Abstract
The transport of 5-fluorouracil (5-FU) and its prodrugs across the duodenum, jejunum, ileum, colon, and rectum of the albino rabbits was examined using the modified Ussing Chamber. 5-FU penetrated the jejunum, most readily, followed by the duodenum, ileum, rectum, and colon in that order. This may be due to an active transport mechanism taking place in the small intestine whereas a simple diffusion process is responsible for the transport across the membranes in the large intestine. By the use of prodrugs, it is feasible to promote the transport of 5-FU across the colon and rectum. On the other hand, the prodrugs showed a decreased total transport of 5-FU across the small intestine, although the mechanism remains to be investigated. These results indicated that the transport of 5 -FU in the lower region of the gastrointestinal tract was improved by the prodrug approach.
