COEXISTENCE OF ENERGY DEPENDENT AND NONDEPENDENT PROCESSES IN HISTAMINE RELEASE MECHANISM OF COMPOUND 48/80 AND SINOMENINE: EXPERIMENTS ON CHOPPED SKIN FROM VARIOUS ANIMAL SPECIES

Compound 48/80 releases histamine from mast cells with accompanying morphological changes characterized by degranulation. These actions are considered to be dependent on energy harnessing processes in mast cells, because the histamine release or degranulation of mast cells was inhibited by anoxia or inhibitors of oxidative phosphorylation when the medium was devoid of glucose, and glucose blocked these inhibitions (1-6). Since, however, evidences for the energy dependent processes involved in the histamine release action of 48/80 have been obtained from the experiments on only limited animal species, such as rat (2-9), cat (1) or hamster (10), despite the fact that not all the species are equally susceptible to the action of 48/80, further investigations on this point are to be extended over other animal species. Mongar and Schild (11) reported that the in vitro histamine release by 48/80 from guinea-pig lung tissue was not inhibited by anoxia and metabolic inhibitors while the histamine release induced by antigen was clearly inhibited. Sinomenine releases histamine from rat mast cells in a very similar fashion to 48/80 (12). In vitro histamine release from guinea-pig lung by this compound was also not inhibited by anoxia like the release by 48/80 (13). In the present study, in vitro histamine release by compound 48/80 as well as sinomenine from chopped skin of different animal species including guinea pig was compared under aerobic and anaerobic conditions, and it was found that the release of histamine in all these species consisted of two different types of release: the one which is dependent on energy-yielding processes and the other which does not depend on the processes. Concerning the mechanism of the latter type of histamine release further studies were made.