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Título: Thermal injury increases TMR induced angiogenesis in the ischemic myocardium
Autores: Bousette, Nicolas.
Fecha: 2001
Publicador: McGill University
Fuente: Ver documento
Tipo: Electronic Thesis or Dissertation
Tema: Health Sciences, Medicine and Surgery.
Descripción: 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.
Idioma: en