scholarly journals Resistance training and dietary protein: effects on glucose tolerance and contents of skeletal muscle insulin signaling proteins in older persons

2007 ◽  
Vol 85 (4) ◽  
pp. 1005-1013 ◽  
Author(s):  
Heidi B Iglay ◽  
John P Thyfault ◽  
John W Apolzan ◽  
Wayne W Campbell
Keyword(s):  
Skeletal Muscle ◽  
Resistance Training ◽  
Glucose Tolerance ◽  
Insulin Signaling ◽  
Dietary Protein ◽  
Older Persons ◽  
Signaling Proteins

scholarly journals AVE0991, a Nonpeptide Angiotensin 1-7 Receptor Agonist, Improves Glucose Metabolism in the Skeletal Muscle of Obese Zucker Rats: Possible Involvement of Prooxidant/Antioxidant Mechanisms

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Viktoria Dobrocsyova ◽  
Miroslava Slamkova ◽  
Katarina Krskova ◽  
Lucia Balazova ◽  
Maciej Suski ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Glucose Tolerance ◽  
Insulin Signaling ◽  
Receptor Agonist ◽  
Colorimetric Assay ◽  
Whole Body ◽  
Zucker Rats ◽  
Ros Generation ◽  
Morbidly Obese ◽  
Obese Zucker Rats

Angiotensin 1-7 (Ang 1-7) enhances insulin signaling and glucose transport activity in the skeletal muscle. The aim of our study was to evaluate the effect of AVE0991, a nonpeptide Mas receptor agonist, on the metabolic parameters, expression of RAS components and markers of oxidative stress, and insulin signaling in the skeletal morbidly obese rats. 33-week-old male obese Zucker rats were treated with vehicle and AVE0991 (0.5 mg/kg BW/day) via osmotic minipumps for two weeks. Gene expressions were determined by qPCR and/or Western blot analysis in musculus quadriceps. The enzymatic activities were detected flourometrically (aminopeptidase A) or by colorimetric assay kit (protein tyrosine phosphatase 1B). Administration of AVE0991 enhanced insulin signaling cascade in the skeletal muscle, reflected by improved whole-body glucose tolerance. It has been shown that reactive oxygen species (ROS) have insulin-mimetic action in muscle. The expression of renin receptor, transcription factor PLZF, and prooxidant genes was upregulated by AVE0991 accompanied by elevated expression of genes coding enzymes with antioxidant action. Our results show that AVE0991 administration activates genes involved in both ROS generation and clearance establishing a new prooxidant/antioxidant balance on a higher level, which might contribute to the improved insulin signaling pathway and glucose tolerance of obese Zucker rats.

Resistance training enhances components of the insulin signaling cascade in normal and high-fat-fed rodent skeletal muscle

2004 ◽  
Vol 96 (5) ◽  
pp. 1691-1700 ◽  
Author(s):  
Adam D. Krisan ◽  
Dale E. Collins ◽  
Andrew M. Crain ◽  
Connie C. Kwong ◽  
Mohenish K. Singh ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Resistance Training ◽  
Insulin Signaling ◽  
High Fat Diet ◽  
Protein Concentration ◽  
Signaling Cascade ◽  
Insulin Receptor Substrate ◽  
High Fat ◽  
Skeletal Muscle Insulin Resistance ◽  
Pkc Ζ

