Effect of infusing epinephrine on liver and muscle glycogenolysis during exercise in rats

1986 ◽  
Vol 250 (6) ◽  
pp. E641-E649 ◽  
Author(s):  
D. A. Arnall ◽  
J. C. Marker ◽  
R. K. Conlee ◽  
W. W. Winder
Keyword(s):  
Muscle Glycogen ◽  
Vastus Lateralis ◽  
Plasma Concentrations ◽  
Physiological Saline ◽  
Threshold Concentration ◽  
Plasma Epinephrine ◽  
Glycogen Depletion ◽  
Epinephrine Infusion ◽  
Liver Glycogenolysis ◽  
Epinephrine Concentration

To determine the possibility of a threshold concentration of plasma epinephrine that stimulates liver glycogenolysis during exercise, adrenodemedullated (ADM) and sham-operated (SHAM) rats were infused with saline or epinephrine at rates that produced plasma concentrations ranging between 0.01 ng/ml (0.06 nM) and 4.3 ng/ml (23.7 nM). During the infusion rats were run on a rodent treadmill for 0, 30, or 60 min at 21 m/min up a 15% grade. Liver glycogen decreased at similar rates in all exercising rats regardless of plasma epinephrine concentration. Epinephrine infusion stimulated significant muscle glycogen depletion in the soleus and red and white vastus lateralis muscles. ADM saline-infused animals exhibited the least muscle glycogen depletion. Blood glucose and lactate in exercising ADM rats increased as the epinephrine infusion concentration increased. During exercise, there was no epinephrine concentration that stimulated liver glycogenolysis more effectively than physiological saline.

scholarly journals Effect of epinephrine on muscle glycogenolysis during exercise in trained men

1998 ◽  
Vol 84 (2) ◽  
pp. 465-470 ◽  
Author(s):  
M. A. Febbraio ◽  
D. L. Lambert ◽  
R. L. Starkie ◽  
J. Proietto ◽  
M. Hargreaves
Keyword(s):  
Oxygen Uptake ◽  
Muscle Glycogen ◽  
Respiratory Exchange Ratio ◽  
Peak Oxygen Uptake ◽  
Plasma Epinephrine ◽  
Epinephrine Infusion ◽  
Glycogen Utilization ◽  
Muscle Glycogen Concentration ◽  
Epinephrine Concentration

Febbraio, M. A., D. L. Lambert, R. L. Starkie, J. Proietto, and M. Hargreaves. Effect of epinephrine on muscle glycogenolysis during exercise in trained men. J. Appl. Physiol. 84(2): 465–470, 1998.—To test the hypothesis that an elevation in circulating epinephrine increases intramuscular glycogen utilization, six endurance-trained men performed two 40-min cycling trials at 71 ± 2% of peak oxygen uptake in 20–22°C conditions. On the first occasion, subjects were infused with saline throughout exercise (Con). One week later, after determination of plasma epinephrine levels in Con, subjects performed the second trial (Epi) with an epinephrine infusion, which resulted in a twofold higher ( P < 0.01) plasma epinephrine concentration in Epi compared with Con. Although oxygen uptake was not different when the two trials were compared, respiratory exchange ratio was higher throughout exercise in Epi compared with Con (0.93 ± 0.01 vs. 0.89 ± 0.01; P < 0.05). Muscle glycogen concentration was not different when the trials were compared preexercise, but the postexercise value was lower ( P < 0.01) in Epi compared with Con. Thus net muscle glycogen utilization was greater during exercise with epinephrine infusion (224 ± 37 vs. 303 ± 30 mmol/kg for Con and Epi, respectively; P < 0.01). In addition, both muscle and plasma lactate and plasma glucose concentrations were higher ( P < 0.05) in Epi compared with Con. These data indicate that intramuscular glycogen utilization, glycolysis, and carbohydrate oxidation are augmented by elevated epinephrine during submaximal exercise in trained men.

Effect of epinephrine on muscle glycogenolysis and insulin-stimulated muscle glycogen synthesis in humans

1998 ◽  
Vol 274 (1) ◽  
pp. E130-E138 ◽  
Author(s):  
Didier Laurent ◽  
Kitt Falk Petersen ◽  
Raymond R. Russell ◽  
Gary W. Cline ◽  
Gerald I. Shulman
Keyword(s):  
Muscle Glycogen ◽  
Glycogen Synthesis ◽  
Whole Body ◽  
Synthesis Rate ◽  
Initial Increase ◽  
Plasma Epinephrine ◽  
Epinephrine Infusion ◽  
Euglycemic Hyperinsulinemic Clamp ◽  
Muscle Glycogen Synthesis ◽  
Epinephrine Concentration

