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.

Effect of estradiol on tissue glycogen metabolism in exercised oophorectomized rats

1987 ◽  
Vol 63 (2) ◽  
pp. 492-496 ◽  
Author(s):  
Z. V. Kendrick ◽  
C. A. Steffen ◽  
W. L. Rumsey ◽  
D. I. Goldberg
Keyword(s):  
Skeletal Muscle ◽  
Exercise Performance ◽  
Sunflower Oil ◽  
Glycogen Content ◽  
Vastus Lateralis ◽  
Glycogen Metabolism ◽  
Submaximal Exercise ◽  
Total Work ◽  
Glycogen Utilization ◽  
Glycogen Sparing

The effect of both physiological and pharmacological doses of estradiol on exercise performance and tissue glycogen utilization was determined in oophorectomized estradiol-replaced (ER) rats. Doses of beta-estradiol 3-benzoate (0.02, 0.04, 0.1, 0.2, 1, 2, 4, or 10 micrograms.0.1 ml of sunflower oil-1.100 g body wt-1) were injected 5 days/wk for 4 wk. Controls were sham injected (SI). After treatment, the animals were run to exhaustion on a motorized treadmill. ER animals receiving the 0.02-microgram dose ran significantly longer and completed more total work than the SI group. ER animals receiving doses of greater than or equal to 0.04 microgram ran longer and performed more work than the 0.02-microgram group. At exhaustion, myocardial glycogen content was significantly decreased in animals that were ER with less than or equal to 0.1 microgram, whereas those replaced with doses greater than 0.1 microgram utilized significantly less glycogen. With the 10-micrograms dose no significant decrease in heart glycogen content was observed at exhaustion. A submaximal 2-h run significantly reduced glycogen content in heart, red and white portions of the vastus lateralis, and the livers of SI animals. The latter effect was attenuated in skeletal muscle and liver, and there was no effect in the hearts of the ER animals receiving 2 micrograms. These data indicate that estradiol replacement in oophorectomized rats influenced myocardial glycogen utilization during exhaustive exercise and spared tissue glycogen during submaximal exercise. These glycogen sparing effects may have contributed to the significant improvements in exercise performance observed in this study.

Metabolic fuel homeostasis in golden hamsters: effects of fasting, refeeding, glucose, and insulin

1984 ◽  
Vol 247 (1) ◽  
pp. R57-R62 ◽  
Author(s):  
N. Rowland
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Glycogen Content ◽  
Liver Glycogen ◽  
Acid Synthesis ◽  
Ingestive Behavior ◽  
Metabolic Responses ◽  
Exogenous Insulin ◽  
Rapid Reversal

Experiments were conducted to investigate possible metabolic correlates of the unusual ingestive behavior of hamsters after food deprivation. A hypothesis of metabolic refractoriness predicts that hamsters, unlike rats, should not show changes in plasma metabolic fuels, adipose tissue, or liver after fasting and subsequent refeeding. This hypothesis was discredited by findings that fasted hamsters, like rats, have increased plasma ketones and free fatty acids and decreased liver glycogen. On refeeding, hamsters showed rapid reversal of these changes, with supranormal glycogen content and apparent fatty acid synthesis in liver. Additional studies examined the metabolic responses of hamsters and rats to exogenous insulin or glucose administration. Incorporation of 3H2O into liver fatty acids was greatly elevated in rats by both insulin and glucose, but in hamsters only insulin was effective. Some of these metabolic differences may help our understanding of the unusual refractoriness of hamster food intake to various stimuli.

scholarly journals Tea Seed Oil Prevents Obesity, Reduces Physical Fatigue, and Improves Exercise Performance in High-Fat-Diet-Induced Obese Ovariectomized Mice

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 980 ◽  
Author(s):  
Yu-Tang Tung ◽  
Yi-Ju Hsu ◽  
Yi-Wen Chien ◽  
Chi-Chang Huang ◽  
Wen-Ching Huang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Body Weight ◽  
Exercise Performance ◽  
High Fat Diet ◽  
Seed Oil ◽  
Physical Fatigue ◽  
High Fat ◽  
Tea Seed Oil ◽  
Ovariectomized Mice ◽  
Total Fat