Our laboratory recently reported that chronic resistance training (RT) improved insulin-stimulated glucose transport in normal rodent skeletal muscle, owing, in part, to increased GLUT-4 protein concentration (Yaspelkis BB III, Singh MK, Trevino B, Krisan AD, and Collins DE. Acta Physiol Scand 175: 315-323, 2002). However, it remained to be determined whether these improvements resulted from alterations in the insulin signaling cascade as well. In addition, the possibility existed that RT might improve skeletal muscle insulin resistance. Thirty-two male Sprague-Dawley rats were assigned to four groups: control diet (Con)-sedentary (Sed); Con-RT; high-fat diet (HF)-Sed; and HF-RT. Animals consumed their respective diets for 9 wk; then RT animals performed 12 wk of training (3 sets, 10 repetitions at 75% one-repetition maximum, 3×/wk). Animals remained on their dietary treatments over the 12-wk period. After the training period, animals were subjected to hindlimb perfusions. Insulin-stimulated insulin receptor substrate-1-associated phosphatidylinositol-3 kinase activity was enhanced in the red gastrocnemius and quadriceps of Con-RT and HF-RT animals. Atypical PKC-ζ/λ and Akt activities were reduced in HF-Sed and normalized in HF-RT animals. Resistance training increased GLUT-4 protein concentration in red gastrocnemius and quadriceps of Con-RT and HF-RT animals. No differences were observed in total protein concentrations of insulin receptor substrate-1, Akt, atypical PKC-ζ/λ, or phosphorylation of Akt. Collectively, these findings suggest that resistance training increases insulin-stimulated carbohydrate metabolism in normal skeletal muscle and reverses high-fat diet-induced skeletal muscle insulin resistance by altering components of both the insulin signaling cascade and glucose transporter effector system.

Exercise does not alter subcellular localization, but increases phosphorylation of insulin-signaling proteins in human skeletal muscle

2006 ◽  
Vol 290 (2) ◽  
pp. E341-E346 ◽  
Author(s):  
Chris Wilson ◽  
Mark Hargreaves ◽  
Kirsten F. Howlett
Keyword(s):  
Skeletal Muscle ◽  
Signal Transduction ◽  
Subcellular Localization ◽  
Insulin Receptor ◽  
Protein Content ◽  
Insulin Signaling ◽  
Human Skeletal Muscle ◽  
Cellular Function ◽  
Cytosolic Fraction ◽  
Signaling Proteins

The subcellular localization of insulin signaling proteins is altered by various stimuli such as insulin, insulin-like growth factor I, and oxidative stress and is thought to be an important mechanism that can influence intracellular signal transduction and cellular function. This study examined the possibility that exercise may also alter the subcellular localization of insulin signaling proteins in human skeletal muscle. Nine untrained males performed 60 min of cycling exercise (∼67% peak pulmonary O2 uptake). Muscle biopsies were sampled at rest, immediately after exercise, and 3 h postexercise. Muscle was fractionated by centrifugation into the following crude fractions: cytosolic, nuclear, and a high-speed pellet containing membrane and cytoskeletal components. Fractions were analyzed for protein content of insulin receptor, insulin receptor substrate (IRS)-1 and -2, p85 subunit of phosphatidylinositol 3-kinase, Akt, and glycogen synthase kinase-3 (GSK-3). There was no significant change in the protein content of the insulin signaling proteins in any of the crude fractions after exercise or 3 h postexercise. Exercise had no significant effect on the phosphorylation of IRS-1 Tyr612 in any of the fractions. In contrast, exercise increased ( P < 0.05) the phosphorylation of Akt Ser473 and GSK-3α/β Ser9/21 in the cytosolic fraction only. In conclusion, exercise can increase phosphorylation of downstream insulin signaling proteins specifically in the cytosolic fraction but does not result in changes in the subcellular localization of insulin signaling proteins in human skeletal muscle. Change in the subcellular protein localization is therefore an unlikely mechanism to influence signal transduction pathways and cellular function in skeletal muscle after exercise.

scholarly journals Polycystic Ovary Syndrome Is Associated with Tissue-Specific Differences in Insulin Resistance

2009 ◽  
Vol 94 (1) ◽  
pp. 157-163 ◽  
Author(s):  
Theodore P. Ciaraldi ◽  
Vanita Aroda ◽  
Sunder Mudaliar ◽  
R. Jeffrey Chang ◽  
Robert R. Henry
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Glucose Tolerance ◽  
Polycystic Ovary ◽  
Whole Body ◽  
Glucose Disposal ◽  
Signaling Proteins ◽  
Impaired Insulin ◽  
Isolated Adipocytes ◽  
Insulin Responsiveness

