Influence of oxygen tension and cortisol environment upon growth and cortisone conversion to cortisol by cultured human fetal lung fibroblasts.

Growth and conversion of cortisone to cortisol by human fetal lung fibroblasts in monolayer cell culture have been found to be sensitive to steady-state oxygen concentrations or to acute oxidant stresses. Oxygen-dependent differences are significantly modified by pre-incubation with cortisol. We speculate that cortisol may have an oxygen-protective role, and that the induction of increased conversion of cortisone to cortisol with an increase in oxygen tension, such at that observed at delivery, may be of significance in the prematurely born infant with the respiratory distress syndrome.