Development of chick chorioallantoic membrane as a biological testing membrane

Abstract

This study hypothesized that the CAM would be useful as an in vivo model for assessing absorption of vasoactive drug by evaluating the changes in blood perfusion and diameter of the vessels in response to the drug administered. Laser Doppler perfusion imaging (LDPI) was employed to evaluate blood perfusion of the CAM in response to a range of vasoactive substances. The accuracy and reproducibility of the measurements were found to be significantly affected by the amplitude and threshold settings of the LDPI. Complex drug concentration-blood perfusion relationships were due to inherent compensatory mechanisms of the CAM. A dedicated image analysis software was used for efficient semi-automated determination of the CAM vessel diameters. The changes in vessel diameter in response to different drug concentrations were found to be more reproducible and sensitive as a biological tissue response assessor than the corresponding blood perfusion. In addition, in vitro drug permeation studies showed that the CAM best mimicked the pig buccal mucosa, compared with pig skin, snake skin and pig retina. Overall, the CAM is a useful model that can be used as an alternative `live animal? for assessing drug absorption/permeation through biological membranes, particularly the buccal mucosa.