Exaggerated endothelin release in high-altitude pulmonary edema.
BACKGROUND
Exaggerated pulmonary hypertension is thought to play an important part in the pathogenesis of high-altitude pulmonary edema (HAPE). Endothelin-1 is a potent pulmonary vasoconstrictor peptide that also augments microvascular permeability.


RESULTS
We measured endothelin-1 plasma levels and pulmonary artery pressure in 16 mountaineers prone to HAPE and in 16 mountaineers resistant to this condition at low (580 m) and high (4559 m) altitudes. At high altitude, in mountaineers prone to HAPE, mean (+/-SE) endothelin-1 plasma levels were approximately 33% higher than in HAPE-resistant mountaineers (22.2+/-1.1 versus 16.8+/-1.1 pg/mL, P<0.01). There was a direct relationship between the changes from low to high altitude in endothelin-1 plasma levels and systolic pulmonary artery pressure (r=0.82, P<0.01) and between endothelin-1 plasma levels and pulmonary artery pressure measured at high altitude (r=0.35, P=0.05).


CONCLUSIONS
These findings suggest that in HAPE-susceptible mountaineers, an augmented release of the potent pulmonary vasoconstrictor peptide endothelin-1 and/or its reduced pulmonary clearance could represent one of the mechanisms contributing to exaggerated pulmonary hypertension at high altitude.
Sartori
C
C
Department of Internal Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
Vollenweider
L
L
Löffler
B M
BM
Delabays
A
A
Nicod
P
P
Bärtsch
P
P
Scherrer
U
U
D000328:Adult; D000531:Altitude; D001794:Blood Pressure / Q000502:physiology; D004198:Disease Susceptibility; D019332:Endothelin-1 / Q000097:blood / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009051:Mountaineering / Q000502:physiology; D011651:Pulmonary Artery / Q000503:physiopathology; D011654:Pulmonary Edema / Q000209:etiology* / Q000378:metabolism* / Q000503:physiopathology; D013599:Systole
D019332:Endothelin-1