OBJECTIVETo investigate the effect of Thymosin and growth hormone(GH) on inflammatory response in burn rats or burn rats with sepsis.

METHODSSixty-four SD rats were randomly divided into normal control group (NC, without treatment), sepsis group (S, with injection of LPS), sepsis + Thymosin group (ST, with successive injection of Thymosin and LPS), sepsis + GH group [SGH, with successive injection of recombinant human GH (rhGH) and LPS], burn group, burn + sepsis group (BS, with injection of LPS after burn), burn + sepsis + Thymosin group (BST, with successive injection of Thymosin and LPS after burn), burn + sepsis + GH (BSGH, with successive injection of rhGH and LPS after burn), with 8 rats in each group. Specimens of spleen tissues were harvested to determine HLA-DR in lymphocyte and evaluate inflammatory cell infiltration (score). Specimens of peripheral blood were collected to determine Toll-like receptor 4 (TLR4) level in monocyte and serum level of TNF-alpha, IL-4, IL-6, IL-10.

RESULTSCompared with those in NC group, serum level of IL-10 in S group decreased obviously, while other indices increased obviously (P < 0.01). The levels of HLA-DR and TLR4 and serum level of TNF-alpha were similar between SGH and ST groups (P > 0.05). Compared with those in SGH group [(2.87 +/- 0.04) score, and IL-6 (0.0083 +/- 0.0018) microg/mg, IL-4 (0.0102 +/- 0.0021) microg/mg, IL-10 (0.0310 +/- 0.0027) microg/mg, respectively], degree of inflammatory cell infiltration (1.50 +/- 0.76) score and serum levels of IL-6, IL-4, IL-10 of rats in ST group decreased obviously (0.0064 +/- 0.0012, 0.0058 +/- 0.0024, 0.0230 +/- 0.0021 microg/mg, respectively, P < 0.01). The levels of HLA-DR, TLR4 and inflammatory cell infiltration degree of spleen in B group were respectively higher than those in NC group and lower than those in BS group. Compared with those in NC group, serum levels of TNF-alpha, IL-6 in B group increased significantly, while IL-4, IL-10 showed an opposite tendency. There was no obvious difference between BST and BSGH groups in serum levels of HLA-DR and IL-6 (P > 0.05). Compared with those in BST group, inflammatory cell infiltration degree in spleen and the levels of TLR, TNF-alpha obviously decreased (P < 0.01), while IL-4 and IL-10 levels increased in BSGH group (P < 0.01).

CONCLUSIONSInhibitive effects between Thymosin and GH on extensive inflammatory reaction were similar with or without trauma, and GH has better effect as compared with Thymosin when with trauma.