PRODUCTION OF PROSTAGLANDIN-E-1 AND PROSTAGLANDIN-E-2 BY ADULT HUMAN RED-BLOOD-CELLS

We showed that human adult red blood cells (RBCs) produce prostaglandi n E-1 (PGE(1)) and E-2 (PGE(2)). RBCs that were mechanically stressed in the presence of extracellular Ca2+ by being injected rapidly throug h a fine needle produced PGE(1) and PGE(2) within 30 min after this me chanical stress. The amounts of PGE(1) and PGE(2) produced by 1 x 10(9 ) mechanically stressed RBCs were approximately 50 pg and 100 pg, resp ectively, which were determined in the cytosolic fraction from sonicat ed RBCs using a competitive enzyme immunoassay method. A Western blot analysis using anti-cyclooxygenase-2 antibody revealed a band at the 7 0-kDa position in the samples from RBCs producing PGE(1) and PGE(2). T reatment with 10 mu g/mL indomethacin completely inhibited the product ions of PGE(1) and PGE(2). The present results may indicate a new role of RBCs in microcirculation.