scholarly journals Regulation of pyruvate dehydrogenase and pyruvate dehydrogenase phosphate phosphatase activity in rat epididymal fat-pads. Effects of starvation, alloxan-diabetes and high-fat diet

1976 ◽  
Vol 154 (1) ◽  
pp. 225-236 ◽  
Author(s):  
D Stansbie ◽  
R M Denton ◽  
B J Bridges ◽  
H T Pask ◽  
P J Randle
Keyword(s):  
Phosphatase Activity ◽  
Dehydrogenase Activity ◽  
Pyruvate Dehydrogenase ◽  
High Fat Diet ◽  
Alloxan Diabetes ◽  
Mitochondrial Activity ◽  
High Fat ◽  
Epididymal Fat ◽  
Fat Pads

1. Pyruvate dehydrogenase phosphate phosphatase activity in rat epididymal fat-pads was measured by using pig heart pyruvate dehydrogenase [32P]phosphate. About 80% was found to be extramitochondrial and therefore probably not directly concerned with the regulation of pyruvate dehydrogenase activity. The extramitochondrial activity was sensitive to activation by +, but perhaps less sensitive than the mitochondrial activity.

Lipogenesis in adipose tissue of rats fed different diets

1961 ◽  
Vol 201 (6) ◽  
pp. 1041-1043 ◽  
Author(s):  
J. M. Khanade ◽  
M. C. Nath
Keyword(s):  
Adipose Tissue ◽  
Glucose Uptake ◽  
Alloxan Diabetes ◽  
High Protein ◽  
Vitamin B ◽  
High Fat ◽  
Epididymal Fat ◽  
Increase Glucose Uptake ◽  
Fat Pads

Lipogenesis and glucose uptake by epididymal fat pads of rats fed different diets have been investigated. Lipogenesis was found to be depressed in rats fed high fat, high fat and high protein, thyroid, thiouracil, and thiamine-deficient diets. The same dose of insulin causes varying degrees of lipogenesis in the tissues, depending on the type of diet fed previously. Lipogenesis is above normal in hydrolyzed glucose-cycloacetoacetate-fed rats but glucose uptake is not appreciably affected. The glucose uptake of adipose tissue is significantly depressed in rats fed high fat, high fat with high protein, and vitamin B1 deficient diets, and in rats with hypothyroidism. Both hyperthyroidism and hydrolyzed glucose-cycloacetoacetate feeding increase glucose uptake by the tissue. Alloxan diabetes reduces lipogenesis as well as glucose uptake.

scholarly journals Inactivation of rat adipocyte pyruvate dehydrogenase by palmitate. Protection against this effect by insulin in the presence of glucose

1979 ◽  
Vol 184 (1) ◽  
pp. 59-62 ◽  
Author(s):  
S R Sooranna ◽  
E D Saggerson
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Dehydrogenase Activity ◽  
Pyruvate Dehydrogenase ◽  
Protective Action ◽  
Active Form ◽  
Rat Plasma ◽  
Epididymal Fat ◽  
Fat Pads

1. Adipocytes from rat epididymal fat-pads were incubated for 30 min with 5 mM-glucose and concentrations of lactate, pyruvate and amino acids typical of those found in rat plasma. 2. PDHa (active form of pyruvate dehydrogenase) activity was significantly increased after incubation of the cells with insulin (200 micro-i.u./ml), and decreased by incubation with palmitate (0.5–2 mM). 3. In the presence of insulin, palmitate did not decrease PDHa activity. 4. Dichloroacetate (1 mM) increased PDHa activity in the absence of palmitate to the same extent as did insulin. In the presence of dichloroacetate but the absence of insulin, palmitate decreased PDHa activity. In the presence of dichloroacetate and insulin, palmitate again did not decrease PDHa activity. 5. It is concluded that, in the presence of glucose, insulin has a strong protective action against inactivation of adipocyte PDHa by fatty acids.

scholarly journals High-Fat Diet Leads to Reduced Protein O-GlcNAcylation and Mitochondrial Defects Promoting the Development of Alzheimer’s Disease Signatures

2021 ◽  
Vol 22 (7) ◽  
pp. 3746
Author(s):  
Ilaria Zuliani ◽  
Chiara Lanzillotta ◽  
Antonella Tramutola ◽  
Eugenio Barone ◽  
Marzia Perluigi ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Insulin Resistance ◽  
Alzheimer's Disease ◽  
High Fat Diet ◽  
Mitochondrial Activity ◽  
High Fat ◽  
Hexosamine Biosynthetic Pathway ◽  
Neurodegenerative Process ◽  
The Brain

