The functional response of the dog ileum to one hour's ischaemia.

1. The function and structure of dog ileal mucosa was examined immediately after arterial ischaemia for 1 h and 1, 3 or 7 days after the trauma. 2. Immediately after the ischaemia, there was a net movement of water and ions into a luminal perfusate in vivo. One day later, there was no net movement of water and electrolytes but net absorption returned on the third day. 3. Active transport of phenylalanine or beta-methylglucoside by mucosal strips in vitro was abolished immediately after the trauma but was largely restored 1 day later. There was a close correlation between glucose absorption in vivo and beta-methylglucoside uptake in vitro. 4. Morphological study revealed pronounced desquamation of enterocytes immediately after the trauma. The regenerating mucosa had shorter villi and crypts, and lower enzyme activities assessed histochemically 1 day later. Most parameters had returned to normal by the third post-operative day.