Menopause is associated with changes in body composition (a decline in lean body mass and an increase in total fat mass), leading to an increased risk of metabolic syndrome, nonalcoholic fatty liver disease, and heart disease. A healthy diet to control body weight is an effective strategy for preventing and treating menopause-related metabolic syndromes. In the present study, we investigated the effect of long-term feeding of edible oils (soybean oil (SO), tea seed oil (TO), and lard oil (LO)) on female ovariectomized (OVX) mice. SO, TO, and LO comprise mainly polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), and saturated fatty acids (SFA), respectively. However, there have been quite limited studies to investigate the effects of different fatty acids (PUFA, MUFA, and SFA) on physiological adaption and metabolic homeostasis in a menopausal population. In this study, 7-week-old female Institute of Cancer Research (ICR) mice underwent either bilateral laparotomy (sham group, n = 8) or bilateral oophorectomy (OVX groups, n = 24). The OVX mice given a high-fat diet (HFD) were randomly divided into three groups: OVX+SO, OVX+TO, and OVX+LO. An HFD rich in SO, TO, or LO was given to the OVX mice for 12 weeks. Our findings revealed that the body weight and relative tissues of UFP (uterus fatty peripheral) and total fat (TF) were significantly decreased in the OVX+TO group compared with those in the OVX+SO and OVX+LO groups. However, no significant difference in body weight or in the relative tissues of UFP and TF was noted among the OVX+SO and OVX+LO groups. Furthermore, mice given an HFD rich in TO exhibited significantly decreased accumulation of liver lipid droplets and adipocyte sizes of UFP and brown adipose tissue (BAT) compared with those given an HFD rich in SO or LO. Moreover, replacing SO or LO with TO significantly increased oral glucose tolerance. Additionally, TO improved endurance performance and exhibited antifatigue activity by lowering ammonia, blood urea nitrogen, and creatine kinase levels. Thus, tea seed oil (TO) rich in MUFA could prevent obesity, reduce physical fatigue, and improve exercise performance compared with either SO (PUFA)- or LO(SFA)-rich diets in this HFD-induced obese OVX mice model.

scholarly journals The Role of Hormones in the Regulation of Glycogen Metabolism in the Clawed Toad Xenopus Laevis (Daudin)

2019 ◽  
pp. 17-24
Author(s):  
Daphna Atar-Zwillenberg ◽  
Michael Atar ◽  
Gianni Morson ◽  
Udo Spornitz
Keyword(s):  
Blood Glucose ◽  
Xenopus Laevis ◽  
Muscle Glycogen ◽  
Hormonal Regulation ◽  
Glycogen Content ◽  
Glycogen Metabolism ◽  
Liver Glycogen ◽  
Hepatic Glycogen ◽  
Lipid Levels ◽  
Liver Glycogen Content

The hormonal regulation of amphibian glycogen metabolism was studied in Xenopus laevis as a typical member of the anurans (tailless amphibians).The main focus of this study was given to the effects of various hormones on the glycogen/glucose balance in adult toads. We determined biochemically the liver and muscle glycogen contents as well as the blood glucose and lipid levels for a number of hormones and also diabetes inducing substances. Additionally, we examined ultrastructure changes in hepatocytes induced by the various treatments, and also investigated the activity of carbohydrate-relevant enzymes by histochemistry. With one exception, the liver glycogen content of Xenopus remained basically unchanged by the treatments or was even slightly enhanced. Only human chorionic gonadotropin, through which the vitellogenic response is triggered, prompts a significant decrease of liver glycogen in females. Under the same conditions the male liver glycogen content remained stable. Muscle glycogen contents were not affected by any of the treatments. Blood glucose and lipid levels on the other hand were elevated considerably in both sexes after application of either epinephrine or cortisol. The ultrastructural examination revealed a proliferation of Rough Endoplasmic Reticulum (RER) in hepatocytes from epinephrine treated toads of both sexes as well as from HCG treated females. By histochemistry, we detected an elevated glucose-6-phosphatase activity in the hepatocytes from toads treated with either epinephrine or cortisol. These treatments also led to enhanced glycogen phosphorylase activity in males, and to a slightly elevated glyceraldehyde-3-phosphate dehydrogenase activity in females. Our results show that the hepatic glycogen is extremely stable in adult Xenopus. Only vitellogenesis causes a marked utilization of glycogen. Since the blood glucose levels are elevated in epinephrine or cortisol treated toads without the liver glycogen being affected, we conclude that either protein and/or lipid metabolism are involved in carbohydrate metabolism in Xenopus laevis.

