Cellular proliferation of intestinal epithelia in the rat two months after partial resection of the ileum.

Sprague-Dawley rats subjected 2 months previously to partial resection (10 per cent) of the small intestine and their controls were injected with tritiated thymidine and sacrificed at 2 and 23 hours. Segments of the duodenum, jejunum, and ileum were autoradiographed, and the migration of the labelled cells during the period between 2 and 23 hours was measured with an eyepiece micrometer. The cells had migrated 35, 42, and 34 per cent of the total distance from the crypts to the tips of the villi in the control segments of duodenum, ileum, and jejunum respectively, and 43, 90, and 82 per cent, respectively, in similar segments from resected animals.