Search results for "intestinal absorption"
showing 10 items of 179 documents
Immunologic and absorptive tests in celiac disease: can they replace intestinal biopsies?
1993
The sensitivity and specificity of several immunologic and absorption tests were determined in infants with celiac disease (31 male, 39 female; median age, 2.6 years) in different phases of the disease and in a group of control subjects with chronic diarrhea of different etiologies (32 male, 28 female; median age, 1.2 years). Intestinal biopsy was performed both in the patients and in the controls as a 'gold standard' for the diagnosis. The anti-gliadin antibody (AGA) IgG values showed a sensitivity of 89% and a specificity of 47%; AGA IgA were 69% sensitive and 92% specific; anti-endomysial antibodies (EmA) were 100% sensitive and 97% specific; the xylose test was 71% sensitive and 53% spe…
Partition of oleic acid between the lymph and portal blood in rats having a diverted bile–pancreatic duct
1996
AbstractThe present study examines the suggestion that in the absence of adequate bile and pancreatic juice, which support the absorption from the gut of long-chain fatty acidsinto lymph, the fatty acids are absorbed directly into the portal blood. Oleic acid (18:l) partitioning between lymph and portal blood was investigated in intact and bile- and pancreatic juice-diverted rats. In a first set of experiments, 18: 1 absorption from the gut into lymph and blood was studied by continuous recovery of the mesenteric lymph for 6 h and mesenteric portal venous blood for 1 h. In a second set of experiments, esterification processes were investigated by study of the mucosal distribution of labelle…
Nanoaggregates Based on New Poly-Hydroxyethyl-Aspartamide Copolymers for Oral Insulin Absorption
2013
The aim of this work was to produce copolymers with an appropriate hydrophilic/hydrophobic balance able to form nanoaggregates with protein molecules and to be used as ideal materials in the field of oral peptide/protein delivery. New anionic polymers obtained by the conjugation of carboxy-bearing ligands, like succinic anhydride and/or cysteine, to hydrophobized α,β-poly(N-2-hydroxyethyl)-dl-aspartamide (PHEA) copolymers have been synthesized and characterized. Starting copolymer was synthesized by the partial derivatization of hydroxyl groups on the PHEA backbone with butylamine (C4) (obtaining the PHEA-C4 copolymer, bearing a butyl moiety). The consecutive reaction of PHEA-C4 with succin…
Lactaturia and loss of sodium-dependent lactate uptake in the colon of SLC5A8-deficient mice.
2008
SLC5A8 is a member of the sodium/glucose cotransporter family. It has been proposed that SLC5A8 might act as an apical iodide transporter in the thyroid follicular cells or as a transporter of short chain monocarboxylates. We have directly addressed the functional role of SLC5A8 in vivo by generation of SLC5A8 mutant mice. We found that SLC5A8 is responsible for the re-absorption of lactate at the apical membrane of the kidney proximal tubules and of serous salivary gland ducts. In addition, SLC5A8 mediated the uptake of lactate into colonocytes under physiological conditions. We did not find any evidence of SLC5A8 being essential for the apical iodide transport in the thyroid gland, even i…
Six years of progress in the oral biopharmaceutics area - A summary from the IMI OrBiTo project.
2020
OrBiTo was a precompetitive collaboration focused on the development of the next generation of Oral Biopharmaceutics Tools. The consortium included world leading scientists from nine universities, one regulatory agency, one non-profit research organisation, three small/medium sized specialist technology companies together with thirteen pharmaceutical companies. The goal of the OrBiTo project was to deliver a framework for rational application of predictive biopharmaceutics tools for oral drug delivery. This goal was achieved through novel prospective investigations to define new methodologies or refinement of existing tools. Extensive validation has been performed of novel and existing biop…
Nonlinearities in amoxycillin pharmacokinetics. II. Absorption studies in the rat.
1992
Most factors influencing amoxycillin oral absorption are, even today, unknown. Since many dosage schedules have been shown to lead to incomplete absorption, it would be desirable to find a suitable animal model where these factors could be studied in depth. In this paper, it is shown that, in the rat, plasma level curves obtained after oral doses of 7 and 28 mg kg-1 are poorly fitted using first-order absorption kinetics and that the best fit is obtained through the use of an input equation combining zero and first-order kinetics. In contrast, plasma level curves found after intraduodenal administration of amoxycillin solutions (7 mg kg-1) are well fitted by first-order input kinetics. It w…
INTESTINAL ABSORPTION KINETICS OF AMIODARONE IN RAT SMALL INTESTINE
1997
Amiodarone is a widely used antiarrhythmic agent with highly variable therapeutic effects. These seem to be related, at least in part, to the pharmacokinetics of the drug and particularly to some features of its gastrointestinal absorption process. The drug exhibits physico-chemical properties highly suitable for diffusion across lipophilic absorbing membranes, but its low aqueous solubility can act as the rate limiting step for absorption, making the process erratic and variable. In order to gain an insight into the intestinal absorption mechanism of the drug and detect possible non-linearities, a series of experiments using a classical rat gut in situ preparation were carried out with thr…
In Situ Study of the Effect of Naringin, Talinolol and Protein-Energy Undernutrition on Intestinal Absorption of Saquinavir in Rats
2011
To study the potential interactions of naringin (NAR), talinolol (TAL) and protein-energy undernutrition (PEU) in the absorption process of saquinavir (SQV), perfusion experiments were performed in the small intestine of rats at different SQV concentrations. The results obtained demonstrated that SQV intestinal absorption was described by simultaneous passive diffusion (kdif = 3.44 hr) and saturable absorption (Vma = 127.31 lM ⁄ hr; Kma =1 0.50lM) together with a capacity-limited efflux (Vms = 270.53 lM ⁄ hr; Kms =2 3.44lM). The competitive inhibition constants of NAR on the SQV input and efflux processes were (IC50)a =3 .98l Ma nd(IC50)s = 5.00 lM, respectively. NAR significantly decreased…
Intestinal transport in constipation and diarrhoea.
1988
Approximatively 10 liters of fluid enter the gastrointestinal tract with food and endogenous secretions, and only less than 100 ml or 1% leave it with the faeces. Minor changes of this equilibrium in the intestinal transport may cause diarrhoea or constipation. Functions of small and large intestine differ markedly in transport of electrolytes and water. The relatively leaky epithelium of the small intestine allows for rapid equilibrium of osmolality in both directions while the tight epithelium of the colon preserves electrolytes and water once they have been absorbed. It may compensate secretory diarrhoea of the small intestine for instance caused by bacterial toxins to a certain degree u…
Nonlinear intestinal absorption kinetics of cefuroxime axetil in rats.
1997
Cefuroxime is commercially available for parenteral administration as a sodium salt and for oral administration as cefuroxime axetil, the 1-(acetoxy)ethyl ester of the drug. Cefuroxime axetil is a prodrug of cefuroxime and has little, if any, antibacterial activity until hydrolyzed in vivo to cefuroxime. In this study, the absorption of cefuroxime axetil in the small intestines of anesthetized rats was investigated in situ, by perfusion at four concentrations (11.8, 5, 118 and 200 microM). Oral absorption of cefuroxime axetil can apparently be described as a specialized transport mechanism which obeys Michaelis-Menten kinetics. Parameters characterizing absorption of prodrug in free solutio…