Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Intestinal Absorption”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 919 records · Page 51Linked to original sources

Total intestinal absorption of glucose and L-methionine in broilers infected with Eimeria acervulina, E. mivati, E. maxima or E. brunetti.

The in vitro absorption of glucose and L-methionine in the intestine of broiler chickens was measured 7, 14 and 21 days post-inoculation (p.i.) with sporulated oocysts of Eimeria acervulina, E. mivati, E. maxima or E. brunetti. The small intestine of each bird was divided into 8 regions of equal length and absorption was measured on 3 tissue disks of equal size from each region. The absorption rate of each substrate with each coccidial species was measured based on (1) an equal area from each region, (2) an equal weight from each region, (3) the total absorption in each region, and (4) the total potential absorption in the intestine. Comparisons of absorption rate of equal areas in each intestinal region demonstrated that infected birds at 7 days p.i. absorbed significantly less substrate per unit area in the regions of maximum infection than uninfected controls. Malabsorption was less apparent when the weight of the region was used as the unit of measurement. Compensatory absorption was seen in some uninfected regions with E. acervulina. The total potential intestinal absorption at 7 days p.i. was reduced with E. mivati, E. maxima and E. brunetti but not with E. acervulina. At 14 days p.i., total L-methionine and glucose absorption in some regions of the intestine was significantly increased with E. acervulina but not with E. mivati, E. maxima or E. brunetti. No absorption differences were seen at 21 days p.i. with any species.

Animals↗

Effects of folic acid and amino acids supplementation on zinc intestinal absorption in the progeny of ethanol-treated rats.

This study was designed to examine the effects of supplementation with folic acid and amino acids in dams that consumed ethanol during gestation and lactation to see whether there is an improvement in the intestinal absorption of zinc in pup rats on the 21st day after birth. The rats were randomized into two groups: Ethanol-rats (EG) were administered ethanol during the pregnancy and lactation periods; the ethanol-folic acid group (EFG) received a folic acid and amino acid supplement concomitantly with ethanol administration during pregnancy and lactation. The dams were mated to obtain the first offspring. Two sets of experiments were performed on the offspring at 21 days after birth. In general, in the first set, jejunal zinc absorption in the offspring of EG and EFG groups showed a gradual increase along with increased perfusion time at all assayed concentrations. Jejunal zinc absorption expressed as nmol/intestinal surface was higher in the ethanol-folic acid group than in ethanol animals at all assayed concentrations except at 25 microM concentration. In the second set of experiments, distal ileum zinc absorption in the offspring of ethanolfolic acid dams showed a significant increase at all concentrations tested. These results indicate that supplementation of folic acid and amino acids to dams that consume ethanol during gestation and lactation increase serum and milk zinc levels, although the zinc ingestion is lower. In pups of the supplemented dams, the jejunal and ileal absorption of zinc increased; as a consequence, the serum zinc levels increased. The activity of alcohol dehydrogenase, a metaloenzyme dependent on zinc levels, also increased.

Amino Acids↗

Improvement by chlorine of the intestinal absorption of inorganic and organic Mg compounds and of their protective effect against adrenergic cardiopathy.

Comparative studies on the therapeutic effects of MgSO4, MgCl2, Mg aspartate, and Mg aspartate hydrochloride were carried out in Sprague-Dawlwy rats. In general, the intestinal absorption of Mg and its uptake into bone were improved after oral or intraduodenal administration of the two compounds containing chlorine; however, in these animals, gain in body weight was reduced, especially after MgCl2. Treatment with 9-alpha-fluorocortisol plus epinephrine resulted in cardiac hypertrophy and necroses. All Mg compounds fed in amounts leading to marked hypermagnesemia prevented hypertrophy; as regards the incidence and severity of necroses, however, MgSO4 and Mg aspartate proved ineffective. Significant protective effects were observed only after MgCl2 and Mg aspartate hydrochloride, indicating the central pathogenic role of extracellular hypochloremic alkalosis in metabolic heart necroses.

Animals↗

Effect of hypothermia on the intestinal absorption of uracil and L-dopa in the rat.

