Abstract
Synchronous production of pulmonary surfactant by the alveolar type II cell is critical for neonatal survival. The timing of this event depends on the maturation of the fibroblast, which produces fibroblast pneumonooyte factor (FPF), a low molecular weight protein, in response to various hormones. Fibroblast maturation can be structurally and functionally accelerated (glucocorticoids) or delayed (androgens, insulin). The type II cell subsequently shows augmented or delayed surfactant production in association with the onset of FPF production by the fibroblast.,(A) The type II cell is able to respond to exogenous FPF in vitro as early as day 15 in the fetal rat (70% increase, p<0.001), 4 to 5 dare before the fibroblast can produce FPF. (B) Incorporation of 3H-choline into 3H-saturated phosphatidylcholine by type II cells exposed to FPF is increased 50-100% over control (p<0.01), but no increase is noted when conditioned medium from fibroblasts which are unable to produce FPF is mixed with FPF. These data suggest that (A) type II cells are competent to respond to FPF before fibroblasts can make it, and that (B) immature fibroblasts actively inhibit the response of type II cells to FPF. Such a highly labile cell-cell interaction, consisting of both a “brake” and an “accelerator”, in which the titer of biologically active FPF is the rate limiting factor, would explain the coordinated quantal increase observed in surfactant synthesis near term. Supported by NIH SCOR grant HL34616
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Torday, J. FIBROM ASPS REGULATE TYPE II CELL MATURATION VIA BOTH INHIBITION ADD STIMULATION OF THE FPF MECHANISM. Pediatr Res 21 (Suppl 4), 222 (1987). https://doi.org/10.1203/00006450-198704010-00338
Issue Date:
DOI: https://doi.org/10.1203/00006450-198704010-00338