Effect of pretreatment with interleukin-1β on inflammatory infiltrates and tissue damage after experimental endotoxic challenge

Objective: To evaluate the effect of treatment with murine recombinant interleukin-1β on inflammatory infiltrate and tissue damage after experimental endotoxic challenge. Design: Randomized, controlled study. Setting: Experimental Unit, Virgen de las Nieves University Hospital. Subjects: Seventy-two female CBA/H mice, 20-21 g, supplied by the animal center of the Experimental Unit. Intervention: The mice were randomized into three groups of 24. Group 1 (sham) received two intraperitoneal doses of 0.1 mL of phosphate-buffered saline; group 2 (lipopolysaccharide) was injected with 125 mg/kg lipopolysaccharide (Escherichia coli, intraperitoneally) 24 hrs after 0.1 mL of phosphate-buffered saline; group 3 was pretreated with 80 ng of recombinant interleukin-1β per mouse (intraperitoneally) 24 hrs before the endotoxic challenge. Measurements and Main Results: At 1, 2, 4, and 24 hrs after the endotoxic challenge, we studied inflammatory infiltrate and tissue damage in lung, liver, and intestine by determining myeloperoxidase and malondialdehyde tissue concentrations. When we compared the pretreated group with the lipopolysaccharide group, myeloperoxidase concentrations decreased significantly in lung (p <.001) and liver (p <.001) at all study times, and in intestine (p <.001) at 2, 4, and 24 hrs; malondialdehyde concentrations significantly decreased in lung at 1 (p <.05), 2 (p <.01), and 24 (p <.001) hrs, in liver at 2 (p <.001), 4 (p <.01), and 24 (p <.001) hrs, and in intestine at 1 (p <.001), 2, 4 (p <.05), and 24 (p <.001) hrs. Conclusion: Pretreatment with recombinant interleukin-1β significantly reduces inflammatory infiltrate and tissue damage in mouse lung, liver, and intestine after an experimental endotoxic challenge.