Abstract
BACKGROUND: This study investigated the potential effects of 3-iodothyronamine (T1AM) on myocardial ischemia reperfusion injury (MIRI) and the underlying molecular mechanisms. METHODS: A total of 16 adult male Sprague-Dawley rats were randomly divided into 4 groups and administered the following: control [60% dimethyl sulfoxide (DMSO) and 40% saline, pH 7.4], T1AM (25 mg/kg), T1AM (50 mg/kg), or T1AM (100 mg/kg). The rectal temperatures of the rats were measured at different time points. A further 30 adult male Sprague-Dawley rats were randomized and divided into the following 3 groups (n=10 in each group): sham operation, ischemia/reperfusion (I/R), and I/R + T1AM. In the I/R and I/R + T1AM groups, the left anterior descending (LAD) coronary artery of the rats were occluded for 0.5 hour to induce myocardial ischemia, followed by reperfusion for 3 hours in the I/R group. The electrocardiography (ECG), cardiac function, and 2,3,5-triphenyltetrazolium chloride (TTC) staining were examined in rats to evaluate the myocardial injury. The differences in the expression of apoptosis-related and Akt-FoxO1 signaling-related proteins were determined via Western blot. RESULTS: This work verified that T1AM reduced the body temperature of rats in a dose-dependent manner. Additionally, T1AM improved cardiac function and decreased the infarction size caused by MIRI. T1AM reduced the expression of biochemical parameters and apoptosis of myocardial cells. In addition, after treatment with T1AM, the expression of Glut1, pFoxO1 and Akt were reduced, while the expression of FoxO1 and PPARα were increased significantly. CONCLUSIONS: Pretreatment of cardiomyocytes with T1AM inhibited apoptosis and protected against ischemia reperfusion injury via the Akt/FoxO1 signaling pathway.