Biblioteca Virtual en Salud

Objective To observe the changes of granulocyte-macrophage colony stimulating factor (GM-CSF) expression in mice with radiation and incision combined injury during wound healing and analyze its therapeutic effect, paving a way for exploring the effect of GM-CSF on healing of radiation combination injury. Methods A total of 56 Kunming mice (20-22 g) were randomly divided into two groups; the experimental group and control group (n = 28 for each group). Mice in the experimental group were made into irradiated injury plus skin wound by incising the back immediately after exposing to 6 Gy60 Co γ radiation. Pure incision injury without radiation exposure was made in the mice in control group. Mice were sacrificed on day 1, 3, 5, and 7(7 mice for each time) after model establishment, and skin and thin layer of muscle tissues around the wound were collected. Real-time PCR and immunohistochemical analysis were used to examine the mRNA and protein expression of GM-CSF. Moreover, radiation and incision combined injury models were also established in 40 species, body mass-matched mice using same method described above and the model mice were divided into two groups; treatment group and blank control group (n=20 for each group). The wounds were treated with rhGM-CSF gel (6 000 ng/mL) in the treatment group at 0, 1, 3, 4, 5, 7, 9, 11, and 14 d after model establishment, while blank gel was given to the blank control group. Then the therapeutic effects of rhGM-CSF gel on wound healing were evaluated based on the wound residual area and the level of collagenous fiber around the wound. Results The expression levels of GM-CSF protein and mRNA were significantly lower in the radiation and incision combined injury models during 1-3 days compared with the control group (P<0. 05). The expression of GM-CSF was gradually decreased during 5-7 days in the control group, while it kept unchanged in the experimental group. During the 14 days treatment with rhGM-CSF gel, the wound areas were significantly smaller than those of the blank control group (P<0. 05). Meanwhile, Masson staining showed notable proliferation, widely distributed, and tightly arranged collagenous fiber after rhGM-CSF gel treatment at the injury sites. Conclusion The level of GM-CSF is lower in radiation and incision combined injury compared with the control, and continuous rhGM-CSF (6 000 ng/mL) treatment can greatly promote the healing of radiation and incision combined injury.