Moya F R, Montes H F, Thomas V L, Mouzinho A M, Smith J F, Rosenfeld C R
Department of Pediatrics, University of Texas Southwestern Medical Center at Dallas 75235.
Am J Respir Crit Care Med. 1994 Dec;150(6 Pt 1):1672-7. doi: 10.1164/ajrccm.150.6.7952631.
We measured surfactant protein A (SP-A) by ELISA using a rabbit antihuman SP-A polyclonal antibody and saturated phosphatidylcholine (SPC) by thin-layer chromatography in sequential tracheal fluid samples obtained from 16 preterm neonates without lung disease and 37 with respiratory distress syndrome (RDS). SP-A and SPC were lower in neonates with RDS than in control infants (1.0 +/- 0.1 versus 8.9 +/- 2.2 ng SP-A/microgram protein [p < 0.0001] and 0.20 +/- 0.05 versus 0.70 +/- 0.19 mumol SPC/mg protein [p < 0.01], respectively). Initial SP-A concentrations correlated inversely with severity of RDS (r = 0.45, p < 0.01) but did not correlate with initial SPC levels. Significant increases in SP-A were detectable within 12 to 24 h after birth in neonates with RDS. Further increases occurred subsequently and were similar for neonates treated with either a synthetic (Exosurf) or a modified natural (Survanta) surfactant. Using two-dimensional gel electrophoresis, SP-A in tracheal fluid obtained during the early and recovery phases of RDS exhibited lesser degrees of posttranslational modification than SP-A forms from control neonates. Administration of Exosurf or Survanta resulted in comparable increases in SPC in tracheal fluid. Preterm neonates with RDS seem to have an immature SP-A metabolism that persists for several days after birth. The type of surfactant used does not modify the recovery of SP-A or SPC in tracheal fluid from infants with RDS.
我们采用酶联免疫吸附测定法（ELISA），使用兔抗人表面活性蛋白A（SP-A）多克隆抗体来检测表面活性蛋白A，并通过薄层色谱法检测了16例无肺部疾病的早产新生儿和37例患有呼吸窘迫综合征（RDS）的早产新生儿连续气管液样本中的饱和磷脂酰胆碱（SPC）。患有RDS的新生儿的SP-A和SPC水平低于对照婴儿（分别为1.0±0.1 ng SP-A/μg蛋白与8.9±2.2 ng SP-A/μg蛋白 [p<0.0001]，以及0.20±0.05 μmol SPC/mg蛋白与0.70±0.19 μmol SPC/mg蛋白 [p<0.01]）。初始SP-A浓度与RDS严重程度呈负相关（r = 0.45，p<0.01），但与初始SPC水平无关。患有RDS的新生儿在出生后12至24小时内可检测到SP-A显著增加。随后进一步增加，接受合成表面活性剂（Exosurf）或改良天然表面活性剂（Survanta）治疗的新生儿情况相似。使用二维凝胶电泳法，在RDS早期和恢复阶段获得的气管液中的SP-A，与对照新生儿的SP-A形式相比，翻译后修饰程度较低。给予Exosurf或Survanta导致气管液中SPC有相当程度的增加。患有RDS的早产新生儿似乎具有不成熟的SP-A代谢，这种情况在出生后会持续数天。所使用的表面活性剂类型不会改变患有RDS的婴儿气管液中SP-A或SPC的恢复情况。
