ABSTRACT
The cysteinyl-leukotrienes (LTC4, LTD4, and LTE4) are peptido-lipid conjugates formed following lipoxygenation of arachidonic acid. These eicosanoids have received much attention for their potential role in inflammatory diseases, especially asthma (for review, see Refs. 1-7). Recently, the development of potent leukotriene synthesis and receptor antagonists has further linked leukotrienes with asthma. This has generated an interest in the measurement of leukotrienes in a variety of biological fluids in humans, as a means both to verify the presence of the leukotrienes and to monitor the effectiveness of inhibitors. The aim of this chapter is to discuss important considerations and potential problems of measuring leukotrienes in human fluids. The focus will be primarily on the peptidoleukotrienes because of their tight linkage with asthma and other inflammatory disease, but LTB4 and other lipoxygenase products have been measured in fluids and many of the general considerations apply to these metabolites as well. This chapter will briefly review many of the studies that have measured peptidoleukotrienes in fluids. Since urine has been the major fluid utilized for leukotriene measurement, greater emphasis will be placed on reviewing studies utilizing this fluid. Studies examining urine LTE4 have been subdivided into those concerned with basal levels, levels in asthmatics stimulated spontaneously or clinically, levels following pharmacological manipulation, and levels measured in inflammatory diseases other than asthma.
