Corpus ID: 21611254

Characteristics of the transport of pteroylglutamate and amethopterin in rat jejunum.

  title={Characteristics of the transport of pteroylglutamate and amethopterin in rat jejunum.},
  author={Williamson B. Strum},
  journal={The Journal of pharmacology and experimental therapeutics},
  volume={216 2},
  • W. Strum
  • Published 1981
  • Chemistry, Medicine
  • The Journal of pharmacology and experimental therapeutics
Intestinal transport of pteroylglutamate and amethopterin, a folate antagonist, was further characterized in everted sacs of rat jejunum. The system is composed of two distinguishable processes: active, pH-dependent, carrier-mediated transport and diffusion. The active process is specific for the pteroylglutamate molecule and requires sodium. When active transport is blocked completely by cyanide, iodoacetate, p-chloromercuriphenylsulfonate, the absence of sodium or high concentrations (50-100… Expand
21 Citations
Transport of pteroylglutamic acid into brush border membrane vesicles from rat small intestine is a partially carrier-mediated process
It could be concluded that uptake is mediated by a PteGlu−/OH−-antiporter at low substrate concentrations and occurs by non-ionic diffusion at higher concentrations or in the absence of a pH gradient. Expand
Inhibitory effect of unconjugated bile acids on the intestinal transport of 5-methyltetrahydrofolate in rat jejunum in vitro.
It is shown that intestinal transport and tissue uptake of 5-CH3H4PteGlu are inhibited by unconjugated bile acids in a dose-dependent fashion and the clinical and physiological implications are discussed. Expand
Inhibitory effect of bile salts on the enterohepatic circulation of methotrexate in the unanesthetized rat: Inhibition of methotrexate intestinal absorption
It is demonstrated that a variety of organic anions inhibit MTX intestinal absorption, including folic acid and 5-methyltetrahydrofolate and the organic anion rose bengal and sulfobormophthalein were also inhibitory to MTX absorption. Expand
Na+ and pH dependence of 5-methyltetrahydrofolic acid and methotrexate transport in freshly isolated hepatocytes.
  • D. Horne
  • Chemistry, Medicine
  • Biochimica et biophysica acta
  • 1990
The results suggest the possibility that 5-CH3-H4PteGlu may be cotransported along with H+ ions in hepatocytes, although they do not rule out a 'catalytic coupling' whereby protons interact with the carrier to stimulate substrate flux without concomitant H+ transport. Expand
Effect of human milk folate binding protein on folate intestinal transport.
The results show that human milk FBP decreases the rate of transport of 5- CH3H4PteGlu in the jejunum and suggest that FBP-bound 5-CH3H5-4PTEGlu may utilize the same transport system as free 5-Ch3H 4Pteglu. Expand
Cyclic adenosine-3',5'-monophosphate and folate transport in rat jejunum.
  • H. Said, W. Strum
  • Chemistry, Medicine
  • Biochemical and biophysical research communications
  • 1983
The intestinal transport of 5-methyltetrahydrofolate and pteroylmonoglutamate was examined in everted sacs of rat jejunum exposed to compounds which increase intracellular cyclic adenosine-3',Expand
Carrier-mediated approaches for oral drug delivery
Abstract Intestinal brush-border and basolateral membrane transport mechanisms for monosaccharides, monocarboxylic acids, phosphate and several water-soluble vitamins are summarized and possibleExpand
Evidence of competitive inhibition of methotrexate absorption by leucovorin calcium in rat small intestine
Abstract The effect of leucovorin calcium on the intestinal absorption of methotrexate in rat small intestine was investigated using an in situ rat gut technique. First, the kinetic absorption inExpand
Fluorescein-methotrexate transport in brush border membrane vesicles from rat small intestine.
The transport of F-MTX in BBMVs was shown to be mediated in part by the reduced folate transporter (RFC) which was known to transport MTX through the epithelium of small intestine. Expand
Non-steroidal anti-inflammatory drugs affect the methotrexate transport in IEC-6 cells.
It seems likely that the ATP content in IEC-6 cells with the NSAIDs decreased due to the uncoupling effect of oxidative phosphorylation of theNSAIDs, resulting in the inhibition of the secondary active transport of MTX in I EC-6 Cells. Expand