The disturbance of protein O-GlcNAcylation is emerging as a possible link between altered brain metabolism and the progression of neurodegeneration. As observed in brains with Alzheimer’s disease (AD), flaws of the cerebral glucose uptake translate into reduced protein O-GlcNAcylation, which promote the formation of pathological hallmarks. A high-fat diet (HFD) is known to foster metabolic dysregulation and insulin resistance in the brain and such effects have been associated with the reduction of cognitive performances. Remarkably, a significant role in HFD-related cognitive decline might be played by aberrant protein O-GlcNAcylation by triggering the development of AD signature and mitochondrial impairment. Our data support the impairment of total protein O-GlcNAcylation profile both in the brain of mice subjected to a 6-week high-fat-diet (HFD) and in our in vitro transposition on SH-SY5Y cells. The reduction of protein O-GlcNAcylation was associated with the development of insulin resistance, induced by overfeeding (i.e., defective insulin signaling and reduced mitochondrial activity), which promoted the dysregulation of the hexosamine biosynthetic pathway (HBP) flux, through the AMPK-driven reduction of GFAT1 activation. Further, we observed that a HFD induced the selective impairment of O-GlcNAcylated-tau and of O-GlcNAcylated-Complex I subunit NDUFB8, thus resulting in tau toxicity and reduced respiratory chain functionality respectively, highlighting the involvement of this posttranslational modification in the neurodegenerative process.

scholarly journals Anti-obesity Effect of (8-E)-Nüzhenide, a Secoiridoid from Ligustrum lucidum, in High-fat Diet-induced Obese Mice

2014 ◽  
Vol 9 (10) ◽  
pp. 1934578X1400901 ◽  
Author(s):  
Qing Liu ◽  
Sang Hyun Kim ◽  
Seon Beom Kim ◽  
Yang Hee Jo ◽  
Eun Sil Kim ◽  
...  
Keyword(s):  
Body Weight ◽  
High Fat Diet ◽  
Body Weight Gain ◽  
Treated Group ◽  
The Body ◽  
Metabolic Parameters ◽  
Obese Mice ◽  
High Fat ◽  
Ligustrum Lucidum ◽  
Epididymal Fat

The effect of the extract of Ligustrum lucidum fruits (LFE) and its major secoiridoid (LFS), (8- E)-nüzhenide, on obesity was investigated using high fat-diet (HFD)-induced C58BL/6J obese mice. LFE and LFS were administered at the doses of 300 mg/kg and 30 mg/kg, respectively, for 6 weeks. The anti-obesity activity was evaluated by measuring body weight, epididymal fat and metabolic plasma parameters. On Day 42, the body weight of the LFS-treated group was significantly lower compared with the HFD-treated group. Body weight gain was also reduced by 23.2% and 32.0% in the LFE- and LFS-treated groups, respectively, compared with the HFD group. In addition, the weight of the epididymal fat in the mice was significantly decreased in the HFD+LFS group. The food efficiency ratios (FERs) of the HFD+LFE and HFD+LFS groups were also lower compared with the HFD group with the same food intake. Metabolic parameters that had increased in the HFD group were decreased in the HFD+LFE and HFD+LFS groups. In particular, the increased triglyceride values were significantly reduced in the HFD+LFS group. These results show that treatment with LFE and LFS decreased HFD-induced obesity, mainly by improving metabolic parameters, such as fats and triglycerides. Therefore, LFE and LFS have potential benefits in regulation of obesity.

Lactobacillus rhamnosus NCDC17 ameliorates type-2 diabetes by improving gut function, oxidative stress and inflammation in high-fat-diet fed and streptozotocintreated rats

2017 ◽  
Vol 8 (2) ◽  
pp. 243-255 ◽  
Author(s):  
S. Singh ◽  
R.K. Sharma ◽  
S. Malhotra ◽  
R. Pothuraju ◽  
U.K. Shandilya
Keyword(s):  
Oxidative Stress ◽  
Type 2 Diabetes ◽  
High Fat Diet ◽  
Lactobacillus Rhamnosus ◽  
Density Lipoprotein ◽  
Diabetic Rats ◽  
Lipoprotein Cholesterol ◽  
High Fat ◽  
Epididymal Fat

