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At least 541 records · Page 30Linked to original sources
PubMed1992

Effects of nicarbazin on sugar intestinal absorption in rabbits.

Nicarbazin is an anticoccidial drug, used mainly in birds, which can also be used in rabbits. It has been shown to produce several effects, such as inhibition of growth and feed efficiency in poultry. The aim of the present work was to determine whether nicarbazin alters intestinal absorption of sugar. Results obtained show that nicarbazin decreases D-galactose accumulation in the jejunal tissue and increases mucosal to serosal transepithelial fluxes of this sugar, in both cases in a dose-dependent way. Furthermore, nicarbazin seems not to modify the sugar diffusion across the intestinal epithelium. The drug also stimulates the sugar uptake in brush border and basolateral membrane vesicles. The results suggest that in rabbits nicarbazin increases sugar intestinal absorption mediated by carriers.

Animals↗
PubMed1982

Lysosomal proliferation in rachitic avian intestinal absorptive cells following 1,25-dihydroxycholecalciferol.

Lysosomes in chick intestinal absorptive cells from rachitic (vitamin D-deficient) and vitamin D-replete animals were studied utilizing transmission electron microscopic histochemistry and ultrastructural morphometry. Absorptive cells from rachitic animals, serum calcium = 7.3 +/- 0.3 mg%, contained an average of 4.0 +/- 0.3 supranuclear lysosomes. In rachitic chicks sacrificed 9 hr post-injection of 1,25-dihydroxycholecalciferol, the active metabolite of vitamin D, the values for both serum calcium, 9.8 +/- 0.2 mg%, and the number of apical absorptive cell lysosomes, 12.9 +/- 0.6, were increased over non-injected or vehicle-only injected animals. Lysosomes in vitamin D-replete absorptive cells were characterized by their intense staining with pyroantimonate, indicative of their high calcium content. The same organelles also produced a positive reaction for acid phosphatase. Rachitic lysosomes, also acid phosphatase positive, were only lightly stained with pyroantimonate. The lysosomal proliferation apparently induced by 1,25-dihydroxycholecalciferol may be a further indication that these organelles play a role in intestinal calcium transport and/or intracellular calcium homeostasis within the absorptive cell.

Acid Phosphatase↗
PubMed1988

[Indirect evaluation of the effect of 1 alpha-hydroxyvitamin D3 on intestinal absorption of aluminum].

In a former study we have shown that 1 alpha OH vitamin D3 given to hemodialyzed patients taking A1(OH)3 at a constant dose increased their plasma concentrations of aluminium. Two mechanisms can explain this increase: increased intestinal absorption or decreased tissue storage of aluminium. We have, in the present study, given 1 alpha(OH)3 at the same dose (6 micrograms per week) and during the same duration (4 weeks) to 15 stable hemodialyzed patients after aluminium hydroxide has been discontinued 6 weeks before. Under A1(OH)3 treatment mean plasma aluminium was 2.33 +/- 2.36 mumol/l. After A1(OH)3 discontinuation, plasma aluminium decreased significantly as soon as the 2nd week of the control period (1.39 mumol/l). The decrease was maintained in plateau throughout the 5 weeks of the control period (1.38 mumol/l and, the 4 weeks of 1 OH Vit D3 administration (1.40 mumol/l). After 1 alpha OH D3 discontinuation there has been a non significant transient drop of aluminemia followed by a plateau at a level comparable to the previous plateau. Plasma calcium and phosphate concentrations increased significantly with 1 alpha(OH)3 and decreased thereafter confirming biological activity of 1 alpha(OH)3. Since 1 alpha(OH)3 increases plasma aluminium in hemodialyzed patients only when they are taking simultaneously A1(OH)3, it is suggested that this increase is mainly explained by an increase of the intestinal absorption of aluminium.

Adult↗
PubMedDate not supplied

[Study of intestinal absorption of calcium using 47Ca and whole body counter in renal calculosis with hypercalciuria].