Circadian rhythm of liver glycogen metabolism in rats: effects of hypothalamic lesions

1980 ◽  
Vol 238 (1) ◽  
pp. E21-E25 ◽  
Author(s):  
K. Ishikawa ◽  
T. Shimazu
Keyword(s):  
Circadian Rhythm ◽  
Glycogen Content ◽  
Glycogen Metabolism ◽  
Liver Glycogen ◽  
Circadian Rhythmicity ◽  
Hypothalamic Nucleus ◽  
Electrolytic Lesions ◽  
Late Evening ◽  
Bilateral Lesions ◽  
Lateral Hypothalamic Nucleus

The effects of electrolytic lesions of the suprachiasmatic nucleus (SCN) and ventromedial nucleus (VMH) of the hypothalamus on the circadian rhythm of liver glycogen metabolism were studied in rats fed during the dark period (2000–0800 h). Bilateral lesions of the SCN did not affect appreciably the circadian rhythmicity in three parameters of liver glycogen metabolism, i.e., glycogen content and glycogen synthetase I and phosphorylase a activities. In contrast, bilateral lesions of the VMH resulted in almost complete loss of circadian rhythmicity in phosphorylase a activity by lowering the high activity normally observed in late evening. VMH lesions also reduced the amplitudes of the rhythms of synthetase I activity and glycogen content, but did not abolish their rhythmicities. These results suggest that the integrity of the VMH, rather than the SCN, is important for regulation or expression of the food-triggered circadian rhythm of liver phosphorylase a activity. The implication of the lateral hypothalamic nucleus in regulation of the circadian rhythm of liver synthetase I is also discussed.

Adipose triacylglycerol lipase deletion alters whole body energy metabolism and impairs exercise performance in mice

2009 ◽  
Vol 297 (2) ◽  
pp. E505-E513 ◽  
Author(s):  
Elisabeth Huijsman ◽  
Caro van de Par ◽  
Catherine Economou ◽  
Chris van der Poel ◽  
Gordon S. Lynch ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Exercise Performance ◽  
Liver Glycogen ◽  
Carbohydrate Oxidation ◽  
Hormone Sensitive Lipase ◽  
Whole Body ◽  
Endurance Capacity ◽  
Triacylglycerol Lipase ◽  
Plasma Ffa ◽  
Exercise Induced

Adipose triacylglycerol lipase (ATGL) and hormone-sensitive lipase (HSL) are essential for efficient lipolysis in adipose tissue and skeletal muscle. Herein, we utilized whole body knockout mice to address the importance of ATGL and HSL for metabolic function and exercise performance. ATGL deletion severely disrupts whole-body substrate partitioning at rest; reducing plasma free fatty acid (FFA) availability (WT: 0.49 ± 0.06 vs. ATGL−/− 0.34 ± 0.03 mM), which in turn enhances carbohydrate oxidation during fasting (mean RER, WT: 0.86 ± 0.02, ATGL−/− 0.90 ± 0.01) and is associated with depleted muscle and liver glycogen stores. While plasma FFA was modestly reduced (23%) and whole body carbohydrate metabolism increased in HSL−/− mice, resting glycogen storage was not compromised. Studies in isolated muscles revealed that the capacity of ATGL and HSL−/− muscle to transport exogenous fatty acids is not compromised and the capacity to oxidize fatty acids is actually increased (3.7- and 1.3-fold above WT for ATGL and HSL). The exercise-induced increase in plasma FFA and glycerol was blunted with ATGL or HSL deletion, demonstrating an impaired capacity for exercise-induced lipolysis in these mice. Carbohydrate oxidation was increased concomitantly during exercise in ATGL−/− and HSL−/− mice, resulting in more muscle and liver glycogen depletion. Maximal running velocity and endurance capacity were reduced by 42% and 46% in ATGL−/− mice, but not in HSL−/− mice. The reduction in performance in ATGL−/− mice was not due to defective muscle contractile performance. These results demonstrate an essential role for both ATGL and HSL in maintaining adequate FFA supply to sustain normal substrate metabolism at rest and during exercise.

