scholarly journals Reduced Muscle Glycogen Differentially Affects Exercise Performance and Muscle Fatigue

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jay H. Williams ◽  
Timothy W. Batts ◽  
Simon Lees
Keyword(s):  
Muscle Fatigue ◽  
Muscle Glycogen ◽  
Exercise Performance ◽  
Central Fatigue ◽  
Voluntary Exercise ◽  
Male Rats ◽  
Control Group ◽  
Free Access ◽  
Lower Blood ◽  
Access To Food

This investigation examined the effects of reduced muscle glycogen on exercise performance and muscle fatigue. Male rats were assigned to a low glycogen group (LG) that participated in a protocol of exercise and fasting, a high glycogen group (HG) that exercised but were allowed free access to food, or control group (CON) that did not exercise but were allowed free access to food. Following the protocol, muscle glycogen content of the LG animals was reduced by 45%. The LG animals also performed 79 and 81% less voluntary treadmill exercise than the HG and CON groups. At exhaustion, the LG group had lower blood glucose than HG and CON but exhibited no reduction in sarcoplasmic reticulum (SR) function. During 30 min of in situ stimulation, the rates and magnitudes of muscle fatigue were not significantly different between groups, and fatigue-induced reductions in SR function were similar between groups. The results indicate that reduced muscle glycogen markedly impairs voluntary exercise performance but does not appreciably affect isolated muscle function. It is likely that exercise exhaustion due to reduced muscle glycogen is due, in large part, to hypoglycemia and central fatigue as opposed to peripheral mechanisms.

Changes in body composition attendant on force feeding

1959 ◽  
Vol 196 (5) ◽  
pp. 965-968 ◽  
Author(s):  
Clarence Cohn ◽  
Dorothy Joseph
Keyword(s):  
Body Weight ◽  
Metabolic Pathways ◽  
Male Rats ◽  
Free Access ◽  
Carbohydrate Diet ◽  
Experimental Animals ◽  
Force Feeding ◽  
Feeding Regimen ◽  
Ad Libitum ◽  
Access To Food

Normal young adult male rats were either force-fed or allowed to eat ad libitum a moderate carbohydrate diet for 3–4 weeks. The force-fed animals were given either the amount of diet consumed by the animals eating ad libitum (pair-fed) or 80% of this amount (underfed). After a 2-week period of observation, we found that the rats eating ad libitum gained 65 gm of body weight, the pair-fed, force-fed 62 gm and the underfed, force-fed 40 gm. On the basis of the water, fat and protein content of the skin, viscera and carcass of control animals killed at the beginning of the feeding regimen and of similar constituents of the experimental animals after 2 weeks of feeding, the composition of the newly formed tissues of the various groups of animals consisted of the following: a) the rat with free access to food—water = 67.8%, fat = 7.8% and protein = 22.4%; b) the pair-fed, force-fed animal—water = 55.5%, fat = 23.6% and protein = 17.7%; c) the underfed, force-fed animal—water = 64.4%, fat = 7.9% and protein = 20.0%. The ratio of calories retained in newly formed tissue to the calories ingested over the 2-week period was 11.9% for the animals eating ad libitum, 20.6% for the pair-fed, force-fed animals and 9.5% for the underfed, force-fed rats. Force feeding appears to change intermediary metabolic pathways in the direction of increased ‘efficiency’ with resultant greater fat deposition.

scholarly journals Histological Effect of Allium sativum (Garlic) on the Liver of White Rabbits

2021 ◽  
pp. 28-35
Author(s):  
Osuloye Oluwaseum Olayemi ◽  
Olojo Oluwatobi Omotola ◽  
Philip Abutu
Keyword(s):  
Allium Sativum ◽  
Cell Damage ◽  
Basal Diet ◽  
Liver Glycogen ◽  
Treated Group ◽  
Control Group ◽  
Free Access ◽  
Glycogen Depletion ◽  
Garlic Powder ◽  
Access To Food

Allium sativum commonly referred to as garlic has been known over the years for its medicinal and culinary purposes. It has also been reported to have several toxic effects when used excessively. However, the purpose of this study was to determine the histological effects of Allium sativum (garlic) powder on the liver of white rabbits at different dosages. Twenty rabbits were randomly divided int.o five groups with free access to food and water for a period of four weeks. Four groups B, C, D, and E were fed with garlic supplemented basal diet containing different concentrations of garlic powder i.e. 100mg, 200mg, 500mg, and 1000mg respectively. These groups were called the treated group. Group A was fed with basal diet only and was considered as the control group. The results obtained showed some histological changes such as the presence of cellular necrosis, vacuolations, lipofuscin pigments, pyknosis and nuclear hypertrophy which were as a result of liver glycogen depletion and hepatic cell damage which may be due to relatively high dosage of garlic used in some of the groups.

PHOSPHORUS METABOLISM IN COLD-EXPOSED RATS

1963 ◽  
Vol 41 (11) ◽  
pp. 2209-2214 ◽  
Author(s):  
John R. Beaton
Keyword(s):  
Urinary Excretion ◽  
Cold Exposure ◽  
Inorganic Phosphorus ◽  
Male Rats ◽  
Free Access ◽  
Lipid Phosphorus ◽  
Blood Concentrations ◽  
Adenosine Phosphates ◽  
Access To Food ◽  
Phosphorus Levels

Male rats weighing 207 ± 2.38 g were exposed to cold (2–3 °C) for a period of 7 days during which urine and faeces were collected daily and analyzed for phosphorus. As a consequence of cold exposure, urinary excretion of phosphorus is increased. With free access to food, the increased food (and hence phosphorus) intake of the animals compensates for the increased urinary excretion and a normal phosphorus balance results. Cold exposure was without significant effect upon blood concentrations of acid-soluble, inorganic, organic, or lipid phosphorus. Increased inorganic and decreased organic, non-lipid phosphorus levels were observed in livers of cold-exposed rats. These observations suggest the breakdown of organic phosphates (e.g. hexose and triose phosphates, adenosine phosphates, phosphocreatine) to inorganic phosphorus.

PHOSPHORUS METABOLISM IN COLD-EXPOSED RATS

1963 ◽  
Vol 41 (1) ◽  
pp. 2209-2214
Author(s):  
John R. Beaton
Keyword(s):  
Urinary Excretion ◽  
Cold Exposure ◽  
Inorganic Phosphorus ◽  
Male Rats ◽  
Free Access ◽  
Lipid Phosphorus ◽  
Blood Concentrations ◽  
Adenosine Phosphates ◽  
Access To Food ◽  
Phosphorus Levels

Male rats weighing 207 ± 2.38 g were exposed to cold (2–3 °C) for a period of 7 days during which urine and faeces were collected daily and analyzed for phosphorus. As a consequence of cold exposure, urinary excretion of phosphorus is increased. With free access to food, the increased food (and hence phosphorus) intake of the animals compensates for the increased urinary excretion and a normal phosphorus balance results. Cold exposure was without significant effect upon blood concentrations of acid-soluble, inorganic, organic, or lipid phosphorus. Increased inorganic and decreased organic, non-lipid phosphorus levels were observed in livers of cold-exposed rats. These observations suggest the breakdown of organic phosphates (e.g. hexose and triose phosphates, adenosine phosphates, phosphocreatine) to inorganic phosphorus.

scholarly journals BIOCHEMICAL AND HISTOPATHOLOGICAL CHANGES OF TRADITIONAL SIDDHA FORMULATION ON CCL4 INDUCED LIVER FIBROSIS IN RATS

2017 ◽  
Vol 9 (7) ◽  
pp. 120
Author(s):  
Diwakar Manickam ◽  
Sri Kamatchi Priya Ramamoorthy ◽  
B. Santhosh Kumar ◽  
Samu Subramaniam ◽  
Shyama Subramaniam
Keyword(s):  
Liver Fibrosis ◽  
Serum Levels ◽  
Control Group ◽  
Albino Rats ◽  
Intragastric Administration ◽  
Free Access ◽  
Equal Proportion ◽  
Histopathological Changes ◽  
Wistar Albino Rats ◽  
Access To Food

ABSTRACTObjective:The main objective of this study is to evaluate therapeutic activity of traditional siddha formulation on CCl4 induced liver fibrosis in rats.Methods:Plant materials collected, shade dried, mixed equal proportion. This mixture was used for extract or kasayam preparation. Twenty four male Wistar albino rats were randomly divided into four groups of six rats each. The normal control group was allowed free access to food and water. Drug control group was allowed to daily intragastric administration of traditional siddha formulation 400mg per kg b.wt per day. Liver damage was performed in the remaining two groups with an i.p.injection of a 1.0 mL/kg b.wt CCl4 and olive oil (2:3 v/v) mixture, twice weekly for 8 weeks. All rats, with the exception of the injury model group, were intragastrically administered traditional siddha formulation (TSF) dosage 400 mg/ kg b.wt /day from 5th week to end of experiment of CCl4 intoxicated rats. The serum levels of hepatic markers and hydroxyproline (Hyp) in the rat livers were measured. Histopathological changes in the liver were assessed for each group using H&E staining and Masson Trichrome examination.Results:Traditional siddha formulation significantly reverse the liver function in CCl4 intoxicated rats correlate with both biochemical and histopathological changesConclusion:Traditional siddha formulation a promising drug for treating liver fibrosis.Keywords: Traditional siddha formulation, Liver fibrosis, CCl4 and Vaithiyars

scholarly journals RAPD Profiling, DNA Fragmentation, and Histomorphometric Examination in Brains of Wistar Rats Exposed to Indoor 2.5 Ghz Wi-Fi Devices Radiation

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
A. O. Ibitayo ◽  
O. B. Afolabi ◽  
A. J. Akinyemi ◽  
T. I. Ojiezeh ◽  
K. O. Adekoya ◽  
...  
Keyword(s):  
Young Male ◽  
High Technology ◽  
Male Rats ◽  
Free Access ◽  
Agarose Gel Electrophoresis ◽  
Vascular Congestion ◽  
Access To Food ◽  
The Brain ◽  
Group 1 ◽  
Brain Tissues

The advent of Wi-Fi connected high technology devices in executing day-to-day activities is fast evolving especially in developing countries of the world and hence the need to assess its safety among others. The present study was conducted to investigate the injurious effect of radiofrequency emissions from installed Wi-Fi devices in brains of young male rats. Animals were divided into four equal groups; group 1 served as control while groups 2, 3, and 4 were exposed to 2.5 Ghz at intervals of 30, 45, and 60 consecutive days with free access to food and water ad libitum. Alterations in harvested brain tissues were confirmed by histopathological analyses which showed vascular congestion and DNA damage in the brain was assayed using agarose gel electrophoresis. Histomorphometry analyses of their brain tissues showed perivascular congestion and tissue damage as well.

Glucocorticoid amelioration of nephrotoxicity: a study of cephaloridine- methylprednisolone interaction in the rat

1995 ◽  
Vol 14 (7) ◽  
pp. 554-561 ◽  
Author(s):  
PW Harvey ◽  
G. Healing ◽  
IR Major ◽  
M. McFarlane ◽  
KA Purdy ◽  
...  
Keyword(s):  
Clinical Utility ◽  
Male Rats ◽  
Control Group ◽  
Marker Enzymes ◽  
Challenge Dose ◽  
Kidney Weight ◽  
Tubular Necrosis ◽  
Methyl Prednisolone ◽  
Lower Blood ◽  
Urinary Glucose