Intestinal calcium absorption was studied using orally administered 47Ca and whole body counting. Using this method, we examined 82 patients suffering from recurrent calcium urolithiasis associated with idiopathic hypercalciuria, to evaluate the incidence of elevated intestinal absorption of this ion. An oral dose of 111 kBq (3 microCi) of 47Ca chloride, together with 250 mg of stable calcium as carrier, was given to each patient. Two hours and one week later, the total body radioactivity of each subject was measured. The retention of 47Ca, as percentage of the administered dose, was then calculated. The measurements were performed with a whole body counter consisting of a two-crystal moving system with shadow shield. Forty age-matched healthy volunteers were also examined. The whole body retention of 47Ca resulted significantly higher (p less than 0.0002) in the group of patients than in the control sample, whose m +/- SD was 22.0 +/- 6.0%. In particular, by defining the normality range as 10-34% (m +/- 2SD of control results), enhanced intestinal absorption of calcium was found in 28% of the examined patients. The use of this simple examination seems to be helpful in the physiopathologic assessment of subjects suffering from calcium urolithiasis and idiopathic hypercalciuria and consequently, in their appropriate management.

Adolescent↗
PubMed1977

[Oral iron treatment: intestinal absorption and the influence of a meal (author's transl)].

Intestinal iron absorption after a single dose of a special galenic preparation (50 and 100 mg iron as ferrous glycocoll sulphate in micropellets) was investigated in 105 persons with normal iron stores (42), latent (40) or manifest iron deficiency (23). Absorption rate rate on fasting as well as after breakfast was measured in 21 persons. Intestinal absorption increased in persons with iron deficiency, but maximal absorption after a single dose of 100 mg did not exceed 25%. This absorption rate was already reached in persons with latent iron deficiency. There was no significant reduction of absorption when the preparation was given at the end of breakfast.

Administration, Oral↗
PubMed2002

Effects of insulin-like growth factor-I and its analogue, long-R3-IGF-I, on intestinal absorption of 3-O-methyl-D-glucose are less pronounced than gut mucosal growth responses.

The relationship between insulin-like growth factor-I (IGF-I) peptide-induced increases in bowel mass and functional improvement is unclear. We utilised three independent methods to investigate the effects of IGF-I peptides on intestinal absorption of the glucose analogue, 3-O-methyl-D-glucose (3MG) in rats. Rats received vehicle, IGF-I or the more potent analogue, long-R3-IGF-I via subcutaneously implanted mini-pump, for 7 days, at which time intestinal absorption was assessed by: (1) plasma 3MG appearance following oral gavage, (2) single-pass- or (3) recirculating-perfusion of a jejunal segment. 3MG (320 or 800 mg) was gavaged on day 7 to rats treated with vehicle, IGR-I or long-R3-IGF-I. With the lower 3MG dose, only long-R3-IGF-I increased (40%) the initial rate of 3MG appearance in plasma. IGF-I had no significant effect, whilst at the higher 3MG dose neither peptide was effective. Utilising perfusion techniques, long-R3-IGF-I, but not IGF-I, significantly increased 3MG uptake per cm of jejunum by up to 69%, although significance was lost when expressed as a function of tissue weight. Long-R3-IGF-I, but not native IGF-I, enhanced 3MG absorption from the intestinal lumen, presumably reflecting an increased mucosal mass rather than an up-regulation of specific epithelial glucose transporters.

3-O-Methylglucose↗
PubMed1984

Effect of dietary fat on plasma glutathione peroxidase levels and intestinal absorption of 75Se-labeled sodium selenite in chicks.

The effect of dietary fat on the availability of selenium was investigated in chicks fed either 4 or 20% butter, olive oil, rape oil, corn oil or sunflower oil in the diet for 3 weeks after hatching. Plasma glutathione peroxidase (GSH-Px) activity was used as an indicator of the body selenium status. In addition, the intestinal absorption of sodium selenite (75Se-labeled) was determined by using both the in vivo ligated loop procedure and oral administration of the isotope. The plasma GSH-Px levels increased with increasing proportion of the polyunsaturated fatty acids in the diet. Increasing the amount of fat from 4 to 20% significantly enhanced the GSH-Px activity in the groups receiving butter or olive oil, but had no effect in animals fed the unsaturated fats. The absorption of [75Se]selenite from the ligated duodenal loops tended to be reduced in chicks fed corn oil or sunflower oil as compared to the animals receiving butter in their diet. On the other hand, the type of dietary fat did not appear to affect the absorption of the orally administered selenite. The present study demonstrates that the type of dietary fat can affect the plasma GSH-Px levels in chicks without altering the intestinal absorption of selenite. However, the results on the absorption of the intraduodenally injected sodium selenite suggest that dietary fat plays some role in the intestinal transport of selenium.

Animals↗
PubMed1968

Rate-limiting steps in steady-state intestinal absorption of trioctanoin-1-14C. Effect of biliary and pancreatic flow diversion.

