The effects of recombinant human interleukin-1 (IL-1) on the release of prostaglandins (PG) from dermal fibroblasts and rabbit brain tissue will be studied. Specifically, three main topics will be investigated: a. the effects (i.e. time course) of IL-1 on the release of PG from fibroblasts and rabbit brain tissue. b. the nature of the interaction of isotopically-labeled IL-1 with its receptor on fibroblasts c. the role of Ca++ and regulatory phosphoinositides on the IL-I - induced release of PG from fibroblasts. The above experiments will utilize, for the first time, recombinant IL-1. Data derived from this grant will supply additional information about the inflammatory response and provide details about how IL-1 may exert some of its immunologic and inflammatory effects.