To examine the effects of a physiological increase in plasma epinephrine concentration (∼800 pg/ml) on muscle glycogenolysis and insulin-stimulated glycogenesis, we infused epinephrine [1.2 μg ⋅ (m2 body surface)−1 ⋅ min−1] for 2 h and monitored muscle glycogen and glucose 6-phosphate (G-6- P) concentrations with13C/31P nuclear magnetic resonance (NMR) spectroscopy. Epinephrine caused an increase in plasma glucose (Δ ∼50 mg/dl), lactate (Δ ∼1.4 mM), free fatty acids (Δ ∼1,200 μM at peak), and whole body glucose oxidation (Δ ∼0.85 mg ⋅ kg−1 ⋅ min−1) compared with levels in a group of control subjects ( n = 4) in the presence of slight hyperinsulinemia (∼13 μU/ml, n = 8) or basal insulin (∼7 μU/ml, n = 7). However, epinephrine did not induce any detectable changes in glycogen or G-6- P concentrations, whereas muscle inorganic phosphate (Pi) decreased by 35%. Epinephrine infusion during a euglycemic-hyperinsulinemic clamp ( n = 8) caused a 45% decrease in the glucose infusion rate that could be mostly attributed to a 73% decrease in muscle glycogen synthesis rate. After an initial increase to ∼160% of basal values, G-6- Plevels decreased by ∼30% with initiation of the epinephrine infusion. We conclude that a physiological increase in plasma epinephrine concentration 1) has a negligible effect on muscle glycogenolysis at rest, 2) decreases muscle Pi, which may maintain phosphorylase activity at a low level, and 3) causes a major impairment in insulin-stimulated muscle glycogen synthesis, possibly due to inhibition of glucose transport-phosphorylation activity.

Dose-response relationship between plasma epinephrine concentration and alveolar liquid clearance in dogs

1998 ◽  
Vol 85 (5) ◽  
pp. 1702-1707 ◽  
Author(s):  
Michael B. Maron
Keyword(s):  
Dose Response ◽  
Respir Crit ◽  
Plasma Concentrations ◽  
Neurogenic Pulmonary Edema ◽  
Response Relationship ◽  
Plasma Epinephrine ◽  
Dose Response Relationship ◽  
Alveolar Liquid Clearance ◽  
Epinephrine Concentration ◽  
Alveolar Liquid

Previously, alveolar liquid clearance (ALC) was observed to increase in a canine model of neurogenic pulmonary edema (NPE) by adrenal epinephrine (S. M. Lane, K. C. Maender, N. E. Awender, and M. B. Maron. Am. J. Respir. Crit. Care Med. 158: 760–768, 1998). In this study the dose-response relationship between plasma epinephrine concentration and ALC was determined in anesthetized dogs by infusing epinephrine to produce plasma concentrations of 256 ± 37, 1,387 ± 51, 15,737 ± 2,161, and 363,997 ± 66,984 (SE) pg/ml ( n = 6 for each concentration) for 4 h and measuring the resultant ALC. The latter was determined by mass balance after instillation of autologous plasma into a lower lung lobe. These plasma concentrations produced ALCs of 14.3 ± 1.2, 20.5 ± 1.9, 30.1 ± 1.5, and 37.9 ± 2.7% of the instilled volume, respectively. ALC after the lowest infusion rate was not different from that previously observed under baseline conditions (14.1 ± 2.1%), whereas in a previous study of NPE, plasma epinephrine concentration increased to 7,683 ± 687 pg/ml and ALC was 30.4 ± 1.6%. These data indicate that, during recovery from canine NPE, ALC is not maximally stimulated and suggest that it might be possible to pharmacologically produce further increases in the rate of resolution of this form of edema.

scholarly journals Regulation of muscle glycogenolytic flux during intense aerobic exercise after caffeine ingestion

1998 ◽  
Vol 275 (2) ◽  
pp. R596-R603 ◽  
Author(s):  
Alan Chesley ◽  
Richard A. Howlett ◽  
George J. F. Heigenhauser ◽  
Eric Hultman ◽  
Lawrence L. Spriet
Keyword(s):  
Aerobic Exercise ◽  
Muscle Glycogen ◽  
Glycogen Phosphorylase ◽  
Vastus Lateralis ◽  
Energy Status ◽  
Caffeine Ingestion ◽  
Sparing Effect ◽  
Muscle Biopsies ◽  
Glycogen Sparing ◽  
Epinephrine Concentration

This study examined the effects of caffeine (Caf) ingestion on muscle glycogen use and the regulation of muscle glycogen phosphorylase (Phos) activity during intense aerobic exercise. In two separate trials, 12 untrained males ingested either placebo (Pl) or Caf (9 mg/kg body wt) 1 h before cycling at 80% maximum O2 consumption (V˙o 2 max) for 15 min. Muscle biopsies were obtained from the vastus lateralis at 0, 3, and 15 min of exercise. In this study, glycogen “sparing” was defined as a 10% or greater reduction in muscle glycogen use during exercise after Caf ingestion compared with Pl. Muscle glycogen use decreased by 28% (Pl 255 ± 38 vs. Caf 184 ± 24 mmol/kg dry muscle) after Caf in six subjects [glycogen sparers (Sp)] but was unaffected by Caf in six other subjects [nonsparers (NSp), Pl 210 ± 35 vs. Caf 214 ± 37 mmol/kg dry muscle]. In both groups, Caf significantly increased resting free fatty acid concentration, significantly increased epinephrine concentration by twofold during exercise, and increased the Phos a mole fraction at 3 min of exercise compared with Pl, although not significantly. Caf improved the energy status of the muscle during exercise in the Sp group: muscle phosphocreatine (PCr) degradation was significantly reduced (Pl 47.9 ± 3.6 vs. Caf 40.4 ± 6.7 mmol/kg dry muscle at 3 min) and the accumulations of free ADP and free AMP (Pl 6.8 ± 1.3 vs. Caf 3.1 ± 1.4 μmol/kg dry muscle at 3 min; Pl 8.7 ± 0.8 vs. Caf 4.7 ± 1.1 μmol/kg dry muscle at 15 min) were significantly reduced. Caf had no effect on these measurements in the NSp group. It is concluded that the Caf-induced decrease in flux through Phos (glycogen-sparing effect) is mediated via an improved energy status of the muscle in the early stages of intense aerobic exercise. This may be related to an increased availability of fat and/or ability of mitochondria to oxidize fat during exercise preceded by Caf ingestion. It is presently unknown why the glycogen-sparing effect of Caf does not occur in all untrained individuals during intense aerobic exercise.

Adrenodemedullation affects endurance but not hepatic fructose 2,6-bisphosphate

1988 ◽  
Vol 254 (4) ◽  
pp. R572-R577 ◽  
Author(s):  
H. T. Yang ◽  
R. L. Hammer ◽  
T. L. Sellers ◽  
J. Arogyasami ◽  
D. T. Carrell ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Adrenal Medulla ◽  
Endurance Exercise ◽  
Glycogen Content ◽  
Vastus Lateralis ◽  
Liver Glycogen ◽  
Glycogen Depletion ◽  
Epinephrine Infusion ◽  
Liver Glycogen Content

Sham-operated (SHAM) and saline (ADM-S)- or epinephrine (ADM-E)-infused adrenodemedullated rats were run on a treadmill (21 m/min, 15% grade) for 80 min or until exhaustion. ADM-S rats had significantly lower endurance run times (116 +/- 6 min) than ADM-E rats (136 +/- 8 min) and SHAM rats (150 +/- 6 min). Liver glycogen content dropped from 56 +/- 4 to 10 +/- 2 mg/g in SHAM and from 54 +/- 4 to 18 +/- 5 mg/g in ADM-S and to 20 +/- 8 mg/g in ADM-E rats at 80 min. Liver glycogen was depleted in all rats at exhaustion. Liver fructose 2,6-bisphosphate was decreased markedly in exercising rats, and the extent of decrease was not influenced by adrenodemedullation or by epinephrine infusion. ADM-S rats showed impaired glycogen depletion in the white vastus lateralis and soleus muscles, hypoglycemia, and low blood lactate at 80 min and at exhaustion. Infusion of epinephrine into ADM rats reversed these deficiencies. These data indicate that the adrenal medulla is unessential for normal endurance exercise as long as liver glycogen is available. After liver glycogen is depleted, epinephrine from the adrenal medulla prevents hypoglycemia and is essential for allowing continuation of exercise.

