Metabolic functions of the lung

In addition to their primary function in respiration, the lungs are important in the metabolism of many biologically important compounds. Because of the high pulmonary uptake of many vasoactive compounds, the lungs may acts as a chemical filter to protect the systemic circulation. The lungs also modulate systemic vascular tone through the de novo synthesis and activation of endogenous vasoactive compounds. Furthermore, the pulmonary circulation displays a high degree of selectivity in its handling of chemically very similar compounds. Xenobiotics are handled in a very specific way because of their physiochemical properties and may display important drug-drug interactions of special concern to the anesthesiologist. The lung emerges as a highly complex metabolic organ vital to the regulation and maintenance of homeostasis.