naa a22 4500 510806007 CHVBK 20180411083418.0 cr unu---uuuuu 180411e20130301xx s 000 0 eng 10.1007/s12576-012-0240-9 doi (NATIONALLICENCE)springer-10.1007/s12576-012-0240-9 Effect of phenylephrine and endothelium on vasomotion in rat aorta involves potassium uptake [Elektronische Daten] [Javier Palacios, José Vega, Adrián Paredes, Fredi Cifuentes] Vasomotion is defined as the rhythmic contractions in blood vessels, consisting of two components: vasoconstriction and oscillations of the plasma membrane potential. To determine whether vasomotion is associated with changes in K+ uptake, we measured the effect of phenylephrine (PE) and acetylcholine (ACh) on the K+ uptake and vascular reactivity in rat aortic rings. We found that the incubation of aortic rings with 10−7M PE (210±28mg maximum amplitude), and 10−6M ACh (177±6mg maximum amplitude) produced the highest rhythmic contractions. Both 10−7M PE and 10−6M ACh significantly increased K+ uptake in endothelium-intact aorta versus control (121% PE, 117% ACh). Removal of the endothelium blunted rhythmic contractions and decreased K+ uptake in presence of vasoactive substances (88% PE, 81% ACh). The inhibition of nitric oxide synthase with 10−4M l-NNA significantly reduced the rhythmic contractions, and it was reversed in the presence of 10−8M sodium nitroprusside (SNP; a nitric oxide donor). Also, we found that 10−4M l-NNA significantly decreased the effect of 10−7M PE on K+ uptake in aortic rings (104% PE+l-NNA vs. control). The incubation of endothelium-denuded rings with 10−8M SNP significantly increased the K+ uptake (116% SNP vs. control), similar to those observed in the presence of 10−6 M ACh. The inhibition of protein kinase G with KT-5823 blocked SNP-mediated increase in K+ uptake. In conclusion, these data suggest that a certain range of K+ uptake is necessary to induce the rhythmic contractions in response to vasoactive substances. The Physiological Society of Japan and Springer Japan, 2012 Vasomotion nationallicence Potassium uptake nationallicence Aorta nationallicence Rat nationallicence Palacios Javier Departamento de Química, Universidad Católica del Norte, Av. Angamos, 0610, Antofagasta, Chile aut Vega José Experimental Physiology Laboratory (EPhyL), Universidad de Antofagasta, Antofagasta, Chile aut Paredes Adrián Laboratorio de Productos Naturales, Departamento de Química, Universidad de Antofagasta, Antofagasta, Chile aut Cifuentes Fredi Experimental Physiology Laboratory (EPhyL), Universidad de Antofagasta, Antofagasta, Chile aut The Journal of Physiological Sciences Springer Japan 63/2(2013-03-01), 103-111 1880-6546 63:2<103 2013 63 12576 https://doi.org/10.1007/s12576-012-0240-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s12576-012-0240-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Palacios Javier Departamento de Química, Universidad Católica del Norte, Av. Angamos, 0610, Antofagasta, Chile aut NATIONALLICENCE 700 1- Vega José Experimental Physiology Laboratory (EPhyL), Universidad de Antofagasta, Antofagasta, Chile aut NATIONALLICENCE 700 1- Paredes Adrián Laboratorio de Productos Naturales, Departamento de Química, Universidad de Antofagasta, Antofagasta, Chile aut NATIONALLICENCE 700 1- Cifuentes Fredi Experimental Physiology Laboratory (EPhyL), Universidad de Antofagasta, Antofagasta, Chile aut NATIONALLICENCE 773 0- The Journal of Physiological Sciences Springer Japan 63/2(2013-03-01), 103-111 1880-6546 63:2<103 2013 63 12576 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer