title: Spatial distribution and mechanical function of elastin in resistance arteries: a role in bearing longitudinal stress.
abstract: OBJECTIVE
  Despite the role that extracellular matrix (ECM) plays in vascular signaling, little is known of the complex structural arrangement between specific ECM proteins and vascular smooth muscle cells. Our objective was to examine the hypothesis that adventitial elastin fibers are dominant in vessels subject to longitudinal stretch.
  
  
  RESULTS
  Cremaster muscle arterioles were isolated, allowed to develop spontaneous tone, and compared with small cerebral arteries. 3D confocal microscopy was used to visualize ECM within the vessel wall. Pressurized arterioles were fixed and stained with Alexa 633 hydrazide (as a nonselective ECM marker), anti-elastin, or anti-type 1 collagen antibody and a fluorescent nuclear stain. Exposure of cremaster muscle arterioles to elastase for 5 minutes caused an irreversible lengthening of the vessel segment that was not observed in cerebral arteries. Longitudinal elastin fibers were demonstrated on cremaster muscle arterioles using 3D imaging but were confirmed to be absent in cerebral vessels. The fibers were also distinct from type I collagen fibers and were degraded by elastase treatment.
  
  
  CONCLUSIONS
  These results indicate the importance of elastin in bearing longitudinal stress in the arteriolar wall and that these fibers constrain vascular smooth muscle cells. Differences between skeletal muscle and cerebral small arteries may reflect differences in the local mechanical environment, such as exposure to longitudinal stretch.
authors: Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65211, USA.
authors: Philip S
authors: PS
authors: Clifford
authors: Srikanth R
authors: SR
authors: Ella
authors: Aaron J
authors: AJ
authors: Stupica
authors: Zahra
authors: Z
authors: Nourian
authors: Min
authors: M
authors: Li
authors: Luis A
authors: LA
authors: Martinez-Lemus
authors: Kim A
authors: KA
authors: Dora
authors: Yan
authors: Y
authors: Yang
authors: Michael J
authors: MJ
authors: Davis
authors: Ulrich
authors: U
authors: Pohl
authors: Gerald A
authors: GA
authors: Meininger
authors: Michael A
authors: MA
authors: Hill
mesh_terms: D000818:Animals; D001160:Arterioles / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D001696:Biomechanical Phenomena; D002536:Cerebral Arteries / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D024042:Collagen Type I / Q000378:metabolism; D004549:Elastin / Q000502:physiology*; D005109:Extracellular Matrix / Q000378:metabolism / Q000473:pathology; D008297:Male; D018613:Microscopy, Confocal; D023421:Models, Animal; D018482:Muscle, Skeletal / Q000098:blood supply; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D010196:Pancreatic Elastase / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013312:Stress, Physiological / Q000502:physiology*
chemical_list: D024042:Collagen Type I; D004549:Elastin; D010196:Pancreatic Elastase