Groups of ten male rats were treated with a high challenge dose of cephaloridine (CPH, 3750 mg kg -1), with methyl prednisolone (MP, 100 mg kg-1) or with cephaloridine and methylprednisolone (CPH + MP) by single subcutaneous injection. A control group received the injection vehicles only. Urine was collected from all animals daily over 18-h collection periods, up to 96 h after treatment. Blood was collected at 24, 48, 72 and 96 h after treatment. At necrop sy, kidneys were weighed, processed and examined histopathologically. Results show that methylprednisolone significantly ameliorated the nephrotoxicity of the challenge dose of cephaloridine. CPH-only treated rats had severe toxic nephrosis characterised by acute tubular necrosis, and elevated blood urea and creatinine. By contrast, the major ity of CPH + MP treated rats had only a slight or moderate toxic nephrosis, and had lower blood urea and creatinine levels compared with rats treated with CPH only, indicat ing preservation of kidney function. Interestingly, rats treated with CPH + MP had higher urinary enzymes (alka line phosphatase, lactate dehydrogenase, gamma glu tamyltransferase and N-acetyl-B-glucosaminidase) as well as protein and glucose, compared with rats treated with CPH only. This is taken to indicate that rats treated with CPH only had such marked kidney damage and necrosis that the population of cells able to produce these marker enzymes was significantly and rapidly depleted, but the protection afforded by methylprednisolone allowed CPH + MP treated rats to sustain urinary enzyme output. Effects on urinary glucose and other parameters such as body weight and kidney weight demonstrate interactions between glucocorticoid pharmacology and cephaloridine nephrotoxicity. Finally, the significance of these findings is discussed in terms of a generic mechanism of protection conferred by glucocorticoids in certain types of nephrotox icity and related to similar findings in rats treated intra venously with cisplatin, an anti-neoplastic agent for which the clinical utility in man is often limited by adverse effects on the kidney.

scholarly journals The effect of aspartame and sucralose intake on body weight measures and blood metabolites: role of their form (solid and/or liquid) of ingestion

2021 ◽  
pp. 1-21
Author(s):  
M.E. Ragi ◽  
R. El-Haber ◽  
F. El-Masri ◽  
O.A. Obeid
Keyword(s):  
Drinking Water ◽  
Body Weight ◽  
Caloric Intake ◽  
Blood Metabolites ◽  
Control Group ◽  
Plain Water ◽  
Free Access ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Access To Food

Abstract The ingestion of non-caloric sweeteners from food and/or drink was intended to reduce caloric intake without compromising palatability. However, the inconclusive relation between non-caloric sweeteners and body weight may partially relate to their form of ingestion (solid or liquid). Thus, two paralleled experiments (Aspartame and Sucralose) were conducted. In each, Sprague Dawley rats (7-week-old male) were randomly divided into 4 groups. In experiment 1, aspartame (0.05%) was added to the diet (AD) or drinking water (AW) or both diet and water (ADW), and a control group (C) was given a non-sweetened diet with plain water. In experiment 2, sucralose (0.016%) was similarly provided in the diet (SD) or drinking water (SW) or both diet and water (SDW), with a control group (C). All rats had free access to food and water for 7 weeks. Energy intake, body weight, and body composition were monitored and blood metabolites were determined. Results showed that aspartame ingestion significantly increased body weight and fat mass mainly due to an increase in energy efficiency. The effect was related to the amount rather than the form of ingestion. Additionally, aspartame ingestion was associated with glucose intolerance. Sucralose ingestion had a similar impact to that of aspartame though to a lesser extent. In conclusion, 7-week ingestion of aspartame and sucralose had adverse effects on body measures that were not related to the form of ingestion.

scholarly journals Low-Carbohydrate-High-Fat Diet: Can it Help Exercise Performance?

