title: Characterization of the thoracodorsal artery: morphology and reactivity.
abstract: OBJECTIVE
  In this paper, we describe the histological and contractile properties of the thoracodorsal artery (TDA), which indirectly feeds the spinotrapezius muscle.
  
  
  METHODS
  We used immunolabelling techniques to histologically characterize the TDA while the contractile properties were assessed using pressure arteriography.
  
  
  RESULTS
  Our results demonstrate that the TDA is composed of approximately one to two layers of smooth muscle cells, is highly innervated with adrenergic nerves, and develops spontaneous tone at intraluminal pressures above 80 mmHg. The reactivity of the TDA in response to various contractile agonists such as phenylephrine, noradrenaline, angiotensin II, serotonin, endothelin 1, and ATP, as well as vasodilators, shows that the TDA exhibits a remarkably comparable reactivity to what has been observed in mesenteric arteries. We further studied the different components of the TDA response to acetylcholine, and found that the TDA was sensitive to TRAM 34, a blocker of the intermediate conductance potassium channel, which is highly suggestive of an endothelium-dependent hyperpolarization.
  
  
  CONCLUSIONS
  We conclude that the TDA exhibits comparable characteristics to other current vascular models, with the additional advantage of being easily manipulated for molecular and ex vivo vasoreactivity studies.
authors.affiliation: Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA.
authors.forename: Marie
authors.initials: M
authors.lastname: Billaud
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Lohman
authors.forename: Adam C
authors.initials: AC
authors.lastname: Straub
authors.forename: Thibaud
authors.initials: T
authors.lastname: Parpaite
authors.forename: Scott R
authors.initials: SR
authors.lastname: Johnstone
authors.forename: Brant E
authors.initials: BE
authors.lastname: Isakson
mesh_terms: D000818:Animals; D001158:Arteries / Q000033:anatomy & histology* / Q000502:physiology*; D008297:Male; D051379:Mice; D008955:Models, Cardiovascular; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000098:blood supply*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents