Exercise Effects on γ3-AMPK Activity, Akt Substrate of 160 kDa Phosphorylation, and Glucose Uptake in Muscle of Normal and Insulin Resistant Female Rats

2021 ◽  
Author(s):  
Haiyan Wang ◽  
Edward B. Arias ◽  
Jonas T. Treebak ◽  
Gregory D. Cartee
Keyword(s):  
Glucose Uptake ◽  
High Fat Diet ◽  
Skeletal Muscles ◽  
Acute Exercise ◽  
Female Rats ◽  
Male Rats ◽  
Signaling Proteins ◽  
Insulin Resistant ◽  
Low Fat Diet ◽  
Ampk Activity

Previous studies demonstrated that acute exercise can enhance glucose uptake (GU), γ3-AMPK activity, and Akt Substrate of 160 kDa (AS160) phosphorylation in skeletal muscles from low fat diet (LFD) and high fat diet (HFD) fed male rats. Because little is known about exercise-effects on these outcomes in females, we assessed postexercise GU by muscles incubated ±insulin, delta-insulin GU (GU of muscles incubated with insulin minus GU uptake of paired muscles incubated without insulin), and muscle signaling proteins from female rats fed a LFD or brief-HFD (2wk). Rats were sedentary (LFD-SED, HFD-SED) or swim-exercised. Immediately postexercise (IPEX) or 3h postexercise (3hPEX), epitrochlearis muscles were incubated (no insulin IPEX; ±insulin 3hPEX) to determine GU. Muscle γ3-AMPK activity (IPEX, 3hPEX) and phosphorylated AS160 (pAS160; 3hPEX) were also assessed. γ3-AMPK activity and insulin-independent GU of IPEX-rats exceeded sedentary-rats without diet-related differences in either outcome. At 3hPEX, both GU by insulin-stimulated muscles and delta-insulin GU exceeded their respective diet-matched sedentary controls. GU by insulin-stimulated muscles, but not delta-insulin GU for LFD-3hPEX exceeded HFD-3hPEX. LFD-3hPEX versus LFD-SED had greater γ3-AMPK activity and greater pAS160. HFD-3hPEX exceeded HFD-SED for pAS160, but not for γ3-AMPK activity. pAS160 and γ3-AMPK at 3hPEX did not differ between diet-groups. These results revealed that increased γ3-AMPK activity at 3hPEX was not essential for greater GU in insulin-stimulated muscle or greater delta-insulin GU in HFD-female rats. Similarly elevated γ3-AMPK activity in LFD-IPEX versus HFD-IPEX and pAS160 in LFD-3hPEX versus HFD-3hPEX may contribute to the comparable, delta-insulin GU at 3hPEX in both diet groups.

scholarly journals Skeletal muscle fiber type-selective effects of acute exercise on insulin-stimulated glucose uptake in insulin-resistant, high-fat-fed rats

2019 ◽  
Vol 316 (5) ◽  
pp. E695-E706 ◽  
Author(s):  
Mark W. Pataky ◽  
Carmen S. Yu ◽  
Yilin Nie ◽  
Edward B. Arias ◽  
Manak Singh ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Glucose Uptake ◽  
Acute Exercise ◽  
Fiber Type ◽  
Single Fiber ◽  
Male Rats ◽  
Type I ◽  
Fiber Types ◽  
High Fat ◽  
Insulin Resistant

