Factors affecting lecithin synthesis by fetal lung cells in culture.

Abstract

Extract: In monolayer cultures prepared from fetal rabbit lungs of 28 days gestation, cortisol, dexamethasone, and L-thyroxine enhanced choline incorporation into lecithin, but had no effect on the methylation pathway. Heroin did not affect the incorporation of either precursor. Hyperoxia and metabolic acidosis decreased lecithin biosynthesis from both precursors. Over 90% of the lecithin was recovered from the cells after 6 hr of incubation. Release of newly synthesized lecithin was low until 10–12 hr, then rapidly increased, reaching 40–50% after 24 hr. The proportion of the lecithin which was disaturated was not different between the intracellular and extracellular compartments. None of the experimental variables altered the degree of saturation. Short term mixed cell cultures provide a useful approach to the study of mammalian lung development. Speculation: The study of mixed populations of fetal lung cells under conditions of short term monolayer culture provides a simple means of studying the influence of various agents and culture conditions on the biosynthesis of disaturated lecithin, a biochemical index of pulmonary maturation. This approach allows the study of viable, functioning cells under conditions which can be precisely controlled and which can be manipulated in a variety of ways. Inductive effects, which may require a lag time of hours or days, can be demonstrated readily.