Total Body Irradiation-induced Changes in Rat Serum IL-1, IL-6 and TNF Activities

Publisher Summary This chapter presents a study on the effects of various radiation doses on the rat serum interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF) activities. The study was performed by using male 8–10-week-old Albino Oxford (AO) strain rats, which were total body irradiated with 4 (LD 10/30 ), 6.7 (LD 50/30 ), 9 (LD 95–100/30 ), and 12 Gy (LD 100/30 ). IL-1 activity was measured by incorporating tritiated thymidine into IL-1-sensitive D10S cells derived from the murine T-helper cell line D10.G4.1. Serum IL-6 activity was measured by a B9 bioassay, and TNF activity was determined by an L929 fibroblast cell lytic assay. The specificity of the IL-1 and IL-6 assay was confirmed by using appropriate rabbit polyclonal anti-human IL-1 and IL-6 antibodies. The findings of this study showed that radiation doses ranging from a low lethal dose to an absolutely lethal dose caused the early increase (1–3 hours after irradiation) of the serum activity of IL-1 and IL-6, whereas the peak activity of TNF was found after 24 hours. At 6 hours and later, IL-1 activity in the sera of irradiated rats was significantly decreased. The second peak of IL-6 activity was found 3–5 days after irradiation. The study also demonstrated that IL-6 and dexamethasone produce the typical pattern of acute phase protein gene expression in the hepatoma cell line when given in combination.