title: Synchrotron radiation coronary microangiography for morphometric and physiological evaluation of myocardial neovascularization induced by endothelial progenitor cell transplantation.
abstract: BACKGROUND
  Therapeutic effect of stem cell transplantation (SCTx) for myocardial neovascularization has been evaluated by histological capillary density in small animals. However, it has been technically difficult to obtain imaging evidence of collateral formation by conventional angiography.
  
  
  RESULTS
  Peripheral blood CD34+ and CD34- cells were isolated from patients with critical limb ischemia. PBS, CD34- cells, or CD34+ cells were intramyocardially transplanted after ligating LAD of nude rats. Coronary angiography of ex vivo beating hearts 5 and 28 days after the treatment was performed using the third generation synchrotron radiation microangiography (SRM), which has potential to visualize vessels as small as 20 microm in diameter. The SRM was performed pre and post sodium nitroprusside (SNP) to examine vascular physiology at each time point. Diameter of most collateral vessels was 20 to 120 microm, apparently invisible size in conventional angiography. Rentrop scores at day 28 pre and post SNP were significantly greater in CD34+ cell group than other groups (P<0.01). To quantify the extent of collateral formation, angiographic microvessel density (AMVD) in the occluded LAD area was analyzed. AMVD on day 28 post SNP, not pre SNP, was significantly augmented in CD34+ cell group than other groups (P<0.05). AMVD post SNP closely correlated with histological capillary density (R=0.82, P<0.0001).
  
  
  CONCLUSIONS
  The SRM, capable of visualizing microvessels, may be useful for morphometric and physiological evaluation of coronary collateral formation by SCTx. The novel imaging system may be an essential tool in future preclinical/translational research of stem cell biology.
authors.affiliation: Stem Cell Translational Research, Kobe Institute of Biomedical Research and Innovation/RIKEN Center for Developmental Biology, 2-2 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Iwasaki
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Fukushima
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Kawamoto
authors.forename: Keiji
authors.initials: K
authors.lastname: Umetani
authors.forename: Akira
authors.initials: A
authors.lastname: Oyamada
authors.forename: Saeko
authors.initials: S
authors.lastname: Hayashi
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Masakazu
authors.initials: M
authors.lastname: Ishikawa
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Shibata
authors.forename: Hiromi
authors.initials: H
authors.lastname: Nishimura
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Hirai
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Mifune
authors.forename: Miki
authors.initials: M
authors.lastname: Horii
authors.forename: Kazuro
authors.initials: K
authors.lastname: Sugimura
authors.forename: Shigefumi
authors.initials: S
authors.lastname: Suehiro
authors.forename: Takayuki
authors.initials: T
authors.lastname: Asahara
mesh_terms: D000368:Aged; D000818:Animals; D006348:Cardiac Surgical Procedures; D003097:Collateral Circulation; D017023:Coronary Angiography / Q000379:methods*; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000473:pathology* / Q000503:physiopathology; D016638:Critical Illness; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000473:pathology; D005121:Extremities / Q000098:blood supply; D005260:Female; D006801:Humans; D007511:Ischemia / Q000473:pathology; D008297:Male; D008833:Microcirculation / Q000000981:diagnostic imaging / Q000503:physiopathology; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D009204:Myocardial Revascularization / Q000379:methods*; D018919:Neovascularization, Physiologic; D036102:Peripheral Blood Stem Cell Transplantation; D051381:Rats; D011923:Rats, Nude; D013234:Stem Cells / Q000473:pathology; D017356:Synchrotrons; D013997:Time Factors; D014183:Transplantation, Heterologous