Induction of histidine and ornithine decarboxylase activities in mouse tissues by recombinant interleukin-1 and tumor necrosis factor

Abstract

The injection of recombinant interleukin-1 (IL-1) into mice induced histidine decarboxylase (HDC) activity in the bone marrow, spleen, lung and liver and ornithine decarboxylase (ODC) activity in the spleen and liver. The ability of IL-1 to induce these responses was the most potent of the various cytokines tested. The induction of these responses by IL-1 seemed to be more rapid than that produced by a lipopolysaccharide. The potency of IL-1α to induce both HDC and ODC activities was similar to that of IL-lβ, and their combination did not potentiate the induction of these responses. In contrast, although the ability of recombinant tumor necrosis factor-α (TNFα) to induce these responses was less potent than that of IL-1α or IL-1β, the combination of TNFβ and IL-1β produced higher HDC and ODC activities in some tissues tested than those induced by the combination of IL-1α and IL-1β. These results suggest that the syntheses of histamine and putrescine are regulated by IL-1 and/or TNFα in inflammatory or immune responses. Through these experiments, it was noticed that, in spite of a marked induction of HDC activity in the bone marrow, there was no detectable induction of ODC activity in this tissue. The meaning of HDC induction in the bone marrow is discussed.