Ischaemic exercise test in myoadenylate deaminase deficiency and McArdle's disease: measurement of plasma adenosine, inosine and hypoxanthine

1986 ◽  
Vol 70 (4) ◽  
pp. 399-401 ◽  
Author(s):  
S. P. T. Sinkeler ◽  
E. M. G. Joosten ◽  
R. A. Wevers ◽  
R. A. Binkhorst ◽  
F. T. Oerlemans ◽  
...  
Keyword(s):  
Exercise Test ◽  
Diagnostic Value ◽  
Myoadenylate Deaminase Deficiency ◽  
Control Subjects ◽  
Mcardle's Disease ◽  
Before And After ◽  
Myoadenylate Deaminase ◽  
Mcardle’S Disease ◽  
Forearm Exercise ◽  
Plasma Adenosine

1. Plasma adenosine, inosine and hypoxanthine concentrations were assayed in seven control subjects, five myoadenylate deaminase deficient (MADD) patients and six McArdle patients before and after ischaemic forearm exercise. 2. The plasma adenosine increase was very low in all test groups and there were no significant differences. 3. The MADD patients showed a significantly lower increase of plasma inosine and hypoxanthine after exercise as compared with the controls. 4. In the McArdle patients the increase in plasma inosine and hypoxanthine after exercise did not differ significantly from the values measured in the controls. 5. The ischaemic exercise test with measurement of plasma inosine and hypoxanthine might be of diagnostic value in MADD, but not in McArdle's disease.

Hypoxanthine and inosine release induced by ischemic forearm exercise in McArdle's disease and myoadenylate deaminase deficiency

1984 ◽  
Vol 86 (3) ◽  
pp. 231-232
Author(s):  
S.P.T. Sinkeler ◽  
F.T.J. Oerlemans ◽  
C.A. van Bennekom ◽  
M.M. Coerwinkel ◽  
T.L. Oei ◽  
...  
Keyword(s):  
Myoadenylate Deaminase Deficiency ◽  
Mcardle's Disease ◽  
Myoadenylate Deaminase ◽  
Mcardle’S Disease ◽  
Forearm Exercise

McArdle's disease with myoadenylate deaminase deficiency: Observations in a combined enzyme deficiency

Neurology ◽  
1987 ◽  
Vol 37 (6) ◽  
pp. 1039-1039 ◽  
Author(s):  
S. L. Heller ◽  
K. K. Kaiser ◽  
G. J. Planer ◽  
J. M. Hagberg ◽  
M. H. Brooke
Keyword(s):  
Enzyme Deficiency ◽  
Myoadenylate Deaminase Deficiency ◽  
Mcardle's Disease ◽  
Myoadenylate Deaminase ◽  
Mcardle’S Disease

Respiratory gas exchange and metabolic responses during exercise in McArdle's disease

1993 ◽  
Vol 75 (2) ◽  
pp. 745-754 ◽  
Author(s):  
M. Riley ◽  
D. P. Nicholls ◽  
A. M. Nugent ◽  
I. C. Steele ◽  
N. Bell ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Anaerobic Threshold ◽  
Adenosine Monophosphate ◽  
Co2 Production ◽  
Control Subjects ◽  
Mcardle's Disease ◽  
Small Rise ◽  
Mcardle’S Disease ◽  
Purine Metabolite ◽  
Abrupt Rise

During normal progressive exercise, the gas exchange anaerobic threshold occurs when CO2 production (VCO2) and ventilation (VE) increase so as to depart from a linear relationship to O2 consumption (VO2). This is thought to represent a gas exchange response to metabolic acidosis due to lactate accumulation. Patients with McArdle's disease have previously been reported to exhibit a steepened ventilatory response relative to VCO2, despite an inability to produce lactate. However, the VCO2 response has not been studied. We therefore investigated the VCO2-VO2 and VE-VO2 relationships in seven McArdle's disease patients and seven control subjects during symptom-limited maximal treadmill exercise. Analysis of gas exchange showed that whereas all control subjects had an easily identifiable anaerobic threshold, four of the patients had none and the other three displayed an attenuated threshold. The occurrence of the threshold in one patient was associated with a small rise in lactate and in another patient with an abrupt rise in leg discomfort, suggesting a pain response. Ammonia and the purine metabolite hypoxanthine were elevated during exercise in all patients, suggesting that ammonia may be a product of adenosine monophosphate degradation. Free fatty acid levels were also elevated, and a shift toward utilization of lipid may contribute to abnormal gas exchange responses. It is concluded that lactic acidosis contributes to the gas exchange anaerobic threshold but that other factors, such as discomfort, may be involved in the excess Ve seen during heavy exercise.

