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 degranula tion 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.
MATERIALS AND METHODSPreparation of chopped skin tissue The skin used was obtained from dog, cat, rabbit, guinea pig, rat, mouse and man. The human skin was procured from the sides of midventral line at surgical operation. Dog and cat were anesthetized with nembutal, rabbit, guinea pig, rat and mouse struck on the head and bled to death. Shaved skin was cut out at the midventral region . After remov ing the subcutaneous fat tissue the skin was chopped into pieces of about 0 .5 mm x 3 mm with razor blade in a cold room . These pieces were rinsed in Krebs-Ringer or in Tyrode solution for a few minutes, then gross moisture was removed with a filter paper and these were divided into 200 mg mass each.With the lung from guinea pig and rat, small pieces of about 1 mm x 1 mm x 3 mm were prepared and treated in a similar fashion as with skin.In vitro histamine release from the chopped skin For this experiment Warburg's flasks were employed . In the main chamber of the flask 1.8 ml Krebs-Ringer solution [NaC1 128 mm , KC1 5.1 mm, CaCl2.2H2O 2.8 mm, MgSO4. 7H2O 1.3 mm, and phosphate buffer pH 7 .4 (Na2HPO4.12H20 100 mm and HC1 20 mm) 10% v/vJ or Tyrode solution not containing glucose (NaCl 137 mm, KC1 2.7 mm, CaCl2.2H2O 1.8 mm, MgC12.6H20 1.1 mm, NaH2PO4.2H2O 0....