RT Journal Article
SR Electronic
T1 Release of endothelins and platelet-activating factor by a rat pleural mesothelial cell line
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 170
OP 176
DO 10.1183/09031936.00.15117000
VO 15
IS 1
A1 I Kimura
A1 Y Sakamoto
A1 M Shibasaki
A1 Y Kobayashi
A1 H Matsuo
YR 2000
UL http://erj.ersjournals.com/content/15/1/170.abstract
AB Thrombin is a multifunctional serine protease. It is generated in inflammatory processes and induces the proliferation and chemotaxis of a variety of cells including mesothelial cells (MTCs). MTCs are epithelial cells derived from the mesoderm, as are the vascular endothelial cells. Since thrombin acts on endothelial cells to produce platelet-activating factor (PAF) and endothelin (ET)-1, it was hypothesized that MTCs also produce PAF and ET via the action of thrombin. Rat pleural MTC (RMTC, 4/4 R.M.-4) monolayers were cultural in tissue culture dishes for various periods. The supernatants were fractionated by means of high-performance liquid chromatography to determine the ET isoforms and PAF species present. Immunoreactive ET was measured using an enzyme-linked immunosorbent assay, and PAF was measured by means of a bioassay using a platelet aggregometer. ET-1, ET-2 and ET-3 were detected in RMTC-conditioned medium, and the predominant isoforms were ET-1 and ET-2. RMTCs mainly released C16:0 PAF into the supernatant. Immunoreactive ET and PAF were released via the action of thrombin. Synthetic PAF significantly induced secretion of ET, but the PAF receptor antagonists, WEB2086 and E6123, failed to modulate thrombin-induced ET release. These results indicate that thrombin acts on pleural rat mesothelial cells to release ET and PAF, which may play a role in the development of pleurisy.