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 703 records · Page 39Linked to original sources
PubMed2006

Dietary inulin intake and age can affect intestinal absorption of zinc and copper in rats.

Nondigestible inulin-type fructan intake can stimulate intestinal mineral absorption in both humans and animals. However, this stimulatory effect may depend on experimental conditions such as the duration of the experience, mineral levels in the diet, and the animal's physiological status. The aim of this study was to determine the effect of inulin intake on Zn and Cu absorption in rats at different ages. Male Wistar rats (n = 80) of 4 different ages (2,5, 10, and 20 mo) were randomly assigned to a control group or a group administered 3.75% inulin in their diet for 4 d followed by 7.5% inulin for 26 d. Absorption of Zn67 and Cu65 was determined on d 21 of the experiment by fecal monitoring using Zn67 and Cu65 isotopes. Zn and Cu status was also assessed. Absorption of Zn67 and Cu65 was significantly lower in 11- and 21-mo-old rats than in 3- and 6 mo-old-rats. Moreover, inulin intake significantly increased Zn67 and Cu65 absorption. In conclusion, age and dietary inulin intake can significantly affect intestinal absorption of zinc and copper in rats. Further studies are required to explore this effect over longer periods of inulin intake and to test the effects of inulin in humans.

Aging↗
PubMed1976

[Effect of ursodesoxycholic acid and cholic acid on intestinal absorption of cholesterol].

A study was carried out to investigate the effect of ursodesoxycholic acid and cholic acid on intestinal absorption of cholesterol-4-14C administered p.o. to lymph-fistula rats. The results indicated that within 24 hours, the labeled cholesterol detected in thoracic duct lymph of the control group was 21.0% of the administered cholesterol-4-14C, whereas the group treated with cholic acid (250 mg/kg p.o.) was found to have an increased value of 30.6% absorbed cholesterol. In comparison, the group treated with the same dose of ursodesoxycholic acid showed a decreased value of 12.1%, indicating an inhibitory effect on cholesterol absorption by the compound. This differential effect of the two compounds was also observed in a time-course study.

Animals↗
PubMed1986

Physiological role of somatostatin in the digestive tract: gastric acid secretion, intestinal absorption, and motility.

Somatostatin is found in both endocrine cells and nerve fibres of the gastrointestinal tract and has several inhibitory effects on the digestive tract. Somatostatin is a potent inhibitor of gastrin release; its secretion is regulated predominantly by the cholinergic pathway, which inhibits somatostatin and thus stimulates gastrin release. Gastric acid secretion is inhibited by both the paracrine and circulating peptide (hormonal) effects of somatostatin. Somatostatin secretion is a direct effect of acid on the somatostatin cell, since it is unaffected by the axonal blocker tetrodotoxin. Somatostatin antiserum eliminates the inhibitory effect of somatostatin and thus augments acid secretion. It therefore appears that somatostatin plays a physiological role in regulating gastric acid secretion, and it is possible that a lack of the inhibitory function of somatostatin is an aetiological factor in peptic ulcer disease. Postprandially, a rise in serum somatostatin concentration occurs which is twice as high with protein and fat as it is with carbohydrates. Several studies have shown that somatostatin inhibits nutrient absorption, indicating that somatostatin might be a physiological regulator in the homeostasis of ingested nutrients by modulating the intestinal absorption rate. Experiments have also demonstrated that somatostatin infusion inhibits intestinal motility; the interval between migrating myoelectric complexes is increased, and transit time is increased.

Animals↗
PubMed1983

Fructose: incomplete intestinal absorption in humans.

