Postexercise muscle and liver glycogen metabolism in male and female rats

1987 ◽  
Vol 62 (3) ◽  
pp. 1250-1254 ◽  
Author(s):  
P. A. Ivey ◽  
G. A. Gaesser
Keyword(s):  
Sex Difference ◽  
Muscle Glycogen ◽  
Exercise Bout ◽  
Glycogen Metabolism ◽  
Liver Glycogen ◽  
Female Rats ◽  
Glycogen Depletion ◽  
Male And Female ◽  
Glycogen Repletion ◽  
Fast Twitch

Male and female Wistar rats were run for 5 min at 1.7 mph at a 17% grade to determine whether a sex difference exists in the rate of glycogen resynthesis during recovery in fast-twitch red muscle, fast-twitch white muscle, and liver. Rats were killed at one of three time points: immediately after the exercise bout, and at 1 or 4 h later. Males had significantly higher resting muscle glycogen levels (P less than 0.05). Exercise resulted in significant glycogen depletion in both sexes (P less than 0.01). Males utilized approximately 50% more glycogen during the exercise bout than females (P less than 0.05). During the food-restricted 4-h recovery period, muscle glycogen was repleted significantly during the 1st h (P less than 0.05). Liver glycogen was not depleted as a result of the exercise bout, but fell during the first h of recovery (P less than 0.05) and remained low during the subsequent 3 h. The greater glycogen utilization in red and white fast-twitch muscle during exercise by males could represent a true sex difference but could also be attributable in part to the males having performed more work as a result of 20% greater body mass. We conclude that no sex difference was observed in the rates of muscle glycogen repletion after exercise or in liver glycogen metabolism during and after exercise, and rapid postexercise muscle glycogen repletion occurred at a time of accelerated liver glycogen depletion.

Effects of exercise and glycogen depletion on glyconeogenesis in muscle

1994 ◽  
Vol 76 (4) ◽  
pp. 1753-1758 ◽  
Author(s):  
A. Bonen ◽  
D. A. Homonko
Keyword(s):  
Skeletal Muscle ◽  
Muscle Glycogen ◽  
Extensor Digitorum Longus ◽  
Treadmill Exercise ◽  
Glycogen Depletion ◽  
Epinephrine Injection ◽  
Slow Twitch ◽  
Glycogen Repletion ◽  
Fast Twitch

In the present study, we investigated the hypotheses that 1) skeletal muscle glyconeogenesis will increase after exercise, 2) greater changes in glyconeogenesis will be observed after exercise in fast-twitch muscles than in slow-twitch muscles, and 3) glycogen repletion will reduce the rates of glyconeogenesis. Mouse soleus and extensor digitorum longus (EDL) glycogen depots were reduced to the same levels by treadmill exercise (60 min) or epinephrine injection (75 micrograms/100 g body wt ip). Untreated animals were used as controls. We were able to prevent glycogen repletion by incubating muscles in vitro with sorbitol (75 mM) and to increase glycogen concentrations in vitro by incubating muscles with glucose (75 mM). The experimental results showed that glyconeogenesis was increased by exercise (EDL, +51%; soleus, +82%) when glycogen levels were kept low. When glycogen depots were increased, the rate of glyconeogenesis was lowered in the exercised EDL (P < 0.05) but not in the soleus (P > 0.05). Reductions in muscle glycogen by epinephrine did not change the rate of glyconeogenesis in EDL, either when glycogen depots were kept low or were repleted (P > 0.05). In contrast, in the soleus, epinephrine-induced reductions in glycogen did stimulate glyconeogenesis (P < 0.05). Analyses in EDL showed that in nonexercised muscles glycogen concentrations were minimally effective in altering the rates of glyconeogenesis. A 30% decrement in glycogen increased glyconeogenesis by 5% in resting muscles, whereas the same decrement increased glyconeogenesis by 51% in exercised muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

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)

Glycogen resynthesis in leg muscles of rats during exercise

1984 ◽  
Vol 247 (5) ◽  
pp. R880-R883 ◽  
Author(s):  
S. H. Constable ◽  
J. C. Young ◽  
M. Higuchi ◽  
J. O. Holloszy
Keyword(s):  
Muscle Glycogen ◽  
Prolonged Exercise ◽  
Liver Glycogen ◽  
Treadmill Running ◽  
Moderate Intensity ◽  
Glycogen Depletion ◽  
Moderate Intensity Exercise ◽  
Glycogen Resynthesis ◽  
Leg Muscles ◽  
Insulin In Plasma

