title: Angiogenesis in mesenteric microvascular networks from spontaneously hypertensive versus normotensive rats.
abstract: OBJECTIVE
  Elevated blood pressure during hypertension has been associated with microvascular rarefaction, defined as a loss of microvessels. However, whether rarefaction is a result of impaired angiogenesis remains unclear. The objective of this study was to compare angiogenesis across the time course of mesenteric microvascular network remodeling in adult spontaneously hypertensive versus normotensive rats.
  
  
  METHODS
  Angiogenic responses in 15- to 16-week-old SHR and Wistar rats at 0, 3, 5, 10 or 25 days post 20-minute exteriorization of the mesentery were quantified.
  
  
  RESULTS
  Consistent with the phenomenon of rarefaction, vascularized area in unstimulated SHR was decreased compared to Wistar. By 25 days, SHR vascular area had increased to the Wistar level and vascular length density and capillary sprouting were comparable. At 3 and 5 days, SHR and Wistar tissues displayed an increase in the capillary sprouting and vascular density relative to their unstimulated controls. At 10 days, capillary sprouting in the SHR remained elevated. The percent change in vascular density was elevated in the SHR compared to the Wistar group at 3 and 5 days and by 25 days the rate of change was more negative.
  
  
  CONCLUSIONS
  Our results suggest that SHR networks undergo an increased rate of growth followed by an increased rate of pruning.
authors.affiliation: Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana 70118, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
authors.forename: Mario
authors.initials: M
authors.lastname: Aragon
authors.forename: Walter L
authors.initials: WL
authors.lastname: Murfee
mesh_terms: D000818:Animals; D002196:Capillaries / Q000503:physiopathology*; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008643:Mesentery; D018919:Neovascularization, Physiologic; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D013152:Splanchnic Circulation