HIGH GLUCOSE CAUSES DELAYED FETAL LUNG MATURATION AS MEASURED BY FLUORESCENCE ANISOTROPY

Fluorescence anisotropy has been used to estimate the microviscosity of the surfactant phospholipid bilayer and to predict fetal lung maturity in human amniotic fluid; its usefulness in in vitro systems has been recently demonstrated. To investigate the effect of high glucose on lung development, anisotropy measurements were performed on 20-day fetal rat lung explant homogenates and culture media after culture for 48 hours in medium containing final concentrations of 10, 50, and 100mM glucose. Anisotropy of lung tissue cultured in 100mM glucose was significantly increased when compared to those cultured in 10mM glucose (p <.01). After 48 hours, the media from samples grown in 100mM glucose had significantly higher anisotropy (.2210 ±.0031) than did media from explants grown in 50mM glucose (.2027 ±.0079; p <.05), or in 10mM glucose (.1886 ±.0046; p <.001). Relative fluorescence intensity of explants grown in 100mM glucose was 74.4 ± 5.7% of those grown in 10mM glucose (p <.01). Fluorescence intensity of media was also decreased by 15-30% under higher glucose concentrations (p <.05). These data suggest that surfactant synthesized and secreted under high glucose conditions, such as exist in the infant of the diabetic gestation, may have qualitative as well as quantitative changes. © 1993 Academic Press, Inc.