This study was undertaken to determine whether glycogen resynthesis can occur in glycogen-depleted muscles in response to glucose feeding during prolonged exercise. Rats were exercised for 40 min with a treadmill running program designed to deplete muscle glycogen. One group was studied immediately after the glycogen-depletion exercise. A second group was given 1 g glucose by stomach tube and exercised for an additional 90 min at a running speed of 22 m/min on a treadmill set at an 8 degree incline; they were given additional 1-g glucose feedings after 30 and 60 min of running. The initial 40-min run resulted in liver glycogen depletion, large decreases in plasma glucose and insulin concentrations, and a marked lowering of muscle glycogen. The glucose feedings resulted in greater than twofold increases in the concentrations of glucose and insulin in plasma, and of glycogen in leg muscles, during the 90 min of running. No repletion of liver glycogen occurred. These results provide evidence that glycogen resynthesis can occur in glycogen-depleted muscle despite continued moderate intensity exercise if sufficient glucose is made available.

Sex Difference and Postnatal Change of Maternal Behavioral Patterns in Juvenile Male and Female Rats

2005 ◽  
Vol 22 (6) ◽  
pp. 695-699
Author(s):  
Satoshi Shima ◽  
Aya Urano ◽  
Lajos Korányi ◽  
Korehito Yamanouchi
Keyword(s):  
Sex Difference ◽  
Female Rats ◽  
Behavioral Patterns ◽  
Juvenile Male ◽  
Male And Female ◽  
Male And Female Rats ◽  
Postnatal Change

Exercise and glycogen depletion: effects on ability to activate muscle phosphorylase

1986 ◽  
Vol 60 (5) ◽  
pp. 1518-1523 ◽  
Author(s):  
S. H. Constable ◽  
R. J. Favier ◽  
J. O. Holloszy
Keyword(s):  
Muscle Contraction ◽  
Muscle Glycogen ◽  
Contractile Activity ◽  
Strenuous Exercise ◽  
Glycogen Depletion ◽  
Significant Difference ◽  
Muscle Phosphorylase ◽  
Glycogen Repletion ◽  
Stimulation Of

Phosphorylase activation reverses during prolonged contractile activity. Our first experiment was designed to determine whether this loss of ability to activate phosphorylase by stimulation of muscle contraction persists following exercise. Phosphorylase activation by stimulation of muscle contraction was markedly inhibited in rats 25 min after exhausting exercise. To evaluate the role of glycogen depletion, we accelerated glycogen utilization by nicotinic acid administration. A large difference in muscle glycogen depletion during exercise of the same duration did not influence the blunting of phosphorylase activation. Phosphorylase activation by stimulation of contraction was more severely inhibited following prolonged exercise than after a shorter bout of exercise under conditions that resulted in the same degree of glycogen depletion. A large difference in muscle glycogen repletion during 90 min of recovery was not associated with a significant difference in the ability of muscle stimulation to activate phosphorylase, which was still significantly blunted. Phosphorylase activation by epinephrine was also markedly inhibited in muscle 25 min after strenuous exercise but had recovered completely in glycogen-repleted muscle 90 min after exercise. These results provide evidence that an effect of exercise other than glycogen depletion is involved in causing the inhibition of phosphorylase activation; however, they do not rule out the possibility that glycogen depletion also plays a role in this process.

The effect of magnesium oxide supplementation on muscle glycogen metabolism before and after exercise and at slaughter in sheep

2001 ◽  
Vol 52 (7) ◽  
pp. 723 ◽  
Author(s):  
G. E. Gardner ◽  
R. H. Jacob ◽  
D. W. Pethick
Keyword(s):  
Magnesium Oxide ◽  
Muscle Glycogen ◽  
Glycogen Metabolism ◽  
Post Exercise ◽  
Exercise Regimen ◽  
Before And After ◽  
Series Of Experiments ◽  
Glycogen Repletion ◽  
Exercise Muscle ◽  
Muscle Biopsies

This study was a series of experiments designed to test the influence of supplemental magnesium oxide (MgO) on muscle glycogen concentration in sheep exposed to stress (exercise) and the commercial slaughter process, and to test the effectiveness of this supplement in the commercial scenario. In Expt 1, Merino wethers maintained on a mixed ration (metabolisable energy 11 MJ/kg and crude protein 16.3% in DM) were supplemented with MgO at the rate of 0%, 0.5%, or 1% of their ration for 10 days prior to a single bout of exercise and for 10 days prior to slaughter at a commercial abattoir. The exercise regimen consisted of 4 intervals of 15 min, with muscle biopsies taken by biopsy drill from the m. semimembranosis (SM) and m. semitendinosis (ST) pre-exercise and immediately post-exercise, and at 36 and 72 h post-exercise. Muscle biopsies were also taken 1 week prior to slaughter from the SM and ST, with further samples taken approximately 30 min post-slaughter. Ultimate pH (pHu) of the SM, ST, and m. longissimus dorsi (LD) was measured 48 h after slaughter. Sheep supplemented with MgO lost less muscle glycogen in the ST during exercise, and repleted more muscle glycogen in the SM during the post-exercise repletion phase, than unsupplemented sheep. The supplemented animals also had higher muscle glycogen concentrations in the ST at slaughter. In Expt 2, MgO was administered to Merino wether lambs for 4 days prior to slaughter in the form of a water-borne slurry at a rate equivalent to 1% of their ration. This treatment resulted in significantly reduced muscle glycogen concentrations in both the SM and ST at slaughter. In Expts 3–5, MgO was used as an ‘in-feed’ supplement in the commercial scenario. In each case, slaughter-weight Merino lambs were supplemented with MgO at the rate of 1% of their ration for 4 days prior to commercial slaughter. Positive responses were seen in 2 of the 3 experiments, with increased glycogen concentrations and a reduced pHu. The animals that demonstrated no response to MgO had the lowest pHu after slaughter, suggesting a minimal stress load, thus providing very little scope for an effect of the MgO supplement. We conclude that MgO can reduce the effects of exercise, leading to a subsequent reduction in glycogen loss, and an increase in the rate of glycogen repletion in skeletal muscle following exercise. The results support MgO supplementation as a viable option for reducing the stress associated with commercial slaughter.

A SEX DIFFERENCE IN THE TEMPERATURE RESPONSE OF RATS TO EXERCISE

1965 ◽  
Vol 43 (3) ◽  
pp. 437-443 ◽  
Author(s):  
G. E. Thompson ◽  
J. A. F. Stevenson
Keyword(s):  
Sex Difference ◽  
Core Temperature ◽  
Temperature Response ◽  
Female Rats ◽  
Male And Female ◽  
Male And Female Rats ◽  
The Difference ◽  
Colonic Temperature ◽  
Response To Exercise ◽  
Skin Temperatures

The changes of colonic and tail skin temperatures were measured in male and female rats exercised on a motor-driven treadmill at a speed of 4.6 m/minute. The pattern of changes in these temperatures was the same in the two sexes except that the females tolerated a significantly higher colonic temperature than the males before beginning to vasodilate in the tail, and, perhaps as a result, the females regulated core temperature at a significantly higher level as exercise continued. Ovariectomy or prolonged (7–14 days) treatment with progesterone (12 mg/day) resulted in the temperature response to exercise of the female approaching that of the male, but not entirely eliminating the difference.

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.

scholarly journals NMR of glycogen in exercise

1999 ◽  
Vol 58 (4) ◽  
pp. 851-859 ◽  
Author(s):  
Thomas B. Price ◽  
Douglas L. Rothman ◽  
Robert G. Shulman
Keyword(s):  
Time Resolution ◽  
Muscle Glycogen ◽  
Time Course ◽  
Glycogen Synthesis ◽  
Liver Glycogen ◽  
Invasive Technique ◽  
Human Populations ◽  
Glycogen Depletion ◽  
Non Invasive ◽  
C Nmr

Natural-abundance 13CNMR spectroscopy is a non-invasive technique that enables in vivo assessments of muscle and/or liver glycogen concentrations. Over the last several years, 13C NMR has been developed and used to obtain information about human glycogen metabolism with diet and exercise. Since NMR is non-invasive, more data points are available over a specified time course, dramatically improving the time resolution. This improved time resolution has enabled the documentation of subtleties of muscle glycogen re-synthesis following severe glycogen depletion that were not previously observed. Muscle and liver glycogen concentrations have been tracked in several different human populations under conditions that include: (1) muscle glycogen recovery from intense localized exercise with normal insulin and with insulin suppressed; (2) muscle glycogen recovery in an insulin-resistant population; (3) muscle glycogen depletion during prolonged low-intensity exercise; (4) effect of a mixed meal on postprandial muscle and liver glycogen synthesis. The present review focuses on basic 13C NMR and gives results from selected studies.

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