Assessment of muscular metabolism in peripheral arterial occlusive disease using31P nuclear magnetic resonance spectroscopy

Abstract

The behaviour of muscular metabolism was investigated in 10 patients with peripheral arterial occlusive disease stage II at rest and after maximum ergometric calf exercise. The intracellular concentrations of phosphocreatine, inorganic phosphate and adenosine triphosphate as well as muscle pH were measured by means of 31P magnetic resonance spectroscopy and compared with those from a control group. In addition, arteriovenous differences in concentrations of lactate, pyruvate, ammonia, hypoxanthine and alanine in the femoral blood were determined. The fall in intracellular phosphocreatine concentration during exercise was significantly greater in the calf muscles of patients with arterial occlusion than in controls and correlated linearly with the increase in femoral arteriovenous differences in lactate, ammonia and alanine. A significant fall in intracellular pH occurred during muscular activity only in the patient group, but not in the identically exercised control group. The fall in pH correlated closely with the rise in arteriovenous lactate difference in the femoral blood. The intramuscular ATP concentration remained constant throughout the exercise procedure. The behaviour of both the directly and indirectly measured metabolites permits the deduction of activation of the creatine kinase reaction, glycolysis, myokinase reaction and the purine nucleotide cycle during exercise-induced hypoxia in the presence of arterial occlusive disease. The anaerobic production of energy is sufficient to maintain the ATP concentration even during claudication pain.(ABSTRACT TRUNCATED AT 250 WORDS)

Review of the adaptation of skeletal muscle in intermittent claudication

“…The median recovery time of phosphocreatine was prolonged in patients with PAD compared to health individuals [71,72]. The same difference was also noted for ADP, inorganic phosphate [66,72] and pH [72].…”

“…The median recovery time of phosphocreatine was prolonged in patients with PAD compared to health individuals [71,72]. The same difference was also noted for ADP, inorganic phosphate [66,72] and pH [72]. The ratio of PCr/ATP (p = 0.03) and Pi/ATP (p = 0.04) were marginally, but significantly elevated [71,72], this was attributed to a reduced level of ATP in patients, a finding contradicted by other groups who found no difference in the ratios at rest or during, or the muscle's post exercise pH (p = 0.07) [71].…”

“…Minimal changes in pH and PCr during exercise have been attributed to the type of exercise performed, namely oxidative, isometric exercise [72]. In health, the isometric (exercise which involves static muscle contraction without and change in the angle of the joint) and isotonic (exercise results in an alteration in the muscle length secondary to the movement of the body part) exercises [73] have been assessed, with isotonic exercise found to be more metabolically stressful than isometric exercise.…”

Fatigue-related firing of distal muscle nociceptors reduces voluntary activation of proximal muscles of the same limb

“…In the present study the combination of maximal isometric exercise and subsequent ischemia likely activates a subset of group III and IV muscle afferents that respond to noxious stimuli similar to other forms of high-intensity exercise (11,28) and ischemic exercise that is painful, like that in patients with vaso-occlusive disease (17,35,48). During the 2 min of ongoing ischemia, subjects reported Moderate to Strong pain levels suggesting high nociceptive input.…”

Abnormal skeletal muscle oxidative capacity after lung transplantation by 31P-MRS.

“…This suggests that, as with one-legged exercise, blood flow The early pHi threshold after transplantation and the unaltered relationship between blood lactate and pHi are consistent with a net increase in lactic acid production in muscle, but not with a primary abnormality of lactate transport out of the to the quadriceps musclegroup should be enhanced during graded leg extension relative to that during cycling. In addition, neither an imposed reduction in skeletal muscle blood flow (14), peripheral arterial disease (15), nor congestive heart failure (16) is associated with a decrease in resting pHi. It is therefore unlikely that abnormal cardiac output can account for all of the abnormalities of aerobic metabolism in the current study.…”