PRODUCTION OF PROSTAGLANDINS E1 AND E2 BY ADULT HUMAN RED BLOOD CELLS

Abstract We showed that human adult red blood cells (RBCs) produce prostaglandin E 1 (PGE 1 ) and E 2 (PGE 2 ). RBCs that were mechanically stressed in the presence of extracellular Ca 2+ by being injected rapidly through a fine needle produced PGE 1 and PGE 2 within 30 min after this mechanical stress. The amounts of PGE 1 and PGE 2 produced by 1 × 10 9 mechanically stressed RBCs were approximately 50 pg and 100 pg, respectively, which were determined in the cytosolic fraction from sonicated RBCs using a competitive enzyme immunoassay method. A Western blot analysis using anti-cyclooxygenase-2 antibody revealed a band at the 70-kDa position in the samples from RBCs producing PGE 1 and PGE 2 . Treatment with 10 μg/mL indomethacin completely inhibited the productions of PGE 1 and PGE 2 . The present results may indicate a new role of RBCs in microcirculation.