Muscle glycogen recovery after exercise during glucose and fructose intake monitored by13C-NMR

1996 ◽  
Vol 81 (4) ◽  
pp. 1495-1500 ◽  
Author(s):  
Adrianus J. Van Den Bergh ◽  
Sibrand Houtman ◽  
Arend Heerschap ◽  
Nancy J. Rehrer ◽  
Hendrikus J. Van Den Boogert ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Muscle Glycogen ◽  
Glycogen Content ◽  
Vastus Lateralis ◽  
Glycogen Depletion ◽  
Glycogen Concentration ◽  
Fructose Intake ◽  
Glycogen Stores ◽  
Male Subjects ◽  
C Nmr

Van Den Bergh, Adrianus J., Sibrand Houtman, Arend Heerschap, Nancy J. Rehrer, Hendrikus J. Van Den Boogert, Berend Oeseburg, and Maria T. E. Hopman. Muscle glycogen recovery after exercise during glucose and fructose intake monitored by13C-NMR. J. Appl. Physiol. 81(4): 1495–1500, 1996.—The purpose of this study was to examine muscle glycogen recovery with glucose feeding (GF) compared with fructose feeding (FF) during the first 8 h after partial glycogen depletion by using13C-nuclear magnetic resonance (NMR) on a clinical 1.5-T NMR system. After measurement of the glycogen concentration of the vastus lateralis (VL) muscle in seven male subjects, glycogen stores of the VL were depleted by bicycle exercise. During 8 h after completion of exercise, subjects were orally given either GF or FF while the glycogen content of the VL was monitored by13C-NMR spectroscopy every second hour. The muscular glycogen concentration was expressed as a percentage of the glycogen concentration measured before exercise. The glycogen recovery rate during GF (4.2 ± 0.2%/h) was significantly higher ( P < 0.05) compared with values during FF (2.2 ± 0.3%/h). This study shows that 1) muscle glycogen levels are perceptible by 13C-NMR spectroscopy at 1.5 T and 2) the glycogen restoration rate is higher after GF compared with after FF.

Effect of epinephrine on alveolar liquid clearance in the rat

1999 ◽  
Vol 87 (2) ◽  
pp. 611-618 ◽  
Author(s):  
Paul D. Charron ◽  
J. Phillip Fawley ◽  
Michael B. Maron
Keyword(s):  
Pulmonary Edema ◽  
Mass Balance ◽  
Sodium Transport ◽  
No Reduction ◽  
Plasma Epinephrine ◽  
Epinephrine Infusion ◽  
Baseline Values ◽  
Alveolar Liquid Clearance ◽  
Epinephrine Concentration ◽  
Alveolar Liquid

Endogenous epinephrine has been found to increase alveolar liquid clearance (ALC) in several pulmonary edema models. In this study, we infused epinephrine intravenously for 1 h in anesthetized rats to produce plasma epinephrine concentrations commonly observed in this species under stressful conditions and measured ALC by mass balance. Epinephrine increased ALC from 31.5 ± 3.2 to 48.9 ± 1.1 (SE)% of the instilled volume ( P < 0.05). The increased ALC was prevented by either propranolol or amiloride. To determine whether ALC returns to normal after plasma epinephrine concentration normalizes, we measured ALC 2 h after stopping an initial 1-h epinephrine infusion and found ALC to be at baseline values. Finally, to determine whether desensitization of the liquid clearance response occurs, we evaluated the effects of both repeated 1-h infusions and a continuous 4-h infusion of epinephrine on ALC and found no reduction in ALC under either condition. We conclude that epinephrine increases ALC by stimulating β-adrenoceptors and sodium transport, that the increase is reversible once plasma epinephrine concentration normalizes, and that desensitization of the ALC response does not appear to occur after 4 h of continuous epinephrine exposure.

Effects of cocaine on plasma catecholamine and muscle glycogen concentrations during exercise in the rat

1991 ◽  
Vol 70 (3) ◽  
pp. 1323-1327 ◽  
Author(s):  
R. K. Conlee ◽  
D. W. Barnett ◽  
K. P. Kelly ◽  
D. H. Han
Keyword(s):  
Blood Lactate ◽  
Muscle Glycogen ◽  
Glycogen Content ◽  
Vastus Lateralis ◽  
Male Rats ◽  
Vastus Lateralis Muscle ◽  
Plasma Catecholamine ◽  
Plasma Epinephrine ◽  
Exercise Endurance ◽  
Insight Into

