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PubMed1994

[Effect of Enterued administration on the intestinal absorption of orally active cefem antibiotics].

The effect of simultaneous administration of Enterued, an elemental diet, which is composed of oligopeptides (egg white hydrolyzate), on the orally active cefems was investigated. Ceftibuten (CETB) administered together with Enterued to man was excreted slower in the urine. AUC from the plasma concentrations of CETB after the oral administration with Enterued was markedly decreased compared to that without Enterued in rat. In contrast, neither urinary excretion of cephalexin (CEX) in man nor the AUC from the plasma profile of CEX in rat was changed by Enterued. Furthermore, the disappearance, tissue accumulation, net absorption of CETB from the rat jejunal loop were significantly inhibited by Enterued. However, the net absorption of CEX has no alternation in the presence of Enterued, although the apparent disappearance decreased on the basis of the diminishment of tissue accumulation. Additionally, Hepan ED, which is an elementary diet composed of amino acids, and the mineral solution containing neither peptides nor vitamins have also exhibited the decreasing effect on the CETB absorption behaviour. These results suggested that the inhibitory effects of Enterued on the absorption of these antibiotics were not due to the inhibition of peptide-transport systems.

Administration, Oral↗
PubMed1982

Effect of cadmium and chromium on the intestinal absorption of glucose in the snakehead fish, Channa punctatus.

The effect of five concentrations of cadmium and chromium (10 mM, 1 mM, 0.1 mM, 0.01 mM and 0.001 mM) on the rate of absorption of glucose from the intestine of te snakehead fish, channa punctatus, was studied at 23 degrees C. All concentrations of cadmium decreased the rate of glucose transport. Maximum decrease was recorded with 10 mM of cadmium. The rate of transport decreased with an increase in the concentration of cadmium used. Chromium increased glucose absorption rate at all concentrations examined; the highest rate of absorption occurred at 0.001 mM of chromium.

Amino Acids↗
PubMed2005

Catecholamines potentiate the effect of thyroid hormone on intestinal absorption of glucose in the rat.

The study is to investigate the role of catecholamines on the increased absorption of glucose from the gut by thyroxine, the effect of graded doses of adrenaline and noradrenaline on glucose absorption was studied in euthyroid (ET), hyperthyroid (TH-) and hypothyroid rats (Thx). Glucose absorption was deduced in vivo from intestinal segment perfused with Kreb's bicarbonate solution containing 5.6 mM glucose and in vitro using the everted sac technique. In vivo, basal glucose absorption was significantly increased in the hyperthyroid and decreased in the hypothyroid rats (1.97 +/- 0.19 mM/g, P<0.01, and 0.92 +/- 0.10 mM/g, p<0.05 respectively) when compared with the euthyroid group (1.34 +/- 0.15 mM/g). Adrenaline (20 mg/dl - 80 mg/dl) increased glucose absorption in a dose dependent manner in all the groups. However, the responsiveness of the gut glucose absorption to adrenaline (as evidenced by the dose producing half- maximal absorption or ED50) was reduced by thyroidectomy (ED50 = 26.09 mg/100 ml) and increased by chronic thyroxine treatment (ED50 = 11.13 mg/100 ml). The ED50 in the euthyroid animals was 14.6 mg/100 ml. In vitro, glucose absorption from the isolated segments in both Thx and TH- rats were significantly reduced (P<0.05). Incubation of the isolated intestinal segments with graded doses of adrenaline caused a significan and dose related increases in glucose absorption. However thyroidectomy shifted the dose-response curve for glucose uptake from the isolated intestinal sac incubated with adrenaline to the right of the curve for euthyroid rats. It is concluded that catecholamines may play a role in the increase in intestinal absorption by thyroid hormones.

Animals↗
PubMed1986

[Mechanisms of intestinal absorption of nutrients].

