Thermal injury increases TMR induced angiogenesis in the ischemic myocardium

Background. A growing number of patients suffering from ischemic cardiomyopathy are not eligible for conventional revascularization. This has prompted new research in the field of angiogenesis. This study hypothesized that since inflammation is probably the mechanism behind TMR induced angiogenesis; a larger inflammatory response induced by thermal injury may lead to increased angiogenesis. / Methods. The model used for this study was coronary artery ligation in the Rat. Four groups of animals were used to compare the novel experimental approach with conventional TMR and with ischemia alone. Neovascularization was determined by immunohistochemical techniques using anti-Factor VIII antibody. Evaluation of VEGF, Ang-1 and Ang-2 expression was also carried out using immunohistochemistry. / Results. The experimental "HOT" TMR technique resulted in significantly increased angiogenesis presumably due to the thermal injury induced by the novel technique. Also a significant increase in VEGF expression was observed in all ischemic groups. Ang-1 expression was decreased in the experimental group while it was similar in the other groups. Finally Ang-2 was induced by ischemia as evidenced by increased expression among all ischemic groups. However Ang-2 expression did not significantly vary among ischemic groups. / Conclusions. The addition of thermal injury by heating of the needle led to an increased angiogenic response compared to ischemia alone and compared to conventional TMR. This increased angiogenesis was associated with increased VEGF expression at one week, however there was a significant inverse correlation between VEGF expression and angiogenesis among the ischemic groups. Also angiopoietin expression was in agreement with expression characteristics described in the literature.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.31198
Date January 2001
CreatorsBousette, Nicolas.
ContributorsShennib, Hani (advisor)
PublisherMcGill University
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Formatapplication/pdf
CoverageMaster of Science (Division of Surgical Research.)
RightsAll items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated.
Relationalephsysno: 001804012, proquestno: MQ70387, Theses scanned by UMI/ProQuest.

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