Insulin-stimulated glucose uptake (GU) by skeletal muscle is enhanced several hours after acute exercise in rats with normal or reduced insulin sensitivity. Skeletal muscle is composed of multiple fiber types, but exercise’s effect on fiber type-specific insulin-stimulated GU in insulin-resistant muscle was previously unknown. Male rats were fed a high-fat diet (HFD; 2 wk) and were either sedentary (SED) or exercised (2-h exercise). Other, low-fat diet-fed (LFD) rats remained SED. Rats were studied immediately postexercise (IPEX) or 3 h postexercise (3hPEX). Epitrochlearis muscles from IPEX rats were incubated in 2-deoxy-[3H]glucose (2-[3H]DG) without insulin. Epitrochlearis muscles from 3hPEX rats were incubated with 2-[3H]DG ± 100 µU/ml insulin. After single fiber isolation, GU and fiber type were determined. Glycogen and lipid droplets (LDs) were assessed histochemically. GLUT4 abundance was determined by immunoblotting. In HFD-SED vs. LFD-SED rats, insulin-stimulated GU was decreased in type IIB, IIX, IIAX, and IIBX fibers. Insulin-independent GU IPEX was increased and glycogen content was decreased in all fiber types (types I, IIA, IIB, IIX, IIAX, and IIBX). Exercise by HFD-fed rats enhanced insulin-stimulated GU in all fiber types except type I. Single fiber analyses enabled discovery of striking fiber type-specific differences in HFD and exercise effects on insulin-stimulated GU. The fiber type-specific differences in insulin-stimulated GU postexercise in insulin-resistant muscle were not attributable to a lack of fiber recruitment, as indirectly evidenced by insulin-independent GU and glycogen IPEX, differences in multiple LD indexes, or altered GLUT4 abundance, implicating fiber type-selective differences in the cellular processes responsible for postexercise enhancement of insulin-mediated GLUT4 translocation.

29-LB: Exercise Effects on ?3-AMPK Activity, Akt Substrate of 160 kDa Phosphorylation, and Glucose Uptake in Muscle of Normal and Insulin-Resistant Female Rats

Diabetes ◽  
2021 ◽  
Vol 70 (Supplement 1) ◽  
pp. 29-LB
Author(s):  
HAIYAN WANG ◽  
EDWARD B. ARIAS ◽  
AMY ZHENG ◽  
SEONGEUN KWAK ◽  
JIAHUI ZHAO ◽  
...  
Keyword(s):  
Glucose Uptake ◽  
Female Rats ◽  
Insulin Resistant ◽  
Ampk Activity

Trafficking of dietary fat in obesity-prone and obesity-resistant rats

2006 ◽  
Vol 291 (5) ◽  
pp. E1083-E1091 ◽  
Author(s):  
Matthew R. Jackman ◽  
Robert E. Kramer ◽  
Paul S. MacLean ◽  
Daniel H. Bessesen
Keyword(s):  
Dietary Fat ◽  
High Fat Diet ◽  
Skeletal Muscles ◽  
Tracer Uptake ◽  
Female Rats ◽  
Male Rats ◽  
Gi Tract ◽  
Feeding Tubes ◽  
Male And Female Rats ◽  
Gastric Feeding

The trafficking of dietary fat was assessed in obesity-prone (OP) and obesity-resistant (OR) male and female rats. Test meals containing [1-14C]palmitate were delivered through gastric feeding tubes while rats consumed a high-carbohydrate diet (HCD) or after 5 days of a high-fat diet (HFD). Over the subsequent 24 h, the appearance of 14C was followed in the GI tract, skeletal muscles (SM), liver, adipose tissues (AT), and expired CO2. There was no difference in the production of 14CO2 between OP and OR rats consuming a HCD. However, after 5 days on HFD, OR rats produced significantly more 14CO2 after the test meal than OP rats ( P < 0.001 females, P = 0.03 males). The differential oxidation of dietary fat between OP and OR rats on HFD was not due to differences in absorption but rather was associated with preferential disposition of tracer to AT in OP rats. Measurements of lipoprotein lipase in part explained increased tracer uptake by AT in OP rats but were not consistent with increased SM tracer uptake in OR rats. Surprisingly, female rats oxidized more tracer than male rats irrespective of phenotype or diet. These results are consistent with the notion that differences in the partitioning of dietary fat between storage in AT and oxidation in SM and liver that develop shortly after the introduction of a HFD may in part underlie the differential tendency for OR and OP rats to gain weight on this diet.