The in situ rat gut technique was used to explore the effects of hypothermia on the intestinal absorption of L-dopa and uracil. A hypothermic state was induced when male Sprague-Dawley rats, weighing between 300 and 370 g, were exposed to an atmosphere of helox (helium:oxygen, 80:20) at 0-4 degrees C. After 4 to 5 h, the rectal temperatures were decreased from 37 to 20 degrees C. The rewarming process for hypothermic animals undergoing anesthesia appears to be prolonged. The animals were prepared for surgery using ether as anesthetic after a rectal temperature of 20 degrees C was attained. Hypothermia showed a significant influence on decreasing L-dopa and uracil disappearances from the intestinal lumen. About 40 percent reduction of the rates of disappearance was observed with a 10 degrees C reduction of the rectal temperature. Additionally, a rapid drop of the rate of drug disappearance was observed in the beginning stage of rectal temperature decrease (31-36 degrees C) as well as in the hypothermic state with rectal temperatures < 26 degrees C. There appears to be a thermal stable region for absorption between 26 and 30 degrees C. Water efflux was studied in both normothermic and hypothermic animals. Normothermic rats showed greater average cumulative water efflux over a period of 30 min (71 and 61% for L-dopa and uracil, respectively) in comparison with that of hypothermic rats (34 and 41% for L-dopa and uracil, respectively). The cold-treated animals showed decreased rates of disappearance associated with the decreased water efflux. Therefore, the reduction of the rates of drug disappearance from the intestinal lumen caused by hypothermia may be partially related to the decrease of water efflux during hypothermia.

Animals↗

Effect of soy protein on calves' intestinal absorptive ability and morphology determined by scanning electron microscopy.

Neonatal calves were fed whole milk (control) or one of three milk replacers with one-third of the total protein supplied by casein, Promocaf (a commercial soy protein concentrate), or an experimental soy flour. Xylose absorption was studied at 3 and 8 wk after a 12-h fast. Urine was collected for 5 h, and jugular blood was sampled at 0, 2.5, and 5 h after administration of xylose. Urinary excretions of xylose at 8 wk were 3.4, 5.3, 7.8, and 21.3% of xylose administered, respectively, for calves fed Promocaf, soy flour, casein, and milk. Increases in plasma xylose 2.5 h after administration were 7.7, 21.3, 31.8, and 46.5 mg/dl. Calves were sacrificed at 12 or 14 wk and duodenal tissues sampled for scanning electron microscopy. Micrographs revealed normal intestinal morphology with long, round, tapering villi when milk was fed. Casein feeding produced shorter, broader villi than did feeding whole milk. Abnormalities included absence of villi and short, blunted, convoluted villi on mucosal surfaces of calves fed soy proteins. Reduced surface area for intestinal absorption probably resulted from villous atrophy in calves with abnormal mucosae. Impairment of absorptive ability appears to be associated with morphological changes in intestinal structure.

Animals↗

Intestinal absorption of glucose in rats after continuous challenge with larvae of Nippostrongylus brasiliensis.

The rate of glucose absorption and metabolism and the associated fluid transfer of the small intestine of rats was measured in vitro using an everted sac technique after daily doses of 0, 5, 25 or 225 infective larvae of Nippostrongylus for periods of one to five weeks. Though there were occasional significant changes in the physiology of the intestine there were no obvious patterns or trends with respect to time at any infection level. This differs from the response after a single infection. The possible role of immune adaptation and reduced immunogenicity of the worms during repeated infections is considered.

Animals↗

The mechanism of intestinal absorption of phosphatidylcholine in rats.

