HipoxiaHipoxiayy

Stress OxidativoStress Oxidativo

Claus BehnClaus BehnUniversidad de ChileUniversidad de Chile

HAPPOM, ALFAHAPPOM, ALFAArica, 220405Arica, 220405

Cementerio Cementerio de de montañistas montañistas a 4.800 m a 4.800 m (Chimborazo, (Chimborazo, 6.310 m)6.310 m)

0 2 4 6 8 100

200

300

400

500

600

700

800

37.6 mm Hg

PB

PAO2

253 mm Hg

Altura (km)

Pres

ión

(mm

Hg)

VO2max decrease at HA

30

40

50

60

70

Sandoval et al., 2002

n = 14

SLon return from HAHA3,670 mSLbefore HA

p < 0.01p < 0.01VO

2max

(ml/k

g m

in)

750 700 650 600 550 500 450 4000

20

40

60

80

100

120

140

160

180

Valor observado

Valor esperado

o

O2

oVO

2max

(% v

alor

a n

ivel

del

mar

)

PB (mmHg)

PaO2 PaO2 (mm Hg)(mm Hg)

EdadEdad(años)(años)

.

VOVO22max vs edad en mujeres y hombresmax vs edad en mujeres y hombres

Hipoxia Hipoxia Falta de oxígeno en relación a Falta de oxígeno en relación a los requerimientos de ATP aeróbicolos requerimientos de ATP aeróbico

Stress oxidativoStress oxidativoExceso de factores oxidantes Exceso de factores oxidantes (especies reactivas del oxígeno) (especies reactivas del oxígeno) en relación a en relación a las capacidades antioxidanteslas capacidades antioxidantes

En hipoxia puede aumentar En hipoxia puede aumentar el gasto de ATP por efecto delel gasto de ATP por efecto delstress oxidativostress oxidativo

IschemiaIschemia →→ hypoxia hypoxia →→ ATP depletion ATP depletion →→ CaCa--proteaseprotease

∩∩Xantine dehydrogenase Xantine dehydrogenase →→

xanthine oxidase xanthine oxidasexanthine oxidase xanthine oxidase

∩∩ ∩∩

hypoxanthine hypoxanthine →→ xanthine xanthine →→ uric aciduric acid

∩∩ ∩∩

OO22 OO22..-- OO22 OO22

..--

Haber Haber -- Weiss reactionsWeiss reactions::

O2O2..-- ++ Fe Fe ++++++ →→ FeFe++++ + + OO22

FeFe++++ +H+H22OO22→→ FeFe++++++++ OHOH-- + OH+ OH••

OO22..-- ++ HH22OO22 →→ OO22+OH+OH-- + OH+ OH••

HerHernnáándezndez,L.A.;,L.A.; GrishamGrisham, M.B.;, M.B.; GrangerGranger, D.N. , D.N. ((19871987))Am. Am. J.J. PhysiolPhysiol.,, 253, G49.,, 253, G49--G53.G53.

3 h de isquemia + 1 h de reperfusión 3 h de isquemia + 1 h de reperfusión causan más daño tisular que causan más daño tisular que

4 h de isquemia + 0 h reperfusión4 h de isquemia + 0 h reperfusión

PARKS DA & GRANGER DN (1986)PARKS DA & GRANGER DN (1986)Am. J. Physiol 250:G749Am. J. Physiol 250:G749--G753G753

12 14 16 18 20 22 24

225

250

275

300

325

350

Sandoval et al., 2002

Max

imal

exe

rcis

e in

tens

ity (

Wat

t)

Maximal oxygen pulse (mlO2 / beat)

MOP correlates with maximal ventilation at HA

120 140 160 180 200 22012

14

16

18

20

22

Sandoval et al., 2002

r = 0.76p 0.005

Max

imal

oxy

gen

puls

e (m

lO2/b

eat)

Maximal ventilation (l/min)

[ HCO[ HCO3 3 ]]pH = pK + log pH = pK + log ------------------------------------------------------

a PCOa PCO22

20 30 40 50 60 70 80 90 1000

10

20

30

40no aclimatizados

aclimatizados

PA

CO

2(mm

Hg)

PAO2(mm Hg)

Putre

50

52

54

56

58

60

62

64

*PO

2 cap

(mm

Hg)

Acclimatized Newcomers

pre-exercise post-exercise

2 4 6 8 10 12

80

85

90

95

100

105

110

115

120

r = 0.7; p < 0.01

A & N (0701)Putre (3,600 m)

Postexercise heart rate variability coefficen(SDRR/1/RR)

90 100 110 120 130 140

80

85

90

95

100

105

110

115

120 A & N (0701)Putre (3,600 m)

Max

imal

exe

rcis

e in

tens

ity (W

att)

Postexercise heart rate (beat/min)

2 3 4 5 6 7 8 9 10 11 12 13

-9

-8

-7

-6

-5

-4

-3

-2

-1

0N r = 0.67

p < 0.05D

elta

PC

O2

(mm

Hg)

2 3 4 5 6 7 8 9 10 11 12 13

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

A

2 3 4 5 6 7 8 9 10 11 12 13-8

-6

-4

-2

0

2

4

6

8

10

r = 0.9p < 0.01

Postexercise heart rate variability coefficient(SDRR/1/RR)

2 3 4 5 6 7 8 9 10 11 12 13-8

-6

-4

-2

0

2

4

6

8

10

Del

ta c

apilla

ry [H

CO

3] (m

mol

/l)

Postexercise heart rate variability coefficient (SDRR/1/RR)

CollahuasiCollahuasi

15

20

25

30

35

40

45

50**

**

**

*pCO

2 (m

mH

g)

pre HA post HA pre SL post SL

PrePre-- and postexercise capillary blood and postexercise capillary blood PCOPCO22 at high altitude (HA) and sea level at high altitude (HA) and sea level (SL)(SL) n =16, p< 0,05*; 0,01**; 0,001*** Jiménez et al, n =16, p< 0,05*; 0,01**; 0,001*** Jiménez et al,

20002000

16

18

20

22

24

26

28

preHA post HA pre SL post SL

*

*****

Extr

acel

lula

r HC

O3- (m

mol

/L)

PrePre-- and postexercise extracellular [HCOand postexercise extracellular [HCO33] at high altitude (HA) ] at high altitude (HA) and sea leveland sea level (SL)(SL)

n =16, p< 0,05*; 0,01**; 0,001*** Jiménez et al, 2000n =16, p< 0,05*; 0,01**; 0,001*** Jiménez et al, 2000

7,35

7,40

7,45

7,50

7,55

**

***B

lood

pH

pre HA post HA pre SL post SL

PrePre-- and postexercise capillary blood pH at high altitude (HA) and postexercise capillary blood pH at high altitude (HA) and sea level (SL)and sea level (SL)

n =16, p< 0,05*; 0,01**; 0,001*** Jiménez et al., 2000n =16, p< 0,05*; 0,01**; 0,001*** Jiménez et al., 2000

Base Base excess excess vs. vs. capillarycapillary POPO2 2 atat HAHA

-18 -16 -14 -12 -10

50

52

54

56

58

60

62

64

66

68

Cajigal et al., 2002

r = 0.75p < 0.005

Capi

llary

PO 2

(mm

Hg)

Base excess (mmol/l)

-6.5

-5.5

-4.5

-3.5

-2.5

-1.5

-0.5

0.5

1.5

92 94 96 98 100 102 104 106 108 110 112

[Cl]P (mmol/l)

Bas

e ex

cess

(mm

ol/l)

Photo: Edwards AFB Altitude Chamber

Hypobaric hypoxia effects on erythrocyte bandHypobaric hypoxia effects on erythrocyte band 3 3 NBDNBD--taurine transport and protein oxidative taurine transport and protein oxidative

statestate..

TT5050 Protein carbonylProtein carbonyl(sec) (sec) ((nmolnmol//mg proteinmg protein))

Normoxia Normoxia 420.8 420.8 ±± 28.6 7.9 28.6 7.9 ±± 3.53.5

PosthypoxiaPosthypoxia 487.1 487.1 ±± 49.5 12.4 49.5 12.4 ±± 3.63.6

p p value value 0.02 0.030.02 0.03

ValuesValues are are meansmeans ±± SD. n = 8 SD. n = 8 individualsindividuals..CeledCeledóón et al, 2002n et al, 2002

V.Parinacota, 2001V.Parinacota, 2001

Santiago I (670 m)Santiago I (670 m) Santiago IISantiago II

Calama I(2500 m)Calama I(2500 m) Calama IICalama II

Conchi (3000 m)Conchi (3000 m)

Volcán San Pedro (6125 m)Volcán San Pedro (6125 m)

Camp. Base (5000 m)Camp. Base (5000 m)

A A BBInmunofluorescencia Inmunofluorescencia de proteina banda 3 (AEde proteina banda 3 (AE--1) 1) en glen glóóbulos rojos debulos rojos dell mismo mismo individuo antes de subir 5600 msnm (individuo antes de subir 5600 msnm (AA) y dos d) y dos díías despuas despuéés del descenso (s del descenso (BB). ). NNóótese el aumento del ntese el aumento del núúmero de sitios reconocidos por la IgG autmero de sitios reconocidos por la IgG autóóloga luego del loga luego del descenso.descenso. Araneda et al, 2003Araneda et al, 2003

TOTAL BANDA 3 FRAGMENTOS

0

50000

100000

150000

200000

250000

300000

350000

400000

**

***

UN

IDAD

ES D

ENSI

TOM

ETR

ICAS

Pre-Entrenamiento Post-Entrenamiento

Proteina banda 3 en eritrocitos de ciclistas de montaña. Proteina banda 3 en eritrocitos de ciclistas de montaña. Fragmentación (antígeno senescente) en relación con Fragmentación (antígeno senescente) en relación con entrenamiento en altura (Rio Blanco/ Portillo). entrenamiento en altura (Rio Blanco/ Portillo).

Araneda et al.,2004Araneda et al.,2004

[[ UUric

acid

ric

acid]] PP

(( mg

mg /

dl/dl ))

Band 3 protein sBand 3 protein susceptibiliusceptibility to proteases ty to proteases [[%%]]

3.5

4

4.5

5

5.5

6

6.5

7

7.5

8

0.00 10.00 20.00 30.00 40.00 50.00 60.00

PutrePutre

AricaAricaR = 0.58 R = 0.58 p < 0.02 p < 0.02 n = 14n = 14

IschemiaIschemia →→ hypoxia hypoxia →→ ATP depletion ATP depletion →→ CaCa--proteaseprotease

∩∩Xantine dehydrogenase Xantine dehydrogenase →→

xanthine oxidase xanthine oxidasexanthine oxidase xanthine oxidase

∩∩ ∩∩

hypoxanthine hypoxanthine →→ xanthine xanthine →→ uric aciduric acid

∩∩ ∩∩

OO22 OO22..-- OO22 OO22

..--

Santiago I Calama I Conchi Calama II Santiago II0,00

0,02

0,04

0,06

0,08

0,10

0,12

0,14

0,16

0,18

**m

oles

/Litr

o)(

MD

Aμ

-0,04 0,00 0,04 0,08 0,12 0,16

0

2

4

6

8

10

(Conchi-SantiagoI)

(Cam

p. B

ase)