During continuous intraduodenal infusion of emulsified fat in rats, a steady state of intestinal absorption is achieved. Maximal steady-state absorption of trioctanoin, a medium-chain triglyceride (MCT), by unanesthetized, restrained rats was found to be the same after total bile diversion as in controls (1560 mumoles of fatty acid per hr).After pancreatic and bile diversion, absorption of MCT was still one-third as rapid as in controls, and mucosal uptake apparently occurred in the form of unhydrolyzed triglyceride. Returning bile to the intestinal lumen during pancreatic diversion did not increase the absorption rate.From intestinal tissue lipid-(14)C concentrations measured during steady-state maximal absorption it was possible to calculate turnover times for labeled lipid passing through the mucosal cells. Mucosal turnover times of about 4 min for control and bile-diverted rats, and about 20 min for animals with pancreatic diversion were obtained. The rate-limiting step in octanoic acid absorption in control and bile-diverted rats was probably mucosal penetration. During absorption of unhydrolyzed triglyceride by pancreatic flow-diverted rats, both passage from the lumen into the mucosal cell and intracellular lipolysis were rate-controlling factors.

Absorption↗
PubMed2002

Fractional intestinal absorption of magnesium is directly proportional to dietary magnesium intake in rats.

The precise mechanisms of intestinal Mg absorption are still unclear and the possibility of an adaptative rise in the fraction of Mg absorbed as Mg intake is lowered is controversial. Mg deficiency has been studied extensively in rats where it is readily produced by dietary depletion. In this study, we investigated the effect of Mg intake on fractional absorption of Mg acutely and after adaptation to graded Mg intake in rats. For this purpose, male Wistar rats (n = 30) were fed a basal semipurified diet containing 600 mg Mg/kg (MgO) for 7 d. Three groups of 10 rats were then formed and fed the basal semipurified diet with 600, 300 or 150 mg Mg/kg, for 28 d. Apparent and true intestinal absorptions and fecal endogenous excretion of Mg were determined at the beginning and end of the experiment. As expected, plasma Mg levels were lower in the deficient groups than in the control by d 4 and differences were more marked at the end of the experiment. Erythrocyte Mg levels were significantly lower at the end of the experiment in the group fed the diet containing 150 mg Mg/kg. The amounts of Mg absorbed were directly proportional to the dietary Mg intakes in all three experimental groups at both testing periods. This indicated that the apparent and true intestinal absorption percentages of Mg were not different in rats fed the three different levels of dietary Mg. These results also show that fecal endogenous excretion of Mg was nearly directly proportional to the dietary Mg intakes. These results argue in favor of a passive diffusional process for intestinal Mg absorption.

Animal Nutritional Physiological Phenomena↗
PubMed1998

Mechanism of increased vessel wall nitric oxide concentrations during intestinal absorption.

Vasoactive compounds, including nitric oxide (NO) and hypertonic sodium, may diffuse from venous endothelial cells and blood to the arterial wall during intestinal absorption. This hypothesis was tested by measuring the perivascular NO concentration ([NO]) for paired small arteries and veins with NO-sensitive microelectrodes. Resting arterial and venous wall concentrations for nine vessel pairs (5 rats) were 353 +/- 28 and 401 +/- 48 (SE) nM. During mucosal absorption of 100 and 300 mg/dl glucose, the artery dilated 12 +/- 1.5 and 17 +/- 2%, [NO] increased to 540 +/- 68 and 550 +/- 49 nM, and venous wall [NO] increased to 557 +/- 60 and 633 +/- 70 nM. During venous occlusion to block diffusion of materials from venous blood to the artery wall, the arterial and venous [NO] decreased by 70-80%, and one-half of the arterial dilation subsided. Superfusion with 320 and 360 mosmol/l hypertonic sodium medium to simulate the sodium hyperosmolarity during mucosal absorption of glucose increased the arterial [NO] by 20-30 and 40-50%; 360 mosmol/l saline made hypertonic with mannitol did not significantly increase the [NO]. Although venous to arterial diffusion of NO occurred, the increased arterial [NO] during mucosal glucose absorption was primarily generated by the arterial wall in response to materials that diffused from venous blood, such as hypertonic sodium.

Animals↗
PubMed1978

Demonstration of saturation kinetics in the intestinal absorption of vitamin C in man and the guinea pig.