1. The mechanism of absorption of phosphatidylcholine was studied in rats by injecting into the intestine phosphatidylcholine specifically labelled either in the fatty acid or in the glycerol moiety or with (32)P, when considerable amounts of 1-acyl-lysophosphatidylcholine were found in the intestinal lumen. 2-([(14)C]Acyl)phosphatidylcholine gave markedly more radioactive unesterified fatty acids in the lumen, compared with the 1-([(14)C]acyl) derivative. Some of the radioactivity from either the fatty acid or the glycerol moiety of the injected phosphatidylcholine appeared in the mucosal triacylglycerols. 2. Injection of (32)P-labelled phosphatidylcholine or (32)P-labelled lysophosphatidylcholine led to the appearance of radioactive glycerylphosphorylcholine, glycerophosphate and P(i) in the mucosa. 3. Rat mucosa was found to contain a highly active glycerylphosphorylcholine diesterase. 4. It was concluded that the dietary phosphatidylcholine is hydrolysed in the intestinal lumen by the pancreatic phospholipase A to 1-acylglycerylphosphorylcholine, which on entering the mucosal cell is partly reacylated to phosphatidylcholine, and the rest is further hydrolysed to glycerylphosphorylcholine, glycerophosphate, glycerol and P(i). The fatty acids and glycerophosphate are then reassembled to give triacylglycerols via the Kennedy (1961) pathway.

Animals↗

[Improvement of intestinal absorption of peptide and protein drugs by chemical modification with fatty acids].

It is well known that the oral bioavailability of peptide and protein drugs is generally poor because they are extensively degraded by proteases in the gastrointestinal tract and impermeable through the intestinal mucosa. Therefore, various approaches have been examined to overcome the delivery problems of these peptides and to improve their absorption via the gastrointestinal tract. Of these approaches, a potentially useful approach to solve these delivery problems may be chemical modification of peptides and proteins to produce prodrugs and analogues. Thus, it is plausible that this approach may protect peptides against degradation by peptidases and other enzymes present at the mucosal barrier and renders the peptides and proteins more lipophilic, resulting in increased bioavailability. From these standpoints, we synthesized lipophilic derivatives of peptides and proteins such as thyrotropin-releasing hormone (TRH), tetragastrin (TG), calcitonin and insulin by chemical modification with fatty acids. The pharmacological activities of these derivatives were relatively high as compared with the native peptides. A significant increase in the intestinal absorption of these derivatives of peptides was observed in comparison with native peptides. Overall, the effects of acylation on the intestinal absorption of these peptides were more predominant in the large intestine than those in the small intestine. In addition, these derivatives were more stable than the parent peptides in homogenates of the various intestinal mucosae. We also examined the intestinal transport characteristics of TG and its acyl derivatives using Caco-2 cell monolayers in order to assess the contribution of enzymatic and transport barriers on their intestinal absorption. The degradation clearance of TG on the apical membrane was decreased by chemical modification with fatty acids. In addition, the permeability clearance of TG was improved by the acylation. On the other hand, the intestinal absorption of thyrotropin releasing hormone (TRH), which is transported by a carrier-mediated process, was also enhanced by chemical modification with lauric acid. In summary, this chemical modification approach may be useful to improve the intestinal absorption of peptide and protein drugs.

Acylation↗

In vitro studies on the intestinal absorption of curcumin in rats.

When everted sacs of rat intestines were incubated with 50-750- micrograms of curcumin in 10 ml incubation medium, 30-80% of the added curcumin disappeared from the mucosal side. No curcumin was however detectable in the serosal fluid. Less than 3% of the added curcumin was found in the tissue at the highest concentration. In experiments with [3H[ curcumin, 5-6% of added radioactivity was found in the serosal side. TLC examination of the mucosal extract showed the presence of 2 compounds, 1 corresponding to curcumin and the other to a less polar, colourless compound. The serosal fluid had no curcumin but a compound whose RF was identical with the colourless compound present in the mucosal side. These experiments indicated that curcumin undergoes transformation during absorption from the intestine.

Animals↗

Labeled acetate to assess intestinal absorption in critically ill patients.

