title: [Radiobiologic in-vivo investigation of angiogenesis in the yolk sac vascular system of chicken embryos].
abstract: OBJECTIVE
  The aim of this study was to investigate whether the yolk sac blood vessel system of chick embryos represents a useful model of in-vivo measurements of angiogenesis in radiobiology.
  
  
  METHODS
  The fertilized eggs of the crossbreeding White Plymouth Rox X Sussex were used for the study of the extraembryonic vascularisation after irradiation with different fractionation and dosage. On day 3 of incubation an oval window was cut into the shell and then the area vasculosa was irradiated with 1.0 cm in diameter. Forty-eight hours after irradiation in-vivo photographs were taken for quantitative evaluation of blood vessel density.
  
  
  RESULTS
  Irradiation from 2.0 to 8.0 Gy in a single fraction leads to a slight decrease in vascular density. After a single fraction of 10.0 Gy a distinct increase in vascular density occurs. Fractionated irradiation leads to a considerable clear increasing of vascular density in comparison with the single fraction and same total dose.
  
  
  CONCLUSIONS
  Our model of the fertilized egg enables in-vivo measurements of angiogenesis in radiobiology.
authors.affiliation: Klinik für Strahlentherapie, Universität Erlangen-Nürnberg.
authors.forename: L
authors.initials: L
authors.lastname: Plasswilm
authors.forename: J
authors.initials: J
authors.lastname: Höper
authors.forename: R
authors.initials: R
authors.lastname: Sauer
mesh_terms: D000818:Animals; D002642:Chick Embryo; D005306:Fertilization; D008833:Microcirculation / Q000528:radiation effects; D018919:Neovascularization, Physiologic / Q000528:radiation effects*; D011829:Radiation Dosage; D015017:Yolk Sac / Q000098:blood supply*