Effects of combination of immunomodulators and an adrenochrome derivative on survival of irradiated mice

The combined effects of the immunomodulators lithium or OK432 (polysaccharide prep. from Streptococcus haemolyticus) and adrenochrome monoaminoguanidine methanesulfonate (AMM), an agent found to activate granulocyte-macrophage colony stimulating activity, on the survival of irradiated ddY mice is described. ddY mice at 4-5 weeks old were whole body irradiated with X-rays at 8.5 Gy. Sole injection and combined injection of AMM and/or one of the immunomodulators were performed before or after irradiation. Then, survival was monitored daily for 30 days after irradiation. Lithium at 60 mg/kg had no radioprotective effect; rather it accelerated radiation induced death. Sole treatment with AMM (100 mg/kg) had no effect on survival of irradiated mice. However, combination of both drugs caused a slight radioprotection. OK432 (25 KE/kg), which activates a variety of cellular effector cells had radioprotective effect. When combined with AMM, however, it totally lost radioprotective effect. Lithium chloride cannot be used as a radioprotector because of its adverse effect. Combination with AMM showed slight radioprotection, but the extent thereof may not be clinically useful. OK432 was proved to be a potent radioprotector. However, combination with AMM should be avoided, since the radioprotection was totally eliminated. 17 refs., 3 figs