OBJECTIVE: To compare the absorption of carbon-13(13C) acetate-enriched nutrients with D-xylose absorption. DESIGN: Prospective cohort observational study. SETTING: Surgical intensive care unit of a university hospital. PATIENTS: A total of 24 critically ill patients requiring enteral nutritional support. INTERVENTION: The patients were divided into three groups according to the route of 13C acetate administration: 1) gastric, 2) jejunal, and 3) intravenous. D-xylose was administered via the same route as enteral nutrition. MEASUREMENTS AND MAIN RESULTS: 13C acetate absorption and oxidation were reflected by pulmonary 13CO2 excretion. Breath 13CO2 isotopic enrichment was measured by mass spectrometry. 13C acetate absorption was rapid, and D-xylose absorption was depressed in all three groups, compared with the normal values (p <.0001). Breath CO isotopic enrichment was similar after intravenous and jejunal administration but slightly delayed during the first 240 mins after gastric administration (p <.01). Enteral feeding was well tolerated: mean energy delivery amounted to 77%, 88%, and 86% of measured resting energy expenditure on days 1-3. CONCLUSIONS: Gastric and jejunal 13C acetate are rapidly absorbed in critically ill surgical patients requiring enteral nutrition, contrasting with a depressed or delayed D-xylose absorption. 13CO2 recovery kinetics was similar after jejunal or intravenous 13C acetate and slightly depressed after gastric administration. Further studies are required to determine the value of labeled nutrients to assess gastric emptying and intestinal absorption.

Acetates↗

Biochemical studies on oral toxicity of ricin. V. The role of lectin activity in the intestinal absorption of ricin.

In order to investigate a possible role of lectin activity of ricin in its absorption from the small intestine, we prepared two ricin derivatives. BMH-ricin, prepared by crosslinking A and B chains of ricin with 1,6-bismaleimidohexane, was nearly non-toxic but the lectin activity was unaltered. And, NBS-ricin, prepared by the oxidation of tryptophanyl residues of ricin with N-bromosuccinimide, was not only non-toxic but also non-lectinic. After the oral administration of ricin derivatives to rats, their interaction with the digestive tract and absorption into the circulatory systems have been compared with those of ricin, immunochemically and histologically. It was shown by immunostaining that ricin and BMH-ricin could bind to the intestinal mucosa, whereas NBS-ricin could not. No appreciable damage in the small intestine from rats treated with either BMH-ricin or NBS-ricin has been observed, in contrast to ricin treatment where severe impairment of the small intestinal tissues resulted after 5 h. Immunoreactive ricin in the liver has been determined with the ricin enzyme immunoassay (EIA). When compared at 48 h after oral administration, NBS-ricin was not detected, whereas BMH-ricin was found to be 38 micrograms/liver and ricin 100 micrograms/liver. From these results, it was inferred that the lectin activity of ricin plays an important role in the absorption of ricin from the small intestine and that the absorption of ricin protein was enhanced by its high toxicity.

Administration, Oral↗

[Intestinal absorption of radiocalcium after long-term treatment with sodium fluoride in senile osteoporpsis].

Prolonged administration of sodium fluoride (NaF) in patients suffering from osteoporosis or Paget's disease leads to a positive calcium balance together with positivization of the calcium balance may mean an ins, intestinal absorption of calcium was evaluated directly with the oral rrotic patients; 6 months treatment with NaF led to a significant imprt is difficult to say how this finding is connected with the drug's actide apatite crystals; the crystals' greater stability probably leads to greater resistance of fluorated bone to the action of parathormone, thus bring on hypocalcaemia which homeostatically stimulates parathyroid hyperiirect pointer to parathyroid hyperincretion. The therapeutic effectiveness of NaF in diffuse decalcifying osteopathies is, however, limited by the drug's toxicity.

Age Factors↗

Intestinal absorption of octreotide using trimethyl chitosan chloride: studies in pigs.

PURPOSE: To investigate the enhancing effect of trimethyl chitosan chloride (TMC) on the enteral absorption of octreotide and to delineate the required doses of both TMC and peptide in vivo in juvenile pigs. METHODS: Six female pigs (body weight, 25 kg) were operated to induce a stoma at the beginning of their jejunum and to insert an in-dwelling fistula for intrajejunal (IJ) administration of the formulations. A silicone cannula was inserted at the jugular vein for blood sampling. One week after surgery the pigs received IJ octreotide solution administrations with or without TMC at pH 7.4 or chitosan HCl at pH 5.5. For determining bioavailability (F) values, the pigs also received an octreotide solution intravenously (IV). Blood samples were taken from the cannulated jugular vein and subsequently analyzed by radioimmunoassay. RESULTS: Intrajejunal administration of 10 mg octreotide without any polymer (control solution) resulted in F values of 1.7 +/- 1.1% (mean +/- SE). Chitosan HCl 1.5% (w/v) at pH 5.5 led to a 3-fold increase in F compared to the control (non-polymer containing) formulations. Co-administration of octreotide with 5 and 10% (w/v) TMC at pH 7.4 resulted in 7.7- and 14.5-fold increase of octreotide absorption, respectively (F of 13.9 +/- 1.3% and 24.8 +/- 1.8%). IJ administration of 5 mg octreotide solutions resulted in low F values of 0.5 +/- 0.6%, whereas co-administration with 5% (w/v) TMC increased the intestinal octreotide bioavailability to 8.2 +/- 1.5%. CONCLUSIONS: Cationic polymers of the chitosan type are able to enhance the intestinal absorption of the peptide drug octreotide in pigs. In this respect, TMC at neutral pH values of 7.4 appears to be more potent than chitosan HCl at a weak acidic pH of 5.5.

