Blood flow responses to small bowel resection.

The objective of this study was to determine whether the gastrointestinal blood flow response to small bowel resection is related to the compensatory hyperplasia resulting from resection. In one group of rats, a laparotomy was performed and 80% of the small bowel resected, reanastomosing proximal jejunum with distal ileum. In the second group (controls), a transection followed by reanastomosis was performed either in the jejunum or ileum. One, two, three, or five days later, the animals were anesthetized, and blood flows to the stomach, jejunum, ileum, cecum, colon, and pancreas were measured using the radioactive microsphere technique. Samples of these tissues were obtained for determination of thymidine incorporation and DNA content. Growth, as evidenced by increases in tissue weight, DNA content, and rate of DNA synthesis, occurred in all tissues. Blood flow was elevated in the pancreas and in bowel segments (ileum and cecum) distal to the site of resection. Gastric, jejunal and colonic blood flows were not affected by bowel resection, in spite of similar trophic changes. Paired-value analyses did not reveal any correlation between blood flow and rate of DNA synthesis. The results of these studies suggest that humoral, rather than metabolic, factors are responsible for the gastrointestinal and pancreatic hyperemia that occurs after small bowel resection.