Intestinal Obstruction. Iv. the Mechanism of Absorption from the Mucosa of Closed Duodenal Loops.*

In an earlier paper ( I ) we have shown that the poison of closed duodenal loops, which is responsible for the intoxication in that condition, is not absorbed by the mucosa of the unobstructed gut. We also tested the absorption of the same toxic fluid when introduced into recently isolated duodenal loops, and found that the dogs whose closed loops contain a double lethal dose of duodenal loop poison show no more intoxication than control dogs with empty closed loops, and die in about the same period, from which it is concluded that absorption from the lumen of the closed loop may be a secondary factor of intoxication and the important fraction is absorbed from the mucosa and not from the lumen of the loop. The observation of drained-loop dogs showing fatal intoxication confirms the conclusion that the greater part of the poison is absorbed from the mucosa itself, regardless of the amount of toxic material present in the lumen. Similar experiments made by Davis (2) in this laboratory show that a closed duodenal loop is just as toxic when left washed and empty at operation or distended with a lethal dose of duodenal loop fluid from another animal. Davis also showed that repeated washing out of the stomach and duodenum, after ligating the bile and pancreatic ducts and establishing a low duodenal fistula, yields a certain amount of the toxic substance, a fact which may be interpreted to mean that the substance is excreted normally by the duodenal mucosa; and yet such a statement may exceed the facts. It