Animals↗

Effect of Walker 256 tumor growth on intestinal absorption of leucine, methionine and glucose in newly weaned and mature rats.

In tumor-bearing rats, most of the serum amino acids are used for synthesis and oxidation processes by the neoplastic tissue. In the present study, the effect of Walker 256 carcinoma growth on the intestinal absorption of leucine, methionine and glucose was investigated in newly weaned and mature rats. Food intake and carcass weight were decreased in newly weaned (NT) and mature (MT) rats bearing Walker 256 tumor in comparison with control animals (NC and MC). The tumor/carcass weight ratio was higher in NT than in MT rats, whereas nitrogen balance was significantly decreased in both as compared to control animals. Glucose absorption was significantly reduced in MT rats (MT = 47.3 +/- 4.9 vs MC = 99.8 +/- 5.3 nmol min-1 cm-1, Kruskal-Wallis test, P < 0.05) but this fact did not hamper the evolution of cancer. There was a significant increase in methionine absorption in both groups (NT = 4.2 +/- 0.3 and MT = 2.0 +/- 0.1 vs NC = 3.7 +/- 0.1 and MC = 1.2 +/- 0.2 nmol min-1 cm-1, Kruskal-Wallis test, P < 0.05), whereas leucine absorption was increased only in young tumor-bearing rats (NT = 8.6 +/- 0.2 vs NC = 7.7 +/- 0.4 nmol min-1 cm-1, Kruskal-Wallis test, P < 0.05), suggesting that these metabolites are being used for synthesis and oxidation processes by the neoplastic cells, which might ensure their rapid proliferation especially in NT rats.

Animals↗

Quinidine as a probe for the role of p-glycoprotein in the intestinal absorption and clinical effects of fentanyl.

The mechanism of individual variability in the fentanyl dose-effect relationship is unknown. The efflux pump P-glycoprotein (P-gp) regulates brain access and intestinal absorption of numerous drugs. Evidence exists that fentanyl is a P-gp substrate in vitro, and P-gp affects fentanyl analgesia in animals. However, the role of P-gp in human fentanyl disposition and clinical effects is unknown. This investigation tested the hypothesis that plasma concentrations and clinical effects of oral and intravenous fentanyl are greater after inhibition of intestinal and brain P-gp, using the P-gp inhibitor quinidine as an in vivo probe. Two randomized, double-blind, placebo-controlled, balanced, two-period crossover studies were conducted in normal healthy volunteers (6 males and 6 females) after obtaining informed consent. Pupil diameters and/or plasma concentrations of fentanyl and norfentanyl were evaluated after oral or intravenous fentanyl (2.5 microg/kg), dosed 1 hour after oral quinidine (600 mg) or placebo. Quinidine did not alter the magnitude or time to maximum miosis, time-specific pupil diameter, or subjective self-assessments after intravenous fentanyl but did increase the area under the curve (AUC) of miosis versus time (13.6 +/- 5.3 vs. 8.7 +/- 5.0 mm*h, p< 0.05) and decreased the effect of elimination (k(el) 0.35 +/- 0.16 vs. 0.52 +/- 0.24 h(-1), p < 0.05). Quinidine increased oral fentanyl plasma C(max) (0.55 +/- 0.19 vs. 0.21 +/- 0.1 ng/mL) and AUC (1.9 +/- 0.5 vs. 0.7 +/- 0.3 ng*h*mL(-1)) (both p < 0.05) but had no effect on apparent elimination. Plasma norfentanyl/fentanyl AUC ratios were not diminished by quinidine. Quinidine significantly increased maximum miosis after oral fentanyl (3.4 +/- 1.3 vs. 2.3 +/- 1.3 mm, p< 0.05), commensurate with increases in plasma concentrations, but concentration-effect relationships and the rate constant for the transfer between plasma and effect compartment (k(e0)) (1.9 +/- 1.0 vs. 3.6 +/- 2.6 h(-1)) were not significantly different. Quinidine increased oral fentanyl plasma concentrations, suggesting that intestinal P-gp or some other quinidine-sensitive transporter affects the absorption, bioavailability, and hence clinical effects of oral fentanyl. Quinidine had less effect on fentanyl pharmacodynamics, suggesting that if quinidine is an effective inhibitor of brain P-gp, then P-gp appears to have less effect on brain access of fentanyl.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Oral mercuric chloride exposure in mice: effects of dose on intestinal absorption and relative organ distribution.

