Lipid mediator quantification in isolated human and guinea pig airways - an expanded approach for respiratory research

The clinical importance of prostaglandins and leukotrienes in asthma is well recognized; however, the biochemical role of other lipid mediators (often termed oxylipins) in the regulation of airway tone and inflammation remains unclear. We therefore developed a workflow to investigate oxylipin physiology and pharmacology in two in vitro models, the intact human bronchus and the guinea pig trachea. Airways were isolated and smooth muscle contraction was measured in an organ bath following stimulation with either anti-IgE or ovalbumin. The associated release of oxylipins over time into the organ bath was quantified using three developed LC–MS/MS methods capable of collectively measuring 130 compounds. Oxylipin extraction recoveries were 71% on average, method accuracy was 90–98%, coefficient of variation was 4.3–9.4%, and matrix effects were on average 11%. At baseline, low levels of primarily prostaglandins and associated metabolites were observed in both tissue preparations. The mast cell-induced airway co...