scholarly journals Triiodothyronine improves age-induced glucose intolerance and increases the expression of sirtuin-1 and glucose transporter-4 in skeletal muscle of aged rats

2018 ◽  
Vol 37 (06) ◽  
pp. 677-686 ◽  
Author(s):  
Sahar M. El
2012 ◽  
Vol 60 (45) ◽  
pp. 11366-11371 ◽  
Author(s):  
Yoko Yamashita ◽  
Lihua Wang ◽  
Zhang Tinshun ◽  
Toshiyuki Nakamura ◽  
Hitoshi Ashida

2019 ◽  
Vol 20 (10) ◽  
pp. 2436 ◽  
Author(s):  
Manabu Ueda-Wakagi ◽  
Hironobu Nagayasu ◽  
Yoko Yamashita ◽  
Hitoshi Ashida

It is known that green tea helps prevent obesity and diabetes mellitus. In this study, we aimed to determine whether green tea ameliorates hyperglycemia and the mechanism involved in diabetic rodents. Green tea consumption reduced blood glucose and ameliorated glucose intolerance, which was assessed using an oral glucose tolerance test in both streptozotocin-induced type 1 diabetic rats and type 2 diabetic KK-Ay mice. Green tea also reduced the plasma fructosamine and glycated hemoglobin concentrations in both models. Furthermore, it increased glucose uptake into the skeletal muscle of both model animals, which was accompanied by greater translocation of glucose transporter 4 (GLUT4). Moreover, epigallocatechin gallate (EGCG), the principal catechin in green tea, also ameliorated glucose intolerance in high-fat diet-induced obese and diabetic mice. These results suggest that green tea can ameliorate hyperglycemia in diabetic rodents by stimulating GLUT4-mediated glucose uptake in skeletal muscle, and that EGCG is one of the effective compounds that mediate this effect.


2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Mei-Hsing Chen ◽  
Cheng-Hsiu Lin ◽  
Chun-Ching Shih

The objective of this study was to evaluate the antihyperlipidemic and antihyperglycemic effects and mechanism of the extract ofClitocybe nuda(CNE), in high-fat- (HF-) fed mice. C57BL/6J was randomly divided into two groups: the control (CON) group was fed with a low-fat diet, whereas the experimental group was fed with a HF diet for 8 weeks. Then, the HF group was subdivided into five groups and was given orally CNE (including C1: 0.2, C2: 0.5, and C3: 1.0 g/kg/day extracts) or rosiglitazone (Rosi) or vehicle for 4 weeks. CNE effectively prevented HF-diet-induced increases in the levels of blood glucose, triglyceride, insulin (P<0.001,P<0.01,P<0.05, resp.) and attenuated insulin resistance. By treatment with CNE, body weight gain, weights of white adipose tissue (WAT) and hepatic triacylglycerol content were reduced; moreover, adipocytes in the visceral depots showed a reduction in size. By treatment with CNE, the protein contents of glucose transporter 4 (GLUT4) were significantly increased in C3-treated group in the skeletal muscle. Furthermore, CNE reduces the hepatic expression of glucose-6-phosphatase (G6Pase) and glucose production. CNE significantly increases protein contents of phospho-AMP-activated protein kinase (AMPK) in the skeletal muscle and adipose and liver tissues. Therefore, it is possible that the activation of AMPK by CNE leads to diminished gluconeogenesis in the liver and enhanced glucose uptake in skeletal muscle. It is shown that CNE exhibits hypolipidemic effect in HF-fed mice by increasing ATGL expression, which is known to help triglyceride to hydrolyze. Moreover, antidiabetic properties of CNE occurred as a result of decreased hepatic glucose production via G6Pase downregulation and improved insulin sensitization. Thus, amelioration of diabetic and dyslipidemic states by CNE in HF-fed mice occurred by regulation of GLUT4, G6Pase, ATGL, and AMPK phosphorylation.


