scholarly journals Testosterone activates glucose metabolism through AMPK and androgen signaling in cardiomyocyte hypertrophy

2021 ◽  
Vol 54 (1) ◽  
Author(s):  
Mayarling Francisca Troncoso ◽  
Mario Pavez ◽  
Carlos Wilson ◽  
Daniel Lagos ◽  
Javier Duran ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Cardiac Hypertrophy ◽  
Glucose Uptake ◽  
Male Rats ◽  
Cardiomyocyte Hypertrophy ◽  
Mrna Levels ◽  
Elevated Glucose ◽  
Amp Activated Protein Kinase ◽  
Cultured Cardiomyocytes

Abstract Background Testosterone regulates nutrient and energy balance to maintain protein synthesis and metabolism in cardiomyocytes, but supraphysiological concentrations induce cardiac hypertrophy. Previously, we determined that testosterone increased glucose uptake—via AMP-activated protein kinase (AMPK)—after acute treatment in cardiomyocytes. However, whether elevated glucose uptake is involved in long-term changes of glucose metabolism or is required during cardiomyocyte growth remained unknown. In this study, we hypothesized that glucose uptake and glycolysis increase in testosterone-treated cardiomyocytes through AMPK and androgen receptor (AR). Methods Cultured cardiomyocytes were stimulated with 100 nM testosterone for 24 h, and hypertrophy was verified by increased cell size and mRNA levels of β-myosin heavy chain (β-mhc). Glucose uptake was assessed by 2-NBDG. Glycolysis and glycolytic capacity were determined by measuring extracellular acidification rate (ECAR). Results Testosterone induced cardiomyocyte hypertrophy that was accompanied by increased glucose uptake, glycolysis enhancement and upregulated mRNA expression of hexokinase 2. In addition, testosterone increased AMPK phosphorylation (Thr172), while inhibition of both AMPK and AR blocked glycolysis and cardiomyocyte hypertrophy induced by testosterone. Moreover, testosterone supplementation in adult male rats by 5 weeks induced cardiac hypertrophy and upregulated β-mhc, Hk2 and Pfk2 mRNA levels. Conclusion These results indicate that testosterone stimulates glucose metabolism by activation of AMPK and AR signaling which are critical to induce cardiomyocyte hypertrophy.

scholarly journals SGK1-Sensitive Regulation of Cyclin-Dependent Kinase Inhibitor 1B (p27) in Cardiomyocyte Hypertrophy

2015 ◽  
Vol 37 (2) ◽  
pp. 603-614 ◽  
Author(s):  
Jakob Voelkl ◽  
Tatsiana Castor ◽  
Katharina Musculus ◽  
Robert Viereck ◽  
Sobuj Mia ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Kinase Inhibitor ◽  
Protein Localization ◽  
Phosphorylation Site ◽  
Cardiomyocyte Hypertrophy ◽  
Mrna Levels ◽  
Cyclin Dependent Kinase ◽  
Transcript Levels ◽  
Hypertrophic Response ◽  
Cyclin Dependent Kinase Inhibitor

Background/Aims: The serum- and glucocorticoid-inducible kinase SGK1 participates in the orchestration of cardiac hypertrophy and remodeling. Signaling linking SGK1 activity to cardiac remodeling is, however, incompletely understood. SGK1 phosphorylation targets include cyclin-dependent kinase inhibitor 1B (p27), a protein which suppresses cardiac hypertrophy. The present study explored how effects of SGK1 on nuclear p27 localization might modulate the hypertrophic response in cardiomyocytes. Methods: Experiments were performed in HL-1 cardiomyocytes and in SGK1-deficient (sgk1-/-) and corresponding wild-type (sgk1+/+) mice following pressure overload by transverse aortic constriction (TAC). Transcript levels were quantified by RT-PCR, protein abundance by Western blotting and protein localization by confocal microscopy. Results: In HL-1 cardiomyocytes, overexpression of constitutively active SGK1 (SGK1S422D) but not of inactive SGK1 (SGK1K127N) increased significantly the cell size and transcript levels encoding Acta1, a molecular marker of hypertrophy. Those effects were paralleled by almost complete relocation of p27 in the cytoplasm. Treatment of HL-1 cardiomyocytes with isoproterenol was followed by up-regulation of SGK1 expression. Moreover, isoproterenol treatment stimulated the hypertrophic response and was followed by disappearance of p27 from the nuclei, effects prevented by the SGK1 inhibitor EMD638683. The effect of SGK1S422D overexpression on Acta1 mRNA levels was disrupted by overexpression of p27 and of the p27T197A mutant lacking the SGK1 phosphorylation site, but not of the phosphomimetic p27T197D mutant. In sgk1+/+ mice, TAC increased significantly SGK1 and Acta1 mRNA levels and decreased the nuclear to cytoplasmic protein ratio of p27 in cardiac tissue, effects blunted in the sgk1-/- mice. Conclusion: SGK1-induced hypertrophy of cardiomyocytes involves p27 phosphorylation at T197, which fosters cytoplasmic p27 localization.