AMS

Scor

e

Δ MDA

Sant Pre Sant Post Lag Pre Lag Post0,00

0,02

0,04

0,06

0,08

0,10

0,12

0,14

0,16

0,18

0,20

0,22

(μm

oles

/Litr

o)M

DA

*

HuaynaHuayna--PotosíPotosí

Bolivianos vs ChilenosBolivianos vs Chilenos

Gasometría ArterialGasometría ArterialParámetros La Paz (3600) p La Paz (3600)

pH 7.24 ± 0.29 0.27 7.44 ± 0.38PaO2(mmHg) 59.57 ± 4.82 0.33 57.28 ± 3.63

PaCO2(mmHg) 29.12 ± 4.43 0.52 30.40 ± 2.47SaO2(%) 91.68 ± 2.15 0.66 91.21 ± 1.82

HCO3(mEq/L) 19.27 ± 2.19 0.14 20.72 ± 1.30Base Excess(mEq/L) -6.76±3.25 0.97 -6.81±2.18

Parámetros Huayna Postosi(4800) p Huayna Potosi (4800)pH 7.44 ± 0.21 0.74 7.45 ± 0.29

PaO2(mmHg) 43.71 ± 2.92 0.94 43.83 ± 3.37PaCO2(mmHg) 24.80 ± 2.80 0.25 26.80 ± 3.16

SaO2(%) 81.78 ± 3.46 0.43 83.16 ± 2.47HCO3(mEq/L) 16.67 ± 1.27 0.003* 19.48 ± 1.43

Base Excess(mEq/L) -9.02±1.84 0.84 9.23±1.94

Cytosol free amino groups (upper) and red cell membrane SH Cytosol free amino groups (upper) and red cell membrane SH groups (lower) in highlanders (A) and lowlanders (B)groups (lower) in highlanders (A) and lowlanders (B)

Fetos Madres0

5

10

15

20

25

30

35

40

45

Tiol

es P

lasm

atic

os (n

Mol

es/m

g P

rot)

*

Fetos Madres0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

*

Tiol

es P

lasm

a/M

embr

ana

GR

Fetos Abajo Fetos Arriba0

10

20

30

40

50

*Ti

oles

Pla

smat

icos

(nM

oles

/mg

Pro

t)

-1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 141618202224262830323436384042444648

R=0,54Ti

oles

Pla

smat

icos

(nM

oles

/mg

Pro

t)

Hidroperoxidos Plasmaticos (uMoles/Litro)

MadresFetos

Antioxidant capacity and remnant, protease susceptible band 3 protein

0 10 20 30 40 50 60160

180

200

220

240

260

280

300

Benitez et al., 2002

r=0.74p<0.002n=16

Plas

ma

antio

xida

nt c

apac

ity (u

M T

rolo

x eq

uiv)

Remnant protease susceptible band 3 protein ( % )

HCO3-

HCO3

Cl-CO2

CO2 + H2O

H+

H+ +

Lac-

+

CO2 H2O HCO3-

Na+Lac-Na+

H+

H2O+

+

H+H2OCO2+ HCO3

-

Músculo

EspacioInstersticial

Plasma

Soldados NA - Arica

r=0.28p>0.05n=15

0

5

10

15

20

25

30 35 40 45 50

Soldados NA - Putre

r=0.62p<0.05n=15

0

2

4

6

8

10

12

14

16

30 35 40 45 50 55 60

dife

renc

ia d

e la

ctat

o (m

mol

/L)

r=0.08p>0.05n=15

0

2

4

6

8

10

12

14

16

30 35 40 45 50 55VO2 max (ml/kg/min)

dife

renc

ia d

e la

ctat

o (m

mol

/L)

r=0.60p<0.05n=15

0

2

4

6

8

10

12

14

16

18

30,00 35,00 40,00 45,00 50,00

VO2 max (ml/kg/min)

Soldados A - Arica Soldados A - Putre

-60

-50

-40

-30

-20

-10

0

10

20

30

40D

elta

Pow

er/[L

acta

te] (

Wat

t/mm

ol/l)

p<0.0001

Río Blanco groupLive low-train low

Portillo groupLive high-train low

Haber Haber -- Weiss reactionsWeiss reactions::

O2O2..-- ++ Fe Fe ++++++ →→ FeFe++++ + + OO22

FeFe++++ +H+H22OO22→→ FeFe++++++++ OHOH-- + OH+ OH••

OO22..-- ++ HH22OO22 →→ OO22+OH+OH-- + OH+ OH••

HerHernnáándezndez,L.A.;,L.A.; GrishamGrisham, M.B.;, M.B.; GrangerGranger, D.N. , D.N. ((19871987))Am. Am. J.J. PhysiolPhysiol.,, 253, G49.,, 253, G49--G53.G53.

Maximal oxygen pulse (SL vs. HA)

13 14 15 16 17 18 19

13

14

15

16

17

Viola et al., 2002

Max

imal

oxy

gen

puls

e at

HA

(ml O

2/ be

at)

Maximal oxygen pulse at SL(ml O2/beat) )

MOP decrease and [Fe]s at HA

80 100 120 140 160 180

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Viola et al., 2002

r = 0.6p < 0.05

Δ M

OP

SL -

HA (m

L/be

at)

Serum iron concentration at HA (ug/ dl)

[Fe]s changes on HA - SL commuting

1 20

20406080

100120140160180200220240260

Viola et al., 2002

**

*

Pre ExercisePost Exercise

SLHA

Seru

m ir

on c

once

ntra

tion

(ug/

dl)

[Fe]s at HA vs [Fe]s change SL - HA

80 100 120 140 160 180-60

-40

-20

0

20

40

60

80

100

120

140

Viola et al., 2002

Fes c

once

ntra

tion

chan

ge S

L-H

A(u

g/dL

)

Serum iron concentration at HA (ug/dl)

Plasma antioxidant capacity vs. [Fe]p

40 60 80 100 120 140 160 180160

180

200

220

240

260

280

300

Viola et al., 2002

R=-0,48p<0,06n=16

Plasma Fe concentration (ug/dl)

Plas

ma

antio

xida

nt c

apac

ity (u

M T

rolo

x)

Plasma antioxidant capacity vs. transferrin saturation

10 20 30 40 50 60160

180

200

220

240

260

280

300

Viola et al., 2002

Pl

asm

a an

tioxi

dant

cap

acity

(u

M T

rolo

x)R=-0,55p<0,03n=16

Percent transferrin saturation

Plasma antioxidant capacity vs. [Ferritin]p

40 60 80 100 120 140 160 180 200 220 240160

180

200

220

240

260

280

300

Viola et al, 2002

r=-0.77p<0.001n=16

Pla

sma

antio

xida

nt c

apac

ity

(uM

Tro

lox)

Plasma ferritin concentration(ng/dl)

Summary•• Hypobaric hypoxia (HH) decreasesHypobaric hypoxia (HH) decreases VOVO22maxmax•• The decrease of maximal oxygenThe decrease of maximal oxygen pulsepulse at HHat HH

directlydirectly relatesrelates to serum iron concentrationto serum iron concentration..•• Fe Fe inverselyinversely relatesrelates to to plasmaplasma antioxidant capacity antioxidant capacity •• Antioxidant supplementationAntioxidant supplementation preservespreserves oxygen supply oxygen supply

and work performance at high altitudeand work performance at high altitude..•• Antioxidant capacity may playAntioxidant capacity may play a role ina role in acclimatization acclimatization

toto high altitude by protecting anion exchangehigh altitude by protecting anion exchange, , thus thus allowing compensation of respiratory alkalosisallowing compensation of respiratory alkalosis. .

•• ByBy loweringlowering base base excessexcess, , anan antioxidantantioxidant protectedprotectedanionanion exchange should increase ventilation and Hb exchange should increase ventilation and Hb desaturationdesaturation, , thus favouring Othus favouring O2 2 deliverydelivery atat HHHH

HipoxiaHipoxiayy

Stress OxidativoStress OxidativoClaus BehnClaus Behn

Universidad de ChileUniversidad de Chilecbehn@med.uchile.clcbehn@med.uchile.cl

HAPPOM, ALFAHAPPOM, ALFAArica, 220405Arica, 220405