Biological Activity: Fully biologically active when compared to standard. The ED50 as determined by a cell proliferation assay using murine D10S cells is less than 10 pg/mL, corresponding to a specific activity of > 1.0 x 108 IU/mg.
Relevance: Produced by activated macrophages, IL-1 stimulates thymocyte proliferation by inducing IL-2 release, B-cell maturation and proliferation, and fibroblast growth factor activity. IL-1 proteins are involved in the inflammatory response, being identified as endogenous pyrogens, and are reported to stimulate the release of prostaglandin and collagenase from synovial cells. Synonyms: IL-1 alpha,