Abstract
Summary: The developmental pattern of choline kinase and ethanolamine kinase activity (the first enzymes of the choline incorporation and phosphatidylethanolamine methylation pathways for phosphatidylcholine synthesis) was studied in normal chick lungs, between 8 and 21 days of incubation and after hatching, and in the lungs of hypophysectomized chick embryos from 10–20 days of incubation. The 10,000 × g supernatant of lung homogenate was incubated with [14C]-choline or [14C]-ethanolamine. [14C]-phosphorylcholine or [14C]-phosphorylethanolamine was separated by paper chromatography and quantitated. Enzyme activity was expressed as nanomoles [14C]-phosphorylcholine or [14C)-phosphorylethanolamine produced/mg protein/min. Choline kinase activity decreased between days 8 (13.0), 10 (10.4) and 12 (4.0). It then increased on days 14 (6.4) and 19 (5.1). In hypophysectomized animals, choline kinase activity dropped from 10.0 on day 10 to 5.9 on day 14, increased to 8.6 on day 16, and then decreased on day 19 to 6.7. Choline kinase activity was significantly higher in the lungs of hypophysectomized embryos on days 16, 17, 18, and 20 of incubation. In normal embryos, ethanolamine kinase activity decreased from 1.8 on day 12 to 0.8 by day 14 and again from 1.2 on day 19 to 0.6 by day 20. In the hypophysectomized embryo, ethanolamine kinase activity decreased from 3.2 on day 10 to 1.3 on day 14 and from 1.6 on day 18 to 0.8 on day 19. Ethanolamine kinase activity was significantly higher hi the lungs of hypophysectomized animals on days 10, 16, 17, and 18. Choline kinase activity was significantly higher than ethanolamine kinase activity in the normal chick lung on all days of incubation and also after hatching, but was not higher in the adult lung. In the hypophysectomized embryo, choline kinase activity was higher on days 14–20. These data suggest that activity of both enzymes is, at least partially, under endocrine control.
Speculation: Inasmuch as many of the biochemical and morphologic properties of the developing chick lung are similar to those of the mammal, we postulate that at least some of the regulatory mechanisms for lung maturation are also similar. Because the avian embryo is isolated from maternal influences and can be readily hypophysectomized, it promises to be an extremely useful model system in which to study endocrine influences on lung development.
Similar content being viewed by others
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Compton, S., Goeringer, G. Lung Development in the Chick Embryo II. Choline and Ethanolamine Kinase Activity in the Developing Lungs of Normal and Hypophysectomized Chick Embryos. Pediatr Res 16, 561–565 (1982). https://doi.org/10.1203/00006450-198207000-00014
Issue Date:
DOI: https://doi.org/10.1203/00006450-198207000-00014