Effects of swimming training on tissue glycogen content in experimental thyrotoxic rats

2012 ◽  
Vol 90 (5) ◽  
pp. 587-593 ◽  
Author(s):  
Luiz Fernando Paulino Ribeiro ◽  
Inaian Pignatti Teixeira ◽  
Glaucio Aparecido da Silva ◽  
Rodrigo Augusto Dalia ◽  
Marcelo Costa Júnior ◽  
...  
Keyword(s):  
Glycogen Content ◽  
Fiber Type ◽  
Experimental Period ◽  
Liver Glycogen ◽  
Male Rats ◽  
Swimming Training ◽  
Transition Intensity ◽  
Specific Manner ◽  
Glycogen Stores

Thyrotoxicosis, a condition in which there is an excessive amount of circulating thyroid hormones, leads to reduced glycogen content in different tissues. In this study we analyzed the effects of aerobic swimming training on liver, heart, and skeletal muscle glycogen content in experimentally induced thyrotoxicosis. Wistar male rats were divided into euthyroid sedentary (ES, n = 12), euthyroid trained (ET, n = 11), thyrotoxic sedentary (TS, n = 12), and thyrotoxic trained (TT, n = 10) groups. Thyrotoxic groups received daily i.p. doses of T4 (sodium levothyroxine, 25 µg/100 g body mass) through the experimental period, and trained groups swam for 1 h at 80% of the aerobic–anaerobic transition intensity, 5 days/week for 4 weeks. Heart and liver glycogen stores were ∼30% lower in T4 treated compared with nontreated groups, but were not changed by training status. On the other hand, glycogen content in mixed fiber type gastrocnemius of TT was 1.5- to 2.3-fold greater than those in other groups, whereas no significant differences were found for the slow soleus muscle. Increased gastrocnemius but not soleus, liver, or heart glycogen indicates that in mild long-term thyrotoxicosis chronic swimming affects glycogen stores in a tissue-specific manner.

Effect of fasting on myocardial substrates in male and female rats

1988 ◽  
Vol 254 (4) ◽  
pp. C560-C563 ◽  
Author(s):  
D. A. Arnall ◽  
W. K. Palmer ◽  
W. C. Miller ◽  
L. B. Oscai
Keyword(s):  
Experimental Period ◽  
Plasma Free Fatty Acid ◽  
Liver Glycogen ◽  
Female Rats ◽  
Male Rats ◽  
Fasting Period ◽  
Male And Female ◽  
Male And Female Rats ◽  
Entire Experiment ◽  
Beta Hydroxybutyrate

Adult male and female rats were fasted for 1, 2, or 3 days to determine its effect on circulating and endogenous fuels available to the heart. Liver glycogen was depleted within the first 24 h of food restriction. Plasma glucose decreased approximately 2.5 mM in both sexes during the 3 days. Fasting significantly increased plasma beta-hydroxybutyrate to approximately the same level in female and male rats. Plasma free fatty acid (FFA) increased approximately 0.2 mM in both groups during the first 24 h without food and remained elevated over the next 2 days. FFA concentrations were higher in fed female than in fed male rats and remained significantly higher in female rats throughout the experimental period. Myocardial glycogen increased 64% during the first 2 days of fasting in the male rats and stayed elevated on the third day of fasting. In contrast, heart glycogen of female rats remained unchanged from an initial value of 3.13 mg/g throughout the 3-day fasting period. Endogenous triglyceride (TG) of male rats decreased from 2.14 +/- 0.09 to 1.41 +/- 0.21 mumol/g during the first 24 h without food and remained at that level during the second and third days. Heart TG in female rats fell progressively from 2.36 +/- 0.19 to 1.02 +/- 0.12 mumol/g during the fasting period. Cardiac FFA were higher in female than in male animals throughout the entire experiment. These data indicate that quantitative and qualitative metabolic differences exist between male and female rats stressed by fasting.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals ANTIHYPERGLYCEMIC AND ANTIHYPERLIPIDEMIC ACTIVITY OF JATROPHA GOSSYPIFOLIA METHANOLIC EXTRACT IN STREPTOZOTOCIN-NICOTINAMIDE INDUCED DIABETIC RATS

2017 ◽  
Vol 10 (11) ◽  
pp. 326 ◽  
Author(s):  
Issac Praveen Kumar ◽  
Ishan Malhotra ◽  
Sujatha Sundaresan ◽  
Alwin Dev
Keyword(s):  
Liver Function ◽  
Glycogen Content ◽  
Methanolic Extract ◽  
Density Lipoprotein ◽  
Experimental Period ◽  
Liver Glycogen ◽  
Treated Group ◽  
Diabetic Rats ◽  
Antihyperlipidemic Activity ◽  
Jatropha Gossypifolia

