The Two- and Three-Dimensional Structure of the Microcirculation of the Chick Chorioallantoic Membrane

Abstract

The chick chorioallantoic membrane (CAM) is a common model for studying biological processes, but descriptions of the CAM circulatory system and especially experimental preparations of the CAM in shell-less eggs are both scant and controversial. We studied the CAM structure and the three-dimensional spatial configuration of the CAM vessels using five methods: in vivo stereoscopic observations, whole-mount preparations, histological sections, corrosion cast microinjection techniques and the reconstruction of a three-dimensional wax model. Our findings show that the CAM consists of a superficial two-dimensional layer composed of a network of a very dense capillary mesh, floating over and enclosing a deeper three-dimensional space in which medium and larger free-floating vessels are seen to supply and drain the superficial layer. It is interesting to note that no tips or sprouts of blood vessels were observed during the development of the CAM vessels. In a shell-less egg preparation, the capillaries were found in the mesoderm layer of the CAM and not in or superficial to the ectoderm as is the case in the CAM of the intact egg which adheres to the shell membrane.

Photodynamic parameters in the chick chorioallantoic membrane (CAM) bioassay for topically applied photosensitizers

“…The CAM as an in vivo bioassay for PDT has been described previously [43][44][45][46][47] and was adopted here with minor modifications. Briefly, fertilized chicken eggs were disinfected and transferred to a hatching incubator set at 388C and 60% humidity.…”

“…The CAM consists of an external layer, derived from the chorion ectoderm, a mesodermal layer containing the extraembryonic vascular network, and an internal layer derived from the allantoic endoderm [43,44]. In the present study we have refined the classification of PDT-induced vascular damage in the CAM mesoderm [45][46][47][48].…”

The chick embryo chorioallantoic membrane as a model to study tumor metastasis

“…The umbilical artery, after emerging from the embryonic adnominal wall, branches into two primary chorioallantoic artery, and the CAM is drained by a single chorioallantoic vein. Fuchs and Lindenbaum [8] described 6 or 7 generations of branches of the allantoic artery. The first 5 or 6 are located in a plane parallel to the CAM surface and deep to the vein, which has a similar distribution.…”

The Chick Chorioallantoic Membrane as a Model Tissue for Surgical Retinal Research and Simulation

“…Smaller vessels (Ͻ200 m diameter) are embedded within the main layer. 17 Immediately external to the primary layer of CAM is a capillary plexus, or blood sinus. 14 Above this sinus lies a thin stratum (approximately 1 m) that is composed of four sublayers originally derived from the chorion (basement membrane, epithelial cell layer, peptidoglycan extracellular matrix, and basal lamina).…”