title: Luminal and basolateral polyamine uptake by rat small intestine stimulated to grow by Phaseolus vulgaris lectin phytohaemagglutinin in vivo.
abstract: Luminal and basolateral uptake of polyamines by the rat small intestine was studied in vivo. In the concentration range studied (0.1-5 mg per rat) 23-47% of the individual polyamines given intragastrically were found in the body after 1 h, with the small intestine retaining 4-12% of the dose. With spermidine or spermine, labelled polyamines accounted for 85-96% of the counts in the small intestine and between 72-82% were in the form given. However, with putrescine only 29-39% of the label found in the tissue remained in polyamine form and even less, 11-15%, as putrescine. Luminal uptake of polyamines was linear, non-saturable and was not stimulated when small intestinal growth was stimulated by phytohaemagglutinin (PHA). On the basolateral side of the gut, polyamine uptake was stimulated by PHA in a time-dependent way in advance of detectable growth. Overall polyamine recoveries were high (89-99%) with intraperitoneally administered spermidine and spermine. Moreover, a large proportion of the counts in the tissue (63-89%) were still in the original form. Even with putrescine, total recoveries of polyamines (72-88%) and putrescine (24-33%) were elevated in comparison with those from the lumen. Treatment of rats with alpha-difluoromethylornithine (DFMO), an inhibitor of ornithine decarboxylase, reduced tissue polyamine content, although it had slight effects only on basolateral polyamine transport. The PHA-stimulated increase of polyamine uptake was not abolished in the presence of DFMO.
authors.affiliation: Rowett Research Institute, Aberdeen, U.K.
authors.forename: S
authors.initials: S
authors.lastname: Bardocz
authors.forename: D S
authors.initials: DS
authors.lastname: Brown
authors.forename: G
authors.initials: G
authors.lastname: Grant
authors.forename: A
authors.initials: A
authors.lastname: Pusztai
mesh_terms: D000818:Animals; D000518:Eflornithine / Q000494:pharmacology; D007887:Fabaceae; D007421:Intestine, Small / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010835:Phytohemagglutinins / Q000494:pharmacology*; D037121:Plant Lectins; D010946:Plants, Medicinal; D011073:Polyamines / Q000493:pharmacokinetics*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D010835:Phytohemagglutinins; D037121:Plant Lectins; D011073:Polyamines; D000518:Eflornithine