Intestinal absorption of ascorbic acid is believed to be mediated through a sodium-dependent active transport process in man and in the guinea pig, both species having a nutritional requirement for the vitamin. Vitamin C transport was studied in man and in the guinea pig by in vivo intestinal perfusion of concentrations of vitamin C ranging from physiologic to clearly pharmacologic levels. Triple lumen intestinal perfusion of seven human volunteers with vitamin C concentrations ranging from 0.85 to 11.36 mM demonstrated saturation kinetics of absorption with a Km = 5.44 mM. Net secretion of water was observed in three of seven humans with the highest (11.36 mM) concentration of vitamin C. Perfusion of isolated segments of guinea pig intestines with intact blood supply also revealed saturation kinetics (Km = 5.54 mM) in the range of 1.42 to 56.8 mM vitamin C but linear absorption below this range. The phenomenon of decreased water absorption noted with incremental vitamin C dose in human volunteers could not be reproduced in the guinea pig, nor were the intestinal tissue levels of cyclic AMP and GMP increased by high-dose vitamin C in this species. This study suggests that "megavitamin" doses of vitamin C (greater than 1 Gm) are probably not as efficiently absorbed as smaller multiple doses of the vitamin. Intestinal secretion of water may contribute to the diarrhea which is the most common side effect of large doses of vitamin C. The guinea pig is a useful but limited model for vitamin C absorption in man.

Adult↗
PubMed1983

Intestinal absorption of amino acid derivatives: structural requirements for membrane hydrolysis.

The intestinal absorption of L-lysine-p-nitroanilide, L-alanine-p-nitroanilide, and glycine-p-nitroanilide was studied in perfused rat intestine in the presence of a variety of potential competitive inhibitors. The results indicate that the hydrolysis site(s) show side-chain specificity, and that inhibitors require a free amino group in the alpha-position and must be in the L-configuration to be effective. Glycyl-L-proline, a peptide transport inhibitor, had no effect on the absorption rate.

Alanine↗
PubMed1977

[Effect of plant gums (swelling materials) on intestinal absorption in experimental animals].

The influence of various gums on the intestinal absorption of glucose and maltose was investigated in the experimental animal. The alterations in the concentrations of sodium and potassium were determined additionally. The following gums were used: alginate (sodium, potassium, calcium salts), Carrageenan, guaran, methylcellulose, carboxymethylcellulose. The absorption of glucose (concentration: 5% = 278 mmol/l) and maltose (concentration: 5% = 139 mmol/l) was not influenced by the addition of gums (concentration: 1%-2%). The hydrolysis of maltose was not inhibited also. Sodium was absorbed from the intestinal lumen if the concentration was higher than 120-150 mmol/l, otherwise sodium was excreted into the lumen. Potassium was absorbed if the potassium concentration was raised above 6-10 mmol/l, otherwise potassium was excreted into the lumen. The neutral gums did not influence the alterations in ion concentration. The gums tested do not influence the digestion and absorption of maltose or glucose. The acid gums are present in the small intestine in the form of their sodium salts. In the large intestine, sodium is exchanged for potassium.

Alginates↗
PubMed1996

Effect of glucose and lipids on intestinal absorption of sorbitol: role of gastric emptying.

The aim of our study was to test the hypothesis that the better absorption of sorbitol when ingested with glucose could be related to a delayed gastric emptying. We tested the effect of the ingestion of glucose and lipids on the gastric emptying and intestinal absorption of sorbitol in six healthy volunteers, using gastric scintigraphy and hydrogen breath test. After an overnight fast, subjects ingested in random order, on 48-h test periods separated by at least one week, the following solutions: (a) 20 g sorbitol alone; (b) 20 g sorbitol and 20 g glucose; (c) 20 g sorbitol and 9 g lipids. Isotopic acquisitions were taken for 3 h following the ingestion of sorbitol labelled with 111Indium. Hydrogen concentration was measured in end-expiratory samples during 5 h, and the areas under the breath hydrogen curve, reflecting the amounts of sorbitol unabsorbed in the small bowel, were compared between periods. Mean area under the curve was 397 +/- 159 when sorbitol was ingested alone, and this was significantly lower when ingested with glucose or lipids (313 +/- 181 and 337 +/- 135, respectively; P < 0.05). The three curves of sorbitol gastric emptying differed significantly from each other, the gastric emptying being the slowest for sorbitol plus lipids, and the fastest for sorbitol taken alone. We found a positive correlation between the half-emptying time and the hydrogen areas under the curve (r = 0.46, P = 0.05). In conclusion, our study demonstrates that adding glucose or lipids to a solution of sorbitol slows the gastric emptying of sorbitol, resulting in a better intestinal absorption of sorbitol.

Adult↗