Early inflammatory cytokine and acute phase protein response under the stress of thermal injury in rats.

The acute inflammatory response associated with thermal injury was examined in rats. The appearance of mediators of inflammation in the systemic circulation, including cytokines interleukin-1 (IL-1), tumor necrosis factor (TNF) and interleukin-6 (IL-6) and acute phase proteins were assessed during initial 72 h following thermal injury. Increased levels of activity were noted for all three cytokines, but with a different time-course. While serum IL-1 activity was elevated throughout the 3-day period of observation, the levels of serum TNF activity were enhanced after 12 h and on days 1 and 3 following scalding injury. The values of IL-6 were already increased one hour after thermal injury and increased progressively up to day 1 following scalding. Alpha2-macroglobulin and haptoglobin levels were increased 12 h after thermal injury, rising further on days 1 and 3. Positive correlation was found between the time-course of increased serum IL-6 activity and alpha2-macroglobulin, as well as between TNF and haptoglobin in the serum.