Human intoxications with inorganic mercury occur via the oral or pulmonar routes. However, earlier experimental studies of the acute toxicity of inorganic mercury primarily used parenteral administration of soluble inorganic mercury salts. The present study evaluated the effect of dose size on intestinal absorption and relative organ distribution of orally administered mercuric chloride. Experiments were performed with male mice of 2 strains (inbred CBA/Bom and outbred Bom: NMRI). At the highest dose of HgCl2, a delay in fecal elimination of non-absorbed mercury was observed indicating a decreased peristaltic rate. The fractional whole-body retention of mercury at 14 days after dosage was inversely related to the dose size, conceivably due either to saturation of the uptake mechanism or to damage to the kidneys resulting in loss of mercury with the urine at the highest dose levels. The relative organ distribution of mercury after oral exposure was quantitatively different from that reported in the literature after parenteral administration of inorganic mercury. Thus, the relative hepatic deposition was larger than after injection of mercury, presumably due to the first pass effect. A dose dependency in the relative organ distribution of retained mercury was observed, characterized by increasing relative deposition in liver, stomach, intestines, testes, spleen and carcass but decreasing relative renal deposition with increasing dose. The toxicokinetics of inorganic mercury was similar in the 2 mice strains. The present study demonstrates that the toxicokinetics of orally administered inorganic mercury is different from that of parenterally administered inorganic mercury as earlier reported in the literature.

Animals↗

Impact of Mrp2 on the biliary excretion and intestinal absorption of furosemide, probenecid, and methotrexate using Eisai hyperbilirubinemic rats.

PURPOSE: This study assesses the impact of rat multidrug resistance-associated protein 2 (Mrp2) on the biliary excretion and oral absorption of furosemide, probenecid, and methotrexate using Eisai hyperbilirubinemic rats (EHBR). METHODS: To assess Mrp2-mediated biliary excretion, rats received a 2-h intravenous infusion of furosemide, probenecid, or methotrexate. Blood and bile samples were collected at specified intervals. To assess Mrp2's impact on oral absorption, rats received furosemide, probenecid, or methotrexate orally at 5 mg/kg. Jugular and portal blood samples were obtained at timed intervals. All samples were analyzed by LC-MS/MS. Pharmacokinetic parameters were estimated using WinNonlin and standard pharmacokinetic equations. RESULTS: Thirty seven- and 39-fold reductions in biliary clearance were observed in EHBR as compared to control rats for probenecid and methotrexate, respectively. Biliary clearance was comparable between EHBR and control rats for furosemide. In all cases, no significant difference in absorption was observed between EHBR and control rats. CONCLUSIONS: This study provides the first evidence that Mrp2 mediates the biliary excretion of probenecid but not furosemide. Additionally, Mrp2 apparently has a less profound impact on intestinal absorption than biliary excretion of its substrates. Furthermore, alteration in systemic clearance in EHBR indicates that a potential compensatory mechanism may occur in EHBR.

ATP-Binding Cassette Transporters↗