Abstract P247: Triiodothyronine Ameliorates Endothelial Dysfunction in Rats Following Acute Myocardial Infarction

Autor: Kuo Zhang, Yi-Da Tang, Youhua Zhang, Ying Li, Olga Savinova, Kaie Ojamaa, A. Martin Gerdes, Maria Alicia Carrillo Sepulveda
Rok vydání: 2017
Předmět:
Zdroj: Hypertension. 70
ISSN: 1524-4563
0194-911X
DOI: 10.1161/hyp.70.suppl_1.p247
Popis: Background: Low thyroid hormone (TH) function is recognized as a significant contributor in the pathogenesis after acute myocardial infarction (MI). Endothelial dysfunction contributes significantly to the poor prognosis of MI. We hypothesize that long-term treatment with low dose T3 improves endothelial function and cardiac contractile activity compared to beta blocker, the current recommended therapy for MI. Methods: Adult female Sprague-Dawley rats were subjected to left anterior descending coronary artery ligation (MI) or sham surgeries. Survivors were randomly assigned to vehicle (MI, n=11), T3 (MI+T3, n=11) and metoprolol (MI+Meto, n=11). Vehicle, T3 (5 ug/kg/day) and metoprolol (2 mg/kg/day) were supplied in drinking water ad libitum immediately following MI for 2 months. Heart function and LV hemodynamics were measured. Isolated thoracic aortic rings were used to test relaxation response to acetylcholine (ACh) in a wire myograph. The maximal effect elicited by ACh (E max ) and the sensitivity to ACh (pEC 50 ) were analyzed. One-way ANOVA with Bonferroni correction was used for multiple comparisons. Results: Serum concentration of free and total T3 were normal in all the experimental groups. T3 and metoprolol improved LV contractile function measured by fractional shortening (21.88±2.06 vs 17.88±1.23%, pp /d t (7307±1128 vs 5479±810 mmHg/s, p50 (6.65±0.22 vs 7.19±0.16, pmax (90.56±3.55 vs 79.50±3.98%, p Conclusion: Long-term treatment with a physiological dose of T3 following MI is equally effective as metoprolol on LV function while improving endothelial function as an additional benefit.
Databáze: OpenAIRE
Externí odkaz: