HIGH ALTITUDE PHYSIOLOGY AND PHYSIOPATHOLOGY, FROM … · 2006. 2. 3. · high altitude physiology and physiopathology, from the organism to the molecule - happom pregnangy and high

HIGH ALTITUDE PHYSIOLOGY AND PHYSIOPATHOLOGY,

FROM THE ORGANISM TO THE MOLECULE - HAPPOM

PREGNANGY AND HIGH ALTITUDE

DR. ANÍBAL LLANOSFACULTAD DE MEDICINA, UNIVERSIDAD DE CHILE

APRIL 18, 2005

ATMOSPHERIC O2 LEVEL VS TIME

EL O2 ES UN PRODUCTO DE DESHECHO DELMETABOLISMO VEGETAL, PARTICULARMENTEDE LA FOTOSÍNTESIS

ESTE PRODUCTO DE DESHECHO ES UTILIZADOPOR LOS ANIMALES COMO NUTRIENTE

O2 + GLUCOSA ! CO2 + H2O + ENERGIA

ESTA ENERGÍA ES EMPLEADA EN FUNCIONESDE SÍNTESIS, TRANSPORTE, METABOLISMO BASAL, CRECIMIENTO Y DESARROLLO, ETC.

BIRTH WEIGHT FALLS WITH INCREASING ALTITUDE

TOTAL O2 CONSUMPTION IS REDUCED IN FETUSESAND NEWBORN WITH GROWTH RESTRICTION

EFFECTS OF HIGH ALTITUDE ON INFANTBIRTH WEIGHT

AND INFANT OXIGENATION

a

Is high altitude a greater determinant than poor nutritionof intrauterine growth retardation and low birth weight ?

High Altitude

Highincome

La Paz Santa CruzLow Altitude

Hypothesis: Babies born at high altitude have a lower birth weight than babies born at low altitude, independent of maternal economic status

Lowincome

Highincome

Lowincome

Effects of altitude vs. economic status on birth weightand body shape at birth

Giussani, D.A., Phillips, P.S., Anstee, S. & Barker, D.J.P.

Pediatric Research 49: 490, 2001

2600

3000

3400

3800

a,b a

0.55

0.65

0.75 a,ba b

Birthweight

(g)

Headcircumference:

body length

La Paz Santa Cruz

incomehigh low

income

high low

a, P

HypothesisIf oxygen has a role on fetal growth independent of genetic andnutritional factors, then:

Chick embryos from lowland hens incubated at high altitude shouldlead to fetal growth retardation

Chick embryos from hens native to high altitude, usually with growth restriction,should recover their growth whenincubated at sea level

1

2

Blood gas status : Chorio-allantoic vein

0

2

4

6

8

pH

0

20

40

60

80

PO2(mmHg)

SLSLSLHA

HAHAHASL

n = 16n = 16

n = 16n = 16

a

b

Fetal biometry at day 20 of a 21d incubation

Egg weight prior toincubation (g)

0

20

40

60

80

a a

SLSLSLHA

HAHAHASL

n = 16n = 16n = 16n = 16

Fetalweight (g)

0

10

20

30

b

c

Body length (mm)

0

20

40

60

80

Bi-parietal diameter (mm)

0

4

8

12

16b

a

SLSLSLHA

HAHAHASL

n = 16n = 16

n = 16n = 16

Fetal biometry at day 20 of a 21d incubation

0

HASLHASL

SLSL SLHA

1

2

3

4

5

6

7

8

SLSL SLHA

AORTICwall:lumen area

HAHAHAHA

*

500 μm

SummaryHuman and chick embryo

Fetal oxygenation, independent of genetic or nutritional factors, has an important role in the control of fetal growth

Generations of residence at high altitude may influence the effects of hypoxia on the developing fetus

HYPOTHESIS

THE CHRONICALLY HYPOXIC NEONATAL SHEEP AT PUTRE (3,600m) HAVE AN ALTERED CARDIOVASCULAR AND HORMONAL STATUSBASALLY AND DURING A SUPERIMPOSED EPISODE OF ACUTE

HYPOXIA

Figure 1 Herrera EA et alNEWBORN SHEEP NEWBORN LLAMA

0

10

20

30

40

B B + LNAME

PAP

(mm

Hg)

SLSHHLSH

0

10

20

30

40

B B + LNAME

PAP

(mm

Hg)

SLLLHLLL

0

0,1

0,2

0,3

B B + LNAME

PVR

(mm

Hg.

mL-

1 .min

.Kg)

0

0,1

0,2

0,3

B B + LNAME

PVR

(mm

Hg.

mL-

1 .min

.Kg)

ab

a

bc

b

a

ab

a

bc

aa

c

A. PAP in NB sheep with and without L-NAME, B. PAP in NB llama with and without L-NAME, C. PVR in NB sheep with and without L-NAME, D. PVR in NB llama with and without L-NAME

A. B.

C. D.

Significant differences p

0

50

100

150

SAP

(mm

Hg)

0

100

200

300

400

HR

(min

-1)

0 60 120 180 Time (min)

0,00

0,20

0,40

Basal Hypoxemia Recovery

SVR

(mm

Hg.

ml-1

.min

.Kg)

†* *

SYSTEMIC CIRCULATION - NEWBORN SHEEP

p

0

5

10

FBF

(ml m

in-1

kg-

1 )

HYPOXEMIA

0

10

20

30

FVR

(mm

Hg

ml-1

min

kg)

FEMORAL CIRCULATION - NEWBORN SHEEP

0 60 120 180

TIME (min)

HAHA

SLSL

POSSIBLE MECHANISMS INVOLVED IN THE PULMONARY VESSEL RESPONSES TO CHRONIC HYPOXIA

• NITRIC OXIDE• CARBON MONOXIDE• sGC AND PDE; cGMP• PROSTACYCLIN AND THROMBOXANE• ENDOTHELINS • OTHERS

GUANYLATE CYCLASE MECHANISMS OF SMOOTH MUSCLE RELAXATION

Figure 2 Herrera EA et al

0

15

30

45

60

SLSH HLSH SLLL HLLL

L-ci

trul

ine

form

atio

n (p

mol

. μg

prot

-1.3

0 m

in-1

)

0

0,25

0,5

0,75

1

SLSH HLSH SLLL HLLL

eNO

S/β-

actin

(a

rbitr

ary

units

)

0

0,25

0,5

0,75

1

SLSH HLSH SLLL HLLL

mR

NA

eN

OS/β-

actin

(a

rbitr

ary

units

)

0

0,25

0,5

0,75

1

SLSH HLSH SLLL HLLL

sGC

/ β-a

ctin

(a

rbitr

ary

units

)

A. B.

C. D.

A. RT-PCR of eNOS, B. Western blot of eNOS, C. NOS total activity, D. Western blot of sGCSignificant differences p

Figure 3 Herrera EA et al

0

0,25

0,5

0,75

1

SLSH HLSH SLLL HLLL

HO

-1/ β

-act

in

(arb

itrar

y un

its)

0

0,5

1

1,5

SLSH HLSH SLLL HLLL

HO

-2/ β

-act

in

(arb

itrar

y un

its)

0

0,5

1

1,5

SLSH HLSH SLLL HLLL

mR

NA

HO

-1/ β-

actin

(a

rbitr

ary

units

)

0

0,5

1

1,5

SLSH HLSH SLLL HLLL

mR

NA

HO

-2/ β-

actin

(a

rbitr

ary

units

)

A. B.

C. D.

A. RT-PCR of HO-1, B. RT-PCR of HO-2, C. Western blot of HO-1, D. Western blot of HO-2. Significant differences p

0

1

2

0

3

6

PUTREPUTRESTGO STGO

COX-1 COX-2

CO

X-1

/βac

tin

CO

X -2

/βac

tin

*

* p

SUMMARY

• HIGH ALTITUDE NEWBORN LAMBS HAD PULMONARY HYPERTENSION WITH INCREASED PULMONARY VASCULAR RESISTANCE WHEN COMPARED TO LOWLAND NEWBORN LAMBS. HIGH ALTITUDE NEWBORN LAMBS HAD AN IMPORTANT NITRIC OXIDE TONE IN THE PULMONARY CIRCULATION

• NEWBORN LAMBS NATIVE TO HIGH ALTITUDE SHOW INCREASED CARDIAC OUTPUT AND LOWER SYSTEMIC VASCULAR RESISTANCE THAN LOWLAND NEWBORN SHEEP.

• FEMORAL BLOOD FLOW DECREASED AND FEMORAL VASCULAR RESISTANCE INCREASED BRISKLY DURING HYPOXIA IN HIGH ALTITUDE NEWBORN LAMBS .

SUMMARY (cont)•eNOS EXPRESSION MEASURED BY WESTERN BLOT, IS DECREASED IN THE LUNG OF HIGHLAND NEWBORN SHEEP. NEVERTHELESS IS ACTIVITY IS INCREASED

• sGC, HO-1, EXPRESSION MEASURED BY WESTERN BLOT, IS DECREASED IN THE LUNG OF HIGHLAND NEWBORN SHEEP

• COX-2 mRNA EXPRESSION, ENZYMES INVOLVED IN THE PRODUCTION OF SEVERAL PG, AMONG THEM PGI2 ARE REDUCED IN THE LUNG OF HIGHLAND NEWBORN SHEEP

SINCE CHRONIC HYPOXIA MODIFIES THE CONTRACTILE CAPACITY OF SMALL ARTERIES, WE STUDIED THIS VARIABLE IN SMALL RESISTANCE ARTERIES OF HIGHLAND AND LOWLAND NEWBORN SHEEP

HYPOTHESISIN HIGHLAND NEWBORN SHEEP SMALL ARTERIES FROM THE PULMONARY AND SYSTEMIC CIRCULATION HAVE A HIGHER CONTRACTILE CAPACITY THAN SMALL ARTERIES IN LOWLAND NEWBORN SHEEP

Ex vivo RESPONSESPOTASSIUM CHLORIDENOREPINEPHRINESODIUM NITROPRUSSIDE

AIMTO STUDY IN PULMONARY AND FEMORAL SMALL ARTERIES FROM HIGHLAND AND LOWLAND NEWBORN SHEEP

PULMONARY ARTERIESRESPONSE TO KCl

LLNB HLNB

p

PULMONARY ARTERIESRESPONSE TO SODIUM NITROPRUSSIDE

LLNB HLNB

p

0,0

5,0

10,0

15,0

% K

max

0,0

1,0

2,0

pD2

†

FEMORAL ARTERIESRESPONSE TO KCl

LLNB HLNB

p

0

50

100

150

% K

max

0

3

6

pD2

LLNB HLNB

†

FEMORAL ARTERIESRESPONSE TO NOREPINEPHRINE

p

0

50

100

% K

max

0

3

6

pD2

LLNB HLNB

p

FEMORAL ARTERIESRESPONSE TO SODIUM NITROPRUSSIDE

LLNB HLNB2,5

5

7,5

pD2

†

p

CONCLUSIONS

1.- IN THE PULMONARY ARTERIES, HIGHLAND NEWBORN SHEEP SHOW A GREATER CONTRACTILE CAPACITY THAN LOWLAND NEWBORN SHEEP.

2.- IN THE FEMORAL ARTERIES, HIGHLAND NEWBORN SHEEP SHOW A LOWER CONTRACTILE CAPACITY THAN LOWLAND NEWBORN SHEEP, WITH A MAJOR ROLE OF ADRENERGIC-DEPENDENT MECHANISMS.

3.- IN PULMONARY AND FEMORAL ARTERIES, HIGHLAND NEWBORN SHEEP SHOW A GREATER SENSITIVITY TO SNP THAN LOWLAND NEWBORN SHEEP, CONSISTENT WITH AN INCREASED ACTIVITY OF NOS AND THE ROLE OF NO IN THE CONTROL OF THE PULMONARY AND PERIPHERAL VASCULAR BEDS IN THE NEWBORN LAMB OF THE ANDEAN ALTIPLANO.

WHICH IS THE PITUITARY-ADRENAL AXIS FUNCTION INCHRONICALLY HYPOXIC NEWBORN LAMBS?

WE INITIALLY MEASURED ACTH AND CORTISOL PLASMA CONCENTRATION BASALLY AND DURING A SUPERIMPOSED EPISODE OF ACUTE HYPOXIA

NEWBORN SHEEP IN LOW AND HIGH ALTITUDESCORTISOL RESPONSE TO HYPOXIA

0

40

80

120

160

Meanbaseline

H15 H45 R45

Time

Cor

tisol

(ng/

ml)

SLSL

HAHA

0

50

100

150

200

250

0 50 100 150 200 250

ACTH (pg/ml)

Cor

tisol

(ng/

ml)

SLSL

0

50

100

150

200

250

0 50 100 150 200 250

ACTH (pg/ml)

Cor

tisol

(ng/

ml)

HAHA

HIGH AND LOW ALTITUDE NEWBORN LAMBS

THE CORTISOL RESPONSE TO ACTH IS BLUNTED IN THE HIGH ALTITUDE NEWBORN SHEEP

WHETHER THE ADRENAL FUNCTION REMAINED ALTEREDLATER IN LIFE NEEDS TO BE INVESTIGATED AS WELL ASTHE MECHANISMS PRODUCING THIS BLUNTING

• I HAVE SHOWED YOU EFFECTS OF HIGH ALTITUDE CHRONICHYPOXIA ON INFANT BIRTH WEIGHT AND INFANT OXIGENATION

• I HAVE ALSO SHOWED YOU EFFECTS OF HIGH ALTITUDE CHRONIC HYPOXIA ON ANIMAL BIRTH WEIGHT, CARDIOVASCULAR AND ENDOCRINE FUNCTION

• WHETHER THESE CHANGES INDUCED BY CHRONIC HYPOXIACAN PROGRAMME FETAL ORIGINS OF ADULT DISEASE REMAINSTO BE ELUCIDATED