Diisopropylfluorophosphate-evoked inhibition of anaphylactic histamine release from human skin: decrease of the inhibition by storing the skin specimens.

Antigen-induced histamine release from human skin slices passively sensitized with reaginic serum in vitro was inhibited by DFP, suggesting involvement of serine esterase activation in the reaction. The magnitude of DFP-evoked inhibition of the histamine release was not the same in each skin sample and no correlationship was observed between the magnitude of the DFP-evoked inhibition of the histamine release and that of the histamine release in the absence of DFP. The magnitude of the histamine release in the presence of DFP was smaller in the fresh skin than in the stored skin, whereas that in the absence of DFP was greater in the former than in the latter. The inhibitory effect of cytochalasin B on the anaphylactic histamine release from fresh and stored human skin was the reverse of the effect of DFP. The present results indicate that the magnitude of anaphylactic histamine release from human skin does not match that of the activation of serine esterase in the reaction, suggesting the possibility that there may be some factor modulating the activation of serine esterase in the anaphylactic reaction in human skin.