Retinoic Acid Effect on Cerebral Vasculature

• Autor(a) principal: Farinha, Emanuel da Silva
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.6/11484
• topic: Ácido Retinóico; Células do Musculo Liso; Células Endoteliais; Puramicina; Unidade Neurovascular; Domínio/Área Científica::Engenharia e Tecnologia::Bioquímica

The brain represents one of the organs that consumes the most oxygen, having an irreplaceable function in the body. In turn, to perform it correctly needs to be in homeostasis, so it contains a network that is responsible for this homeostasis, which is called the neurovascular unit. This is composedofneurons, astrocytes, endothelial cells, and mural cells, as pericytes and smooth muscle cells that perform different functions within the brain that are essential for good performance on this. This work presents two aims: establishment of a protocol to a pure culture of endothelial cells from cerebral arteries, in whichthe effect of puromycin, an antibiotic that induce cellular death on smooth muscle cells was analysedthrough immunocytochemical assays. The other was the study of the effect of retinoic acid on the contraction and relaxation mechanisms present on the smooth muscle cells, using the Planar Cell Surface Area technique. In the first study, endothelial cell cultures of rat were obtained by extracting the middle cerebral arteries and the basilar artery. In the second study, the culture of smooth muscle cells of rat was obtained onlyextracting the middle cerebral arteries. Thus, in the first study endothelial cells cultures incubated with a concentration of 2µg/ml of puromycin for 24 h, showed a purity of 90% and those of 4 µg/ml approximately 20%. In turn, in the PCSA assay, on the results obtained ingenomic tests, only one of the incubated concentrations of Retinoic Acid presents vasorelaxation, that of 0.5 µmol/L, with a percentage of 5% relaxation. In non-genomic tests, the RA rapid effect, at a concentration of 10 µg/ml, shows a percentage of vasorelaxation in order of 10%. Therefore, in the first study, the results obtained suggest that puromycin can be used as an antibiotic to obtain pure cultures of endothelial cells at a specific concentration, in this case 2 µg/ml. The results obtained on the effect of retinoic acid on smooth muscle cells suggest that, in a 24-h incubation period, retinoic acid at 0.5µg/mL has vasorelaxant effects on smooth muscle cells. Moreover, without incubation witha concentration of 10µg/ml, the results demonstratea relaxant effect.