The consequences of ischaemia after mechanical obstruction of the dog ileum.

A mechanical obstruction was produced in the dog ileum, and four days later, loop of intestine above and below the occlusion were subjected to one hour's ischaemia. This led to widespread morphological and functional damage of the epithelium, indistinguishable from the response of the normal intestine. The recovery of the mucosa of both loops after the ischaemia followed exactly the same pattern as when there was no occlusion superimposed: The transport capacity for phenylalanine in vitro was entirely restored, whereas that of beta-methyl-glucoside, together with oxygen consumption and lactate production, remained depressed; morphometric examination revealed that the recuperating mucosa had smaller villi, shorter crypts and smaller epithelial cells than the contiguous untouched tissue. These results suggest that the regenerative potential of the crypts could not be obliterated by one hour's ischaemia, either in the presence of a noxious obstruction fluid above the occlusion, or in the atrophic mucosa below it.