Evidence for a similar receptor site for binding of [³H]leukotriene E₄ and [³H]leukotriene D₄ to the guinea-pig crude lung membrane

To determine whether the action of leukotriene E₄ is mediated by its cross reaction with leukotriene D₄ receptor sites, we compared [³H]leukotriene E₄ and [³H]leukotriene D₄ binding activities in selected tissues as well as their competition results in the guinea-pig crude lung membrane. We demonstrated good correlation of [³H]leukotriene E₄ and [³H]leukotriene D₄ binding activities among the tissues studied. A significant correlation was demonstrated between the ability of leukotriene C₄, D₄ and E₄, FPL-55712 and arachidonic acid to inhibit lung [³H]leukotriene E₄ and [³H]leukotriene D₄ binding. These correlations suggest that leukotriene E₄ binds to a site which is similar to or close to the leukotrine D₄ receptor.