title: Altered myocardial microvascular 3D architecture in experimental hypercholesterolemia.
abstract: BACKGROUND
  Experimental hypercholesterolemia (HC) impairs intramyocardial microvascular function. However, whether this is associated with alterations in microvascular architecture remained unknown. Using a novel 3D micro-CT scanner, we tested the hypothesis that HC is associated with an alteration in the microvascular architecture.
  
  
  RESULTS
  Pigs were euthanized after 12 weeks of either normal (n=6) or 2% HC (n=6) diet. The hearts were excised and the coronary arteries injected with a radiopaque contrast material. Myocardial samples were scanned with micro-CT, and 3D images were reconstructed with 21-microm cubic voxels. The myocardium was tomographically subdivided into subepicardium and subendocardium, and microvessels (<500 microm in diameter) were counted in situ within each region. In the subendocardium of HC pigs, the intramyocardial density of microvessels was significantly higher than in normal animals (1221.4+/-199.7 versus 758.3+/-90.8 vessels/cm(3), P:<0.05) because of an increase in the number of microvessels <200 microm in diameter (1214.4+/-199.7 versus 746. 6+/-101.5 vessels/cm(3), P:<0.05). The subepicardial vascular density was similar in both groups.
  
  
  CONCLUSIONS
  -HC has differential effects on the spatial density of the subendocardial microvasculature that may play a role in regulation and/or spatial distribution of myocardial blood flow. This study also demonstrates the feasibility of studying myocardial microvascular architecture with micro-CT in pathophysiological states.
authors.affiliation: Department of Internal Medicine, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: M
authors.initials: M
authors.lastname: Rodriguez-Porcel
authors.forename: A
authors.initials: A
authors.lastname: Lerman
authors.forename: E L
authors.initials: EL
authors.lastname: Ritman
authors.forename: S H
authors.initials: SH
authors.lastname: Wilson
authors.forename: P J
authors.initials: PJ
authors.lastname: Best
authors.forename: L O
authors.initials: LO
authors.lastname: Lerman
mesh_terms: D000818:Animals; D002196:Capillaries / Q000473:pathology; D003331:Coronary Vessels / Q000473:pathology*; D005240:Feasibility Studies; D005260:Female; D006321:Heart; D006937:Hypercholesterolemia / Q000473:pathology*; D008833:Microcirculation; D013552:Swine; D014057:Tomography, X-Ray Computed