title: Large artery biomechanical, geometrical, and structural remodeling elicited by long-term propranolol administration in an animal model.
abstract: BACKGROUND
  Limited attention has been paid to the role of beta-adrenergic blocking agents on large artery function/structure, despite being clinically useful for treating many forms of cardiovascular disease.
  
  
  OBJECTIVE
  To assess long-term consequences of beta-blocker administration on the biomechanical properties, geometry, and histological structure of two major elastic arteries.
  
  
  METHODS
  Healthy male rats received water with their food, while beta-blockade was produced in rats by adding propranolol in their drinking water. The thoracic aorta and carotid artery were resected after three months for biomechanical (failure and inflation-extension) testing along with geometrical and histological evaluation.
  
  
  RESULTS
  The thoracic aorta presented increased strength longitudinally in propranolol-treated than untreated rats, resulting from increased adventitial collagen content. The distensibility of carotid artery increased in propranolol-treated rats at low-to-physiologic pressures, resulting from decreased medial collagen content. Structural remodeling was characterized by reduced lumen diameter, wall mass, and thickness-to-radius ratio. The latter, together with the greater resorption of the media than adventitia, related with the measured opening angle decrease in propranolol-treated rats.
  
  
  CONCLUSIONS
  The geometrical/biomechanical remodeling was mediated by the hemodynamic effects of propranolol treatment, namely the reduced blood flow, and served to normalize in vivo hoop stresses as well as vessel compliance.
authors.affiliation: Department of Cardiology, Catheterization Laboratory, Evangelismos General Hospital, Athens, Greece.
authors.forename: Konstantinos M
authors.initials: KM
authors.lastname: Lampropoulos
authors.affiliation: Laboratory of Biomechanics, Center of Clinical, Experimental Surgery, and Translational Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece.
authors.forename: Dimitrios P
authors.initials: DP
authors.lastname: Sokolis
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage*; D000818:Animals; D001013:Aorta, Thoracic / Q000737:chemistry / Q000187:drug effects / Q000473:pathology*; D001696:Biomechanical Phenomena; D002339:Carotid Arteries / Q000737:chemistry / Q000187:drug effects / Q000473:pathology*; D006439:Hemodynamics; D008297:Male; D023421:Models, Animal; D011433:Propranolol / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000319:Adrenergic beta-Antagonists; D011433:Propranolol
keywords: Elastic arteries; beta-blockade; histomorphometry; mechanical testing; propranolol