Lead and active calcium transfer through the intestinal wall in rats.

5-week-old female albino rats were given daily doses of lead as acetate ranging from 2 mug to 20 mg by gastric intubation for 1 week. The animals were sacrificed on the 8th day of the experiment. Calcium-45 and (in some experiments) strontium-85 were used as markers to assess their active transfer through the duodenal wall by the everted gut sac method of Wilson and Wiseman. The active transport ratios of both calcium and strontium, as well as their retention in the intestinal wall were unaffected by the lead treatment of the animals. As the total calcium transport was found earlier to be diminished by lead treatment it is concluded that lead influences the passive transport, possibly by fixation to the intestinal wall.