The nutrient uptake from the intestinal lumen into the distributing blood circulation is mediated by the epithelial cell of the small intestine. The transfer process through this distinctly polar cell consists of three partial events: entrance of substances through the brush-border membrane, traversal of a metabolic active intracellular space and exit through the baso-lateral membrane. The fundamental transfer mechanisms--simple diffusion, facilitated diffusion, antiport and symport systems, electroneutral and electrogenic processes--are described. The significance of nutrient metabolization for transport processes is discussed: proton secretion by the epithelial cell coupled to the glucose and lactate metabolization is quoted as an illustration. The "acid microclimate" resulting from this proton secretion on the mucosal surface has a significant influence on weak-electrolyte absorption. This effect was clearly demonstrated for in vitro uptake of nicotinic acid into the intestinal tissue. It can be assumed that--similar to the role of a Na+-gradient--the proton gradient on the surface of absorptive epithelia is highly significant as a driving force of nutrient absorption.

Animals↗
PubMed1989

Lack of effect of purified cellulose and hemicellulose on the digestion and the intestinal absorption of dietary lipids in the rat.

Fasted adult rats were intragastrically intubated an emulsified test meal containing both 14C-triolein and 3H-cholesterol, in the presence or absence of either purified hemicellulose (xylan) or cellulose (both 10% of meal solids). After a 1-hour digestion period, purified fibers did not significantly modify the rate of gastric emptying of lipids or the extent of triglyceride lipolysis in the stomach and the small intestine. The presence of cellulose or hemicellulose induced no change in the amounts of lipids and cholesterol found in the intestinal content, the mucosa, and the plasma, nor in the site of lipid mucosal uptake. As a whole, the present results show that cellulose or hemicellulose, which are the main fractions of dietary fiber in cereals, did not exert a determinant influence on the biochemical events involved in the digestion of dietary fats.

Animals↗
PubMed1979

Effect of the pH on intestinal absorption of sugars in vivo.

Influence of the pH on the absorption rate of sugars by rat intestine in vivo has been revised by means of a technique for intestinal lumen perfusion with 1 minute absorption periods. Absorption at pH 2.5, 5, 7, 8.5, and 10 has been comparied in each animal. Absorption rate of D-glucose, D-galactose and D-fructose is highest at pH 7 and decreases at the lower or higher pH values. The pH does not affect the absorption of D-arabinose. The pH effect is attributed to changes in the transport system for sugars.

Animals↗
PubMed1976

Clinical evidence of intestinal absorption of Gastrografin.

Experimental evidence suggests that Gastrografin in the neonatal gastrointestinal tract leads to hypertonic dehydration by two mechanisms: loss of water from the circulating blood volume, and absorption of osmolarly active substances across intact, normal mucosa of the gastrointestinal tract. Clinical documentation of absorption of Gastrografin is presented. Renal excretion of contrast material was seen following its use in the treatment of meconium ileus.

Diatrizoate↗
PubMed1981

Intestinal absorption mechanism of amphoteric beta-lactam antibiotics II: Michaelis-Menten kinetics of cyclacillin absorption and its pharmacokinetic analysis in rats.

The absorption of cyclacillin at pH 7.0 by the rat small intestine was investigated using in situ perfusion. At the lowest dose of 95 microgram/ml, the antibiotic disappearance was rapid and followed first-order kinetics, with the disappearance being 85% at 100 min. At the intermediate concentrations of 770 and 1200 microgram/ml, the disappearance after 100 min was 69 and 54%, respectively, and semilogarithmic plots clearly showed convex curvatures. At the highest concentration of 30 mg/ml, cyclacillin disappeared slowly from the perfusate, in an apparent first-order fashion. The disappearance was 26% after 100 min of perfusion and was similar in extent at 5.2 mg/ml. This concentration-time profile was satisfactorily fitted to the simultaneous Michaelis-Menten and first-order kinetic equations. The area under the blood concentration versus time curve (AUC) after a single intraduodenal dose of cyclacillin was almost consistent with the AUC after the equivalent intravenous dose (10 mg/kg). Additional evidence from a pharmacokinetic analysis of steady-state blood concentrations after constant infusion of cyclacillin through the portal vein and the small intestinal lumen indicated that cyclacillin absorption by the rat intestinal tissue at relatively low concentrations (less than 1 mg/ml) followed solely Michaelis-Menten kinetics. Cyclacillin may be transported by certain types of carrier-mediated mechanisms.