Muscle function during repetitive moderate-intensity muscle contractions in myoadenylate deaminase-deficient Dutch subjects

2002 ◽  
Vol 102 (5) ◽  
pp. 531-539 ◽  
Author(s):  
C.J. DE RUITER ◽  
A.M. MAY ◽  
B.G.M. VAN ENGELEN ◽  
R.A. WEVERS ◽  
G.C. STEENBERGEN-SPANJERS ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Exercise Test ◽  
Muscle Contractions ◽  
Moderate Intensity ◽  
Control Subjects ◽  
Generating Capacity ◽  
Myoadenylate Deaminase ◽  
Baseline Values ◽  
Isometric Muscle ◽  
Femoris Muscle

We investigated whether the capacity for repetitive submaximal muscle contraction was reduced in a group of subjects (n = 8) with a primary deficiency of myoadenylate deaminase (MAD). Quadriceps femoris muscle fatigue was evaluated using voluntary and electrically stimulated contractions during 20min of repetitive voluntary isometric contractions at 40% of maximal force-generating capacity (MFGC). After 5min of exercise, MFGC had declined significantly to 70.6±4.1% (mean±S.E.M.) and 87.2±1.6% of baseline values in MAD-deficient and sedentary control subjects (n = 8) respectively (P = 0.002 between groups). After 5min of exercise, the half-relaxation time had increased significantly to 113.4±6.1% of basline in MAD-deficient muscle, but had decreased significantly to 94.1±1.3% in control subjects (P = 0.003 between groups). All control subjects completed the 20-min exercise test. Five of the MAD-deficient subjects had to stop exercising due to early muscle fatigue; however, three of the MAD-deficient subjects were able to complete the 20-min exercise test. In conclusion, although the capacity for repetitive submaximal isometric muscle contractions for the group of MAD-deficient subjects was significantly decreased, it remains uncertain whether MAD deficiency is the sole cause of pronounced muscle fatigue.

AMP deaminase deficiency: Study of the human skeletal muscle purine metabolism during ischaemic isometric exercise

1987 ◽  
Vol 72 (4) ◽  
pp. 475-482 ◽  
Author(s):  
S. P. T. Sinkeler ◽  
R. A. Binkhorst ◽  
E. M. G. Joosten ◽  
R. A. Wevers ◽  
M. M. Coerwinkel ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Exercise Test ◽  
Adenine Nucleotide ◽  
Energy Charge ◽  
Isometric Exercise ◽  
Creatine Phosphate ◽  
Adenylate Energy Charge ◽  
Amp Deaminase ◽  
Control Subjects ◽  
Before And After

1. Muscle biopsies were taken from 10 control subjects and five AMP deaminase (AMPD) deficient individuals before and after an ischaemic isometric exercise test and analysed for purine nucleotide, NAD+, creatine phosphate (CP) and lactate content. 2. The decrease of ATP induced by the exercise test was significantly lower in the AMPD deficient patients than in the controls, but the decrease of creatine phosphate and the increase of lactate did not differ. There were no significant differences in the exertional performance level between patients and controls and no evidence was obtained of an increased energy expenditure per unit of performance in AMPD deficiency. 3. The AMPD deficient individuals were equally capable of maintaining a high adenylate energy charge (EC) as the control subjects, which indicates a normal regulation of the balance between ATP consumption and ATP regeneration. 4. ATP, ADP and total adenine nucleotide (TAN) but not AMP, were significantly elevated in the AMPD deficient patients as compared with the controls before as well as after the exercise test. This underlines the role of AMPD activity in the adenine nucleotide catabolism of skeletal muscle.

