Increased endothelin-1 content in the platelets of hemodialysed patients

• Published in: Clinical nephrology Vol. 48; no. 3; p. 185
• Main Authors: Vlachojannis, J, Tsakas, S, Chinari, E, Orphanos, V, Zoumbos, N, Kurz, P
• Format: Journal Article
• Language: English
• Published: Germany 01.09.1997
• Subjects: Adult; Blood Platelets - chemistry; Blood Platelets - metabolism; Blood Protein Electrophoresis; Case-Control Studies; Electrophoresis, Polyacrylamide Gel; Endothelin-1 - blood; Female; Humans; Kidney Failure, Chronic - blood; Kidney Failure, Chronic - therapy; Male; Platelet Aggregation; Polymerase Chain Reaction; Renal Dialysis
• ISSN: 0301-0430

Patients undergoing hemodialysis, present platelets (PLTs) with physiological dysfunction. Aggregated PLTs stimulate endothelin-1 (ET-1) secretion from endothelial cells. In turn, ET-1 abolishes PLT aggregation. The aim of this study was to determine any presence of ET-1 in the PLTs of hemodialysed patients and to compare its levels with normal subjects. Platelets, isolated from hemodialysed patients, revealed lower aggregation (76 +/- 13%) compared with healthy subjects (96 +/- 2%). Plasma ET-1 was increased in hemodialysed patients 23.5 +/- 3.2 fmol/ml, vs. 10.9 +/- 1.6 fmol/ml in normal subjects. Immunoreactive endothelin-1 was detected in the platelets of both groups. The intraplatelet ET-1 of hemodialysed patients was 13.8 +/- 3.1 fmol/mg protein, vs. 7.9 +/- 1.3 fmol/mg protein in normal individuals. Total RNA was isolated from platelets and reverse transcriptase-mediated polymerase chain reaction (RT-PCR) revealed no presence of the preproET-1 mRNA in either normal or hemodialysed platelets. This suggests that ET-1 is internalized from the plasma. In summary, platelets contain but do not express ET-1. The increased levels of ET-1 in the platelets of the hemodialysed patients may be partly responsible for their lower aggregation.