title: Effects of removing the adventitia on the mechanical properties of ovine femoral arteries in vivo and in vitro.
abstract: BACKGROUND
  The aims were to characterize in muscular arteries (a) the passive and active effects of the adventitia on vessel biomechanical properties and conduit function (CF), and (b) potential differences between the adventitial role in elastic and muscular arteries.
  
  
  RESULTS
  Ovine femoral arteries were studied in vivo and in vitro (reduced smooth muscle-tone) in a circulation mock-up during hemodynamic conditions similar to those found in vivo. Pressure and diameter were assessed before and after removing the adventitia. The arterial compliance, distensibility, stiffness beta-index and CF were quantified. Results were compared with those obtained in brachiocephalic trunks. In vivo, after removing the adventitia there was a nonsignificant diameter reduction and an increase in stiffness (P<0.05). The CF decreased in the early recordings (P<0.02). In vitro, there were no biomechanical changes but vascular dilatation after the adventitia removal. Biomechanical changes associated with the adventitia removal were higher in muscular arteries, whereas diameter changes were major in elastic vessels.
  
  
  CONCLUSIONS
  After removing the adventitia, (a) the arterial stiffness and CF were modified in vivo only, suggesting the changes could be ascribed to variations in smooth muscle tone, and (b) changes in elastic and muscular arteries were quantitatively different.
authors.affiliation: Favaloro University, Aires, Argentina.
authors.forename: Edmundo Cabrera
authors.initials: EC
authors.lastname: Fischer
authors.forename: Daniel Bia
authors.initials: DB
authors.lastname: Santana
authors.forename: Yanina
authors.initials: Y
authors.lastname: Zócalo
authors.forename: Juan
authors.initials: J
authors.lastname: Camus
authors.forename: Eduardo
authors.initials: E
authors.lastname: de Forteza
authors.forename: Ricardo
authors.initials: R
authors.lastname: Armentano
mesh_terms: D000818:Animals; D004547:Elastic Tissue / Q000473:pathology / Q000503:physiopathology*; D005263:Femoral Artery / Q000473:pathology / Q000503:physiopathology*; D006439:Hemodynamics; D009129:Muscle Tonus; D009131:Muscle, Smooth, Vascular; D012756:Sheep; D013312:Stress, Physiological