Growth hormone attenuates the acute-phase response to thermal injury

Objective: To determine the effects of growth hormone (GH) on the hepatic acute-phase response (APR) in a burned rat model. Setting: Laboratory. Material: Male Sprague-Dawley rats (weight, 300-350 g). Interventions: Rats underwent a 40% total body surface area burn injury and received GH or saline solution daily by subcutaneous injection. Unburned rats served as controls. Main Outcome Measures: Hepatic messenger RNA (mRNA) expression and serum levels of α₁-acid glycoprotein and albumin were determined 2, 7, and 14 days after injury. Results: The serum α₁-acid glycoprotein levels in GH-treated animals did not increase on days 2 and 7, whereas saline-treated animals showed a major increase. Hepatic mRNA expression increased dramatically on day 2 for burned groups; however, the mRNA pool levels of GH-treated animals showed a faster rate of decline to control levels on days 7 and 14. The albumin mRNA pool levels of GH-treated and control animals did not show significant differences, whereas the negative APR, as indicated by loss of albumin mRNA, was more pronounced on day 7 in the saline-treated animals. By day 14, mRNA levels were comparable in all 3 groups. Conclusion: Growth hormone attenuated the positive APR, as indicated by a decrease in α₁-acid glycoprotein expression and production, and prevented the negative APR, as seen by an absence of a decline of albumin mRNA pool levels and serum concentration. We conclude that the beneficial effects of GH on thermal injury may be due in part to a modification of the APR.