Post on 13-Jan-2016
description
31P-MRS muscolo scheletrico
Glicogenolisi e glicolisi
Metabolismo ionicoTrasporto del Pi nel mitocondrio
Efflusso di H+ dal citosol
Respirazione mitocondriale
pH intracellulare (citosolico)[Mg2+] libero del citosol
G ATP idrolisi
ATP + H2O ADP + Pi functional ATPases
PiPCr [ADP]
PCr + ADP + H+ Cr + ATP Creatine kinase
PCr + H2O Cr + Pi sum
Stress metabolico
Esercizio muscolare
Respirazione mitocondriale
Glicogenolisi
Trasporto del Pi nel mitocondrio
Glicolisi
PCr + ADP + H+
Cr + ATP
6.70
6.80
6.90
7.00
7.10cy
toso
lic p
H
60 1200recovery time (s)
rest
work recovery
Recupero dall’esercizio
Respirazione mitocondriale
Glicogenolisi
Trasporto del Pi nel mitocondrio
Glicolisi
60 120 180 24000
40
20
10
30
Tempo di recupero (s)
(uni
otà
arb
itra
rie M
RS
) PCrLivello a riposoa
b ultimo livello di lavoro
Y = a (1 – e )-
TC
t
TC = 26 s
[PC
r]
PC
r (m
M)
Glycolytic test
0
10
CUFF ON OFF
REST RECOVERY30
20
WORK
9630 15time (min)
60 120 180 24000
40
20
10
30
Recovery time (s)
MR
S a
rbitr
ary
units
Pi resting level
b last level of work
Y = b e -
TC
t
TC = 28 s
[Pi]
6.70
6.80
6.90
7.00
7.10cy
toso
lic p
H
60 1200recovery time (s)
rest
work recovery
minimum pH
PCr + ADP + H+
ATP + Cr
ATP + Cr PCr + ADP + H+
6.70
6.80
6.90
7.00
7.10cy
toso
lic p
H
60 1200recovery time (s)
rest
work recovery
418 J/min
270 J/min
minimum pH
La velocità di recupero di PCr e di Pi sonoinversamente proporzionali al valore di pH
carrier mitocondriale di Pi(rate limiting)
Driving force: gradiente di pH (pH 8.0 matrice; pH 6.0 citosol)
bassa KM for HPO42-
Affinità del Carrier:(pK2 = 6.68)
6.2 6.4 6.6 6.8 7.0Minimum pH
0
20
60
40
80T
C P
i (s)
(ra
te o
f PC
r re
cove
ry)
Reference range(95% confidence interval)
calf muscle 31P MRS in DMD/BMD carriers
Condizioni per la valutazione della velocità di recupero di PCr dall’esercizio
pH minimo minore di 6,90
Eccesso di substrati:
Alto ADP (> 60 M)Alto Pi (> 25 mM)Alto O2 (iperemia)
__________
6.2 6.4 6.6 6.8 7.0Minimum pH
0
20
60
40
80T
C P
Cr
(s)
(ra
te o
f PC
r re
cove
ry)
Reference range(95% confidence interval)
6.2 6.4 6.6 6.8 7.0Minimum pH
0
20
60
40
80T
C P
Cr
(s)
(ra
te o
f PC
r re
cove
ry)
Reference range(95% confidence interval)
mtDNA mutation at bp 117788
0
6.2 6.4 6.6 6.8 7.0Minimum pH
20
60
40
80T
C P
Cr
(s)
(ra
te o
f PC
r re
cove
ry)
Reference range(95% confidence interval)
case 1
case 2case 3
before training
after training
Chronic Progressive External Ophtalmoplegia (CPEO) mtDNA deletion/s (Cox deficit), RRF
Leber’s Hereditary Optic Neuropathy (LHON) 11778 bp mtDNA mutation (Complex I)
Mitochondrial myopathy (MM) mtDNA deletion/s (Cox / SDH deficit), RRF
Mitochondrial encephalomyopathies MEMMELAS (3243 mtDNA mutation (tRNA-leu), RRF, SCR deficit,)MERRF (Myoclonal epilespsy w. RRF) - 8993 mtDNA mutation (tRNA-lys), RRF
mitochondrial cytopathies
CPEO (Cox deficit) control
normal control MELAS patient
PCr
Pi
2 3 4 5 76
resting Pi (mM)
patients
controls
