核因子-κB在羊水入血大鼠肺组织中的活性变化及地塞米松的干预作用研究

Activity of nuclear factor kappa B in rat pulmonary tissue after entrance of amniotic fluid into blood and inhibition with dexamethasone

目的探讨核因子κB在羊水入血后的大鼠肺组织中的活性变化及地塞米松的干预作用。方法Wistar雌性大鼠30只制成大鼠羊水入血模型,其中16只为羊水组、14只按01mg/100g注入地塞米松注射液作为羊水+地塞米松组;Wistar雌性大鼠34只制成大鼠胎粪入血模型,其中20只为胎粪组、14只按01mg/100g注入地塞米松注射液作为胎粪+地塞米松组。另选6只Wistar雌性大鼠作为对照组。模型制成60min时,采用注射10%氯化钾的方法处死大鼠,提取大鼠肺组织行病理检查。采用免疫印迹法检测大鼠肺组织中的核因子κB结合活性;免疫组化方法检测大鼠肺组织核因子κB阳性细胞率。结果(1)羊水组及胎粪组大鼠肺组织有不同程度水肿,血管丰富,局部可见少量出血,血管及支气管周围可见大量炎性细胞浸润(主要为中性粒细胞);羊水+地塞米松组及胎粪+地塞米松组肺组织病理改变均较羊水组及胎粪组减轻;对照组大鼠肺组织则无明显改变。(2)胎粪组肺组织中核因子κB结合活性为438698±13092,明显高于羊水组的377982±7445及对照组的267691±12382,两者比较,差异有统计学意义(P<001);羊水+地塞米松组及胎粪+地塞米松组肺组织中核因子κB结合活性(分别为308826±13771及339516±17358)均较羊水组及胎粪组显著降低,两者比较,差异有统计学意义(P<005)。(3)?

ObjectiveTo investigate the relationship between nuclear factor kappa B (NF-κB) and pulmonary injury in amniotic fluid embolism model of rat. MethodsSeventy female Wistar rats were divided into five groups randomly: control group(6), amniotic fluid group(16), amniotic fluid + dexamethasone group (14), meconium group (20) and meconium + dexamethasone group(14). Different amniotic fluid was injected into jugular vein (dexamethasone was injected at 0.1 mg/100g after entrance of amniotic fluid into blood) and blood pressure was examined. Pulmonary tissue was taken at 60 minutes. NF-κB activity was measured by Western-blot and percentage of NF-κB p65 positive cells in pulmonary tissue was determined by immunohistochemistry(HE). ResultsDropsy, bleeding and neutrophil(PMN),macrophage,leukomonocyte infiltration were seen in four experimental groups.But none was found in control group. NF-κB activity in meconium group was 438 698±13 092, higher than those in amniotic fluid group, ~377 982 ±7 445, and in control group, 267 691±12 382(F=11.3, P<0.01).With dexamethasone treatment, NF-κB activity was decreased, which was 308 826±13 771 in amniotic group and ~339 516± ~17 358 in meconium group, respectively(t=20.4 and t=13.84, P<0.01).Percentage of NF-κB p65 positive cells was higher in meconium group, 49.1±7.0, than in amniotic fluid group, 33.3±2.7, and control group, 13.3±2.1(F=1.17,P<0.01). With dexamethasone treatment,the percentage decreased significantly to 22.9±3.0 and 21.4±3.6, respectively(t=6.75 and t=10.1,P<0.05). ConclusionsNF-κB activity and percentage of NF-κB p65 positive cells are increased significantly, which is associated with pulmonary injury after entrance of amniotic fluid into blood and dexamethasone could inhibit NF-κB translocation to the nucleus to degrade NF-κB activity and alleviate pulmonary injury. NF-κB may be relevant to the occurrence and development of multiple organ dysfunction syndrome.