Increased resistance against cadmium toxicity by means of pretreatment with low cadmium/zinc concentrations in Bufo arenarum embryos.

A significantly increased resistance against cadmium toxicity in Bufo arenarum embryos was obtained by means of pretreatments with low cadmium/zinc concentrations, allowing embryos to tolerate lethal cadmium concentrations. Slight variations in the pretreatment schedule could result in significant differences within this acclimation phenomenon. The probable mechanisms of action of this protective effect are discussed.