scholarly journals Effects of a brief high-fat diet and acute exercise on the mTORC1 and IKK/NF-κB pathways in rat skeletal muscle

2015 ◽  
Vol 40 (3) ◽  
pp. 251-262 ◽  
Author(s):  
Carlos M. Castorena ◽  
Edward B. Arias ◽  
Naveen Sharma ◽  
Gregory D. Cartee
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Glucose Uptake ◽  
High Fat Diet ◽  
Acute Exercise ◽  
Exercise Session ◽  
High Fat ◽  
Insulin Resistant ◽  
Mtorc1 Pathway ◽  
Exercise Induced

One exercise session can improve subsequent insulin-stimulated glucose uptake by skeletal muscle in healthy and insulin-resistant individuals. Our first aim was to determine whether a brief (2 weeks) high-fat diet (HFD) that caused muscle insulin resistance would activate the mammalian target of rapamycin complex 1 (mTORC1) and/or inhibitor of κB kinase/nuclear factor κB (IKK/NF-κB) pathways, which are potentially linked to induction of insulin resistance. Our second aim was to determine whether acute exercise that improved insulin-stimulated glucose uptake by muscles would attenuate activation of these pathways. We compared HFD-fed rats with rats fed a low-fat diet (LFD). Some animals from each diet group were sedentary and others were studied 3 h postexercise, when insulin-stimulated glucose uptake was increased. The results did not provide evidence that brief HFD activated either the mTORC1 (including phosphorylation of mTORSer2448, TSC2Ser939, p70S6KThr412, and RPS6Ser235/236) or the IKK/NF-κB (including abundance of IκBα or phosphorylation of NF-κBSer536, IKKα/βSer177/181, and IκBSer32) pathway in insulin-resistant muscles. Exercise did not oppose the activation of either pathway, as evidenced by no attenuation of phosphorylation of key proteins in the IKK/NF-κB pathway (NF-κBSer536, IKKα/βSer177/181, and IκBSer32), unaltered IκBα abundance, and no attenuation of phosphorylation of key proteins in the mTORC1 pathway (mTORSer2448, TSC2Ser939, and RPS6Ser235/236). Instead, exercise induced greater phosphorylation of 2 proteins of the mTORC1 pathway (PRAS40Thr246 and p70S6KThr412) in insulin-stimulated muscles, regardless of diet. Insulin resistance induced by a brief HFD was not attributable to greater activation of the mTORC1 or the IKK/NF-κB pathway in muscle, and exercise-induced improvement in insulin sensitivity was not attributable to attenuated activation of these pathways in muscle.

scholarly journals Exercise effects on γ3-AMPK activity, phosphorylation of Akt2 and AS160, and insulin-stimulated glucose uptake in insulin-resistant rat skeletal muscle

2020 ◽  
Vol 128 (2) ◽  
pp. 410-421
Author(s):  
Mark W. Pataky ◽  
Edward B. Arias ◽  
Haiyan Wang ◽  
Xiaohua Zheng ◽  
Gregory D. Cartee
Keyword(s):  
Skeletal Muscle ◽  
Glucose Uptake ◽  
Exercise Session ◽  
Protein Kinase Activity ◽  
Insulin Resistant ◽  
Low Fat Diet ◽  
Ampk Activity ◽  
Exercise Induced ◽  
Amp Activated Protein Kinase ◽  
First Time

