In vivo Effects and Interactions of Recombinant Interleukin 1 and Tumor Necrosis Factor in Radioprotection and Induction of Fibrinogen

摘要

Although interleukin 1 (IL-1) and tumor necrosis factor (TNF) are both produced by stimulated macrophage-monocytes, they are molecularly distinct, act via separate receptors, but show striking resemblance in their biological activity. Both cytokines are pyrogenic, induce colony stimulating factor and acute phase proteins, activate neutrophils, reduce cytochrome P-450 functions, and inhibit lipoprotein lipase. Furthermore, IL-1 and TNF have been reported to induce the release of one another. Because of this mutual induction, the relative contribution of IL-1 or TNF to the induction of a given activity becomes difficult to establish. In an attempt to determine whether these two cytokines act independently, the effect of administrating them separately or in combination is compared on the radioprotection and on the induction of an acute phase reactant - fibrinogen. IL-1 and TNF have synergistic effects on radioprotection and on the levels of circulating fibrinogen. Keywords: Irradiation, Mice, Reprints. (aw)