Norepinephrine responses in rat renal and femoral veins are reinforced by vasoconstrictor prostanoids
MetadataShow full item record
Norepinephrine (NE) responses are larger in renal and femoral veins compared to phenylephrine (PE). These differences may be due to the subtypes of adrenoceptor involved in these responses or to the involvement of local modulatory mechanisms. Therefore, the present study investigated in organ bath the adrenoceptor subtypes involved in the NE and PE responses in both renal and femoral veins as well as the influence of local mechanisms related to NO and to prostanoids upon these responses. The obtained data showed that the NE responses in these veins were not significantly modified by the selective inhibition of β1 or β2-adrenoceptors as well as AT1 or AT2 receptors. However, yohimbine reduced the NE Rmax in renal veins and, in parallel, right shifted the NE concentration-response curves in femoral veins. In both veins, prazosin reduced the NE Rmax and the clonidine induced a measurable contraction. The endothelium removal attenuated the NE responses in femoral veins, thereby abolishing the differences of NE and PE responses. Furthermore, the NE responses in renal and femoral veins were attenuated by indomethacin, which suppressed the statistical difference in relation to the PE response. In conclusion, a synergism between α1- and α2-adrenoceptors is essential to assure full NE contractile responses in both renal and femoral veins. Thus, by acting simultaneously in these adrenoceptors, NE induces more pronounced contractile responses, in comparison to PE, not only in renal but also in femoral veins. Moreover, this pronounced NE response in both renal and femoral veins appears to involve endothelium-derived vasoconstrictor prostanoids.
How to cite this document
Showing items related by title, author, creator and subject.
Effect of the pre-treatment and the drying process on the phenolic composition of raisins produced with a seedless Brazilian grape cultivar Olivati, Carolina ; de Oliveira Nishiyama, Yara Paula ; de Souza, Reginaldo Teodoro; Janzantti, Natália Soares ; Mauro, Maria Aparecida ; Gomes, Eleni ; Hermosín-Gutiérrez, Isidro; da Silva, Roberto ; Lago-Vanzela, Ellen Silva (Food Research International, 2018) [Artigo]The grape is an important fruit regarding economic and health benefit parameters, because of its large consumption around the world and their bioactive phenolic compounds. The drying process of BRS Morena grapes, whether ...
BRS Violeta (BRS Rúbea × IAC 1398-21) grape juice powder produced by foam mat drying. Part I: Effect of drying temperature on phenolic compounds and antioxidant activity Maria de Carvalho Tavares, Iasnaia ; Bonatto Machado de Castilhos, Maurício; Aparecida Mauro, Maria ; Mota Ramos, Afonso; Teodoro de Souza, Reginaldo; Gómez-Alonso, Sergio; Gomes, Eleni ; Da-Silva, Roberto ; Hermosín-Gutiérrez, Isidro; Silva Lago-Vanzela, Ellen (Food Chemistry, 2019) [Artigo]The BRS Violeta grape presents pulp and skin with high content of phenolic compounds (PCs) and intense purplish color. It was used as raw material for the production of juice and dehydrated products using foam mat drying ...
do Amaral Rodrigues, Jessica; de Araújo, Alyne Rodrigues; Pitombeira, Nadia Aline; Plácido, Alexandra; de Almeida, Miguel Peixoto; Veras, Leiz Maria Costa; Delerue-Matos, Cristina; Lima, Filipe Camargo Dalmatti Alves; Neto, Augusto Batagin ; de Paula, Regina Célia Monteiro et al. (International Journal of Biological Macromolecules, 2019) [Artigo]The natural alkaloid epiisopiloturine has recently become the focus of study for various medicinal properties, particularly for its anti-inflammatory and antischistosomal effect. The incorporation of active molecules in ...