This lining fluid also contains a variety of antioxidants. While the lung is said to contain approximately 40 cell types, it is well documented that the type II alveolar epithelial cell is responsible for surfactant synthesis and secretion as well as antioxidant release. Without surfactant present, more energy is required to overcome the surface tension and reopen the alveoli.
Insufficient surfactant is frequently a clinical problem in infants born prior to term.
Oxygen therapy is the life-saving strategy used but this therapy increases the oxidant burden. This increase in oxidant burden results in permanent lung injury. Our studies have focused on the antioxidants present in the epithelial lining fluid of term infants but diminished in preterm infants. Other studies have focused on developing sensitive methods for determination of reduced and oxidized antioxidants in samples from different pathological states associated with pulmonary oxidative injury. Nitric oxide is a gaseous molecule that is an important modulator of signal transduction.