[Radiobiologic in-vivo investigation of angiogenesis in the yolk sac vascular system of chicken embryos].

Purpose: 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.
Material and 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.
Conclusion: Our model of the fertilized egg enables in-vivo measurements of angiogenesis in radiobiology.