Fructose is an increasingly important commercial sweetener. However, some patients report abdominal symptoms after ingesting fructose-containing foods. The completeness of fructose absorption by the small intestine was assessed by breath hydrogen analysis in 16 healthy volunteers and incomplete absorption was defined as a peak rise in breath hydrogen of greater than 20 parts per million. Fructose, 50 g as a 10% solution, was incompletely absorbed in 6 of 16 subjects (37.5%). Incomplete absorption was associated with symptoms of cramps or diarrhea, or both in 5 of these 6 individuals. Incomplete absorption was both concentration- and dose-related. Three subjects incompletely absorbed 37.5 g of fructose. In comparison, all 15 subjects who were studied after ingestion of sucrose, 50 g and a 10% solution, completely absorbed this sugar load. Incomplete absorption of fructose should be considered as a possible case of gastrointestinal symptoms.

Adult↗
PubMed1989

Influence of infusate viscosity on intestinal absorption in the rat. An explanation of previous discrepant results.

Previous studies of the influence of increased luminal viscosity on intestinal absorption have yielded conflicting results ranging from no effect to a marked diminution. We measured the absorption of three probes (carbon monoxide, [14C]warfarin, 5.5 mM glucose) from a saline infusate or from saline containing 0.6% guar, which yielded a 20-fold increase in viscosity. Two animal models were used: (a) conscious nonlaparotomized rats with chronically implanted cannulas and (b) anesthetized laparotomized rats. In the anesthetized laparotomized rats, absorption was independent of perfusate viscosity. In the conscious nonlaparotomized rats, the absorption of each of the three probes was significantly greater than in the anesthetized laparotomized rats and increased viscosity caused a 60%-70% decrease in the clearance of the three probes. In anesthetized laparotomized rats, we have shown that fluid moves with laminar flow, and increased infusate viscosity cannot further reduce luminal stirring (or absorption). In conscious, nonlaparotomized rats, laminar flow is disrupted by normal gut motility causing better luminal stirring. Such stirring is inhibited by a viscous infusate resulting in decreased absorption. We conclude that the conflicting results seen in previous studies can be attributed to the model used. In conscious animals where luminal stirring was good, a viscous infusate caused decreased absorption.

Animals↗
PubMed1993

Site specificity and meal stimulation of the intestinal absorption of water, electrolytes, and bile acids.

Ileal water and electrolyte absorption exceed jejunal absorption in both the basal and meal-stimulated states. The purposes of these experiments were to determine: (1) if luminal bile acids alter basal or meal-stimulated intestinal absorption, and (2) if there is site specificity or meal stimulation of intestinal bile acid absorption. Twenty-five centimeters of canine proximal jejunal and distal ileal Thiry-Vella fistulas were constructed. Simultaneous jejunal and ileal absorption studies (n = 88) were performed with a luminal perfusate containing polyethylene glycol labeled with radioactive carbon-14 to calculate the absorption of water, electrolytes, and the bile acid taurocholate (TC). In group 1, there was no TC in the luminal perfusate, whereas in group 2, 10 mM of TC was present in the luminal perfusate. Half of the observations were performed after a meal stimulus, which consisted of an orally ingested, 480-kcal mixed nutrient meal. Intraluminal TC did not affect basal or meal-stimulated water or electrolyte absorption. In both the basal and meal-stimulated states, ileal absorption of water, electrolytes, and TC significantly exceeded jejunal absorption (p < 0.05). A meal significantly stimulated water and electrolyte absorption in both the jejunum and ileum, but it stimulated absorption of TC in the ileum only (p < 0.05). Intraluminal TC does not alter basal or meal-stimulated intestinal water and electrolyte absorption. A meal stimulates increased water and electrolyte absorption in both the jejunum and the ileum, but it stimulates bile acid absorption in the ileum only. Bile acid absorption is site specific and responsive to a meal stimulus.

Animals↗
PubMed1978

Selective effects of thiazide on intestinal absorption of calcium and adsorptive and renal hypercalciurias.

