Student Presenter(s): Abigail Samuels
Faculty Mentor: Kaie Ojamaa and A. Martin Gerdes
Department: Biomedical Sciences
School/College: College of Osteopathic Medicine, Long Island

Beta-blockers are a mainstay of treatment in heart failure due to their ability to improve cardiac contractility and remodeling. Previous studies in our lab have shown that T3 is comparable to a beta-blocker, metoprolol (Met), in improving left ventricular function and modification in expression of genes involved in thyroid hormone and beta-adrenergic signaling in rats with myocardial infarction. This study aimed to determine if an additive effect was conferred from a combination T3+Met treatment as compared to treatment with Met alone. Adult female Sprague-Dawley rats aged 12 weeks were subjected to left anterior descending (LAD) coronary artery ligation or sham surgery (n=6). Surviving rats were randomly assigned to one of three treatment groups for 8 weeks: MI+Vehicle (n=9), MI+Met (n=10) or MI+Met+T3 (n=13). Results showed that the MI+Met+T3 group was treated adequately with T3 as seen by a significant decrease in serum T4 but without significant change in serum total T3. Infarcts were large enough to cause a significant deficit in the majority of cardiac contractile measurements but treatment with Met or Met+T3 did not provide any significant improvement in echocardiographic or hemodynamic measures. Treatment with Met alone restored MI-induced endothelial dysfunction. Initial analysis of these data leads us to conclude that combined Met+T3 treatment did not confer an advantage to treatment with either drug alone.