Stretch-induced intussuceptive and sprouting angiogenesis in the chick chorioallantoic membrane

Microvasc Res. 2014 Sep;95:60-7. doi: 10.1016/j.mvr.2014.06.009. Epub 2014 Jun 28.

Abstract

Vascular systems grow and remodel in response to not only metabolic needs, but also mechanical influences as well. Here, we investigated the influence of tissue-level mechanical forces on the patterning and structure of the chick chorioallantoic membrane (CAM) microcirculation. A dipole stretch field was applied to the CAM using custom computer-controlled servomotors. The topography of the stretch field was mapped using finite element models. After 3days of stretch, Sholl analysis of the CAM demonstrated a 7-fold increase in conducting vessel intersections within the stretch field (p<0.01). The morphometric analysis of intravital microscopy and scanning electron microscopy (SEM) images demonstrated that the increase vessel density was a result of an increase in interbranch distance (p<0.01) and a decrease in bifurcation angles (p<0.01); there was no significant increase in conducting vessel number (p>0.05). In contrast, corrosion casting and SEM of the stretch field capillary meshwork demonstrated intense sprouting and intussusceptive angiogenesis. Both planar surface area (p<0.05) and pillar density (p<0.01) were significantly increased relative to control regions of the CAM. We conclude that a uniaxial stretch field stimulates the axial growth and realignment of conducting vessels as well as intussusceptive and sprouting angiogenesis within the gas exchange capillaries of the ex ovo CAM.

Keywords: Chorioallantoic membrane; Fluorescence microscopy; Microcirculation; Micromechanics; Scanning electron microscopy; Sprouting and intussusceptive angiogenesis; Stretch.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Capillaries / physiology*
  • Capillaries / ultrastructure
  • Chick Embryo
  • Chorioallantoic Membrane / blood supply*
  • Corrosion Casting
  • Finite Element Analysis
  • Mechanotransduction, Cellular*
  • Microcirculation
  • Microscopy, Electrochemical, Scanning
  • Microscopy, Fluorescence
  • Microscopy, Video
  • Models, Cardiovascular
  • Neovascularization, Physiologic*
  • Stress, Mechanical
  • Time Factors