Endothelin-1 plasma concentrations in patients with retinitis pigmentosa

Purpose: The aim of this study was to investigate the behaviour of plasma endothelin-1 (ET-1) levels in patients affected by retinitis pigmentosa (RP) and syndromic RP. Methods: Blood samples were obtained from a group of 40 consecutive patients with RP matched with 35 healthy subjects (HS) as control. We carried out a complete ophthalmological examination. The study group included 26 patients with RP and 14 patients with syndromic RP. Plasma ET-1 levels were determined in duplicate with a specific radioimmunoassay method. Results: In the HS plasma ET-1 levels were 7.48 +/- 2.58 pg/mL The mean of plasma ET-I concentrations in all patients with RP (16.2 +/- 5.6 pg/mL) was significantly (P<0.01) higher than that of HS. Moreover, in the syndromic RP patients, plasma ET-I levels (18.9 +/- 6.8 pg/mL) were higher than those of HS and RP patients (P<0.01). Conclusion: The increase of plasma ET-1 levels in RP patients suggests that ET-I may play a role in the pathophysiology of the diseases involving retinal pigment epithelial cells and the retinal vascular system such as RP. (C) 2010 Elsevier B.V. All rights reserved.