This study was designed to test the hypothesis that cocaine (C) alters the normal physiological responses to exercise. Male rats were injected with saline (S) or C (12.5 mg/kg) either intravenously (iv) or intraperitoneally (ip). After injection the animals were allowed to rest for 30 min or were run on the treadmill (26 m/min, 10% grade). At rest plasma epinephrine values were 245 +/- 24 pg/ml in the S group and 411 +/- 43 (ip) and 612 +/- 41 (iv) pg/ml in the C groups (P less than 0.05 between S and C). During exercise plasma epinephrine levels were 615 +/- 32 pg/ml in S and 1,316 +/- 58 (ip) and 1,208 +/- 37 (iv) pg/ml in the C groups (P less than 0.05 between S and C). Similar results were obtained for norepinephrine. Glycogen content in the white vastus lateralis muscle was reduced to 31 +/- 2 mumol/g in S after exercise, but after C and exercise the values were 12 +/- 4 (ip) and 16 +/- 3 (iv) mumol/g (P less than 0.05 between S and C). There was no effect of the drug on this parameter at rest. Blood lactate rose to 4.8 +/- 1.0 (ip) and 5.8 +/- 1.3 (iv) mM in the C groups but to only 3.0 +/- 0.2 in the S group after exercise (P less than 0.05 between S and C). These results show that C and exercise combined exert a more dramatic effect on plasma catecholamine, muscle glycogen, and blood lactate concentrations than do C and exercise alone. They provide further insight into explaining the adverse effects of C on exercise endurance observed previously (Bracken et al., J. Appl. Physiol. 66: 377-383, 1989).

scholarly journals A kinetic model of the circulatory regulation of tissue plasminogen activator during exercise, epinephrine infusion, and endurance training

Blood ◽  
1993 ◽  
Vol 81 (12) ◽  
pp. 3293-3302
Author(s):  
WL Chandler ◽  
WC Levy ◽  
RC Veith ◽  
JR Stratton
Keyword(s):  
Blood Flow ◽  
Endurance Training ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Hepatic Blood Flow ◽  
Plasma Epinephrine ◽  
Epinephrine Infusion ◽  
Tissue Plasminogen ◽  
Pai 1 ◽  
Epinephrine Concentration

A computer simulation of the circulatory system was used to kinetically model secretion, inhibition, and clearance of tissue plasminogen activator (t-PA) during three different processes that increase active t-PA levels: epinephrine infusion, exercise, and endurance training. Infusion of epinephrine stimulated an increase in t-PA secretion that was proportional to the plasma epinephrine concentration. In addition, epinephrine infusion increased hepatic blood flow and t-PA clearance, thus slowing the increase of plasma t-PA levels. During exercise, t-PA levels increased due both to increased t-PA secretion and to decreased clearance secondary to reduced hepatic blood flow. The increase in t-PA secretion during exercise was directly proportional to the epinephrine concentration in blood with the same ratio of t-PA secretion to epinephrine as found during epinephrine infusion, suggesting that increased plasma epinephrine during exercise was the primary stimulus for t-PA secretion. Lastly, the simulation predicted that 6 months of endurance training produced a decrease in resting plasminogen activator inhibitor type 1 (PAI-1) secretion, resulting in less t-PA inhibition and an overall increase in active t-PA after training. Accurate analysis of the regulation of active t-PA levels in blood required simultaneous modeling of t-PA and PAI-1 secretion, hepatic clearance, and inhibition of t-PA by PAI-1.

Diminished hormonal responses to exercise in trained rats

1977 ◽  
Vol 43 (6) ◽  
pp. 953-958 ◽  
Author(s):  
H. Galbo ◽  
E. A. Richter ◽  
J. J. Holst ◽  
N. J. Christensen
Keyword(s):  
Muscle Glycogen ◽  
Plasma Concentrations ◽  
Male Rats ◽  
Hepatic Glycogen ◽  
Plasma Glucagon ◽  
Glycogen Depletion ◽  
Hormonal Responses ◽  
Tissue Sensitivity ◽  
Glucagon And Insulin ◽  
Response To Exercise

Male rats (120 g) either were subjected to a 12-wk physical training program (T rats) or were sedentary controls (C rats). Subsequently the rats were killed at rest or after a 45- or 90-min forced swim. At rest, T rats had higher liver and muscle glycogen concentrations but lower plasma insulin. During exercise, blood glucose increased 60% in T rats but decreased 20% in C rats. Plasma glucagon and insulin concentrations did not change in T rats but plasma glucagon increased and insulin decreased markedly in C rats. Plasma epinephrine (90 min: range, 0.78–2.96 ng-ml-1, (T) vs. 4.42–15.67 (C)) and norepinephrine (90 min: 0.70–2.22 (T) vs. 2.50–6.10 (C)) were lower in T than in C rats. Hepatic glycogen decreased substantially and, as with muscle glycogen, the decrease was parallel in T and C rats. The plasma concentrations of free fatty acids were higher but lactate and alanine lower in T than in C rats. In trained rats the hormonal response to exercise is blunted partly due to higher glucose concentrations. In these rats adipose tissue sensitivity to catecholamines is increased, and changes in glucagon and insulin concentrations are not necessary for increased lipolysis and hepatic glycogen depletion during exercise.

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