title: Effect of UV irradiation on expression of membrane IL 1 by rat macrophages.
abstract: The effect of UV-B irradiation on the expression of membrane-associated IL 1 (mIL 1) by rat pulmonary alveolar macrophages (PAM) was studied. We found that although there was an increase in secreted IL 1 by PAM exposed to UV-B, the expression of mIL 1 was inhibited in a dose-dependent manner. Furthermore, PAM that were allowed to express mIL 1 before UV-B irradiation had a faster decay of mIL 1 activity than unirradiated cells. These data suggested that mIL 1 expression is inhibited by UV-B irradiation, and that under normal circumstances, mIL 1 synthesis and degradation is at a steady state, with the half-life of mIL 1 activity being 24 hr when assayed in an IL 1-dependent cell line proliferation assay. These data indicate that secreted forms of IL 1 and mIL 1 are differentially regulated and that the therapeutic effects of UV irradiation may be due to its inhibition of mIL 1 activity.
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D007375:Interleukin-1 / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism / Q000528:radiation effects*; D011650:Pulmonary Alveoli / Q000166:cytology; D051381:Rats; D011917:Rats, Inbred Lew; D012995:Solubility; D014466:Ultraviolet Rays
chemical_list: D007375:Interleukin-1