Ischemic exercise test: Failure to detect partial expression of Mcardle's disease

1987 ◽  
Vol 10 (6) ◽  
pp. 546-551 ◽  
Author(s):  
Robert G. Taylor ◽  
James S. Lieberman ◽  
Margaret M. Portwood
Keyword(s):  
Exercise Test ◽  
Mcardle's Disease ◽  
Mcardle’S Disease ◽  
Test Failure

What can metabolic myopathies teach us about exercise physiology?

2006 ◽  
Vol 31 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Mark A Tarnopolsky
Keyword(s):  
Skeletal Muscle ◽  
Aerobic Capacity ◽  
Human Skeletal Muscle ◽  
Exercise Physiology ◽  
Maximal Aerobic Capacity ◽  
Nutritional Interventions ◽  
Mcardle's Disease ◽  
Metabolic Myopathies ◽  
Myoadenylate Deaminase ◽  
Mcardle’S Disease

Exercise physiologists are interested in metabolic myopathies because they demonstrate how knocking out a component of a specific biochemical pathway can alter cellular metabolism. McArdle's disease (myophosphorylase deficiency) has often been studied in exercise physiology to demonstrate the influence of removing the major anaerobic energy supply to skeletal muscle. Studies of patients with McArdle's disease have shown the increased reliance on blood-borne fuels, the importance of glycogen to maximal aerobic capacity, and the use of nutritional strategies to bypass metabolic defects. Myoadenylate deaminase deficiency is the most common metabolic enzyme deficiency in human skeletal muscle. It is usually compensated for endogenously and does not have a major influence on high-energy power output. Nutritional interventions such as carbohydrate loading and carbohydrate supplementation during exercise are essential components of therapy for patients with fatty acid oxidation defects. Cases of mitochondrial myopathies illustrate the importance of peripheral oxygen extraction for maximal aerobic capacity and show how both exercise and nutritional interventions can partially compensate for these mutations. In summary, metabolic myopathies provide important insights into regulatory and nutritional aspects of the major biochemical pathways of intermediary metabolism in human skeletal muscle. Key words: myoadenylate deaminase deficiency, MELAS syndrome, McArdle's disease, mitochondrial disease, inborn errors of metabolism.

Exercise and recovery ventilatory and VO2 responses of patients with McArdle's disease

1990 ◽  
Vol 68 (4) ◽  
pp. 1393-1398 ◽  
Author(s):  
J. M. Hagberg ◽  
D. S. King ◽  
M. A. Rogers ◽  
S. J. Montain ◽  
S. M. Jilka ◽  
...  
Keyword(s):  
Blood Lactate ◽  
High Intensity ◽  
Maximal Exercise ◽  
Matched Control ◽  
Slow Component ◽  
High Intensity Exercise ◽  
O2 Consumption ◽  
Control Subjects ◽  
Mcardle's Disease ◽  
Mcardle’S Disease

This study was designed to determine whether patients with McArdle's disease, who do not increase their blood lactate levels during and after maximal exercise, have a slow “lactacid” component to their recovery O2 consumption (VO2) response after high-intensity exercise. VO2 was measured breath by breath during 6 min of rest before exercise, a progressive maximal cycle ergometer test, and 15 min of recovery in five McArdle's patients, six age-matched control subjects, and six maximal O2 consumption- (VO2 max) matched control subjects. The McArdle's patients' ventilatory threshold occurred at the same relative exercise intensity [71 +/- 7% (SD) VO2max] as in the control groups (60 +/- 13 and 70 +/- 10% VO2max) despite no increase and a 20% decrease in the McArdle's patients' arterialized blood lactate and H+ levels, respectively. The recovery VO2 responses of all three groups were better fit by a two-, than a one-, component exponential model, and the parameters of the slow component of the recovery VO2 response were the same in the three groups. The presence of the same slow component of the recovery VO2 response in the McArdle's patients and the control subjects, despite the lack of an increase in blood lactate or H+ levels during maximal exercise and recovery in the patients, provides evidence that this portion of the recovery VO2 response is not the result of a lactacid mechanism. In addition, it appears that the hyperventilation that accompanies high-intensity exercise may be the result of some mechanism other than acidosis or lung CO2 flux.

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