Calf Muscle Metabolism in Venous Insufficiency

1993 ◽  
Vol 8 (2) ◽  
pp. 58-61
Author(s):  
L. J. Hands ◽  
G. J. Kemp ◽  
A. Zukowski ◽  
A. N. Nicolaides ◽  
G. K. Radda
Keyword(s):  
Venous Insufficiency ◽  
Muscle Metabolism ◽  
Calf Muscle ◽  
Resonance Spectroscopy ◽  
Metabolic Recovery ◽  
Glycolytic Activity ◽  
Muscle Energy ◽  
Muscle Energy Metabolism ◽  
Phosphorus Metabolites

Objectives: To study the effect of deep venous insufficiency on calf muscle energy metabolism. Design: A paired study of affected and unaffected calf muscle in seven patients with unilateral lower limb deep venous insufficiency. Investigations: Phosphorus-31 magnetic resonance spectroscopy was used to study changes in vivo in pH, phosphocreatine and other phosphorus metabolites during and after exercise. Results: Glycolytic activity was increased in the affected muscle at the start of exercise but metabolic recovery following exercise was normal. Conclusions: Oxidative phosphorylation is impaired, at least at the start of exercise, but appears normal immediately after exercise. This may be due to inadequate blood flow, perhaps secondary to the rise in intramuscular pressure that occurs with exercise.

Skeletal muscle metabolism and work capacity: a 31P-NMR study of Andean natives and lowlanders

1991 ◽  
Vol 70 (5) ◽  
pp. 1963-1976 ◽  
Author(s):  
G. O. Matheson ◽  
P. S. Allen ◽  
D. C. Ellinger ◽  
C. C. Hanstock ◽  
D. Gheorghiu ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Muscle Metabolism ◽  
Work Capacity ◽  
Calf Muscle ◽  
Whole Body ◽  
Resonance Spectroscopy ◽  
Muscle Work ◽  
Nmr Study ◽  
Nuclear Magnetic

Two metabolic features of altitude-adapted humans are the maximal O2 consumption (VO2max) paradox (higher work rates following acclimatization without increases in VO2max) and the lactate paradox (progressive reductions in muscle and blood lactate with exercise at increasing altitude). To assess underlying mechanisms, we studied six Andean Quechua Indians in La Raya, Peru (4,200 m) and at low altitude (less than 700 m) immediately upon arrival in Canada. The experimental strategy compared whole-body performance tests and single (calf) muscle work capacities in the Andeans with those in groups of sedentary, power-trained, and endurance-trained lowlanders. We used 31P nuclear magnetic resonance spectroscopy to monitor noninvasively changes in concentrations of phosphocreatine [( PCr]), [Pi], [ATP], [PCr]/[PCr] + creatine ([Cr]), [Pi]/[PCr] + [Cr], and pH in the gastrocnemius muscle of subjects exercising to fatigue. Our results indicate that the Andeans 1) are phenotypically unique with respect to measures of anaerobic and aerobic work capacity, 2) despite significantly lower anaerobic capacities, are capable of calf muscle work rates equal to those of highly trained power- and endurance-trained athletes, and 3) compared with endurance-trained athletes with significantly higher VO2max values and power-trained athletes with similar VO2max values, display, respectively, similar and reduced perturbation of all parameters related to the phosphorylation potential and to measurements of [Pi], [PCr], [ATP], and muscle pH derivable from nuclear magnetic resonance. Because the lactate paradox may be explained on the basis of tighter ATP demand-supplying coupling, we postulate that a similar mechanism may explain 1) the high calf muscle work capacities in the Andeans relative to measures of whole-body work capacity, 2) the VO2max paradox, and 3) anecdotal reports of exceptional work capacities in indigenous altitude natives.

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.

MUSCLE ENERGY METABOLISM IN MULTIPLE SCLEROSIS MEASURED BY IN VIVO 31P MRS 476

1997 ◽  
Vol 29 (Supplement) ◽  
pp. 83 ◽  
Author(s):  
P. -P. Z. Tang ◽  
A. T. White ◽  
S. Topaz ◽  
J. H. Petajan
Keyword(s):  
Multiple Sclerosis ◽  
Energy Metabolism ◽  
31P Mrs ◽  
Muscle Energy ◽  
Muscle Energy Metabolism

scholarly journals Phosphorus metabolites in the human placenta estimated in vivo by magnetic resonance spectroscopy.

1991 ◽  
Vol 66 (7 Spec No) ◽  
pp. 780-782 ◽  
Author(s):  
A M Weindling ◽  
R D Griffiths ◽  
A S Garden ◽  
P A Martin ◽  
R H Edwards
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Human Placenta ◽  
Resonance Spectroscopy ◽  
Phosphorus Metabolites

Effect of insulin on intracellular pH and phosphate metabolism in human skeletal muscle in vivo

1991 ◽  
Vol 81 (1) ◽  
pp. 123-128 ◽  
Author(s):  
D. J. Taylor ◽  
S. W. Coppack ◽  
T. A. D. Cadoux-Hudson ◽  
G. J. Kemp ◽  
G. K. Radda ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Intracellular Ph ◽  
Inorganic Phosphate ◽  
Human Skeletal Muscle ◽  
Muscle Metabolism ◽  
Normal Subjects ◽  
Phosphate Concentration ◽  
Resonance Spectroscopy ◽  
Phosphorus Containing

1. 31P nuclear magnetic resonance spectroscopy and the hyperinsulinaemic-euglycaemic clamp were used simultaneously to assess the effect of insulin on intracellular pH and the major phosphorus-containing metabolites of normal human skeletal muscle in vivo in four normal subjects. 2. Insulin and glucose were infused for 120 min. Plasma insulin increased approximately 10-fold over pre-clamp levels (5.6 ± 0.9 m-units/l pre-clamp and 54 ± 5 m-units/l over the last hour of infusion; mean ± sem, n = 4). Plasma glucose concentration did not change significantly (5.4 ± 0.2 mmol/l pre-clamp and 5.5 ± 0.1 mmol/l over the last hour of infusion). 3. Insulin and glucose infusion resulted in a decline in the intracellular pH of forearm muscle of 0.027 ± 0.007 unit/h (P < 0.01), whereas in control studies of the same subjects, pH rose by 0.046 ± 0.005 unit/h (P < 0.001). 4. In the clamp studies, intracellular inorganic phosphate concentration rose by 18%/h, whereas ATP, phosphocreatine and phosphomonoester concentrations did not change. In plasma, inorganic phosphate concentration was 1.16 ± 0.05 mmol/l before infusion, and this decreased by a mean rate of 0.14 mmol h−1 l−1. No change was observed in any of these intracellular metabolites in the control studies. 5. The results show that, under physiological conditions, insulin does not raise intracellular pH in human muscle, and thus cannot influence muscle metabolism by this mechanism. The results also suggest that insulin causes a primary increase in the next flux of inorganic phosphate across the muscle cell membrane.

Sign in / Sign up

Export Citation Format

Share Document