Characterization of the role of the AMP-activated protein kinase in the stimulation of glucose transport in skeletal muscle cells

2002 ◽  
Vol 363 (1) ◽  
pp. 167-174 ◽  
Author(s):  
Lee G.D. FRYER ◽  
Fabienne FOUFELLE ◽  
Kay BARNES ◽  
Stephen A. BALDWIN ◽  
Angela WOODS ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Glucose Uptake ◽  
Glucose Transport ◽  
Phorbol Ester ◽  
Hyperosmotic Stress ◽  
Amp Activated Protein Kinase ◽  
Stimulation Of ◽  
Constitutively Active

Stimulation of AMP-activated protein kinase (AMPK) in skeletal muscle has been correlated with an increase in glucose transport. Here, we demonstrate that adenoviral-mediated expression of a constitutively active mutant of AMPKα leads to activation of glucose transport in a skeletal-muscle cell line, similar to that seen following treatment with 5-amino-imidazolecarboxamide (AICA) riboside, hyperosmotic stress or insulin. In contrast, expression of a dominant-negative form of AMPK blocked the stimulation of glucose transport by both AICA riboside and hyperosmotic stress, but was without effect on either insulin or phorbol-ester-stimulated transport. These results demonstrate that activation of AMPK is sufficient for stimulation of glucose uptake into muscle cells, and is a necessary component of the AICA riboside- and hyperosmotic-stress-induced pathway leading to increased glucose uptake. On the other hand, AMPK is not required in the insulin- or phorbol-ester-mediated pathways. Long-term (5 days) expression of the constitutively active AMPK mutant increased protein expression of GLUT1, GLUT4 and hexokinase II, consistent with previous reports on the chronic treatment of rats with AICA riboside. Expression of constitutively active AMPK had no detectable effect on p38 mitogen-activated protein kinase levels, although interestingly the level of protein kinase B was decreased. These results demonstrate that long-term activation of AMPK is sufficient to cause increased expression of specific proteins in muscle. Our results add further support to the hypothesis that long-term activation of AMPK is involved in the adaptive response of muscle to exercise training.

scholarly journals Orlistat reverses intratesticular lactate transport decline and infertility in male obese rats

Reproduction ◽  
2020 ◽  
Vol 160 (6) ◽  
pp. 863-872 ◽  
Author(s):  
Joseph Bagi Suleiman ◽  
Victor Udo Nna ◽  
Zaida Zakaria ◽  
Zaidatul Akmal Othman ◽  
Ainul Bahiyah Abu Bakar ◽  
...  
Keyword(s):  
Erectile Dysfunction ◽  
Glucose Metabolism ◽  
Sexual Behaviour ◽  
Mating Behaviour ◽  
Male Rats ◽  
Cgmp Level ◽  
Mrna Levels ◽  
Sprague Dawley ◽  
Obese Rats ◽  
Fertility Potential