  Objective: The objective of the present study is to explore the antihyperglycemic and antihyperlipidemic activities of Jatropha gossypifolia methanolic extract (ME) in streptozotocin (STZ)-nicotinamide (NIC) induced diabetic model.Methods: Type II diabetes was induced by a single dose of NIC (110 mg/kg) and STZ (50 mg/kg b.w.) intraperitoneally. The diabetic animals were treated with ME (50 mg/kg and 100 mg/kg b.w.) of J. gossypifolia. At the end of experimental period, the effect of the ME on creatinine level, triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL) and very LDL (VLDL) were analyzed. Liver function parameters such as glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) were analyzed and liver glycogen content was estimated spectrophotometrically. After scarification of animals, the liver was collected and subjected to histopathology analysis. Glycogen content was estimated spectrophotometrically.Results: The ME treated diabetic rats showed a significant increase in HDL level and a decrease in creatinine, TG, TC, and VLDL levels. The treated group showed a significant decrease in liver function parameters such as GOT and GPT levels and significantly increased the liver glycogen content.Conclusion: These findings demonstrate that ME possess antihyperglycemic and antihyperlipidemic activity against STZ - NIC induced diabetic rats.

Effect of estradiol on tissue glycogen metabolism and lipid availability in exercised male rats

1991 ◽  
Vol 71 (5) ◽  
pp. 1694-1699 ◽  
Author(s):  
Z. V. Kendrick ◽  
G. S. Ellis
Keyword(s):  
Fatty Acids ◽  
Body Weight ◽  
Exercise Performance ◽  
Glycogen Content ◽  
Day Treatment ◽  
Glycogen Metabolism ◽  
Liver Glycogen ◽  
Male Rats ◽  
Plasma Lactate ◽  
Glycogen Utilization

The effect of 17 beta-estradiol 3-benzoate (10 micrograms.0.1 ml sunflower oil-1.100 g body wt-1) on exercise performance, tissue glycogen utilization, and lipid availability was determined in male rats. In experiment 1, estradiol or oil was administered 1 h or 1–6 days before a treadmill run to exhaustion. No differences in body weight between oil- and estradiol-administered animals were observed during the 6-day treatment. Animals receiving estradiol for 3–6 days ran significantly longer and completed more work than oil-administered animals. Significant degradation of red and white vastus muscle, myocardial, and liver glycogen was observed in all animals run to exhaustion. In experiment 2, animals were administered estradiol for 5 days and then run for 2 h. The submaximal run for 2 h significantly reduced tissue glycogen content in red and white vastus muscle, heart, and liver of oil-administered animals. The latter effect was attenuated in both vastus muscles, liver, and myocardial tissues in the estradiol-administered animals. Estradiol administration significantly increased plasma fatty acids and lowered plasma lactate during the submaximal run. These data indicate that when body weight remained constant between groups of male rats, estradiol administration for 3–6 days increased exercise performance. Furthermore, estradiol administration for 5 days resulted in greater lipid availability and less tissue glycogen utilization during submaximal running for 2 h.

Dietary relations between Moniliformis (Acanthocephala) and laboratory rats

1977 ◽  
Vol 197 (1128) ◽  
pp. 363-383 ◽  
Keyword(s):  
Small Intestine ◽  
Anterior Part ◽  
Experimental Period ◽  
Liver Glycogen ◽  
Reproductive Activity ◽  
Male Rats ◽  
High Starch ◽  
Isocaloric Diets ◽  
Standard Laboratory Diet ◽  
Starch Diet

Aspects of the course of infection of Moniliformis dubius in male rats fed on four purified, isocaloric diets (A, B, C and D) were investigated. Diet A contained no digestible carbohydrate, diet B contained glycerol as a potential source of glucose, diet C contained 3.6 % starch and diet D contained about 59 % starch. After a rat had been adapted to one of the diets, it was infected orally with 20 cystacanths of Moniliformis and allowed to continue feeding on the same diet for periods varying from 1 to 18 weeks. A group of 4 rats was studied in this way on each of the diets for 11 weeks and on diets C and D for a further 7 weeks. The effects of the dietary treatments on the rats were studied by measuring their food intake, growth rate and liver glycogen. At the end of each experi­mental period, the rats were killed and the numbers, location, dry masses and state of reproduction of the worms were recorded. The composition of the diet appeared to have no effect on the establishment of Moniliformis in the small intestine and the populations of worms emigrated against the direction of gastrointestinal flow during the first month of the course of infection irrespective of the diet of the host. Worms from the rats fed on diets A and B hardly grew, their survival in their hosts did not appear to continue after 11 weeks and they showed no evidence of reproductive activity. Worms from rats fed on the low starch diet (C) did not grow as rapidly as those from rats fed on the high starch diet (D) during the first few weeks of the infection, but eventually they grew much larger and lived longer than worms from the hosts feeding on the high starch diet. Worms in the rats fed on diet C appeared to remain in a precise location in the anterior part of the small intestine from 4 weeks after infection of the host until the end of the experimental period. Worms in the rats fed on diet D had begun to move posteriorly in the small intestine from about 7 weeks after the infection of the host. The results of an experiment involving the transfer of rats with established infections of Moniliformis from a standard laboratory diet to diets A, B, C and D supported the conclusion that the survival, growth and reproduction of Moniliformis are dependent on the availability of glucose liberated during digestion in the host. Another experiment demonstrated that Moniliformis can survive periods of at least 14 days during which the host is deprived of an essential amino acid.

