Objective:
Ultrasound BioMicroscopy (UBM), or high-frequency ultrasound, is a novel technique used for assessment of anatomy and physiology small research animals. In this study, we evaluate the UBM assessment of the re-endothelialization process following denudation of the carotid artery in rats.
Methods:
Ultrasound BioMicroscopy data from three different experiments were analyzed. A total of 66 rats of three different strains (Sprague-Dawley, Wistar and Goto-Kakizaki) were included in this study. All animals were subjected to common carotid artery balloon injury and examined with UBM 2 and 4 weeks after injury. Re-endothelialization in UBM was measured as the length from the carotid bifurcation to the distal edge of the intimal hyperplasia.
En face
staining with Evans-blue dye was performed upon euthanization at 4 weeks after injury followed by tissue harvest for morphological and immunohistochemical evaluation.
Results:
A significant correlation (Spearman r=0.63,p<0.0001) and an agreement according to Bland-Altman test was identified when comparing all measurements of re-endothelialization in high frequency ultrasound and
en face
staining. Analysis by animal strain revealed a similar pattern and a significant growth in re-endothelialization length measured in UBM from 2 to 4 weeks could be identified. Immunohistochemical staining for von Willebrand factor confirmed the presence of endothelium in the areas detected as re-endothelialized by the ultrasound assessment.
Conclusion:
Ultrasound BioMicroscopy can be used for longitudinal in vivo assessment of the re-endothelialization following arterial injury in rats.
Doxazosin blocks the angiotensin II-induced smooth muscle cell DNA synthesis in the media, but not in the neointima of the rat carotid artery after balloon injury