ABSTRACT
The lung has had a long-standing and highly significant involvement with the eicosanoids. Early work 1,2 showed that homogenates of lung would synthesize prostaglandins (PGs) from exogenous arachidonic acid (AA), and synthesis of PGs from endogenous AA in lung was demonstrated soon after. 3 It is now generally accepted that synthesis of eicosanoids from endogenous precursor fatty acids depends crucially upon the amount of those substrates present in the unesterified form. Because eicosanoids (or any other biologically active material) formed or released into pulmonary blood can be distributed throughout the systemic arterial circulation, the synthesis of eicosanoids in lung can have systemic effects. Thus, the supply of eicosanoid precursors in lung is important not only in the lung itself but has quasiendocrine significance. In spite of these exciting possibilities, the uptake, distribution, and release of eicosanoid precursors in lung has attracted relatively little attention when compared with similar work carried out with kidney or platelets (see previous chapter written by Holmsen).