Obesity and its accompanying complications predispose to abnormal testicular glucose metabolism, penile erectile dysfunction and subfertility. This study examined the potentials of orlistat in attenuating erectile dysfunction and fertility decline in high-fat diet (HFD)-induced obesity in male rats. Eighteen adult male Sprague–Dawley rats whose weights were between 250 and 300 g were divided into three groups (n = 6/group) namely: normal control (NC), HFD and HFD + orlistat (10 mg/kg body weight/day co-administered for 12 weeks) (HFD+O). During the 11th and 12th week, mating behaviour and fertility parameters were evaluated, and parameters of glucose metabolism were assessed at the end of the 12th week. Orlistat increased testicular mRNA levels of glucose transporters (Glut1 and Glut3), monocarboxylate transporters (Mct2 and Mct4) and lactate dehydrogenase type C (Ldhc), decreased intratesticular lactate and glucose levels, and LDH activity in obese rats. Furthermore, orlistat increased superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) activities, and total antioxidant capacity (TAC), but decreased malondialdehyde level in the penis of obese rats. Similarly, orlistat improved penile cGMP level, sexual behaviour and fertility outcome in obese rats. Penile cGMP level correlated positively with total mounts and intromissions but correlated negatively with mount/intromission ratio. Orlistat improves fertility potential in obese state by targeting testicular lactate metabolism, penile oxidative stress and sexual behaviour in rats. Therefore, orlistat shows a promising protective effect and may preserve the fertility potential of obese men.

scholarly journals Resveratrol Ameliorates High-Fat-Diet-Induced Abnormalities in Hepatic Glucose Metabolism in Mice via the AMP-Activated Protein Kinase Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Caiping Lu ◽  
Hanying Xing ◽  
Linquan Yang ◽  
Kaiting Chen ◽  
Linyi Shu ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Protein Kinase ◽  
Glucose Metabolism ◽  
Glucose Uptake ◽  
High Fat Diet ◽  
Blood Glucose Concentration ◽  
Glycogen Synthesis ◽  
Liver Fat ◽  
High Fat ◽  
Amp Activated Protein Kinase

Diabetes mellitus is highly prevalent worldwide. High-fat-diet (HFD) consumption can lead to liver fat accumulation, impair hepatic glycometabolism, and cause insulin resistance and the development of diabetes. Resveratrol has been shown to improve the blood glucose concentration of diabetic mice, but its effect on the abnormal hepatic glycometabolism induced by HFD-feeding and the mechanism involved are unknown. In this study, we determined the effects of resveratrol on the insulin resistance of high-fat-diet-fed mice and a hepatocyte model by measuring serum biochemical indexes, key indicators of glycometabolism, glucose uptake, and glycogen synthesis in hepatocytes. We found that resveratrol treatment significantly ameliorated the HFD-induced abnormalities in glucose metabolism in mice, increased glucose absorption and glycogen synthesis, downregulated protein phosphatase 2A (PP2A) and activated Ca2+/CaM-dependent protein kinase kinase β (CaMKKβ), and increased the phosphorylation of AMP-activated protein kinase (AMPK). In insulin-resistant HepG2 cells, the administration of a PP2A activator or CaMKKβ inhibitor attenuated the effects of resveratrol, but the administration of an AMPK inhibitor abolished the effects of resveratrol. Resveratrol significantly ameliorates abnormalities in glycometabolism induced by HFD-feeding and increases glucose uptake and glycogen synthesis in hepatocytes. These effects are mediated through the activation of AMPK by PP2A and CaMKKβ.

scholarly journals Dissection of the metabolic actions of insulin in adipocytes from early growth-retarded male rats

1999 ◽  
Vol 162 (2) ◽  
pp. 313-319 ◽  
Author(s):  
SE Ozanne ◽  
CL Wang ◽  
MW Dorling ◽  
CJ Petry
Keyword(s):  
Glucose Tolerance ◽  
Glucose Uptake ◽  
Adult Life ◽  
Early Growth ◽  
Male Rats ◽  
Long Term Effects ◽  
Low Protein ◽  
Pregnancy And Lactation

Numerous studies have shown a relationship between early growth restriction and Type 2 diabetes. Studies have shown that offspring of rats fed a low protein (LP) diet during pregnancy and lactation have a worse glucose tolerance in late adult life compared with controls. In contrast, in young adult life LP offspring have a better glucose tolerance which is associated with increased insulin-stimulated glucose uptake into skeletal muscle. The aim of the present study was to compare the regulation of glucose uptake and lipolysis in adipocytes by insulin in control and LP offspring. LP adipocytes had increased basal and insulin-stimulated glucose uptake compared with controls. There was no difference in basal rates of lipolysis. Isoproterenol stimulated lipolysis in both groups, but it was more effective on LP adipocytes. Insulin reduced lipolytic rates in controls to basal levels but had a reduced effect in LP adipocytes. Protein kinase B activity matched glucose uptake, with LP adipocytes having elevated activities. These results suggest that early growth retardation has long-term effects on adipocyte metabolism. In addition, they show selective resistance to different metabolic actions of insulin and provide insight into the mechanisms by which insulin regulates glucose uptake and lipolysis.

