[Induction of mouse peritoneal cytotoxic factor by OK-432. (3). Comparison between LPS and OK-432 as eliciting...

By injection of OK-432, a cytotoxic factor was induced in peritoneal fluids of mice which had been primed with OK-432. Two-step stimulation (priming and eliciting) was always necessary to induce the cytotoxic factor. OK-432-primed mice did not produce soluble cytotoxic factor spontaneously and no cytotoxic activity was detected in the mice treated by a single injection of OK-432 as an eliciting agent. High doses of OK-432 were required to prime mice for the production of cytotoxic factor, whereas a small amount was enough to elicit it. Pathological studies were also conducted in order to clarify whether the mice were safe under the conditions in which PCF had been induced. Moderate liver damage was observed in the mice injected with OK-432 and LPS, whereas no histological change in the liver or spleen was observed in the mice treated with OK-432 alone. These results suggest that OK-432 is a good candidate as an inducer of cytotoxic factor in the peritoneal cavity.