Restoration of dysbiosed gut microbiota through probiotic may have profound effect on type 2 diabetes. In the present study, rats were fed high fat diet (HFD) for 3 weeks and injected with low dose streptozotocin to induce type 2 diabetes. Diabetic rats were then fed Lactobacillus rhamnosus NCDC 17 and L. rhamnosus GG with HFD for six weeks. L. rhamnosus NCDC 17 improved oral glucose tolerance test, biochemical parameters (fasting blood glucose, plasma insulin, glycosylated haemoglobin, free fatty acids, triglycerides, total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol), oxidative stress (thiobarbituric acid reactive substance and activities of catalase, superoxide dismutase and glutathione peroxidase in blood and liver), bifidobacteria and lactobacilli in cecum, expression of glucagon like peptide-1 producing genes in cecum, and adiponection in epididymal fat, while decreased propionate proportions (%) in caecum, and expression of tumour necrosis factor-α and interlukin-6 in epididymal fat of diabetic rats as compared to diabetes control group. These findings offered a base for the use of L. rhamnosus NCDC 17 for the improvement and early treatment of type 2 diabetes.

Elevated n-3 fatty acids in a high-fat diet attenuate the increase in PDH kinase activity but not PDH activity in human skeletal muscle

2005 ◽  
Vol 98 (1) ◽  
pp. 350-355 ◽  
Author(s):  
Erin A. Turvey ◽  
George J. F. Heigenhauser ◽  
Michelle Parolin ◽  
Sandra J. Peters
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Pyruvate Dehydrogenase ◽  
High Fat Diet ◽  
Human Skeletal Muscle ◽  
Fat Content ◽  
Pyruvate Dehydrogenase Kinase ◽  
High Fat ◽  
High Fat Diets ◽  
Fat Diets

We tested the hypothesis that a high-fat diet (75% fat; 5% carbohydrates; 20% protein), for which 15% of the fat content was substituted with n-3 fatty acids, would not exhibit the diet-induced increase in pyruvate dehydrogenase kinase (PDK) activity, which is normally observed in human skeletal muscle. The fat content was the same in both the regular high-fat diet (HF) and in the n-3-substituted diet (N3). PDK activity increased after both high-fat diets, but the increase was attenuated after the N3 diet (0.051 ± 0.007 and 0.218 ± 0.047 min−1 for pre- and post-HF, respectively; vs. 0.073 ± 0.016 and 0.133 ± 0.032 min−1 for pre- and post-N3, respectively). However, the active form of pyruvate dehydrogenase (PDHa) activity decreased to a similar extent in both conditions (0.93 ± 0.17 and 0.43 ± 0.09 mmol/kg wet wt pre- and post-HF; vs. 0.87 ± 0.19 and 0.39 ± 0.05 mmol/kg wet wt pre- and post-N3, respectively). This suggested that the difference in PDK activity did not affect PDHa activation in the basal state, and it was regulated by intramitochondrial effectors, primarily muscle pyruvate concentration. Muscle glycogen content was consistent throughout the study, before and after both diet conditions, whereas muscle glucose-6-phosphate, glycerol-3-phosphate, lactate, and pyruvate were decreased after the high-fat diets. Plasma triglycerides decreased after both high-fat diets but decreased to a greater extent after the N3, whereas plasma free fatty acids increased after both diets, but to a lesser extent after the N3. In summary, PDK activity is decreased after a high-fat diet that is rich in n-3 fatty acids, although PDHa activity was unaltered. In addition, our data demonstrated that the hypolipidemic effect of n-3 fatty acids occurs earlier (3 days) than previously reported and is evident even when the diet has 75% of its total energy derived from fat.

scholarly journals Colonic dysmotility and inflammation associated with high fat diet-induced obesity: role of the enteric glia

2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Matteo Fornai ◽  
Carolina Pellegrini ◽  
Vanessa D'Antongiovanni ◽  
Laura Benvenuti ◽  
Nunzia Bernardini ◽  
...  
Keyword(s):  
High Fat Diet ◽  
Mucosal Barrier ◽  
Tlr4 Expression ◽  
High Fat ◽  
Glucose Levels ◽  
Diet Induced Obesity ◽  
Epididymal Fat ◽  
Junction Protein ◽  
Colonic Dysmotility

