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Results for “INTESTINAL ABSORPTION”

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At least 91 records · Page 5Linked to original sources
PubMed1980

[Evaluation of intestinal absorption of d-xylose during a controlled exercise test under different thermic conditions].

The study was aimed at investigating the effect of graded exercise performed on a cycle ergometer under different thermal conditions on the intestinal absorption. Intestinal absorption was estimated by d-xylose test in 18 men aged 19--66 prior to--and--following an exercise at neutral and raised temperature (32--33 degrees C). The work--and--thermal load applied corresponded to or even exceeded that experienced by hot working environment workers in not industry. The study failed to demonstrate any significant effect of physical effort and ambient temperature on intestinal d-xylose absorption. The formerly found decrease in intestinal d-xylose absorption during work in industry might be accounted for by combined effects of various factors inherent in occupational work.

Adult↗
PubMed1981

Intestinal absorption of D-galactose and L-leucine and intestinal disaccharidase activities in growing chickens fed different raw legume diets.

A significant (P less than .01) impairment in the rate of growth, along with a significant (P less than .01) inhibition in the rate of in vivo intestinal absorption of D-galactose and L-leucine, and in the in vitro intestinal absorption of D-galactose, was found in growing chickens fed ad libitum over a 60-day period, diets containing the raw legumes Vicia faba, Glycine soja, Vicia ervilia, and Phaseolus vulgaris as the main source of protein. Furthermore, a significant (P less than .01) reduction in the intestinal disaccharidase activity was found in the legume-fed chickens. The possible nature of these effects was discussed.

Animal Feed↗
PubMed1999

The roles of P-glycoprotein and intracellular metabolism in the intestinal absorption of methadone: in vitro studies using the rat everted intestinal sac.

Methadone is used as a treatment for opiate detoxification in methadone maintenance programs. Intra- and inter-patient variations in methadone bioavailability have been observed after oral methadone treatment and this makes it difficult to predict a dosing regimen. Intestinal absorption and metabolism could explain these variations. The in vitro gut sac model was used to study the intestinal absorption of methadone, and it confirmed that methadone is a substrate for P-glycoprotein. The transport of methadone was increased in presence of P-gp inhibitors verapamil and quinidine. The appearance of a major metabolite of methadone, 2-ethylidene-1, 5-dimethyl-3, 3-diphenyl pyrrolidine (EDDP) in the gut sac contents also demonstrated the existence of intestinal metabolism of methadone.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1984

Physical model approach to gastrointestinal absorption of prostaglandins III: In situ rat intestinal absorption of dinoprostone.

In situ absorption studies with dinoprostone in the rat jejunum were carried out to provide a quantitative mechanistic insight of the absorption process. The variables included buffer pH (3.5-9.5), buffer capacity, hydro-dynamics in the lumen, and concentration. The disappearance kinetics from the lumen was first order. The rate decreased with increasing pH in a sigmoidal manner and reached a minimum at about pH 9. These results indicate the effects of the partitioning of nondissociated species in the lipoidal membrane and transport across aqueous pores. The rate was higher with the higher degree of agitation of the lumenal solution. Between two hydrodynamic situations, the differences in the rates were large at pH 4.5 where the transport was largely aqueous diffusion controlled and then tended to become smaller with increasing pH where the transport became effectively membrane controlled. The 15-oxo- and 13,14-dihydro-15-oxo metabolites of dinoprostone were found. The physical model was applied to quantify the permeability coefficients of the aqueous diffusion layer and the aqueous pores of the membrane and the effective membrane transport-bioconversion permeability coefficient at various pH values. The overall absorption dinoprostone was similar to that of the less lipophilic dinoprost reported earlier and also more rapid. Hence, baseline absorption studies were completed with two major reference prostaglandins from which estimations of intestinal absorption can be made for their analogues and derivatives.

Animals↗
PubMed1996

Effectiveness and toxicity screening of various absorption enhancers in the large intestine: intestinal absorption of phenol red and protein and phospholipid release from the intestinal membrane.

The effectiveness and local toxicity of absorption enhancers on the absorption of phenol red (PR) from the large intestine of rats were examined using an in situ loop method. The absorption enhancers used in this study were sodium glycocholate (GC-Na), sodium taurocholate (TC-Na), sodium deoxycholate (DC-Na), EDTA, sodium salicylate (Sal-Na), sodium caprate (Cap-Na), diethyl maleate (DM), N-lauryl-beta-D-maltopyranoside (LM) and mixed micelles (MM), all used at a concentration of 20 mM. Local toxicity was also investigated by assessing protein and phospholipid release as biological markers. DC-Na and MM were the most effective absorption enhancers, but they caused considerable release of proteins and phospholipids. GC-Na, TC-Na and LM, which caused little or only slight membrane damage, promoted PR absorption. Sal-Na, DM and EDTA did not enhance PR absorption. Overall, a correlation exists between the area under the curve of PR and protein and phospholipid release in the presence of absorption enhancers. However, GC-Na, TC-Na and LM promoted the absorption of PR with low toxicity. From these results, we concluded that GC-Na, TC-Na and LM are effective absorption enhancers which have low levels of toxicity at a concentration of 20 mM.

