Anti-inflammatory properties of IL-1 in carrageenan-induced paw oedema

To evaluate any inhibitory effect of a single dose of human recombinant interleukin-1 (hrIL-1) on the severity of carrageenan-induced oedema in rats (a commonly used model of acute inflammation), we first injected 0.1 ml of carrageenan (0.2%, 0.5%, or 2%) to induce mild, moderate, or severe inflammation, respectively into the right rear footpad. Then we promptly injected the interleukin (0.02, 0.2, or 2 g) subcutaneously into the flank. The initial rapid increase in volume of the injected paw (within 2 h of the subplantar injection) was independent of the dose of carrageenan, whereas the increase in volume by 6 to 10 h was dose-dependent, All doses of HrIL-1 inhibited the carrageenan-induced swelling at the 6th hour. In the moderate and severe carrageenan-induced oedemas, the higher dose of HrIL-1 induced a delayed inflammation peaking at 10 h instead at 6 h.