OBJECTIVE: Thyroid hormone (TH) is shown to be protective against cardiac and pancreatic injury. Thus, this study explored the potential effects of TH treatment on the functional status of the postinfarcted diabetic myocardium. Diabetic patients have worse prognosis after acute myocardial infarction (AMI). MATERIALS/ METHODS: AMI was induced by left coronary ligation in rats previously treated with 35 mg/kg streptozotocin (STZ), (DM-AMI). TH treatment was initiated at 2 weeks after AMI and continued for 6 weeks (DM-AMI+TH), while sham-operated animals served as control (DM-SHAM). RESULTS: TH treatment increased cardiac mass, improved wall stress and favorably changed cardiac geometry. TH significantly increased echocardiographic left ventricular ejection fraction (LVEF%): [54.2 (6.5) for DM-AMI+TH vs 37 (2.0) for DM-AMI, p<0.05]. TH treatment resulted in significantly increased insulin and decreased glucose levels in serum. The ratios of phosphorylated (p)-Akt/total Akt and p-mTOR/total mTOR were increased 2.0 fold and 2.7 fold in DM-AMI+TH vs DM-AMI respectively, p<0.05. Furthermore, the ratio of p-AMPK/total AMPK was found to be increased 1.6 fold in DM-AMI+TH vs DM-AMI, p<0.05. CONCLUSION: TH treatment improved the mechanical performance of the post-infarcted myocardium in rats with STZ-induced diabetes, an effect which was associated with Akt/mTOR and AMPK activation.
OBJECTIVE: Thyroid hormone (TH) is shown to be protective against cardiac and pancreatic injury. Thus, this study explored the potential effects of TH treatment on the functional status of the postinfarcted diabetic myocardium. Diabeticpatients have worse prognosis after acute myocardial infarction (AMI). MATERIALS/ METHODS: AMI was induced by left coronary ligation in rats previously treated with 35 mg/kg streptozotocin (STZ), (DM-AMI). TH treatment was initiated at 2 weeks after AMI and continued for 6 weeks (DM-AMI+TH), while sham-operated animals served as control (DM-SHAM). RESULTS: TH treatment increased cardiac mass, improved wall stress and favorably changed cardiac geometry. TH significantly increased echocardiographic left ventricular ejection fraction (LVEF%): [54.2 (6.5) for DM-AMI+TH vs 37 (2.0) for DM-AMI, p<0.05]. TH treatment resulted in significantly increased insulin and decreased glucose levels in serum. The ratios of phosphorylated (p)-Akt/total Akt and p-mTOR/total mTOR were increased 2.0 fold and 2.7 fold in DM-AMI+TH vs DM-AMI respectively, p<0.05. Furthermore, the ratio of p-AMPK/total AMPK was found to be increased 1.6 fold in DM-AMI+TH vs DM-AMI, p<0.05. CONCLUSION: TH treatment improved the mechanical performance of the post-infarcted myocardium in rats with STZ-induced diabetes, an effect which was associated with Akt/mTOR and AMPK activation.
Authors: Kristine M Wadosky; Jessica M Berthiaume; Wei Tang; Makhosi Zungu; Michael A Portman; A Martin Gerdes; Monte S Willis Journal: J Mol Endocrinol Date: 2016-02-09 Impact factor: 5.098
Authors: Alexandre Luz de Castro; Angela Vicente Tavares; Rafael Oliveira Fernandes; Cristina Campos; Adriana Conzatti; Rafaela Siqueira; Tânia Regina G Fernandes; Paulo Cavalheiro Schenkel; Carmem L Sartório; Susana Llesuy; Adriane Belló-Klein; Alex Sander da Rosa Araujo Journal: Mol Cell Biochem Date: 2015-07-10 Impact factor: 3.396
Authors: Yasuhiro Shudo; Jeffrey E Cohen; John W MacArthur; Andrew B Goldstone; Satoru Otsuru; Alen Trubelja; Jay Patel; Bryan B Edwards; George Hung; Alexander S Fairman; Christopher Brusalis; William Hiesinger; Pavan Atluri; Arudo Hiraoka; Shigeru Miyagawa; Yoshiki Sawa; Y Joseph Woo Journal: Tissue Eng Part A Date: 2015-09-18 Impact factor: 3.845