Cadmium-manganese interaction in the rat's duodenum.

Five-week-old female albino rats were given different doses of cadmium chloride (0.002-5.0 mg) by gastric intubation daily for 3 or 7 days. Manganese-54 was used as marker to assess manganese transfer through and retention in the duodenal wall by the "everted gut sac" method. No significant differences were found in these parameters between rats receiving no cadmium and those receiving 0.002 mg cadmium daily, irrespective of the period of treatment. A daily dose of 0.02 mg cadmium decreased manganese transfer significantly but only in animals treated with cadmium for 3 days. Daily doses of 0.2 mg cadmium or higher always decreased manganese transfer and intestinal uptake significantly--an effect which was independent of whether the rats were killed on the 4th or on the 8th days of the experiment. On the whole, the effect of cadmium was much more intense in the 3-day-than in the 7-day-treated animals and it was more pronounced on manganese transfer than on its intestinal uptake.