不同深度的Ⅱ度烧伤创面中单核巨噬细胞生长因子的mRNA表达

Study of mRNA Expression of Growth Factors in Mononuclear Macrophages from Superficial and Deep Ⅱ Degree Burn Wounds in Rats

目的了解不同深度的Ⅱ度烧伤创面内源性生长因子的表达调控特点，以及这些特点与创面愈合过程的关系。方法分别观察大鼠浅Ⅱ度和深Ⅱ度烫伤模型创面渗液单核巨噬细胞生长因子ｍＲＮＡ表达的变化，并比较分析了两者间的差异。这些生长因子有ＴＧＦα、ＴＧＦβ和ＰＤＧＦ。结果对照组、浅Ⅱ度和深Ⅱ度组实验动物的创面单核巨噬细胞ｍＲＮＡ表达明显不同。未烫伤的对照组（单纯植海绵收集创面渗液）伤后１天均达峰值以后呈持续下降；浅Ⅱ度组伤后１周呈更高而持续的表达，伤后２周时回落接近对照组；深Ⅱ度组伤后早期呈低水平表达，于伤后１周时呈较高水平表达，其中ＴＧＦβ迟至伤后２周呈较高水平表达。结论提示创面单核巨噬细胞生长因子表达的启动，达到高峰和回落与损伤类型和创面愈合的状况密切有关，深Ⅱ度创面早期单核巨噬细胞生长因子的低水平表达与这类创面愈合时间较长的关系值得深入探讨。

Aim To investigate the characteristics of the expression of growth factors in superficial and deepⅡ degree burn wounds and their relationship to burn wound healing. Methods With rat burn models, we observed the changes of mRNA expression of growth factors in mononuclear macrophages from superficial and deep second degree burn wounds by in situ hybridization. The growth factors included TGFα, TGFβ and PDGF. Results There were remarkable difference between the control groups, the superficial Ⅱ degree burn group and the deep Ⅱ degree burn group. In controls, mRNA expression of growth factors reached peak 1 day post injury (implanting sponge for collecting exudates ) and gradually decreased to low level at 14 days post injury. In the superficial Ⅱ degree burn group, mRNA expression of growth factors had higher level than that of the controls and it maintained about 1 week postburn and decreased to low level 14 days postburn. In the deep Ⅱ degree burns the expression of growth factors was lower than that of the controls during 1 week postburn and reached peak only at 7 days and 14 days postburn especially TGFβ which reached peak only at 14 days postburn. Conclusion It is indicated that mRNA expression of growth factors in mononuclear macrophages is relative to the types of injury and the time course of wound healing. It needs further exploration for the relationship between delayed healing of deep Ⅱ degree burns and low level of mRNA expression of growth factors in mononuclear macrophages.