肺间质纤维化大鼠体内明胶酶活性的变化

Changes of Matrix Metalloproteinases Activities in Pulmonary Fibrosis Rats

目的观察肺间质纤维化大鼠体内明胶酶活性的变化情况。方法雄性SD大鼠80只,随机分为假手术组(n=40)和博莱霉素组(BLM组,n=40)。向BLM组大鼠气管内一次性注入BLM复制肺纤维化模型,假手术组大鼠则在气管内注入等量生理盐水。两组动物同步于气管内灌注后第1、3、7、14、28d分别随机处死8只。腹主动脉抽血分离血清,支气管肺泡灌洗收集肺泡灌洗液,冰浴匀浆肺组织制备匀浆液,-80℃冻存。采用明胶酶谱法测定基质金属蛋白酶活性。结果与假手术组相比,BLM组各样品中MMP-9活性均有所增加;血清及肺组织匀浆中MMP-9的活性在BLM注入后1d开始升高,血清MMP-9活性在3d达高峰,肺组织匀浆MMP-9活性在7d达高峰,14及28d已与假手术组无明显差异;肺泡灌洗液中MMP-9活性在BLM注入后1d开始增加,7d达高峰,14d趋向平稳,28d回落。BLM组血清样品中MMP-2活性在各时间点均无明显改变;肺泡灌洗液样品中MMP-2活性从14d起开始升高,持续到第28d始终未见有回落;肺组织匀浆样品中MMP-2的活性升高较早,从3d起开始升高,至28d始终未见回落。结论MMP-2和MMP-9在BLM致大鼠肺纤维化过程中的来源及作用均不同。

Objective To observe the changes of matrix metalloproteinases （MMPs） activities in pulmonary fibrosis rats. Methods Eighty male SD rats were randomly divided into sham group （ n = 40 ） and bleomycin group （ BLM, n = 40 ） , in which SD rats were injected with a single intratracheal dose of sham saline or bleomycin respectively. On day 1, 3, 7, 14, and 28 following bleomycin or saline instilla- tion, rats were randomly killed, and serum from abdominal aorta, alveolar fluid from the bronchoalveolar lavage, and the lung homogenate were collected and then stored at -80℃. MMPs activity was determined by zymography. Results Compared with sham group, the levels of MMP-9 in all samples were augmented. MMP-9 activities in the serum were highest on day 3 than those on day 1 and day 7, and in lung tissue homogenate were highest on day 7 ; however, no significant differences were found between BLM group and sham group on day 14 and day 28 ; and that of bronchoalveolar lavage fluid （BALF） was highest on day 7 than those on day 1 and day 14, while no significant difference existed between BLM group and sham group on day 28. Serum MMP-2 level did not change from day 1 to day 28, while the level of BALF MMP-2 began to increase after day 14, even on day 28. Lung tissue homogenate MMP-2 level began to increase early on day 3 and continued to day 28. Conclusion The sources and effects of MMP-2 and MMP-9 differ in BLMinduced rat pulmonary fibrosis.