The release of histamine in anaphylaxis has been shown to be blocked by anoxia and various enzyme inhibitors considered to interfere with metabolic energy-yielding processes (1-5). Several recent works (5-8) have indicated that glycolysis constitutes one of the sources of energy, at least under anoxic conditions, from the fact that presence of glucose prevents blocking actions both of anoxia and of inhibitors which interfere the oxidative metabolim. In our previous paper (3) reporting the enhancing effect of succinate on aerobic histamine release by antigen from sensitized guinea-pig lung tissue, a slight but similar effect of glucose was noted. This glucose effect was confirmed by Diamant (9, 10) not only in guinea-pig but in rat lung, while in the latter species succinate had no effect. Despite these discrepancies, some of energy required for the processes seems, even under aerobic conditions, to be delivered via glycolysis in both species. Therefore, it is interesting to investigate the influences on the glucose effect of substances which may interfere the metabolism of glucose or its transport across the cell membrane, under aerobic and anaerobic conditions. 2-Deoxyglucose, phlorizin, insulin and ouabain were chosen for the present study as such substances. This paper also present observations on the comparative effects of succinate and glucose on the anaphylactic release of histamine, along with the oxygen uptake, from the minced lung tissues of guinea pig and rat.