Histamine release by esterase inhibitors. The regulation of histamine release from human leukocytes of allergic and non-allergic individuals by the serine esterase inhibitors diisopropyl fluorophosphate and pinacolyl methylphosphorofluoridate.

The serine esterase inhibitor diisopropyl fluorophosphate (DFP) has been shown to inhibit IgE-dependent histamine release. Recently, it has been demonstrated that lower concentrations of DFP enhanced IgE-dependent histamine release and inhibited desensitization. This manuscript describes the ability of another esterase inhibitor, pinacolyl methylphosphorofluoridate (soman), to directly cause release of histamine from human leukocytes (basophils) by a process that is IgE-independent. This release process requires calcium and is also temperature-dependent but occurs over a longer period of time than IgE-dependent release. These data suggest that there is a serine esterase which controls histamine release, and inhibition of this esterase causes histamine release.