This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Henderson, B. W. Articles by Donovan, J. M. Search for Related Content PubMed PubMed Citation Articles by Henderson, B. W. Articles by Donovan, J. M.

Release of Prostaglandin E₂ from Cells by Photodynamic Treatment in Vitro¹

Division of Radiation Biology, Department of Radiation Medicine, Roswell Park Memorial Institute, Buffalo, New York 14263

Photodynamic treatment in vitro, using the photosensitizer Photofrin II and light at 630 nm, was found to liberate large amounts of prostaglandin E₂ (PGE₂) from mouse radiation-induced fibrosarcoma tumor cells and peritoneal macrophages, but not from L929 fibroblasts. PGE₂ release was dose dependent and directly related to cell membrane disruption. It occurred rapidly and was complete within 30 min of treatment. PGE₂ release could be inhibited by indomethacin, meclofenamate and extended prior exposure to dexamethasone, indicating that it was due to new production involving both the phospholipase and cyclooxygenase enzyme systems. Removal of calcium ions, necessary for phospholipase activation, from the medium did not inhibit the photodynamically induced elevated PGE₂ production, possibly because of Ca²⁺ resupply from leaking intracellular pools.

¹ This investigation was supported part by USPHS Grant CA 42278 awarded by the National Cancer Institute, Department of Health and Human Services, and by a grant from The Oncologic Foundation of Buffalo.

² To whom requests for reprints should be addressed.

Received 2/ 3/89. Revised 8/11/89. Accepted 9/19/89.