Abstract
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/μg protein [p < 0.0001] and 0.20 ± 0.05 versus 0.70 ± 0.19 μmol 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 than 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.
Original language | English (US) |
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Pages (from-to) | 1672-1677 |
Number of pages | 6 |
Journal | American journal of respiratory and critical care medicine |
Volume | 150 |
Issue number | 6 I |
DOIs | |
State | Published - Dec 1994 |
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Critical Care and Intensive Care Medicine