A chemotactic role for prostaglandins released from polymorphonuclear leucocytes during phagocytosis.

1. Prostaglandin E1 is chemotactic at concentrations down to 10 ng/ml for rabbit polymorphonuclear (PMN) leucocytes. Prostaglandins E2 and F2alpha have little or no chemotactic effect at concentrations up to 10 mug/ml. 2. Washed PMN leucocytes produced a chemotactic agent during phagocytosis, but not in the presence of indomethacin (28 muM). 3. Phagocytosing PMN leucocytes produce up to ten times as much prostaglandin as do resting cells. Some of this is prostaglandin E1 as judged by thin layer chromatography and differential bioassay. This prostaglandin production by PMN leucocytes is abolished by indomethacin (28 muM). 4. Ultrasonicated suspensions of PMN leucocytes produced prostaglandin from arachidonic aicd. This synthesis is inhibited by indomethacin. 5. Homogenates of PMN leucocytes which have been pre-incubated withe bacteria for 30 min show more prostaglandin synthetase activity than homogenates from PMN leucocytes which have not been exposed to bacteria. 6. It is concluded that in some forms of inflammation, prostaglandin E1 may play a controlling role in cellular migration. 7. PMN leucocytes may contribute to the generation of prostaglandins found in some inflammatory lesions.