Time dependence of radioprotective effects of A. flavus conidia.

No essential difference in radioprotection results when conidia of A. flavus are applied to mice within a time lapse of a few minutes up to 48 hours prior to irradiation. When applied 72 hr before irradiation, they fail to affect mouse resistance. Application of conidia provide no protection to mice irradiated for 18-20 hr at the dose rate of 1 R/min; similarly ineffective are the chemoprotectors cistafos and mexamine. A combined administration of conidia and the two protective substances increases survival in mice and prolongs the mean survival period.