Modified low density lipoproteins activate human macrophages to secrete immunoreactive endothelin

Abstract
This study attempted to determine if low density lipoproteins (LDL) induce the production of endothelins (ET) by human macrophages. Non‐protected LDL from macrophage induced oxidation (n‐LDL), copper‐oxidized LDL (Ox‐LDL), acetylated‐LDL (Ac‐LDL), butylated hydroxytoluene‐LDL (BHT‐LDL), BHT‐Ac‐LDL, polyinosinic acid (PiA, 1.5μg/ml), phorbol myristate acetate (PMA; 0.5 μM) and BHT alone (20 μM) were studied. The different compounds had the following potency to stimulate the ET secretion: PMA>Ox‐LDL>Ac‐LDL>n‐LDL>BHT‐LDL>PiA>PiA+Ac‐LDL>BHT. In conclusion, mod stimulated ET secretion by human macrophages.