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.

Adaptations to a high-fat diet that increase exercise endurance in male rats

1984 ◽  
Vol 56 (1) ◽  
pp. 78-83 ◽  
Author(s):  
W. C. Miller ◽  
G. R. Bryce ◽  
R. K. Conlee
Keyword(s):  
High Fat Diet ◽  
Citrate Synthase ◽  
Lactate Production ◽  
Liver Glycogen ◽  
Normal Diet ◽  
Male Rats ◽  
Sprague Dawley ◽  
High Fat ◽  
Sprague Dawley Rats ◽  
Glycogen Stores

Eighty-seven male Sprague-Dawley rats (245–300 g) were randomly assigned to one of two experimental groups. The first group consumed a diet high in fat and low in carbohydrate (LCD), whereas the second group ate a normal diet (ND). After either 1 or 5 wk on the diets, rats from each group were killed either before or after an exhausting run on a rodent treadmill (35 m X min-1, 0% grade). The LCD animals ran significantly longer before exhaustion at both week 1 (44.9 +/- 5.1 vs. 41.6 +/- 4.2 min) and week 5 (47.1 +/- 3.6 vs. 35.5 +/- 3.1 min) (P less than 0.05). Adaptations to the LCD included lower muscle and liver glycogen content, decreased rate of glycogen breakdown during exercise, decreased lactate production, and elevated blood ketone levels. In addition to these substrate changes, the LCD caused increased enzyme activities of muscular 3-hydroxyacyl-CoA dehydrogenase (35–110%) and citrate synthase (15–20%). These data indicate that rats exposed to a high-fat diet are capable of prolonged intense exercise in spite of limited glycogen stores. This improved capacity for exercise appears to be partially the result of muscular adaptations to the diet, which apparently increase the ability to oxidize fat and concomitantly spare glycogen.

Muscle and liver glycogen content: diurnal variation and endurance

1979 ◽  
Vol 47 (2) ◽  
pp. 425-428 ◽  
Author(s):  
J. H. Clark ◽  
R. K. Conlee
Keyword(s):  
Glycogen Content ◽  
Vastus Lateralis ◽  
Liver Glycogen ◽  
Diurnal Variations ◽  
Albino Rats ◽  
Hepatic Glycogen ◽  
Glycogen Depletion ◽  
Liver Glycogen Content ◽  
Exercise Endurance ◽  
Glycogen Stores

The purpose of this study was to determine the influence of diurnal variations of muscle and liver glycogen stores on exercise endurance in male albino rats. Animals were swum to exhaustion at either 0700 or 1900 h, after which samples of soleus, white vastus lateralis, and red vastus lateralis muscles as well as liver were excised and subsequently analyzed for glycogen content. Glycogen content of all tissues from nonexercising control animals was higher in the morning than in the evening. Consequently, animals at 0700 h swam 60% longer than those at 1900 h (209 +/- 20 min vs. 130 +/- 23 min, respectively). However, because the skeletal tissues of the exhausted animals were not totally depleted of glycogen, it was concluded that fatigue under the swim protocol was the result of hypoglycemia secondary to hepatic glycogen depletion. The results of this study demonstrate the physiological consequences of diurnal glycogen fluctuation and establish experimental support for the importance of controlling this variable in rodent exercise investigations.

Hypothalamic HSP10 Impacts Mitochondrial Dynamics, Insulin Signaling, and Liver Glycogen Content

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1801-P
Author(s):  
KRISTINA WARDELMANN ◽  
JOSÉ PEDRO CASTRO ◽  
MICHAELA RATH ◽  
JÜRGEN WEIß ◽  
ANNETTE SCHUERMANN ◽  
...  
Keyword(s):  
Insulin Signaling ◽  
Glycogen Content ◽  
Mitochondrial Dynamics ◽  
Liver Glycogen ◽  
Liver Glycogen Content

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.

Sign in / Sign up

Export Citation Format

Share Document