[Synthesized leukotoxin: its biological activity and establishment of radioimmunoassay].

Leukotoxin, 9: 10-epoxy-12-octadecenoic acid, was reported to exist in human burned skin and neutrophils, and to have toxic effects in experimental animals and antifungal effects against rice blast disease. Leukotoxin was regarded as a toxic and/or defensive substance in living beings. The author synthesized leukotoxin from linoleic acid with peracetic acid and purified practically by thin layer chromatography. The leukotoxin synthesized was injected into guinea pigs intravenously and caused a systemic convulsion of the animal body and cardiac arrest. The leukotoxin synthesized, on the other hand, was conjugated with bovine serum albumin (BSA) by means of the mixed anhydride technique and immunized in rabbits. After immunization of leukotoxin conjugated with BSA over 4 months, the author succeeded in producing anti-leukotoxin antiserum for the first time. According to a titration test of antiserum, sixty-folds diluted antiserum was found to bind approximately 50% of methylated leukotoxin labeled with carbon 14. And unlabeled leukotoxin was detected at least 5 ng in this radioimmunoassay by use of polyethylene glycol precipitation. This antiserum had a strong specificity to leukotoxin and no cross-reactivity to the other analogs tested. The role of leukotoxin in living creatures had not been clarified yet. Therefore both the leukotoxin synthesized by this simple procedure and the anti-leukotoxin antibodies would aid the study of the mechanism of its biological activities and its histochemical investigations.