One exercise session can increase subsequent insulin-stimulated glucose uptake (ISGU) by skeletal muscle. Prior research on healthy muscle suggests that enhanced postexercise ISGU depends on elevated γ3-AMPK activity leading to greater phosphorylation of Akt substrate of 160 kDa (pAS160) on an AMPK-phosphomotif (Ser704). Phosphorylation of AS160Ser704, in turn, may favor greater insulin-stimulated pAS160 on an Akt-phosphomotif (Thr642) that regulates ISGU. Accordingly, we tested if exercise-induced increases in γ3-AMPK activity and pAS160 on key regulatory sites accompany improved ISGU at 3 h postexercise (3hPEX) in insulin-resistant muscle. Rats fed a high-fat diet (HFD; 2-wk) that induces insulin resistance either performed acute swim-exercise (2 h) or were sedentary (SED). SED rats fed a low-fat diet (LFD; 2 wk) served as healthy controls. Isolated epitrochlearis muscles from 3hPEX and SED rats were analyzed for ISGU, pAS160, pAkt2 (Akt-isoform that phosphorylates pAS160Thr642), and γ1-AMPK and γ3-AMPK activity. ISGU was lower in HFD-SED muscles versus LFD-SED, but this decrement was eliminated in the HFD-3hPEX group. γ3-AMPK activity, but not γ1-AMPK activity, was elevated in HFD-3hPEX muscles versus both SED controls. Furthermore, insulin-stimulated pAS160Thr642, pAS160Ser704, and pAkt2Ser474 in HFD-3hPEX muscles were elevated above HFD-SED and equal to values in LFD-SED muscles, but insulin-independent pAS160Ser704 was unaltered at 3hPEX. These results demonstrated, for the first time in an insulin-resistant model, that the postexercise increase in ISGU was accompanied by sustained enhancement of γ3-AMPK activation and greater pAkt2Ser474. Our working hypothesis is that these changes along with enhanced insulin-stimulated pAS160 increase ISGU of insulin-resistant muscles to values equaling insulin-sensitive sedentary controls. NEW & NOTEWORTHY Earlier research focusing on signaling events linked to increased insulin sensitivity in muscle has rarely evaluated insulin resistant muscle after exercise. We assessed insulin resistant muscle after an exercise protocol that improved insulin-stimulated glucose uptake. Prior exercise also amplified several signaling steps expected to favor enhanced insulin-stimulated glucose uptake: increased γ3-AMP-activated protein kinase activity, greater insulin-stimulated Akt2 phosphorylation on Ser474, and elevated insulin-stimulated Akt substrate of 160 kDa phosphorylation on Ser588, Thr642, and Ser704.

scholarly journals Fiber type-specific effects of acute exercise on insulin-stimulated AS160 phosphorylation in insulin-resistant rat skeletal muscle

2019 ◽  
Vol 317 (6) ◽  
pp. E984-E998
Author(s):  
Mark W. Pataky ◽  
Sydney L. Van Acker ◽  
Rhea Dhingra ◽  
Marina M. Freeburg ◽  
Edward B. Arias ◽  
...  
Keyword(s):  
High Fat Diet ◽  
Acute Exercise ◽  
Fiber Type ◽  
Type I ◽  
Fiber Types ◽  
High Fat ◽  
Insulin Resistant ◽  
Specific Effects ◽  
Heterogeneous Tissue ◽  
Whole Muscle

Muscle is a heterogeneous tissue composed of multiple fiber types. Earlier research revealed fiber type-selective postexercise effects on insulin-stimulated glucose uptake (ISGU) from insulin-resistant rats (increased for type IIA, IIB, IIBX, and IIX, but not type I). In whole muscle from insulin-resistant rats, the exercise increase in ISGU is accompanied by an exercise increase in insulin-stimulated AS160 phosphorylation (pAS160), an ISGU-regulating protein. We hypothesized that, in insulin-resistant muscle, the fiber type-selective exercise effects on ISGU would correspond to the fiber type-selective exercise effects on pAS160. Rats were fed a 2-wk high-fat diet (HFD) and remained sedentary (SED) or exercised before epitrochlearis muscles were dissected either immediately postexercise (IPEX) or at 3 h postexercise (3hPEX) using an exercise protocol that previously revealed fiber type-selective effects on ISGU. 3hPEX muscles and SED controls were incubated ± 100µU/mL insulin. Individual myofibers were isolated and pooled on the basis of myosin heavy chain (MHC) expression, and key phosphoproteins were measured. Myofiber glycogen and MHC expression were evaluated in muscles from other SED, IPEX, and 3hPEX rats. Insulin-stimulated pAktSer473 and pAktThr308 were unaltered by exercise in all fiber types. Insulin-stimulated pAS160 was greater for 3hPEX vs. SED on at least one phosphosite (Ser588, Thr642, and/or Ser704) in type IIA, IIBX, and IIB fibers, but not in type I or IIX fibers. Both IPEX and 3hPEX glycogen were decreased versus SED in all fiber types. These results provided evidence that fiber type-specific pAS160 in insulin-resistant muscle may play a role in the previously reported fiber type-specific elevation in ISGU in some, but not all, fiber types.

