Human cultured endothelial cells do secrete endothelin-1.
Endothelin-1 (ET-1) has been identified in the conditioned medium of porcine endothelial cells. Human endothelin (ET-1) cloned from a placenta cDNA library is similar to porcine, but it is not known whether endothelin itself is secreted by human endothelial cells. To answer this question, a conditioned medium taken every 48 h from confluent cultures of umbilical vein endothelial cells was analyzed by HPLC and all fractions were tested for their ability to inhibit [125I]ET-1 binding on human placenta membranes. Only one fraction did inhibit [125I]ET-1 binding. When the conditioned medium was spiked with ET-1, the same single fraction inhibited [125I]ET-1 binding showing that ET-1, itself, is present in the conditioned medium of human endothelial cells. ET-1 accumulates with time, reaching a plateau at 48 h. ET-1 secretion is not increased by a 24-h incubation of endothelial cells with phorbol myristate acetate, interleukin-1, tumor necrosis factor, thrombin or neuropeptide Y.
Clozel
M
M
F. Hoffmann-La Roche and Co., AG, Basel, Switzerland.
Fischli
W
W
D016232:Endothelins; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D010455:Peptides / Q000378:metabolism*; D014471:Umbilical Veins / Q000166:cytology / Q000378:metabolism; D014661:Vasoconstriction / Q000187:drug effects
D016232:Endothelins; D007457:Iodine Radioisotopes; D010455:Peptides