title: Vasodilator effect of ghrelin in the rat aorta.
abstract: OBJECTIVE
  Ghrelin is a hormone mainly produced by the stomach and has been identified as the natural ligand of the growth hormone secretagogue receptor (GHS-R). In addition to its orexigenic effect, ghrelin modulates homeostasis of the cardiovascular system. The aim of this study was to analyze the effect of ghrelin on the vascular reactivity of the aorta.
  
  
  METHODS
  This study was performed in the thoracic aorta of 10-12- week-old male Wistar rats. Passive wall tension and contractile responses to angiotensin II (Ang II) (10(-7) mol/l) in the presence of ghrelin (10(-8) mol/l) were evaluated using the organ bath system. The presence of the functional ghrelin receptor, GHS-R 1a, in vascular smooth muscle cells (VSMCs) of the aorta was determined by Western blot.
  
  
  RESULTS
  VSMCs of the vascular wall of the aorta expressed the GHS-R 1a protein. Incubation of the intact aorta with ghrelin (10(-8) mol/l) induced a reduction (p<0.01) in passive wall tension. In endotheliumdenuded aorta, ghrelin did not modify basal vasomotor tone. However, incubation of endothelium-denuded aorta with ghrelin inhibited (p<0.01) Ang II (10(-7) mol/l)-induced vasoconstriction.
  
  
  CONCLUSIONS
  Ghrelin exerts an endothelium-dependent and -independent depressor action on aortic vascular reactivity. These findings provide additional information on the physiological effect of ghrelin on arterial pressure regulation.
authors.affiliation: Laboratorio de Investigación Metabólica. Clínica Universitaria de Navarra. Pamplona. Navarra. España; CIBER Fisiopatología de la Obesidad y Nutrición. Instituto de Salud Carlos III. Madrid. España.
authors.forename: Amaia
authors.initials: A
authors.lastname: Rodríguez
authors.forename: Javier
authors.initials: J
authors.lastname: Gómez-Ambrosi
authors.forename: Victoria
authors.initials: V
authors.lastname: Catalán
authors.forename: Sara
authors.initials: S
authors.lastname: Becerril
authors.forename: Neira
authors.initials: N
authors.lastname: Sáinz
authors.forename: Beatriz
authors.initials: B
authors.lastname: Ramírez
authors.forename: Javier
authors.initials: J
authors.lastname: Salvador
authors.forename: Javier
authors.initials: J
authors.lastname: Díez
authors.forename: Ana
authors.initials: A
authors.lastname: Fortuño
authors.forename: Gema
authors.initials: G
authors.lastname: Frühbeck