Activation of 5′-AMP-activated protein kinase induces nitric oxide-dependent vasodilatation and uncovers insulin-mediated vasodilatation of skeletal muscle resistance arteries

2006 ◽  
Vol 45 (3) ◽  
pp. 182 ◽  
Author(s):  
Etto C Eringa ◽  
Coen D.A. Stehouwer ◽  
Geerten P van Nieuw Amerongen ◽  
Pieter Sipkema
Diabetologia ◽  
2010 ◽  
Vol 53 (6) ◽  
pp. 1142-1150 ◽  
Author(s):  
A. S. Deshmukh ◽  
Y. C. Long ◽  
T. de Castro Barbosa ◽  
H. K. R. Karlsson ◽  
S. Glund ◽  
...  

2011 ◽  
Vol 121 (10) ◽  
pp. 449-458 ◽  
Author(s):  
Luciana V. Rossoni ◽  
Mark Wareing ◽  
Camilla F. Wenceslau ◽  
Mahmood Al-Abri ◽  
Chris Cobb ◽  
...  

Statins can have beneficial cholesterol-independent effects on vascular contractility, which may involve increases in the bioavailability of NO (nitric oxide) as a result of phosphorylation of eNOS (endothelial NO synthase). Although this has been attributed to phosphorylation of Akt (also known as protein kinase B), studies in cultured cells have shown that statins can phosphorylate AMPK (AMP-activated protein kinase); it is unknown whether this has functional effects in intact arteries. Thus we investigated the acute effects of simvastatin on resistance arterial contractile function, evaluating the involvement of NO, Akt and AMPK. Isolated rat mesenteric resistance arteries were mounted on a wire myograph. The effects of incubation (1 and 2 h) with simvastatin (0.1 or 1 μM) on contractile responses were examined in the presence and absence of L-NNA (N-nitro-L-arginine; 10 μM) or mevalonate (1 mM). Effects on eNOS, phospho-eNOS (Ser1177), and total and phospho-Akt and -AMPK protein expression were investigated using Western blotting. The effect of AMPK inhibition (compound C, 10 μM) on eNOS phosphorylation and contractile responses were also studied. Simvastatin (1 μM, 2 h) significantly reduced constriction to U46619 and phenylephrine and enhanced dilations to ACh (acetylcholine) in depolarized, but not in U46619-pre-constricted arteries. These effects were completely and partially prevented by L-NNA and mevalonate respectively. Simvastatin increased eNOS and AMPKα phosphorylation, but had no effect on Akt protein expression and phosphorylation after 2 h incubation. Compound C prevented the effects of simvastatin on eNOS phosphorylation and contractility. Thus simvastain can acutely modulate resistance arterial contractile function via mechanisms that involve the AMPK/phospho-eNOS (Ser1177)/NO-dependent pathway.


2017 ◽  
Vol 95 (8) ◽  
pp. 3552
Author(s):  
E. M. England ◽  
H. Shi ◽  
S. K. Matarneh ◽  
E. M. Oliver ◽  
E. T. Helm ◽  
...  

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.


2006 ◽  
Vol 60 (5) ◽  
pp. 569-575 ◽  
Author(s):  
Petr Brauner ◽  
Pavel Kopecky ◽  
Pavel Flachs ◽  
Ondrej Kuda ◽  
Jaroslav Vorlicek ◽  
...  

2009 ◽  
Vol 34 (3) ◽  
pp. 315-322 ◽  
Author(s):  
Gregory R. Steinberg

During moderate-intensity exercise, fatty acids are the predominant substrate for working skeletal muscle. The release of fatty acids from adipose tissue stores, combined with the ability of skeletal muscle to actively fine tune the gradient between fatty acid and carbohydrate metabolism, depending on substrate availability and energetic demands, requires a coordinated system of metabolic control. Over the past decade, since the discovery that AMP-activated protein kinase (AMPK) was increased in accordance with exercise intensity, there has been significant interest in the proposed role of this ancient stress-sensing kinase as a critical integrative switch controlling metabolic responses during exercise. In this review, studies examining the role of AMPK as a regulator of fatty acid metabolism in both adipose tissue and skeletal muscle during exercise will be discussed. Exercise induces activation of AMPK in adipocytes and regulates triglyceride hydrolysis and esterfication through phosphorylation of hormone sensitive lipase (HSL) and glycerol-3-phosphate acyl-transferase, respectively. In skeletal muscle, exercise-induced activation of AMPK is associated with increases in fatty acid uptake, phosphorylation of HSL, and increased fatty acid oxidation, which is thought to occur via the acetyl-CoA carboxylase-malony-CoA-CPT-1 signalling axis. Despite the importance of AMPK in regulating fatty acid metabolism under resting conditions, recent evidence from transgenic models of AMPK deficiency suggest that alternative signalling pathways may also be important for the control of fatty acid metabolism during exercise.


2007 ◽  
Vol 32 (5) ◽  
pp. 852-856 ◽  
Author(s):  
Sean L. McGee

Exercise increases the metabolic capacity of skeletal muscle, which improves whole-body energy homeostasis and contributes to the positive health benefits of exercise. This is, in part, mediated by increases in the expression of a number of metabolic enzymes, regulated largely at the level of transcription. At a molecular level, many of these genes are regulated by the class II histone deacetylase (HDAC) family of transcriptional repressors, in particular HDAC5, through their interaction with myocyte enhancer factor 2 transcription factors. HDAC5 kinases, including 5′-AMP-activated protein kinase and protein kinase D, appear to regulate skeletal muscle metabolic gene transcription by inactivating HDAC5 and inducing HDAC5 nuclear export. These mechanisms appear to participate in exercise-induced gene expression and could be important for skeletal muscle adaptations to exercise.


Sign in / Sign up

Export Citation Format

Share Document