida HM, Andrade JP (2010) Effects of chronic red wine consumption on the expression of vascular endothelial growth factor, angiopoietin 1, angiopoietin 2, and its receptors in rat erectile tissue. J Food Sci 75:H79-H86.

Assunção M, Santos-Marques MJ, Carvalho F, Andrade JP (2010) Green tea averts age-dependent decline of hippocampal signaling systems related to antioxidant defenses and survival. Free Radic Biol Med 48:831-838.

Ph.D. THESES COMPLETED

Efeitos protectores de compostos polifenólicos sobre o sistema nervoso central do Rato. Estudo Morfológico, bioquímico e comportamental. Marco Manuel Batista Assunção. Faculdade de Medicina da Universidade do Porto, Porto, Abril de 2010

CONFERENCES

Revision of Abstracts of the 17th Annual Meeting of the Society for Free Radical Biology and Medicine (SFRBM), a joint meeting with the Society for Free Radical Research International
17-21 Novembro 2010, Orlando FL

Contactos
Centro de Morfologia Experimental
Faculdade de Medicina da Universidade do Porto
Al. Professor Hernâni Monteiro
4200-319 Porto
tel. (+351) 22 551 36 16
fax (+351) 22 551 36 17
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© 2017 Departamento de Anatomia / Produção CI FMUP