reference values (95% confidence interval)
4.822.43
60 120 180 24000
40
20
10
30
Recovery time (s)
PC
r re
cove
ry
(M
RS
arb
itrar
y un
its) Control
TC = 38s; pH = 6.58
TC = 58s; pH = 6.62
CPEO (Cox deficit)
6.2 6.4 6.6 6.8 7.0Minimum pH
Reference range(95% confidence interval)
0
20
60
40
80
TC
PC
r (s
) (r
ate
of P
Cr
reco
very
)
100
Multiple logistic regression applied to two independent indicators:
1. [Pi] at rest,
2. rate of PCr recovery
PrD (probability of disease) = 1 + e -(0.538 * Ds + 4.312 P – 23.729)
1
Ds = rate of PCr recovery (sec) P = [Pi] at rest
Rest only 15/31 48.4 %
Recovery only 26/31 83.9 %
Assessment conditionMuscle abnormality
revealed by 31P-MRS
Analysis by multiple logistic regression 31/31 100.0 %
SENSITIVITY 100%; SPECIFICITY 100%
HEADACHE(over 120 patients studied)
(brain – occipital lobes)
Complicated migraine 2.91 + 0.25 39.5
Migraine with aura 3.73 + 0.30 55.3
Migraine withot aura 3.39 + 0.30 50.3
Cluster headache 3.54 + 0.36 52.1Healty volunteers 4.45 + 0.27 83.7
[Phosphocreatine] (mM)
Phosphorylation potential (mM-1)
Failure of mitochondrial energy transductions in the brain of all patiens with headache is a favouring background for the triggering of headache
HEADACHE(over 120 patients studied)
skeletal muscle (gastrocnemius)
The rate of PCr recovery after exercise is a measure of mitochondrial funtionality
dashed area defines the reference interval
Failure of skeletal muscle energy tranductions lead us to put forward the hypothesis that headache is a systemic disease primarely involving energy metabolism
A = MS; B = MwA; C = MwoA; D = CH
Glicogenosi muscolari
McArdleUDPG PLD
glycogen
glucose-1-P
glucose-6-P
fructose-6-P
fructose-1,6-P
glycerldehyde-3-P (2)
3-P-glyceroyl phosphate (2)
3-P-glycerate (2)
2-P-glycerate (2)
Phosphoenolpyruvate (2)
Pyruvate (2)
Lactate (2)
Deficit di PFKUDPG PLD
glycogen
glucose-1-P
glucose-6-P
fructose-6-P
fructose-1,6-P
glycerldehyde-3-P (2)
3-P-glyceroyl phosphate (2)
3-P-glycerate (2)
2-P-glycerate (2)
Phosphoenolpyruvate (2)
Pyruvate (2)
Lactate (2)
patient control
No pH variation during work and recovery
Deficit di PGAMUDPG PLD
glycogen
glucose-1-P
glucose-6-P
fructose-6-P
fructose-1,6-P
glycerldehyde-3-P (2)
3-P-glyceroyl phosphate (2)
3-P-glycerate (2)
2-P-glycerate (2)
Phosphoenolpyruvate (2)
Pyruvate (2)
Lactate (2)
controllo paziente
No pH variation during work and recovery
Valutazione dell’effetto della terapia
trattamento con CoQ pazienti con citopatie mitocondriali
Reference range
6.5 6.7 7.1
minimum pH
6.9
TC
PC
r (s
)
20
40
80
60
100
0
6
7
9
51
23
4
108
oral CoQ (150 mg/day)for 6 months
Mitochondrialmyopathies
31P MRS
Abnormal
BLOOD ANALYSISBiochemistry, molecular geneticMUSCULAR BIOPSY Histochemistry, biochemistry, molecular genetic
Normal
Symptoms and clinical examination suggesting
metabolic myopathy
31P MRS
Diagnosis confirmation
Therapy follow-upAssessment of evolution
Screening of families
Bicycle exercise test Ischaemic test
EMG