2017 ◽  
Vol 56 (1) ◽  
pp. 81-92 ◽  
Author(s):  
Chen-Kang Chang ◽  
Katarina Borer ◽  
Po-Ju Lin
Keyword(s):  
Weight Loss ◽  
Muscle Glycogen ◽  
Exercise Performance ◽  
High Intensity ◽  
Oxidation Rate ◽  
Central Fatigue ◽  
Fat Oxidation ◽  
Metabolic Changes ◽  
High Fat ◽  
Low Carbohydrate

AbstractLow-carbohydrate-high-fat (LCHF) diets have been used as a means of weight loss and control of symptoms in several clinical conditions. There is emerging evidence that the metabolic changes induced by LCHF diets enhance endurance performance. The aims of this review are to examine the evidence of LCHF diets in improving various aspects of athletic performance. Long-term LCHF dietary intake may help control body weight and fat mass while maintaining lean body mass in athletes in weight-sensitive sports. LCHF-adapted endurance athletes can reach the maximal fat oxidation rate of approximately 1.5 g/min, with a lower carbohydrate oxidation rate and similar muscle glycogen content and a resynthesis rate compared to their counterparts consuming high-carbohydrate-low-fat (HCLF) diets. The elevated fat oxidation rate and glycogen sparing effect may improve performance in ultra-endurance events. These metabolic changes may also prevent the decline in performance in later stages of repeated high-intensity movements, in which the aerobic metabolism becomes more important. However, elevated blood concentrations of non-esterified fatty acids and ammonia during exercise after LCHF diets may lead to early development of central fatigue. It appears that at least several months of adaptation to a LCHF diet are required for the metabolic changes and restoration of muscle glycogen to occur. Further investigations on LCHF diets are needed regarding (1) performance after weight loss in weight-categorized sports; (2) repeated high-intensity exercise performance; (3) development of central fatigue during endurance events; (4) perceptual-motor performance during prolonged intermittent sports; and (5) ideal dietary fatty acid compositions.

An orexigenic role for μ-opioid receptors in the lateral parabrachial nucleus

2003 ◽  
Vol 285 (5) ◽  
pp. R1055-R1065 ◽  
Author(s):  
John D. Wilson ◽  
Danielle M. Nicklous ◽  
Vincent J. Aloyo ◽  
Kenny J. Simansky
Keyword(s):  
Food Intake ◽  
Male Rats ◽  
Parabrachial Nucleus ◽  
Opioid Antagonist ◽  
Free Access ◽  
Lateral Parabrachial Nucleus ◽  
Μ Opioid Receptor ◽  
Access To Food ◽  
The Brain ◽  
Μ Opioid Receptors

The pontine parabrachial nucleus (PBN) has been implicated in regulating ingestion and contains opioids that promote feeding elsewhere in the brain. We tested the actions of the selective μ-opioid receptor (μ-OR) agonist [d-Ala2,N-Me-Phe4,Gly5-ol]enkephalin (DAMGO) in the PBN on feeding in male rats with free access to food. Infusing DAMGO (0.5-4.0 nmol/0.5 μl) into the lateral parabrachial region (LPBN) increased food intake. The hyperphagic effect was anatomically specific to infusions within the LPBN, dose and time related, and selective for ingestion of chow compared with (nonnutritive) kaolin. The nonselective opioid antagonist naloxone (0.1-10.0 nmol intra-PBN) antagonized DAMGO-induced feeding, with complete blockade by 1.0 nmol and no effect on baseline. The highly selective μ-opioid antagonist d-Phe-Cys-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP; 1.0 nmol) also prevented this action of DAMGO, but the κ-antagonist nor-binaltorphimine did not. Naloxone and CTAP (10.0 nmol) decreased intake during scheduled feeding. Thus stimulating μ-ORs in the LPBN increases feeding, whereas antagonizing these sites inhibits feeding. Together, our results implicate μ-ORs in the LPBN in the normal regulation of food intake.

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