Folate transport in ileal brush border-membrane vesicles following extensive resection of proximal and middle small intestine in the rat.
Uptake of folic acid (PteGlu) was examined in remnant ileum of rats after resection of 65% of the small intestine with the brush border-membrane vesicle technique. The results were compared to that of sham-operated rats. In both rat groups transport of PteGlu was linear for approximately 40 s of incubation and was similar in the presence of a Na+ and a K+ gradient (out greater than in). In resected rats transport of PteGlu was inhibited by the structural analogues 5-methyltetrahydrofolate (5-CH3H4PteGlu) and methotrexate (MTX), by sulfasalazine, and by 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) and was saturable as a function of concentration (apparent Kt = 18.3 microM). In the ileum of sham-operated rats, on the other hand, transport of PteGlu was not affected by 5-CH3H4PteGlu, MTX, sulfasalazine, or DIDS and was linear with concentration. These results suggest that the PteGlu transport system is induced in remnant ileum of the rat after extensive intestinal resection.
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005492:Folic Acid / Q000378:metabolism*; D007082:Ileum / Q000187:drug effects / Q000378:metabolism*; D007421:Intestine, Small / Q000502:physiology* / Q000601:surgery; D008297:Male; D008727:Methotrexate / Q000494:pharmacology; D008871:Microvilli / Q000187:drug effects / Q000378:metabolism; D011184:Postoperative Period; D051381:Rats; D011919:Rats, Inbred Strains; D012460:Sulfasalazine / Q000494:pharmacology; D013763:Tetrahydrofolates / Q000494:pharmacology
D013763:Tetrahydrofolates; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D012460:Sulfasalazine; D005492:Folic Acid; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; C005984:5-methyltetrahydrofolate; D008727:Methotrexate