scholarly journals Unique mechanism of GLUT3 glucose transporter regulation by prolonged energy demand: increased protein half-life

1998 ◽  
Vol 333 (3) ◽  
pp. 713-718 ◽  
Author(s):  
Zayna A. KHAYAT ◽  
Anthony L. McCALL ◽  
Amira KLIP
Keyword(s):  
Glucose Uptake ◽  
Protein Content ◽  
Glucose Transport ◽  
Half Life ◽  
Glucose Transporter ◽  
Muscle Cells ◽  
Mrna Levels ◽  
Glut1 Protein ◽  
L6 Muscle Cells

L6 muscle cells survive long-term (18 h) disruption of oxidative phosphorylation by the mitochondrial uncoupler 2,4-dinitrophenol (DNP) because, in response to this metabolic stress, they increase their rate of glucose transport. This response is associated with an elevation of the protein content of glucose transporter isoforms GLUT3 and GLUT1, but not GLUT4. Previously we have reported that the rise in GLUT1 expression is likely to be a result of de novo biosynthesis of the transporter, since the uncoupler increases GLUT1 mRNA levels. Unlike GLUT1, very little is known about how interfering with mitochondrial ATP production regulates GLUT3 protein expression. Here we examine the mechanisms employed by DNP to increase GLUT3 protein content and glucose uptake in L6 muscle cells. We report that, in contrast with GLUT1, continuous exposure to DNP had no effect on GLUT3 mRNA levels. DNP-stimulated glucose transport was unaffected by the protein-synthesis inhibitor cycloheximide. The increase in GLUT3 protein mediated by DNP was also insensitive to cycloheximide, paralleling the response of glucose uptake, whereas the rise in GLUT1 protein levels was blocked by the inhibitor. The GLUT3 glucose transporter may therefore provide the majority of the glucose transport stimulation by DNP, despite elevated levels of GLUT1 protein. The half-lives of GLUT3 and GLUT1 proteins in L6 myotubes were determined to be about 15 h and 6 h respectively. DNP prolonged the half-life of both proteins. After 24 h of DNP treatment, 88% of GLUT3 protein and 57% of GLUT1 protein had not turned over, compared with 25% in untreated cells. We conclude that the long-term stimulation of glucose transport by DNP arises from an elevation of GLUT3 protein content associated with an increase in GLUT3 protein half-life. These findings suggest that disruption of the oxidative chain of L6 muscle cells leads to an adaptive response of glucose transport that is distinct from the insulin response, involving specific glucose transporter isoforms that are regulated by different mechanisms.

Abstract P381: Ecklonia Stolonifera Okamura Extract Suppresses Hypertrophic Responses In Cardiomyocytes And Development Of Heart Failure By Inhibiting P300-HAT Activity

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Takahiro Katagiri ◽  
Yoichi Sunagawa ◽  
Masafumi Funamoto ◽  
Yasufumi Katanasaka ◽  
Yusuke Miyazaki ◽  
...  
Keyword(s):  
Heart Failure ◽  
Gene Transcription ◽  
Left Ventricular ◽  
Vehicle Group ◽  
Cardiomyocyte Hypertrophy ◽  
Cell Diameter ◽  
Mrna Levels ◽  
Ecklonia Stolonifera ◽  
Hypertrophic Response ◽  
Cultured Cardiomyocytes