Abstract Objective: The potential differential contributions of skeletal muscle and adipose tissue to whole body insulin resistance were evaluated in subjects with polycystic ovary syndrome (PCOS). Research Design and Methods: Forty-two PCOS subjects and 15 body mass index-matched control subjects were studied. Insulin action was evaluated by the hyperinsulinemic/euglycemic clamp procedure. Isolated adipocytes and cultured muscle cells were analyzed for glucose transport activity; adipocytes, muscle tissue, and myotubes were analyzed for the expression and phosphorylation of insulin-signaling proteins. Results: Fifty-seven per cent of the PCOS subjects had impaired glucose tolerance and the lowest rate of maximal insulin-stimulated whole body glucose disposal compared to controls (P &lt; 0.01). PCOS subjects with normal glucose tolerance had intermediate reduction in glucose disposal rate (P &lt; 0.05 vs. both control and impaired glucose tolerance subjects). However, rates of maximal insulin-stimulated glucose transport (insulin responsiveness) into isolated adipocytes were comparable between all three groups, whereas PCOS subjects displayed impaired insulin sensitivity. In contrast, myotubes from PCOS subjects displayed reduced insulin responsiveness for glucose uptake and normal sensitivity. There were no differences between groups in the expression of glucose transporter 4 or insulin-signaling proteins or maximal insulin stimulation of phosphorylation of Akt in skeletal muscle, myotubes, or adipocytes. Conclusions: Individuals with PCOS display impaired insulin responsiveness in skeletal muscle and myotubes, whereas isolated adipocytes display impaired insulin sensitivity but normal responsiveness. Skeletal muscle and adipose tissue contribute differently to insulin resistance in PCOS. Insulin resistance in PCOS cannot be accounted for by differences in the expression of selected signaling molecules or maximal phosphorylation of Akt.

Abnormal glucose homeostasis in adult female rat offspring after intrauterine ethanol exposure

2007 ◽  
Vol 292 (5) ◽  
pp. R1926-R1933 ◽  
Author(s):  
Xing-Hai Yao ◽  
B. L. Grégoire Nyomba
Keyword(s):  
Skeletal Muscle ◽  
Glucose Tolerance ◽  
Adult Female ◽  
Insulin Signaling ◽  
Glucose Transporter ◽  
Female Offspring ◽  
Female Rat ◽  
Glucose Transporter 4 ◽  
Insulin Resistant ◽  
Rat Offspring

Adverse events during pregnancy, including prenatal ethanol (EtOH) exposure, are associated with insulin-resistant diabetes in male rat offspring, but it is unclear whether this is true for female offspring. We investigated whether prenatal EtOH exposure alters glucose metabolism in adult female rat offspring and whether this is associated with reduced in vivo insulin signaling in skeletal muscle. Female Sprague-Dawley rats were given EtOH, 4 g·kg−1·day−1 by gavage throughout pregnancy. Glucose tolerance test and hyperinsulinemic euglycemic clamp were performed, and insulin signaling was investigated in skeletal muscle, in adult female offspring. We gave insulin intravenously to these rats and determined the association of glucose transporter-4 with plasma membranes, as well as the phosphorylation of phosphoinositide-dependent protein kinase-1 (PDK1), Akt, and PKCζ. Although EtOH offspring had normal birth weight, they were overweight as adults and had fasting hyperglycemia, hyperinsulinemia, and reduced insulin-stimulated glucose uptake. After insulin treatment, EtOH-exposed rats had decreased membrane glucose transporter-4, PDK1, Akt, and PKCζ in the gastrocnemius muscle, compared with control rats. Insulin stimulation of PDK1, Akt, and PKCζ phosphorylation was also reduced. In addition, the expression of the protein tribbles-3 and the phosphatase enzyme activity of phosphatase and tensin homolog deleted on chromosome 10 (PTEN), which prevent Akt activation, were increased in muscle from EtOH-exposed rats. Female rat offspring exposed to EtOH in utero develop insulin-resistant diabetes in association with excessive PTEN and tribbles-3 signaling downstream of the phosphatidylinositol 3-kinase pathway in skeletal muscle, which may be a mechanism for the abnormal glucose tolerance.