Animals↗
PubMed1982

Carbenicillin prodrugs: kinetics of intestinal absorption competing degradation of the alpha-esters of carbenicillin and prediction of prodrug absorbability from quantitative structure-absorption rate relationship.

The intestinal absorption of alpha-esters of carbenicillin disodium, carbenicillin phenyl sodium, and carbenicillin indanyl sodium was investigated using the in situ rat intestinal recirculating method. In the in situ intestinal lumen at pH 7, two prodrugs were rapidly converted to poorly absorbable carbenicillin, possibly by the action of intestinal nonspecific esterase in competition with the slow absorption of prodrugs. At pH 5, the reduced action of esterase and the increased absorption rate after 3 hr resulted in 50 and 60% absorption of carbenicillin phenyl sodium and carbenicillin indanyl sodium, respectively. The absorption rate constants determined for both prodrugs were in good agreement with the prediction from the quantitative structure-absorption rate relationship derived from the two-compartment aqueous diffusion model.

Animals↗
PubMed1984

Intestinal absorption of vitamin A in experimental uremia.

Intestinal absorption of vitamin A was determined in a group of rats rendered uremic by subtotal nephrectomy. The results were compared with those obtained in a group of sham-operated control animals. Absorption studies were performed by in-vivo perfusion of an isolated loop of the proximal jejunum with intact blood and lymphatic supply. The rate of intestinal absorption of vitamin A, in the uremic groups was nearly identical to that found in the control group. It thus appears that intestinal absorption of vitamin A is not affected by experimental uremia in the rat.

Animals↗
PubMed1982

Solvent drag effect in drug intestinal absorption. I. Studies on drug and D2O absorption clearances.

It was shown that the intestinal absorption clearance of D2O (CLD2O) could be a more appropriate index to study the solvent drag effect than water volume flow which was the difference between water influx and outflux in the intestinal lumen. Then, the correlation between the intestinal absorption clearances of drugs (CLdrug) and CLD2O were studied using the in situ recirculating method in the rat small intestine. The drugs used were low molecular drugs, that is, benzoic acid, salicylic acid, p-hydroxybenzoic acid and antipyrine, and comparably high molecular drugs, that is, cephalexin (CEX), cefroxadine (CXD) and cephalothin (CET). CLdrug and CLD2O were obtained in hypertonic, isotonic and hypotonic perfused solution adjusted with sodium chloride. Consequently, the correlations for all drugs except CET were significant and high solvent drag effects were observed. CLdrug of benzoic acid, salicylic acid and antipyrine were approximately equal to CLD2O, suggesting that the intestinal mucosa could not distinguish these lower molecular drugs from water. For the high molecular drugs such as cephalosporins, however, some extent of reflection from the membrane was certainly found in CEX and CXD, and the extent in CET was assumed much larger than CEX and CXD, resulting that the contribution of solvent drag in CET could not be found. Consequently, it was suggested that the solvent drag had some important role in the intestinal absorption of cephalosporins.

Animals↗
PubMed1976

Effects of haemodialysis on fractional intestinal absorption of calcium in uraemia.

Fractional intestinal absorption of calcium was measured in 41 haemodialysed patients 4 hours after an oral dose of 47 Ca. Fractional intestinal calcium absorption was 40.3 +/- 1.9% (SEM) when measured 10 to 12 hours after a haemodialysis session (dialysate calcium concentration: 1.75 mmol/litre). This value was significantly lower (p less than 0.001) than that in 26 healthy controls (56.8 +/- 1.8%) and higher (p less than 0.05) than that of 35 patients with chronic renal failure treated conservatively (34.5 +/- 2.1%). In 17 patients, fractional intestinal calcium absorption was measured just before and just after a dialysis session. Pre-dialysis fractional intestinal calcium absorption (33.7 +/- 3.0%) was not significantly different from fractional intestinal calcium absorption in uraemic patients treated conservatively, while after dialysis fractional intestinal calcium absorption had increased significantly to 42.0 +/- 2.6% (p less than 0.001). It is suggested that the transient increase in fractional intestinal calcium absorption observed after dialysis could be related to dialysis induced volume depletion rather than to a vitamin D-dependent mechanism.

Calcium↗