Cadmium fluxes were studied under low temperature in order to assess the site of action of Cd2+ in taenia coli. Following a treatment with 0.5 mM Cd2+ for 30 min at 37 degrees C, the responses to high-K+ were not reversed after washing with medium containing 0.5 mM disodium edetate (EDTA). However, at 30 min preincubation with 0.5 mM Cd2+ at 4 degrees C, the responses markedly returned by the washing. The cadmium uptake was much slower at 4 degrees C. The cadmium in muscle preincubated at 4 degrees C was markedly eliminated by EDTA. Thus, the increase in the size of the fraction of total cadmium not eliminated by EDTA was temperature dependent. These data suggest the possibility that the total cadmium not eliminated by EDTA in taenia coli may be accumulated in the intracellular compartment where EDTA cannot reach.