Gene expression and cytokine and enzyme activation in the liver after a burn injury

The liver plays a critical role in the inflammatory response to injury; how ever, the mechanisms by which the Liver is affected and how it influences t he rest of the immune system are not cr ell understood. Partial hepatectomy is a direct injury to the liver, whereas a burn is an indirect injury to l iver, but both injuries appear to produce damage to the liver. Zn this stud y, me used a mouse model of 25% total body surface area and 40% total body surface area full-thickness burns to investigate the mechanism of liver dam age and response to burn injury by measuring levels of c-Jun messenger (m)R NA, NF kappa B nuclear protein, interleukin-6, transaminases, and liver tis sue histology over time, c-Tun and NF kappa B are 2 transcription factors t hat are induced by partial hepatectomy and related to hepatocyte injury and growth. Ln both groups of mice with burns, expression of c-Jun mRNA and NF kappa B nuclear protein was activated within 30 minutes after the burn inj ury, followed by increased levels of interleukin-6 and, finally, elevated e nzyme levels. Liver injuries were similar in both groups despite the magnit ude of the burns. We believe that these gene products are initiated in the hepatocyte injury after a burn and that they precede other inflammatory res ponses such as cytokine release, plasma transaminase levels, and histologic changes.