DEMONSTRATION OF A GLUCOCORTICOID-LIKE SUBSTANCE IN THE SPLEEN

1957 ◽  
Vol 15 (4) ◽  
pp. 440-447 ◽  
Author(s):  
I. Gy. FAZEKAS
Keyword(s):  
Fatty Acids ◽  
Glycogen Content ◽  
Liver Glycogen ◽  
Biological Properties ◽  
Splenic Tissue ◽  
Bile Pigments ◽  
Male Mice ◽  
The Brain ◽  
Reducing Properties ◽  
Intact Rats

SUMMARY 1. Fresh splenic tissue from pigs was extracted by the method of Swingle & Pfiffner for adrenocortical extracts, 1 ml. being equivalent to 100 g splenic tissue. 2. The material extracted was readily soluble in ethanol, benzene, acetone and water, but not in petroleum ether. It contained no protein, bile pigments, fat, fatty acids or cholesterol, and had marked reducing properties. 3. Administration of the extract to adrenalectomized male mice caused an increase, continuous with increasing dose of extract, in the glycogen content of liver and muscle. The increase in liver glycogen produced by 1·2 ml. extract was about the same as that caused by 2 mg cortisone. 4. In intact rats the extract caused an increase in blood sugar and in the glycogen content of liver and muscle. Cortisone had a similar effect. 5. Neither the splenic extract nor cortisone raised the glycogen content of the brain in adrenalectomized mice or intact rats. 6. Thus the spleen contains a substance which has a glucocorticoid-like effect on the carbohydrate metabolism of adrenalectomized and intact animals. In view of its chemical and biological properties, this substance is thought to be a glucocorticoid originating in the adrenal cortex. A substance with similar effects has been previously detected in liver, brain and muscle.

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.

Physiologic coupling of glial glycogen metabolism to neuronal activity in brain

1992 ◽  
Vol 70 (S1) ◽  
pp. S138-S144 ◽  
Author(s):  
Raymond A. Swanson
Keyword(s):  
Neuronal Activity ◽  
Tactile Stimulation ◽  
Glycogen Content ◽  
Brain Activity ◽  
Glycogen Metabolism ◽  
Normal Brain ◽  
Brain Glycogen ◽  
Glycogen Utilization ◽  
Glucose Supply ◽  
Stimulation Of

Brain glycogen is localized almost exclusively to glia, where it undergoes continuous utilization and resynthesis. We have shown that glycogen utilization increases during tactile stimulation of the rat face and vibrissae. Conversely, decreased neuronal activity during hibernation and anesthesia is accompanied by a marked increase in brain glycogen content. These observations support a link between neuronal activity and glial glycogen metabolism. The energetics of glycogen metabolism suggest that glial glycogen is mobilized to meet increased metabolic demands of glia rather than to serve as a substrate for neuronal activity. An advantage to the use of glycogen may be the potentially faster generation of ATP from glycogen than from glucose. Alternatively, glycogen could be utilized if glucose supply is transiently insufficient during the onset of increased metabolic activity. Brain glycogen may have a dynamic role as a buffer between the abrupt increases in focal metabolic demands that occur during normal brain activity and the compensatory changes in focal cerebral blood flow or oxidative metabolism.Key words: brain, glia, glycogen, glycolysis, hibernation.

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.

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