Plasma endothelin-1 concentrations in patients with retinal vein occlusions.
OBJECTIVE
To investigate whether plasma levels of endothelin-1 (ET-1), a potent vasoconstricting peptide that is crucial in regulating retinal blood flow, were elevated in patients with retinal vein occlusion (RVO).


METHODS
ET-1 plasma concentrations were determined by radioimmunoassays in a double blind fashion in a group of 18 selected patients with RVO, in 20 healthy age matched non-smoking, normoglycaemic, normotensive control subjects, and in 15 patients with uncomplicated essential hypertension in the same age range.


RESULTS
Patients with RVO had significantly increased ET-1 plasma levels (14.22 (SD 4.6) pg/ml) compared with both normal subjects (7.90 (1.6) pg/ml; p < 0.05) and hypertensive patients (8.50 (2.9) pg/ml; p < 0.05). The highest concentrations of circulating ET-1 were found in patients with RVO of the ischaemic type (16.97 (3.5) pg/ml; p < 0.01; n = 7). Systemic hypertension alone did not account for the observed increase in plasma ET-1 concentrations.


CONCLUSIONS
These findings raise the possibility that the increased circulating ET-1 levels in patients with RVO may be a marker of the occlusive event, thereby suggesting that ET-1 homeostasis may be relevant to RVO pathogenesis and retinal ischaemic manifestations.
Institute of Ophthalmology, University La Sapienza, Rome, Italy.
A
A
Iannaccone
C
C
Letizia
S
S
Pazzaglia
E M
EM
Vingolo
G
G
Clemente
M R
MR
Pannarale
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D004311:Double-Blind Method; D019332:Endothelin-1 / Q000097:blood*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood; D007511:Ischemia / Q000209:etiology; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000097:blood; D012170:Retinal Vein Occlusion / Q000097:blood* / Q000150:complications; D012171:Retinal Vessels
D015415:Biomarkers; D019332:Endothelin-1