DEVELOPMENT OF PULMONARY LIPOPHILIC ANTIOXIDANTS AND PEROXIDIZABLE LIPIDS DURING LUNG MATURATION

The objective of this article is to test whether the concentration of potentially oxidizable lipids (polyunsaturated fatty acids [PUFA], tot al and free cholesterol) and lipophilic antioxidants (plasmalogens, vi tamin E) in the fetal lung correlate with lung maturation (P/S ratio). In amniotic fluid palmitic/stearic acid (P/S) ratio, concentrations o f PUFA, total and free cholesterol, vitamin E, and plasmalogens were m easured. Ratio of PUFA to stearic acid (PUFA/S ratio) was determined i n lung effluent of 15 preterm infants with IRDS and compared with valu es from 15 term healthy infants. Concentrations of plasmalogens, PUFA, total and free cholesterol increase significantly with increasing P/S ratio. No correlation of vitamin E with lung maturation has been foun d. The PUFA/S ratio is significantly lower in lung effluent of preterm (0.79 +/- 0.27) when compared with term infants (2.02 +/- 0.38). Our results suggest that the higher susceptibility of preterm infants for oxidative lung injury is not caused by an unfavorable ratio of oxidiza ble lipids to lipophilic antioxidants in surfactant, but rather by a l ower amount of PUFA containing surfactant lipids. Our results are in a ccordance with data from Sosenko et al. who have shown that high level s of PUFA in the rat lung have a protective effect against oxygen-indu ced lung damage.