Animals↗
PubMed1984

Enhanced intestinal absorption of amino acids and amino acid-like drug by possible formation of enamine in administered solution by the presence of ethylacetoacetate.

Ethylacetoacetate promoted the colonic and the jejunal absorption of amino acids such as L-phenylalanine and D-phenylalanine when administered in aqueous solution. Enhanced absorption of these isomers of amino acid might occur via a formation of enamine, which was observed in aqueous solution by monitoring ultraviolet absorbance at 288 nm. Since mixture of L- or D-phenylalanine and ethylacetoacetate in aqueous solution enhanced colonic absorption of cefmetazole while the solution did not affect so much on the jejunal absorption of cefmetazole compared to the colonic absorption of it, enhancing action of enamine probably produced in aqueous solution may be more effective at the colonic compartment.

Acetoacetates↗
PubMed1982

Effects of dietary phosphorus and calcium on the intestinal absorption of Ca in sheep.

1. Wether sheep were used, some of which were prepared with a Thiry-Vella loop of jejunum. The long-term use of these loops was ensured by regular perfusion with fresh nutrient solution. 2. The net calcium absorption rate from a Thirty-Vella loop of jejunum increased with increasing intraluminal Ca concentration and was increased by the addition of 1 alpha-hydroxy-cholecalciferol (3 micrograms/l) to the loop fluid. 3. When the diet of sheep was changed from one which was normal in Ca to a diet low in Ca there was an increase in the efficiency of net Ca absorption from the jejunal loop. This dietary change was accompanied by an increase in the circulating concentration of 1,25-dihydroxy-cholecalciferol (1,25(OH)2D3). 4. An intravenous infusion of the Ca chelating agent EDTA increased the efficiency of net Ca absorption from the jejunal loop. The use of 47Ca demonstrated that this reflected an increase in the true absorption rate of Ca. 5. Dietary phosphorus deficiency reduced the efficiency of intestinal Ca absorption and was associated with a reduction in the plasma concentration of 1,25(OH)2D3.

Animals↗
PubMed1980

Deficient intestinal absorption of L-tryptophan in progressive myoclonus epilepsy without Lafora bodies.

L-Tryptophan was administered orally to 7 patients with progressive myoclonus epilepsy (PME) without Lafora bodies and 7 controls. Total and free plasma tryptophan wre subsequently measured at intervals. Concentration of free tryptophan was equal in the two groups. Total tryptophan was significantly lower in PME patients and the difference became marked at 120 and 240 min after the oral dose. At the same time urinary excretion of indican rose in PME patients but not in controls but the change was not statistically significant. Urinary 5-HIAA excretion was a little lower in PME patients. The increase of 5-HIAA after administration of L-tryptophan was equal in both groups. Intravenous administration of L-tryptophan produced an equal increase of plasma concentrations in PME patients as in controls, measured at 2-h intervals. These findings suggest incomplete absorption of L-tryptophan through the intestinal tract in PME patients.

Epilepsies, Myoclonic↗
PubMed1996

Inhibitors in tea of intestinal absorption of phenylalanine in rats.

This work studies the effect of tea extract on the mucosal and serosal transport of phenylalanine, and attempts to identify the active ingredient(s) therein by studying the effect of known tea constituents like theophylline, caffeine and tannic acid. Tea and all the constituents tested inhibited the mucosal uptake of phenylalanine. The serosal transport was unaffected by caffeine and tannic acid, but inhibited by theophylline and high concentrations of tea. The in vitro activity of the intestinal Na+-K+ATPase was also assayed from a jejunal homogenate in presence of theophylline, caffeine, tannic acid and cAMP. All were found to inhibit significantly the enzyme. The in vitro activity of a purified Na+-K+ATPase was however stimulated by theophylline and caffeine, and inhibited only by tannic acid. It was concluded that the inhibitory effect of tea is exerted mainly through its constituents which inhibit the Na+-K+ pump directly (tannic acid) or indirectly (theophylline and caffeine), possible by elevating cAMP levels, dissipating thus the sodium gradient needed for the mucosal uptake of the amino acid.

Analysis of Variance↗