2010 ◽  
Vol 74 (5) ◽  
pp. 1062-1067 ◽  
Author(s):  
Nhung Thuy DANG ◽  
Rie MUKAI ◽  
Ken-ichi YOSHIDA ◽  
Hitoshi ASHIDA

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Yueh-Hsiung Kuo ◽  
Cheng-Hsiu Lin ◽  
Chun-Ching Shih

This study was to investigate the antidiabetic and antihyperlipidemic effects of (E)-3-[3, 4-dihydroxyphenyl-1-(piperidin-1-yl)prop-2-en-1-one] (36-13) (TS), one of caffeic acid amide derivatives, on high-fat (HF-) fed mice. The C57BL/6J mice were randomly divided into the control (CON) group and the experimental group, which was firstly fed a HF diet for 8 weeks. Then, the HF group was subdivided into four groups and was given TS orally (including two doses) or rosiglitazone (Rosi) or vehicle for 4 weeks. Blood, skeletal muscle, and tissues were examined by measuring glycaemia and dyslipidemia-associated events. TS effectively prevented HF diet-induced increases in the levels of blood glucose, triglyceride, insulin, leptin, and free fatty acid (FFA) and weights of visceral fa; moreover, adipocytes in the visceral depots showed a reduction in size. TS treatment significantly increased the protein contents of glucose transporter 4 (GLUT4) in skeletal muscle; TS also significantly enhanced Akt phosphorylation in liver, whereas it reduced the expressions of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase). Moreover, TS enhanced phosphorylation of AMP-activated protein kinase (phospho-AMPK) both in skeletal muscle and liver tissue. Therefore, it is possible that the activation of AMPK by TS resulted in enhanced glucose uptake in skeletal muscle, contrasting with diminished gluconeogenesis in liver. TS exhibits hypolipidemic effect by decreasing the expressions of fatty acid synthase (FAS). Thus, antidiabetic properties of TS occurred as a result of decreased hepatic glucose production by PEPCK and G6Pase downregulation and improved insulin sensitization. Thus, amelioration of diabetic and dyslipidemic state by TS in HF-fed mice occurred by regulation of GLUT4, G6Pase, and FAS and phosphorylation of AMPK.


2011 ◽  
Vol 300 (5) ◽  
pp. H1637-H1644 ◽  
Author(s):  
Yukihiro Ohta ◽  
Shintaro Kinugawa ◽  
Shouji Matsushima ◽  
Taisuke Ono ◽  
Mochamad A. Sobirin ◽  
...  

Insulin resistance has been shown to occur as a consequence of heart failure. However, its exact mechanisms in this setting remain unknown. We have previously reported that oxidative stress is enhanced in the skeletal muscle from mice with heart failure after myocardial infarction (MI) ( 30 ). This study is aimed to investigate whether insulin resistance in postinfarct heart failure is due to the impairment of insulin signaling in the skeletal muscle caused by oxidative stress. Mice were divided into four groups: sham operated (sham); sham treated with apocynin, an inhibitor of NAD(P)H oxidase activation (10 mmol/l in drinking water); MI; and MI treated with apocynin. After 4 wk, intraperitoneal insulin tolerance tests were performed, and skeletal muscle samples were obtained for insulin signaling measurements. MI mice showed left ventricular dilation and dysfunction by echocardiography and increased left ventricular end-diastolic pressure and lung weight. The decrease in glucose level after insulin load significantly attenuated in MI compared with sham. Insulin-stimulated serine phosphorylation of Akt and glucose transporter-4 translocation were decreased in MI mice by 61 and 23%, respectively. Apocynin ameliorated the increase in oxidative stress and NAD(P)H oxidase activities measured by the lucigenin assay in the skeletal muscle after MI. It also improved insulin resistance and inhibited the decrease of Akt phosphorylation and glucose transporter-4 translocation. Insulin resistance was induced by the direct impairment of insulin signaling in the skeletal muscle from postinfarct heart failure, which was associated with the enhanced oxidative stress via NAD(P)H oxidase.


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