羊水栓塞妊娠大鼠血清中PLA2和PAF的水平变化研究

Study on the Changes of Plasma Levels of PLA2 and PAF in Pregnant Rats with Amniotic Fluid Embolism

目的:探讨羊水栓塞妊娠大鼠血清中PLA2和PAF的水平变化。方法:30只健康妊娠大鼠均分为生理盐水组(A组)、羊水组(B组)及羊水胎粪混合组(C组)。将健康妊娠大鼠麻醉,麻醉效果生成后,全部切除大鼠子宫后关腹,分离出左颈总动脉,并将二通道生理记录仪与其连接,连续监测血液动力学指标,随后将生理盐水、羊水和羊水胎粪混合液腹腔静脉注射于大鼠,1小时后取大鼠肺组织,用HE、APK染色结合CK16免疫组织化学法来检测模型是否制作成功。实验前后1小时两个取血点时,在制备好的羊水栓塞模型大鼠左颈动脉插管处各取1 m L血。采取酶联免疫检测法,测定血清、羊水及羊水胎粪混合液中PLA2、PAF的含量。获得的数据用SPSS 20.0软件进行处理,采用配对t检验、协方差分析及相关回归分析对血清PLA2、PAF的浓度进行分析。结果:B组和C组的3个血液动力学指标(动脉收缩压、舒张压及平均动脉压)均显著低于A组(P<0.05),而B组与C组的4个血液动力学指标均无显著性差异(P>0.05)。同时,A组、B组与C组之间在心率改变方面无显著性差异(P>0.05)。HE染色中,B组与C组大鼠的肺间质显著变宽,且有充血、水肿及炎性细胞浸润,而A组无此现象。AMP染色中,B组和C组大鼠的肺小管中可见被染成蓝色的不定形物质和桃红色的角化鳞状上皮,而A组无此现象。CK16染色中,B组和C组大鼠的肺小管中,可以看到被染成黄色的颗粒和鳞状上皮,而A组无此现象。实验1小时后所取血液中,B组和C组的PLA2与PAF的含量显著高于A组(P<0.05),且C组中升高程度更大。妊娠大鼠羊水与羊水胎粪混合液中均检测到PLA2和PAF,且羊水胎粪混合液中二者的含量均高。实验1小时前所取的血液中,PLA2和PAF浓度无相关性(P=0.762,R=0.012),而实验1小时后所取血液中,PLA2和PAF浓度呈正相关关系(P=0.002,R=0.437)。结论:羊水栓塞妊娠模型大鼠羊水和胎粪中均有PLA2和PAF,且实验1小时后所取血液中,PLA2和PAF含量在B组和C组中显著高于A组,说明羊水和胎粪中含有使PLA2、PAF水平增高的刺激因子。

Objective: To investigate the changes of serum levels of PLA2 and PAF in pregnant rats with amniotic fluid embolism Methods: The 30 healthy pregnant rats were divided into normal saline group(group A), amniotic fluid group(group B) and amniotic fluid meconium mixture group(group C). Healthy pregnant rats were anesthetized. After the anesthesia effect was generated, the left common carotid artery was isolated from the posterior closure of the uterus, and the two channels of physiological recorder were connected with it to continuously monitor the hemodynamic indicators. The rats were then intravenously injected with saline, amniotic fluid and a mixture of amniotic fluid and meconium. The rat lung tissue was taken 1 hour later. HE and APK staining and CK16 immunohistochemistry were used to detect the success of the model. At two blood points 1 hour before and after the experiment, 1mL of blood was taken from the left carotid artery cannula of the prepared amniotic fluid embolization model rats. The contents of PLA2 and PAF in serum, amniotic fluid and amniotic fluid meconium mixture were determined by enzyme-linked immunoassay. The obtained data were processed by SPSS 20.0 software, and serum PLA2 and PAF concentrations were analyzed by paired t test, covariance analysis and correlation regression analysis. Results: The 3 hemodynamic indexes(systolic, diastolic and mean arterial pressure) of group B and group C were significantly lower than that of group A(P<0.05), while the 4 hemodynamic indexes of group B and group C were not significantly different(P>0.05). Meanwhile, there was no significant difference in heart rate between group A, group B and group C(P>0.05). In HE staining,the lung interstitium of the rats in group B and C was significantly widened, with hyperemia, edema and inflammatory cell infiltration,while that of group A was not observed. In AMP staining, the lung tubules of group B and C showed blue amorphous material and pink keratinized squamous epithelium, while those of group A did not. In CK16 staining, yellow particles and squamous epithelium could be seen in the lung tubules of rats in group B and C, but not in group A. After 1 hour of experiment, the PLA2 and PAF content in group B and C was significantly higher than that in group A(P<0.05), and the elevation was greater in group C. PLA2 and PAF were detected in both the amniotic fluid and the amniotic fluid meconium mixture of pregnant rats, and both were high in the amniotic fluid meconium mixture. There was no correlation between PLA2 and PAF concentrations in the blood taken 1 hour before the experiment(P=0.762,R=0.012), while there was a positive correlation between PLA2 and PAF concentrations in the blood taken 1 hour after the experiment(P=0.002, R=0.437). Conclusion: The results of HE and APK combined with CK16 staining showed that the model of amniotic fluid embolization was successfully made. Both PLA2 and PAF were present in the amniotic fluid and meconium of the rats, and the levels of PLA2 and PAF in the blood taken 1 hour after the experiment were significantly higher in group B combination C than in group A. This suggests that amniotic fluid and meconium contain stimulants that increase PLA2 and PAF levels.