Search for Carrier-Mediated Transport Systems in the Rat Colon.

Kinetic Characterization of Carrier-Mediated Transport Systems for D-Glucose and Taurocholate in the Everted Sacs of the Rat Colon

“…However, the D-glucose carrier in the colon seemed to be an isoform of SGLTs (sodium-dependent glucose transporters) which include SGLT1 that has been suggested to be responsible for D-glucose transport in the small intestine. This was because we also found that D-glucose uptake in the colon was Na ϩ -dependent 3) and completely inhibited by phlorizin (1 mM), a specific inhibitor of SGLTs (data not shown). Since the mRNA of SGLT1 is reportedly present in the rat colon at a trace level (far lower than that in the small intestine), 4) it is possible that the trace level of SGLT1 might be functionally modulated in a different manner in the colon compared with that in the small intestine.…”

“…Values represent computer-fitted parameters: J max , maximum uptake rate; K m , Michaelis constant; a) data from Yuasa et al 6) ; b) Tomei et al 2) cholate transport in the colon was also found to be Na ϩ -dependent in our preceding study, 3) the trace level of ASBT might be functionally modulated in the colon in a different manner to that in the small intestine, or an unidentified ASBT isoform or some other class of carrier might be responsible for taurocholate transport in the colon, like the above speculation about the D-glucose carrier.…”

A Comparative Pharmacology Study Between the Intracolonic and Oral Routes of 5-FU Administration in a Colon Cancer-Bearing Yoshida Sarcoma Rat Model

“…Therefore, this approach allows a reduction in gastrointestinal disorders. Unlike the small intestine, the absorption of 5-FU from the colon does not depend on active transport (11,12), thus inhibiting the excessive absorption of 5-FU into the systemic circulation and reducing myelosuppression. Moreover, a devise to make 5-FU be absorbed from colon cancer tissue and from the vicinity thereof maintains high concentrations of 5-FU in colon cancer tissue for a long time and permits the effective supply of the drug into the portal vein and mesenteric lymph nodes that are considered to constitute the pathway for metastasis.…”