AbstractIntroductionEnteric glial cells (EGCs) contribute to the regulation of bowel motility, and have been implicated in the onset and development of several digestive disorders. However, the involvement of EGCs in obesity-related intestinal dysmotility is unknown. Accordingly, this study examined the role of EGCs in colonic neuromuscular dysfunctions in a mouse model of diet-induced obesity.Materials and MethodsC57BL/6 male mice (n = 6 per group) were fed with standard diet (SD) or high fat diet (HFD) for 8 weeks. Body and epididymal fat weight, and blood fasting glucose levels were evaluated the day before sacrifice. Colonic longitudinal muscle strips were set up in organ baths with Krebs solution and connected to isometric transducers. The effects of fluorocitrate (FC, gliotoxin) were tested on contractile responses mediated by NK1 tachykininergic receptors upon application of electrical stimuli (0.5 ms, 28 V, 10 Hz) [incubation with atropine, guanethidine, L-NAME, GR159897 and SB218795 (NK2 and NK3 antagonists, respectively)] or exogenous substance P (SP). Colonic levels of interleukin (IL)-1β, IL-6, malondialdehyde (MDA) and occludin (a tight junction protein involved the maintenance of mucosal barrier) were measured. Cultured rat EGCs were exposed to palmitate and lipopolysaccharide (LPS), either alone or in combination, to mimic the exposure to HFD. IL-1β and SP levels were then assessed in cell supernatants, while toll-like receptor 4 (TLR4) expression was evaluated in cell lysates.ResultsHFD-mice displayed increments of body weight, epididymal fat weight and blood glucose levels. In in vitro experiments, electrically induced colonic tachykininergic contractions were enhanced in HFD mice, as compared with SD animals. No differences were observed when comparing contractions to exogenous SP. The increase in electrically evoked tachykininergic contractions was blunted upon incubation with the gliotoxin FC. Exogenous SP-induced contractions were not affected by FC. HFD mice displayed an increase in colonic IL-1β, IL-6 and MDA levels and a reduced occludin expression, as compared with SD mice. Exposure of EGCs to palmitate, alone or in combination with LPS, resulted in a significant increase in TLR4 expression, while LPS alone was without effects. The combination of palmitate and LPS increased significantly IL-1β and SP levels in cell supernatants, while single treatments were without effects.DiscussionHFD is characterized by colonic dysmotility along with bowel inflammation, oxidative stress, and an impairment of mucosal barrier integrity. In this setting, the hyperactivation of EGCs, likely via TLR4, appears to contribute to inflammation and colonic tachykininergic motor dysfunctions.

scholarly journals Moderate Aerobic Exercise Training Prevents the Augmented Hepatic Glucocorticoid Response Induced by High-Fat Diet in Mice

2020 ◽  
Vol 21 (20) ◽  
pp. 7582
Author(s):  
Jonatan Dassonvalle ◽  
Francisco Díaz-Castro ◽  
Camila Donoso-Barraza ◽  
Carlos Sepúlveda ◽  
Francisco Pino-de la Fuente ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Energy Balance ◽  
Aerobic Exercise ◽  
High Fat Diet ◽  
Aerobic Exercise Training ◽  
Metabolic Effects ◽  
Obese Mice ◽  
High Fat ◽  
Epididymal Fat ◽  
Glucocorticoid Response

Glucocorticoids (GCs) are critical regulators of energy balance. Their deregulation is associated with the development of obesity and metabolic syndrome. However, it is not understood if obesity alters the tissue glucocorticoid receptor (GR) response, and moreover whether a moderate aerobic exercise prevents the alteration in GR response induced by obesity. Methods: To evaluate the GR response in obese mice, we fed C57BL6J mice with a high-fat diet (HFD) for 12 weeks. Before mice were sacrificed, we injected them with dexamethasone. To assess the exercise role in GR response, we fed mice an HFD and subjected them to moderate aerobic exercise three times a week. Results: We found that mice fed a high-fat diet for 12 weeks developed hepatic GC hypersensitivity without changes in the gastrocnemius or epididymal fat GR response. Therefore, moderate aerobic exercise improved glucose tolerance, increased the corticosterone plasma levels, and prevented hepatic GR hypersensitivity with an increase in epididymal fat GR response. Conclusion: Collectively, our results suggest that mice with HFD-induced obesity develop hepatic GR sensitivity, which could enhance the metabolic effects of HFD in the liver. Moreover, exercise was found to be a feasible non-pharmacological strategy to prevent the deregulation of GR response in obesity.

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