The chicken embryo's chorioallantoic membrane (CAM) is widely used as an in vivo model to study the vascular effects
induced by agents administrated topically or intravenously. Hence, in the vascular plexus of this respiratory membrane,
angiogenic and anti-angiogenic agents, as well as phototoxic effects have been studied.
The main goal of this study was to characterize the capillary network of the CAM after topical administration of
dimethyl sulfoxid (DMSO), a frequently used solvent of lipophylic drugs, including potent anti-VEGF agents. The CAM
capillaries were observed between days 8 and 9 of the embryo development, with an epi-fluorescence microscope
equipped with a sensitive camera by intravenous injection of a fluorescent agent and a non-fluorescing absorber (in the
extra-embryonic cavity) to screen the tissue background fluorescence. The fluorescence images of the CAM vasculature
were then processed in order to obtain a skeleton of the vessels and capillaries. This was done to quantify descriptors
such as the number of branching points/mm2, the mean area value of the vessels network meshes, and the mean of the 3rd
quartile of the histogram of these meshes, were then extracted.
Our results demonstrate that the topical administration of an aqueous solution of 20 μl of DMSO at concentrations equal
or larger than 0.1% turned out to modify the capillary network morphology in a dose-dependent manner as compared to
the control (20 μl of 0.9% NaCl).