Introduction: Heart failure is the leading cause of death in the world. Cardiomyocyte hypertrophy is observed during the development of heart failure, suggesting that its inhibition is a potential target for the prevention and treatment of heart failure. In this study, we screened a natural compound library using cultured cardiomyocytes and found that Ecklonia stolonifera Okamura extract (ESE) suppressed cardiomyocyte hypertrophy. ESE, a perennial brown alga, has been reported to have various bioactive effects, such as antioxidant and anti-inflammatory activity, but its effect on heart failure is still unclear. Therefore, we investigated whether ESE has an inhibitory effect on cardiomyocyte hypertrophic response and on the progression of heart failure in post-myocardial infarction (MI) rats. Methods and Results: First, primary cultured cardiomyocytes from neonatal rats were treated with ESE and then stimulated with phenylephrine (PE) for 48 hours. ESE (1000 μg/mL) significantly suppressed PE-induced increases in cardiomyocyte surface area, hypertrophic response gene transcription, and acetylation of histone H3K9. An in vitro p300-HAT assay indicated that ESE directly inhibited p300-HAT activity (IC50: 505 μg/mL). Next, one week after the ligation of the left anterior descending artery, rats with moderate MI (left ventricular fractioning shorting (LVFS) <40%) were randomly assigned to three groups: vehicle (saline) (n=9), ESE (0.3 g/kg) (n=10), or ESE (1 g/kg) (n=10). Daily oral administration was repeated for 8 weeks. After treatment, LVFS was significantly higher in the ESE (1 g/kg) group (23.3 ± 0.7%, p<0.05) than in the vehicle group (16.6 ± 1.3%). Next, the hearts were isolated and histological analysis, evaluation of gene transcription, and measurement of histone H3K9 acetylation. were performed. ESE treatment significantly suppressed MI-induced increases both in myocardial cell diameter and in the mRNA levels of hypertrophic response genes. ESE also inhibited MI-induced perivascular fibrosis and the acetylation of histone H3K9. Conclusion: These results suggest that ESE suppresses both hypertrophic responses in cardiomyocytes and the development of heart failure by inhibiting p300-HAT activity. Further studies are needed to clarify the effectiveness of ESE for heart failure therapy.

Abstract P454: The Interaction Of P300 With Brg1 Acetylated The Histone H3 Globular Domain In Heart Failure

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
sho uehara ◽  
Tatsuya Morimoto
Keyword(s):  
Heart Failure ◽  
Left Ventricular ◽  
Cardiomyocyte Hypertrophy ◽  
Globular Domain ◽  
Mrna Levels ◽  
Transcriptional Coactivator ◽  
Post Translational Modifications ◽  
Hypertrophic Response ◽  
Cultured Cardiomyocytes

Background: Epigenetic regulatory mechanisms such as histone post-translational modifications are involved in the development of heart failure. Although the acetylation of tail domains, such as H3K9, has been extensively studied, that of H3K122, the globular domain, has received much less attention. Acetylation of the globular domain directly activates transcription by destabilizing histone-DNA binding. However, the acetylation of these domains during the transition from left ventricular hypertrophy (LVH) to heart failure (HF) remains unknown. Methods and Results: Primary cultured cardiomyocytes prepared from neonatal rats were treated with phenylephrine (PE). PE increased the acetylation of H3K9 and H3K122. The acetylation of H3K9 and H3K122 on the promoters of ANF and BNP, which are hypertrophic reaction genes, was increased in cardiomyocyte hypertrophy. To investigate whether the transcriptional coactivator p300 is involved in the acetylation of H3K9 and H3K122, p300 knockdown was used. p300 knockdown suppressed PE-induced cardiomyocyte hypertrophy and the acetylation of H3K9 and H3K122. In Dahl-salt sensitive rats, in vivo chromatin-immunoprecipitation assays revealed that the acetylation of H3K9 on the promoter of the hypertrophic response genes was significantly increased in LVH, but the acetylation of H3K122 was not increased in LVH. However, H3K122 acetylation was significantly increased in HF. On the other hand, there was no difference in the amount of recruitment of p300 in LVH and HF. Interestingly, immunoprecipitation-WB showed that binding of p300 with BRG1, a key component of the SWI/SNF complex, was enhanced in HF. The recruitment of BRG1 increased significantly in HF compared to LVH. Moreover, PFI-3, a BRG1 inhibitor, significantly suppressed a PE-induced increase in cardiomyocyte surface area, the mRNA levels of ANF and BNP, and the acetylation of H3K9 and H3K122 in cultured cardiomyocytes. Conclusion: This study demonstrates that the acetylation of H3K122 is enhanced via the interaction of p300 and BRG1 in heart failure, providing novel insights into the epigenetic regulatory mechanism governing transcriptional activity in these processes.