scholarly journals High-fat diet-induced hypertension is associated with a proinflammatory T cell profile in male and female Dahl salt-sensitive rats

2018 ◽  
Vol 315 (6) ◽  
pp. H1713-H1723 ◽  
Author(s):  
Lia E. Taylor ◽  
Ellen E. Gillis ◽  
Jacqueline B. Musall ◽  
Babak Baban ◽  
Jennifer C. Sullivan
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
High Fat Diet ◽  
Female Rats ◽  
Male Rats ◽  
High Fat ◽  
Male And Female ◽  
The Impact ◽  
Cell Profile

Evidence supports a sex difference in the impact of a high-fat diet (HFD) on cardiovascular outcomes, with male experimental animals exhibiting greater increases in blood pressure (BP) than female experimental animals. The immune system has been implicated in HFD-induced increases in BP, and there is a sex difference in T-cell activation in hypertension. The goal of this study was to determine the impact of HFD on BP and aortic and renal T cell profiles in male and female Dahl salt-sensitive (DSS) rats. We hypothesized that male DSS rats would have greater increases in BP and T cell infiltration in response to a HFD compared with female DSS rats. BP was measured by tail-cuff plethysmography, and aortic and renal T cells were assessed by flow cytometric analysis in male and female DSS rats on a normal-fat diet (NFD) or HFD from 12 to 16 wk of age. Four weeks of HFD increased BP in male and female DSS rats to a similar degree. Increases in BP were accompanied by increased percentages of CD4+ T cells and T helper (Th)17 cells in both sexes, although male rats had more proinflammatory T cells. Percentages of renal CD3+ and CD4+ T cells as well as Th17 cells were increased in both sexes by the HFD, although the increase in CD3+ T cells was greater in male rats. HFD also decreased the percentage of aortic and renal regulatory T cells in both sexes, although female rats maintained more regulatory T cells than male rats regardless of diet. In conclusion, both male and female DSS rats exhibit BP sensitivity to a HFD; however, the mechanisms mediating HFD-induced increases in BP may be distinct as male rats exhibit greater increases in the percentage of proinflammatory T cells than female rats. NEW & NOTEWORTHY Our study demonstrates that male and female Dahl salt-sensitive rats exhibit similar increases in blood pressure to a high-fat diet and an increase in aortic and renal T cells. These results are in contrast to studies showing that female rats remain normotensive and/or upregulate regulatory T cells in response to hypertensive stimuli compared with male rats. Our data suggest that a 4-wk high-fat diet has sex-specific effects on the T cell profile in Dahl salt-sensitive rats.

scholarly journals Herring Milt and Herring Milt Protein Hydrolysate Reduce Weight Gain and Improve Insulin Sensitivity and Pancreatic Beta-Cell Function in Diet-Induced Obese Mice

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1699-1699
Author(s):  
Yanwen Wang ◽  
Sandhya Nair ◽  
Jacques Gagnon
Keyword(s):  
Insulin Resistance ◽  
High Fat Diet ◽  
Cell Function ◽  
Protein Hydrolysate ◽  
Oral Glucose ◽  
High Fat ◽  
Low Fat ◽  
Insulin Resistant ◽  
Low Fat Diet ◽  
Dietary Casein

