Fig. 6.

Brief summary of the study. a demonstrates the major surfactant proteins (SPs) and their functions. SPs are produced by alveolar type II cells in the form of lamellar bodies and later released into the alveolar lumen through exocytosis. CRD domain of SP-A and SP-D recognizes various pathogens like virus, bacteria, and fungi to facilitate microbial aggregation. This enhances opsonization and phagocytosis of microbes by macrophages. SP-A and SP-B also accelerate removal of apoptotic cells from alveolar environment. SP-B and SP-C are involved in maintenance of biophysical functions of lungs and inevitable for respiratory cycle. They can also impart anti-inflammatory function. b demonstrates that, inhalation of prallethrin can expose lung surfactant proteins to this insecticide. Prallethrin has potential to bind SPs through various interactions. Such interactions could disrupt several functions of alveolar SPs. Binding of prallethrin with SP-A and SP-D could impair recognition and opsonization of microbes in lungs. This might increase the risk of severe pathogenic infection/sepsis and inflammatory lung diseases. Binding of prallethrin with SP-B and SP-C could increase the surface tension at air/water interface in alveoli. This might fuel the onset of respiratory distress syndrome, forced breathing, risk of respiratory failure, and development of interstitial lung disease