Effect of heat stress on muscle energy metabolism during exercise

1994 ◽  
Vol 77 (6) ◽  
pp. 2827-2831 ◽  
Author(s):  
M. A. Febbraio ◽  
R. J. Snow ◽  
C. G. Stathis ◽  
M. Hargreaves ◽  
M. F. Carey
Keyword(s):  
Heat Stress ◽  
Energy Metabolism ◽  
Relative Humidity ◽  
Energy Demand ◽  
Adenine Nucleotide ◽  
Creatine Phosphate ◽  
O2 Uptake ◽  
Muscle Energy ◽  
Muscle Energy Metabolism ◽  
Adenine Nucleotide Pool

To examine the effect of heat stress on muscle energy metabolism during submaximal exercise, 12 endurance-trained men cycled on two occasions for approximately 40 min at 70% maximal O2 uptake in an environmental chamber at either 20 degrees C and 20% relative humidity (T20) or 40 degrees C and 20% relative humidity (T40). Trials were conducted > or = 1 wk apart in random order. No difference in mean O2 uptake was observed when exercise in T40 was compared with that in T20. In contrast, exercise in T40 resulted in a higher mean heart rate (P < 0.01) and respiratory exchange ratio (P < 0.05) compared with that in T20. Postexercise rectal and muscle temperatures were also higher (P < 0.01) in T40 than in T20. Lower (P < 0.01) postexercise creatine phosphate and higher creatine (P < 0.01) and ammonia (P < 0.05) were observed in muscle after exercise in T40 compared with T20. In addition, an increased (P < 0.01) muscle glycogenolysis and higher (P < 0.01) postexercise muscle lactate accumulation were observed during exercise in T40 compared with T20. In contrast, no differences were observed in postexercise concentrations of total adenine nucleotide pool (ATP+ADP+AMP), ATP/ADP ratio, or inosine 5′-monophosphate (IMP) when T40 was compared with T20. These results indicate that the rate of ATP utilization may be increased during exercise in the heat but that this increased energy demand is predominantly met by an increase in anaerobic glycolysis and creatine phosphate hydrolysis, preventing a reduction in total adenine nucleotide pool.(ABSTRACT TRUNCATED AT 250 WORDS)

Muscle RING-Finger Protein-1 (MuRF1) as a Connector of Muscle Energy Metabolism and Protein Synthesis

2008 ◽  
Vol 376 (5) ◽  
pp. 1224-1236 ◽  
Author(s):  
Suguru Koyama ◽  
Shoji Hata ◽  
Christian C. Witt ◽  
Yasuko Ono ◽  
Stefanie Lerche ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Energy Metabolism ◽  
Ring Finger ◽  
Ring Finger Protein ◽  
Finger Protein ◽  
Muscle Energy ◽  
Muscle Energy Metabolism

Possible Involvement of Kinins in Muscle Energy Metabolism

1984 ◽  
pp. 63-71 ◽  
Author(s):  
G. Dietze ◽  
E. Maerker ◽  
C. Lodri ◽  
R. Schifman ◽  
M. Wicklmayr ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Muscle Energy ◽  
Muscle Energy Metabolism

scholarly journals Endospanin-2 enhances skeletal muscle energy metabolism and running endurance capacity

JCI Insight ◽  
2018 ◽  
Vol 3 (9) ◽  
Author(s):  
Steve Lancel ◽  
Matthijs K.C. Hesselink ◽  
Estelle Woldt ◽  
Yves Rouillé ◽  
Emilie Dorchies ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Energy Metabolism ◽  
Endurance Capacity ◽  
Muscle Energy ◽  
Muscle Energy Metabolism

Effects of the Anti-Migraine Drug Sumatriptan on Muscle Energy Metabolism: Relationship to Side-Effects

Cephalalgia ◽  
2000 ◽  
Vol 20 (1) ◽  
pp. 39-44 ◽  
Author(s):  
MD Boska ◽  
KMA Welch ◽  
L Schultz ◽  
J Nelson
Keyword(s):  
Skeletal Muscle ◽  
Energy Metabolism ◽  
Side Effects ◽  
Kinetic Data ◽  
Oxygen Storage ◽  
Resonance Spectroscopy ◽  
Sumatriptan Succinate ◽  
Muscle Energy ◽  
Creatine Kinase Reaction ◽  
Muscle Energy Metabolism

Sumatriptan succinate (Imitrex) is a 5-HT(5-hydroxytryptamine) agonist used for relief of migraine symptoms. Some individuals experience short-lived side-effects, including heaviness of the limbs, chest heaviness and muscle aches and pains. The effects of this drug on skeletal muscle energy metabolism were studied during short submaximal isometric exercises. We studied ATP flux from anaerobic glycolysis (An Gly), the creatine kinase reaction (CK) and oxidative phosphorylation (Ox Phos) using 31P nuclear magnetic resonance spectroscopy (31P MRS) kinetic data collected during exercise. It was found that side-effects induced acutely by injection of 6 mg sumatriptan succinate s.c. were associated with reduced oxygen storage in peripheral skeletal muscle 5–20 min after injection as demonstrated by a transient reduction in mitochondrial function at end-exercise. These results suggest that mild vasoconstriction in peripheral skeletal muscle is associated with the action of sumatriptan and is likely to be the source of the side-effects experienced by some users. Migraine with aura patients were more susceptible to this effect than migraine without aura patients.

Cellular energy utilization and supply during hypoxia in embryonic cardiac myocytes

1996 ◽  
Vol 270 (1) ◽  
pp. L44-L53 ◽  
Author(s):  
G. R. Budinger ◽  
N. Chandel ◽  
Z. H. Shao ◽  
C. Q. Li ◽  
A. Melmed ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Cardiac Myocytes ◽  
Energy Demand ◽  
Adenine Nucleotide ◽  
Energy Utilization ◽  
Embryonic Chick ◽  
O2 Uptake ◽  
Progressive Hypoxia ◽  
Cellular Hypoxia

Studies of intact hearts suggest that cardiac myocytes may have the ability to reversibly suppress metabolic activity and energy demand in states of regional hypoperfusion. However, an ability to suppress respiration in response to hypoxia has never been demonstrated in isolated myocytes. To test this, isolated embryonic chick cardiac myocytes were exposed to progressive hypoxia while their rate of O2 uptake and concentrations of lactate, ATP, ADP, AMP, and phosphocreatine were measured. Compared with the value obtained at an oxygen tension (PO2) of 120 Torr, cellular O2 uptake decreased by 28 +/- 14% (SD) at PO2 = 50 Torr and by 64 +/- 25% at PO2 = 20 Torr (P < 0.05). This decrease was similar after 1 min or 2 h of hypoxia, was sustained for 16 h, and was completely reversible within 2 min after reoxygenation. The reduction in O2 uptake was associated with a decrease in the rate of ATP turnover, but no change in adenine nucleotide or phosphocreatine concentrations. In myocytes adherent to glass cover-slips, O2 uptake and contractile motion were decreased after 30-60 min at 50 and 20 Torr, compared with normoxic values. O2 uptake also was significantly decreased at 50 and 20 Torr in myocytes incubated with N,N,N',N'-tetramethyl-p-phenylenediamine, which suggests that the catalytic activity of cytochrome-c oxidase was partially inhibited during hypoxia. In summary, these results demonstrate that embryonic chick cardiac myocytes can suppress their rates of ATP demand, ATP utilization, and O2 uptake during moderate hypoxia through a mechanism that involves a reversible inhibition of cytochrome-c oxidase. This mechanism may represent a protective response to cellular hypoxia.

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