Evidence for a hyporesponsive limbic-hypothalamic-pituitary-adrenal axis following early-life repetitive hypoglycemia in adult male rats

2011 ◽  
Vol 301 (2) ◽  
pp. R484-R490 ◽  
Author(s):  
Ashton E. Lehmann ◽  
Kathleen Ennis ◽  
Michael K. Georgieff ◽  
Raghavendra Rao ◽  
Phu V. Tran
Keyword(s):  
Rat Model ◽  
Early Life ◽  
Regulatory Protein ◽  
Receptor Expression ◽  
Male Rats ◽  
Mrna Levels ◽  
Long Term Effects ◽  
Hypothalamic Pituitary Adrenal ◽  
Lhpa Axis

The developing limbic-hypothalamic-pituitary-adrenal (LHPA) axis is highly vulnerable to programming by early-life environmental factors, including exposure to synthetic glucocorticoids and nutrient deficiencies. Early-life repetitive hypoglycemia (RHG) is a common complication of insulin therapy for type-1 diabetes that may have long-term consequences in adulthood. Recent observations in a rat model of early RHG suggest persistent changes in LHPA axis function, including changes in relevant hormones and affective behaviors, which support a hyperresponsive LHPA axis. Thus, we hypothesized that early RHG would alter the expression of key genes regulating LHPA axis function in adulthood. The present study employed a rat model of insulin-induced RHG spanning postnatal days (P)24–28, a neurodevelopmental equivalent of early childhood in humans, to assess the long-term effects on mRNA levels for proteins relevant to the LHPA function and the corticosterone responses to ACTH stimulation of dispersed adrenocortical cells in vitro and restraint stress in vivo at adulthood. This early RHG model resulted in a hyporesponsive LHPA axis characterized by impaired corticosterone response, increased hippocampal glucocorticoid and mineralocorticoid receptor (GR and MR), decreased hypothalamic corticotropin-releasing hormone, increased adrenal steroidogenic-acute-regulatory protein and GR, and decreased adrenal MR, melanocortin-type-2 receptor and low-density lipoprotein receptor expression. Our findings highlight a complex environmental-gene interaction between RHG and LHPA axis during development that influences regulation of this axis in adulthood. The findings are consistent with the developmental origins of disease and underscore the influences of early-life events on the programming of a major regulatory system.

scholarly journals Nandrolone decanoate inhibits gluconeogenesis and decreases fasting glucose in Wistar male rats

2014 ◽  
Vol 220 (2) ◽  
pp. 143-153 ◽  
Author(s):  
Stephan Pinheiro Frankenfeld ◽  
Leonardo Pires de Oliveira ◽  
Daniele Leão Ignacio ◽  
Raquel Guimarães Coelho ◽  
Mariana Nigro Mattos ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Glucose Metabolism ◽  
Glucose Uptake ◽  
Glycogen Content ◽  
Liver Glycogen ◽  
Serum Levels ◽  
Male Rats ◽  
Nandrolone Decanoate ◽  
Liver Glycogen Content ◽  
The Impact

The use of anabolic–androgenic steroids to improve physical performance or appearance has increased notably. The doses used are 10- to 100- fold higher than the therapeutic dose (TD), and this abuse can cause several side effects. Glucose metabolism is significantly affected by anabolic–androgenic steroid abuse, but studies about glycemic regulation during fasting are scarce. There are some evidences showing that testosterone can antagonize glucocorticoids action, which are crucial to glucose production during fasting. Thus, the aim of this study was to determine the impact of supraphysiological doses (SDs) of nandrolone decanoate (DECA) on rat glucose metabolism during fasting. Male Wistar rats were treated with i.m. injections of vehicle, a low TD (0.016 mg/100 g b.w.-TD group) or a high SD (1 mg/100 g b.w.-SD group) of DECA, once a week for 8 weeks. After 12 h fasting, we evaluated glucose and pyruvate tolerance tests, liver glycogen content, serum levels of gluconeogenic substrates, insulin and corticosterone, glucose uptake and hexokinase (HK) activity in skeletal muscle, and the adrenal catecholamine content. SD group had increased serum insulin levels and a blunted response to insulin regarding glucose uptake in skeletal muscle. Fasting serum glucose decreased significantly in SD group, as well as the pyruvate tolerance test and liver glycogen content. Moreover, serum levels of glycerol were increased in SD group. Our data indicate that SDs of DECA exert effects on different regulatory points of glucose metabolism, resulting in defective gluconeogenesis and decreased skeletal muscle glucose uptake in response to insulin.

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