Abstract |
Sympathetic system activation is considered one of the main factors influencing lactate production during exercise in normal individuals. In order to assess the role of such activation in mitochondrial myopathies, we compared blood catecholamine levels to those of lactate during an intermittent exercise performed at workloads near anaerobic lactate threshold. Following an initial increment, the patients (n = 10) exhibited a steady-state blood lactate shifted right relative to controls (n = 7), the peaks being respectively 665 +/- 29% and 322 +/- 11% of baseline. Plasma catecholamine increase in mitochondrial myopathies was 272 +/- 21% for norepinephrine and 261 +/- 18% for epinephrine, not statistically different from controls. Lactate/ norepinephrine and lactate/ epinephrine area ratios were significantly higher in the subjects than in controls (2.36 versus 1.48 and 2.40 versus 1.57, respectively). The study shows that the abnormal lactate production in mitochondrial myopathies is independent of the catecholaminergic response at the transition from aerobic to anaerobic exercise.
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Authors | G Siciliano, M Renna, M L Manca, C Prontera, G Zucchelli, E Ferrannini, L Murri |
Journal | Neuromuscular disorders : NMD
(Neuromuscul Disord)
Vol. 9
Issue 6-7
Pg. 411-6
(Oct 1999)
ISSN: 0960-8966 [Print] England |
PMID | 10545046
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Lactates
- Norepinephrine
- Epinephrine
|
Topics |
- Adult
- Aged
- Epinephrine
(blood)
- Exercise Test
- Female
- Humans
- Lactates
(blood)
- Male
- Middle Aged
- Mitochondrial Myopathies
(blood, physiopathology)
- Norepinephrine
(blood)
- Physical Exertion
(physiology)
- Reference Values
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