Abstract Objectives The present study was designed to examine the effect of herring milt dry powder (HMDP) on glucose homeostasis and related metabolic phenotypes and compare its efficacy with herring milt protein hydrolysate (HMPH) in diet-induced obese and insulin resistant mice. Methods Male C57BL/6 J mice were pretreated with a high-fat diet for 7 weeks were divided into 3 groups where one group continued on the high-fat diet and used as the obese and insulin resistant control (HFC) and the other two groups were fed a modified HFC diet where 70% of casein was replaced with an equal percentage of protein derived from HMDP or HMPH. A group of mice fed a low-fat diet all the time was used as the normal or low-fat control (LFC). Body weight was obtained weekly and food intake was recorded daily. Semi-fating (4–6 hr) blood glucose was measured every other week using a glucometer using the blood from tail vein. Oral glucose tolerance was measured twice during weeks 5 and 9, respectively, and insulin tolerance was determined during week 7 of the treatment. At the end of the experiment, serum was obtained following overnight fasting for the measurement of fasting insulin, leptin, free fatty acids and lipids as well as other glucose metabolism-related biomarkers. Results During the 9-week treatment period, mice on the high-fat diet maintained significantly higher body weight and semi-fasting blood glucose levels and exhibited impaired oral glucose tolerance and insulin resistance relative to mice on the low-fat diet. At the end of the study, the analysis of fasting blood samples revealed that mice on the high-fat diet had increases in serum insulin, leptin, free fatty acids and cholesterol levels. Mice fed the high-fat diet also showed an increase in insulin resistance index and a decrease in β-cell function index. Compared to mice on the high-fat diet, the 70% replacement of dietary casein with an equal percentage of protein derived from HMDP or HMPH reversed or markedly improved these parameters, and HMDP and HMPH showed similar effects. Conclusions The results demonstrate that replacing dietary casein with the same amount of protein derived from either HMDP or HMPH prevents and improves high-fat-diet-induced obesity and insulin resistance. Funding Sources Atlantic Canada Opportunity Agency through the Atlantic Innovation Fund grant (no. 193,594) and National Research Council of Canada – NHP program.

scholarly journals Study on optimization and stability of a single dose streptozotocin-induced diabetic modeling in rats

2020 ◽  
Author(s):  
Yao Zhang ◽  
jiao Zhang ◽  
Ming Hong ◽  
Jingyi Huang ◽  
Rui Wang ◽  
...  
Keyword(s):  
Blood Glucose ◽  
High Fat Diet ◽  
Female Rats ◽  
Male Rats ◽  
Control Group ◽  
High Fat ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Sd Rats ◽  
Male And Female Rats

Abstract BackgroundOptimization of experimental conditions in streptozotocin induced diabetic model in Sprague Dawley (SD) rats to evaluate the stability of the model.MethodsMale and female SD rats were randomly divided into control group, STZ 45 group (STZ: 45 mg / kg), STZ 65 group (STZ: 65 mg / kg), STZ 85 group (STZ: 85 mg / kg), high fat diet with STZ 45 group (STZ: 45 mg / kg), high fat diet with STZ 65 group (STZ: 65 mg / kg), high fat diet with STZ 85 group (STZ: 85 mg / kg). N = 6 in each group. The changes of body weight and blood glucose were observed dynamically.ResultsThere was no significant difference in blood glucose or body weight between the STZ 45 group and the control group in both male and female rats, whether or not they were on a high-fat diet. However, there were significant differences in blood glucose between the high-dose STZ group and the control group in both male and female rats, regardless of whether the rats were on a high-fat diet or not (P < 0.05 or P < 0.01). Compared with the control group, there were significant differences in blood glucose levels (P < 0.05 or P < 0.01) and higher blood glucose levels in the male rats fed with the normal diet than that in those fed with the high-fat diet.ConclusionsIn this study, male rats fed with ordinary feed and injected STZ dose of 65 mg / kg were the most stable and ideal diabetic rat.

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