Circulation Index as a Quantitative Indicator of Angiogenesis in Chorioallantoic Membrane of Chicken Broilers

Chorioallantoic membrane (CAM) is an extraembryonic membrane very frequently used for in vivo studies in various researches. Since researches require a fast method for quantifying the CAM angiogenic response, there is a need to develop a new precise and unbiased method of quantification of angiogenesis in CAM, which would be easy to perform and suitable for analysis of a large number of samples. The objective of this paper is to apply a new method of quantification of angiogenesis in investigation of the development of blood vessels in the CAM, in particular days of embryonic life considered essential for CAM development. The present research included 75 fertilized eggs of heavy hybrid Ross 308. CAM sampling for stereological analyses was in key phases of embryonic development, namely on the 12^th, 15^th and 19^th day. The results of the present investigation show that the increase in embryonic age results in increase in circulation index, which is also an indicator of angiogenic processes developing in CAM. The lowest value of circulation index (0.1952) was recorded on the first sampling day (E12), while the highest value (0.2666) was recorded on the last sampling day (E19). This method may be applied in researching different factors which affect angiogenesis in CAM.