2010 Annual Meeting Abstracts
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Aged Rats Have Increased Neointimal Thickening And Ephrin-B2 Expression After Carotid Angioplasty
*Sammy D. D. Eghbalieh1,2, *Jose M Pimiento1,2, *Fabio A Kudo1, *Akihito Muto1, *Kenneth R Ziegler1, *Paraag Chowdhary1,2, *Yuka Kondo1, *Lynn Model1, *Xin Li1, *Yuan Y Guo1, Alan Dardik1
1Yale University School of Medicine, New Haven, CT;2The Stanley J. Dudrick Department of Surgery, Waterbury, CT
Objective: Although carotid angioplasty is associated with increased adverse events in elderly patients compared to younger patients, some animal models of carotid angioplasty have previously demonstrated only negative remodeling in aged rats compared with younger rats. Therefore, we examined the response to carotid artery angioplasty using a validated animal model of aging.
Design: Inception cohort study, 2 week outcome
Setting: University Laboratory
Patients: Young adult (6 month) or aged (22-24 month) male Fischer 344 rats.
Interventions: The right common carotid artery of young adult (6 month) or aged (22-24 month) male Fischer 344 rats was injured with a balloon and the ipsilateral external carotid was ligated.
Main Outcome Measures: Common carotid arteries were examined by histology and immunohistochemistry after 2 weeks.
Results: Aged and young adult rats had similar vessel areas after angioplasty (aged: 0.49±0.02mm2; young: 0.4±0.02 mm2; p=.2; n=5-6). However, aged rats had a significant reduction in the lumen area (0.18±0.03 mm2 vs. 0.24±0.01 mm2; p=.02), corresponding to increased neointimal thickening compared with young adult rats (aged: 0.15±0.04 mm2; young: 0.08±0.03 mm2; p=.006). Expression of Ephrin-B2, an arterial marker and ligand for Eph receptor signaling, was increased after angioplasty in both aged and young adult rats, but with higher amounts in aged animals (n=4).
Conclusions: Aged Fischer 344 rats are an accurate model for carotid angioplasty in aged humans, with increased neointimal thickening after carotid angioplasty in aged rats compared with young adult rats. Increased Ephrin-B2 expression after carotid angioplasty suggests additional mechanisms of smooth muscle cell activation that may contribute to the increased neointimal thickening in aged rats and adverse events in aged humans undergoing carotid angioplasty.
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