DOI
https://doi.org/10.25772/78XF-3Z12
Defense Date
2012
Document Type
Thesis
Degree Name
Master of Science
Department
Physiology
First Advisor
Roland Pittman
Abstract
The chick chorio-allantoic membrane (CAM) contains a complex vascular network commonly used to study angiogenesis. The application of chemical factors and oxygen barrier films onto this tissue can easily influence the process of angiogenesis. In this study, oxygen barrier film patches (Krehalon, polyvinylidene chloride, 12 μm thick, O2 transmission rate = 2.19 cm3•ml/100 in2•day•atm) were applied to areas of the CAM. Holes were made in the film and alginate beads incubated in various chemical factors were placed in the holes. After 24 and 48 hours of exposure to the alginate beads, images were taken of the tissue using a stereomicroscope and then processed using ImageJ software (from the National Institue of Health (NIH)). The images were analyzed with the Fractal Analysis plugin of ImageJ (also from NIH) using four parameters. These parameters are the number of vessel segments, the number of vessel bifurcations, the total length of the vessels, and the complexity of the vascular network. From these parameters, the chemical factors can be identified as promoting angiogenesis (pro-angiogenic), inhibiting angiogenesis (anti-angiogenic), or having no effect on angiogenesis (not angiogenic). For the angiogenic beads, significant results were found in at least one of the four parameters. SNAP and H2O2 gave pro-angiogenic responses while Angiotensin II, Losartan, and Adenosine were anti-angiogenic. To test the effect of an oxygen barrier film patch on angiogenesis, images were taken of the tissue under the film patch (virtual holes) and holes exposed to atmospheric oxygen. Analysis of the virtual holes compared to the control holes gave significant results for several of the film patches. These film patches are distinguished by the chemical that was tested on each of the films. The virtual holes containing Angiotensin II, Losartan, Adenosine, and H2O2 gave pro-angiogenic results while SNAP and L-NAME virtual holes were anti-angiogenic. Thus, the chemical factors and the oxygen barrier film patches did have an effect on angiogenesis in the CAM.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
June 2012