Het reaktiemechanisme op verzuring door inspanning lijkt bij ME/CVS-patiėnten verstoord.
Newton en kollega's bestudeerde de efflux (uitstroom) van protonen
die n.a.v. een gewijzigde zuurgraad als gevolg van inspanning ontstaat.
Hiermee stellen de cellen het lichaam in staat te reageren en te herstellen.
De efflux van protonen was bij patiėnten beduidend minder en trager.
Dit gold ook voor de hartslagvariabiliteit (aanpassingsvermogen hartslag: zie ook
hier)
Er lijkt een relatie te bestaan tussen de verstoorde protonenuitstroom en channelopathie.
Abnormalities in pH Handling by Peripheral Muscle and Potential Regulation by the Autonomic Nervous System in Chronic Fatigue Syndrome
Journal of Internal Medicine, Published Online: 20 Aug 2009.
doi: 10.1111/j.1365-2796.2009.02160.x.
David EJ Jones, Kieren G Hollingsworth, Roy Taylor, Andrew M Blamire, Julia L Newton.
Objectives:
To examine
muscle acid handling
following exercise
in Chronic Fatigue Syndrome (CFS/ME) and
the relationship with
autonomic dysfunction.
Design:
Observational study
Setting:
Regional Fatigue Service.
Subjects & Interventions:
CFS/ME (n=16) and
age and sex matched normal controls (n=8)
underwent
phosphorus magnetic resonance spectroscopy (MRS)
to evaluate pH handling
during exercise.
Subjects performed
plantar flexion
at fixed 35% load
Maximum Voluntary Contraction.
Heart rate variability
was performed
during 10 minutes supine rest
using digital photophlethysmography
as a measure of autonomic function.
Results:
Compared to normal controls,
the CFS/ME group
had
significant suppression of proton efflux
both immediately post-exercise
(CFS: 1.1 ± 0.5 mM/min v Normal: 3.6 ± 1.5 mM/min, p<0.001)
and maximally
(CFS: 2.7 ± 3.4 mM/min v Control: 3.8 ± 1.6 mM/min, p<0.05).
Furthermore,
the time taken to reach maximum proton efflux
was significantly prolonged in patients
(CFS: 25.6 ± 36.1s v Normal: 3.8 ± 5.2 s, p<0.05).
In controls
the rate of maximum proton efflux
showed a strong inverse correlation with nadir muscle pH
following exercise
(r2=0.6; p<0.01).
In CFS patients,
in contrast,
this significant normal relationship was lost
(r2=0.003; p=ns).
In normal individuals
the maximum proton efflux
following exercise
were closely correlated with
total heart rate variability (r2=0.7;p=0.007)
this relationship was lost
in CFS/ME patients (r2<0.001;p=ns).
Conclusion:
Patients with CFS/ME
have abnormalities in
recovery of
intramuscular pH
following standardised exercise
degree of which
is related to
autonomic dysfunction.
This study identifies
a novel biological abnormality in patients with CFS/ME
which is potentially open to modification.
http://www3.interscience.wiley.com/journal/122564291/abstract
Met dank aan Rob.
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