Abstract
A basic question in understanding the mechanism of sex differences of fetal surfactant production is whether surfactant synthesis is involved. We studied whether the female fetus synthesizes more surfactant phosphatidylcholine (PC) and saturated phosphatidylcholine (SPC) than the male at the time when the fetal lung is responsive to glucocorticoid. Organ cultures were made of sex specific fetal rabbit lungs of 21 days gestation in Waymouths media +10% charcoal- stripped fetal calf serum±1O−8 R dihydrotestosterone (DHT). After 5 days 14C-glycerol±10−8 M dexamethasone (dex) was added. After 24 hours lamellar bodies (LB) were isolated by centrifugation in discontinuous, sucrose density gradients. Average LB recovery was 33-36%. 14C-PC and C-SPC were quantitated in the LBs. 14C-SPC was significantly higher in female lungs with or without DHT and was enhanced by dex (No dex: females 198±71, males 130+55; CPM/mg prot, meaniSD, p<.005. Dex: females 389±65, males 160±17; p<.02). 14C-PC with DHT or dex had similar results. Dex stimulated females but not males. These data indicate that surfactant sex differences result at least in part from differences in synthesis. The cellular mechanisms causing the sex difference appear to be already operative by 21 days gestation in the rabbit and are not further affected by androgen or glucocorticoid. This is important for ultimate elucidation of the mechanism of sex differences in normal fetal cellular development.
Log in or create a free account to read this content
Gain free access to this article, as well as selected content from this journal and more on nature.com
or
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Nielsen, H., Gebhardt, C. & Warshaw, J. 294 SEX DIFFERENCES IN SURFACTANT SYNTHESIS IN FETAL RABBIT LUNG ORGAN CULTURE. Pediatr Res 19, 159 (1985). https://doi.org/10.1203/00006450-198504000-00324
Issue date:
DOI: https://doi.org/10.1203/00006450-198504000-00324
