31 P-MRS muscolo scheletrico

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


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


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


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


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)


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)


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)


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


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



3-P-glycerate (2)

2-P-glycerate (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



3-P-glycerate (2)

2-P-glycerate (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

31 P-MRS muscolo scheletrico

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