ABSTRACT
The volume and composition of airway surface liquids, "secretions," are controlled by the aggregate ion transport activities of pulmonary epithelia. This chapter explores the role that adenosine triphosphate (ATP), perhaps released in combination with other neuropeptides from afferent nerves located within epithelial lateral intracellular spaces and possibly other sources, may play in this function. It describes the investigation of various epithelial receptor-effector interactions and discusses the consequences for normal mucosal function and potential therapeutic implications. The chapter characterizes the effects of exogenously added extracellular ATP on ion transport activities of human airway epithelia. Primary cultures of human nasal epithelia were studied in Ussing chambers under basal and Cl- secreting modes. The consequence of accelerating Na+ and Cl- absorption from the airway surface liquid compartment is to reduce the quantity of liquid on airway surfaces, concentrate mucins on airway surfaces, and slow mucociliary clearance.
