Neutrophil LTA4 hydrolases and leukotriene B4 receptors: effects of leukotriene epoxides and their enzymatic products.

A selection of inhibitors of rat and human neutrophil LTA4 hydrolases have been studied in vitro using partially purified enzymes. 5(S)trans 5,6 oxido-7,9-trans-11-cis-eicosatrienoic acid (LTA3) and 5(S)trans 5,6 oxido, 7,9-trans, 11,14,17-cis-eicosapentaenoic acid (LTA5) have been shown to inhibit neutrophil LTA4 hydrolases in a time-dependent manner. The products of hydrolysis of LTA3, LTA4 and LTA5 by human and rat neutrophil LTA4 hydrolase have been shown to displace [3H] LTB4 binding to human and rat neutrophil membranes. The order of displacement of [3H] LTB4 is LTB4 = LTB3 greater than LTB5 and this correlated well with their biological potencies for enhancement of neutrophil aggregation and chemokinesis.