The rabbit fetal lung as a glucocorticoid target tissue

Area of Science:

• Biochemistry
• Endocrinology
• Cell Biology

Background:

• Fetal lung maturation is crucial for respiratory adaptation after birth.
• Glucocorticoids are known to influence fetal development, including lung maturation.

Purpose of the Study:

• To investigate the effect of specific glucocorticoids and related steroids on lecithin synthesis in fetal rabbit lung cells.
• To explore the potential role of cortisone conversion to cortisol in mediating this effect.

Main Methods:

• Culturing fetal rabbit lung cells (28-day gestation).
• Incubating cells with cortisol, dexamethasone, and other steroids (e.g., 11-deoxycortisol, cortisone).
• Measuring [3-H] choline incorporation into lecithin as an indicator of synthesis.

Main Results:

• Cortisol and dexamethasone significantly increased lecithin synthesis.
• Inactive steroid analogs had no effect, but inhibited cortisol's effect when co-administered.
• Cortisone also enhanced lecithin synthesis, suggesting conversion to cortisol by lung cells.

Conclusions:

• Glucocorticoids promote lecithin synthesis in fetal lung cells, supporting their role in lung maturation.
• Fetal lung cells possess the capacity to convert cortisone to cortisol, which may be a significant physiological pathway.