Stress hormone secretion and gut signal transducer (STAT) proteins after burn injury in rats.

A burn injury triggers traumatic reactions characteristics of a stress. Here we investigated the early responses of prolactin (PRL), corticosterone (CS), and signal transducer and activator of transcription 5 (STAT5) in male Sprague-Dawley rats after burn injury. PRL and CS levels were determined in blood serum. STAT5 and phospho-STAT5 levels were determined in jejunum total protein extracts. The results confirmed an expected increase of CS between 4 and 6 h after the burn injury. Unexpectedly, PRL secretion was suppressed during the same time frame. These hormone levels returned to normal 6 to 8 h after burn injury. STAT5 was increased in the jejunum after burn injury, and its phosphorylation was increased between 8 and 11 h after burn injury. These changes in STAT5 were not temporally correlated with either the hormone changes that we observed or with previously documented changes of the gut function after burns.