The response of insulin signaling proteins IRS1 and PTP-1B to endurance, HIIT and resistance training in rats with experimental diabetes

2019 ◽  
Vol 34 (3) ◽  
pp. e229-e233
Author(s):  
R. Soori ◽  
A.A. Ravasi ◽  
S. Choobineh ◽  
M. Motiee ◽  
F. Sohrabi ◽  
...  
Keyword(s):  
Resistance Training ◽  
Insulin Signaling ◽  
Experimental Diabetes ◽  
Signaling Proteins ◽  
Ptp 1B

Calorie restriction initiated at middle age improved glucose tolerance without affecting age-related impairments of insulin signaling in rat skeletal muscle

2006 ◽  
Vol 41 (9) ◽  
pp. 837-845 ◽  
Author(s):  
Seongjoon Park ◽  
Toshimitsu Komatsu ◽  
Hiroko Hayashi ◽  
Haruyoshi Yamaza ◽  
Takuya Chiba ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Glucose Tolerance ◽  
Calorie Restriction ◽  
Insulin Signaling ◽  
Middle Age ◽  
Rat Skeletal Muscle ◽  
Age Related

Effects of hormone therapy on insulin signaling proteins in skeletal muscle of cynomolgus monkeys

Steroids ◽  
2004 ◽  
Vol 69 (5) ◽  
pp. 313-318 ◽  
Author(s):  
Melanie K Shadoan ◽  
Li Zhang ◽  
Janice D Wagner
Keyword(s):  
Skeletal Muscle ◽  
Hormone Therapy ◽  
Insulin Signaling ◽  
Signaling Proteins ◽  
Cynomolgus Monkeys

scholarly journals Muscle Specific Insulin Receptor Overexpression Protects Mice from Diet-Induced Glucose Intolerance but Leads to Post-Receptor Insulin Resistance

2020 ◽  
Author(s):  
Ada Admin ◽  
Guoxiao Wang ◽  
Yingying Yu ◽  
Weikang Cai ◽  
Thiago M. Batista ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Glucose Tolerance ◽  
Insulin Receptor ◽  
Insulin Signaling ◽  
Insulin Receptors ◽  
Akt Phosphorylation ◽  
Skeletal Muscle Insulin Resistance ◽  
Diet Induced Obesity ◽  
Similar Body

Skeletal muscle insulin resistance is a prominent early feature in the pathogenesis of type 2 diabetes (T2D). In attempt to overcome this defect, we generated mice overexpressing insulin receptors (IR) specifically in skeletal muscle (IRMOE). On normal chow, IRMOE mice have similar body weight as controls, but an increase in lean mass and glycolytic muscle fibers and reduced fat mass. IRMOE mice also show higher basal phosphorylation of IR, IRS-1 and Akt in muscle and improved glucose tolerance compared to controls. When challenged with high fat diet (HFD), IRMOE mice are protected from diet-induced obesity. This is associated with reduced inflammation in fat and liver, improved glucose tolerance and improved systemic insulin sensitivity. Surprisingly, however, in both chow and HFD-fed mice, insulin stimulated Akt phosphorylation is significantly reduced in muscle of IRMOE mice, indicating post-receptor insulin resistance. RNA sequencing reveals downregulation of several post-receptor signaling proteins that contribute to this resistance. Thus, enhancing early insulin signaling in muscle by overexpression of the insulin receptor protects mice from diet-induced obesity and its effects on glucose metabolism. However, chronic overstimulation of this pathway leads to post-receptor desensitization, indicating the critical balance between normal signaling and hyperstimulation of the insulin signaling pathway.

Sign in / Sign up

Export Citation Format

Share Document