RESUMO
AIM:To investigate the effect of ozone bath on the pathological changes and the expression of cyto-kines,platelet-derived growth factor (PDGF), transforming growth factor-β3(TGF-β3), and tumor necrosis factor-α (TNF-α),in the wounds of deep second-degree burns in rats. METHODS:Male clean-grade SD rats(n=80) were ran-domly divided into 2 groups, ozone bath group and routine dressing group (control group), with 40 rats in each group. Deep second-degree burn wound was established on the back of the rats,and then the examinations were conducted at 3 d, 7 d,14 d and 21 d after burn. For the routine dressing group,the wound was cleaned by normal saline and covered with io-dophor vaseline gauze every 2 d. For the ozone bath group,before the dressing,the rats were put into the clean foam box to accept ozone fumigation for 20 min(50 mg/L),and then accepted dressing change as the same as that in control group every 2 d. At each time point,the tissue specimens from these rat wounds(at wound center) were taken. The rats in ozone bath group received cleaning by saline cotton and then the ozone bath fumigation, while the rats in control group only re-ceived cleaning by saline. After that,the tissue specimens were taken again for HE staining,immunohistochemical staining and semiquantitative observation combined with image data analysis. The concentrations of the cytokines PDGF, TGF-β3 and TNF-α in the wound were measured by double-antibody sandwich ELISA. RESULTS:In ozone bath group, the wounds were smooth with clear edge and slight inflammatory reaction,swelling and exudation were weaker,and the wound healing rate was higher than that in control group with significant difference. Under microscopic observation with HE stai-ning,slighter inflammatory reaction in ozone bath group was observed than that in control group at each time point,and the numbers of fresh capillaries,fibroblasts and epithelial cells were significantly larger than those in control group. The ex-pression levels of PDGF and TGF-β3in the wound tissue homogenate in ozone bath group were higher,and the expression level of TNF-α was significantly lower than those in control group at each time point with significant difference. CONCLU-SION:The ozone bath therapy improves the local pathological changes and promotes the expression of cytokines PDGF and TGF-β3,which are associated with wound healing,as well as reduces the expression of inflammatory mediator TNF-α in the rats with deep second-degree burns,thus promoting the wound healing and anti-inflammatory responses.