Antagonists of mouse paw oedema induced by Habu snake (Trimeresurus flavoviridis) venom. Inhibitions by various antagonists administered alone or in combinations.

When injected into the sole of the hind paw of mice, Habu snake (Trimeresurus flavoviridis) venom produced a prolonged oedema (72 hours). When administered alone, most of the studied drugs (mepyramine, methysergide, cyproheptadine, indomethacin, aspirin, dexamethasone and aprotinin) inhibited this oedema only partially and transiently (less than 7 hours). Some drugs however (EDTA, Biogel P4, zymosan and celluloses) were able to abolish it progressively. Combinations of some of these drugs resulted in various synergisms; in particular important and prolonged inhibitions were observed with aprotinin-dexamethasone, one of these drugs and EDTA, and especially EDTA-zymosan, which abolished totally the oedema from 2 hours after the injection of the venom to its end (72 hours). Antagonisms between components of combinations were also observed. The mechanisms of these synergisms and antagonisms are discussed. In particular, it is suggested that the blockade of the two pathways "classical" and "alternative", of the complement by EDTA and zymosan respectively might account for their important and early synergism. Antagonisms also helped in indicating some mechanisms of action.