The effect of long-term thiazide therapy on the intestinal Ca absorption was measured in 10 well-defined cases of absorptive hypercalciuria with intestinal hyperabsorption of Ca and 8 with renal hypercalciuria ("renal leak" of Ca), many of whom had hyperabsorption of Ca. In most cases of absorptive hypercalciuria, the intestinal hyperabsorption of Ca persisted during treatment, despite restoration of normal urinary Ca. In contrast, the intestinal Ca absorption decreased significantly during thiazide therapy in 7 of 8 patients with renal hypercalciuria commensurate with the "correction" of the renal leak of Ca and secondary hyperparathyroidism. The results support the hypothesis that the intestinal hyperabsorption of Ca in absorptive hypercalciuria may be primary, whereas that in renal hypercalciuria may be associated with the hyperparathyroid state.

Adult↗
PubMed1991

The effect of subchronic poisoning with potassium nitrate and sodium nitrite on the processes of intestinal absorption of D-xylose in rats.

The intestinal transport of D-xylose was studied during subchronic poisoning of male Wistar rats with the oral administration of potassium nitrate and sodium nitrite. The metabolic parameters of small intestine mucosa were determined one hour after xylose administration, i.e., Na+/K(+)-ATPase, alkaline phosphatase, oxygen consumption, and lactic acid level. Nitrite reduced the absorption of xylose and decreased the activity of Na+/K(+)-ATPase and alkaline phosphatase. No effect of sodium nitrite was demonstrated on the aerobic metabolism of intestinal mucosa with an increased lactic acid level. Potassium nitrate did not effect the processes of intestinal absorption of xylose nor the metabolic parameters of small intestine mucosa.

Administration, Oral↗
PubMed2003

Renal function in NHE3-deficient mice with transgenic rescue of small intestinal absorptive defect.

The degree to which loss of the NHE3 Na(+)/H(+) exchanger in the kidney contributes to impaired Na(+)-fluid volume homeostasis in NHE3-deficient (Nhe3(-/-)) mice is unclear because of the coexisting intestinal absorptive defect. To more accurately assess the renal effects of NHE3 ablation, we developed a mouse with transgenic expression of rat NHE3 in the intestine and crossed it with Nhe3(-/-) mice. Transgenic Nhe3(-/-) (tgNhe3(-/-)) mice tolerated dietary NaCl depletion better than nontransgenic knockouts and showed no evidence of renal salt wasting. Unlike nontransgenic Nhe3(-/-) mice, tgNhe3(-/-) mice tolerated a 5% NaCl diet. When fed a 5% NaCl diet, tgNhe3(-/-) mice had lower serum aldosterone than tgNhe3(-/-) mice on a 1% NaCl diet, indicating improved extracellular fluid volume status. Na(+)-loaded tgNhe3(-/-) mice had sharply increased urinary Na(+) excretion, reflective of increased absorption of Na(+) in the small intestine; nevertheless, they remained hypotensive, and renal studies showed a reduction in glomerular filtration rate (GFR) similar to that observed in nontransgenic Nhe3(-/-) mice. These data show that reduced GFR, rather than being secondary to systemic hypovolemia, is a major renal compensatory mechanism for the loss of NHE3 and indicate that loss of NHE3 in the kidney alters the set point for Na(+)-fluid volume homeostasis.

Aldosterone↗
PubMed1992

Site-specific variations in basal and meal-stimulated intestinal absorption.

The ingestion of a meal increases water and electrolyte absorption in the proximal jejunum. The purpose of these experiments was to elucidate any site-specific variations in intestinal absorption, comparing jejunum to ileum, in both the basal and the meal-stimulated states. Twenty-five-centimeter proximal jejunal and distal ileal Thirty-Vella fistulae were constructed in four dogs. Simultaneous jejunal and ileal absorption studies were performed using [14C]PEG to calculate net absorption of water and electrolytes. Two groups were studied: in Group 1 no meal was ingested, while in Group 2, the animals ingested a mixed meal. Each study consisted of a 1-hr basal period and a 3-hr experimental period. In the basal state ileal absorption significantly exceeded jejunal absorption (P less than 0.0001). The ingestion of mixed meal significantly increased water and electrolyte absorption in both the jejunum and the ileum, (P less than 0.001), with the magnitude of meal-stimulated ileal absorption significantly exceeding the magnitude of meal-stimulated jejunal absorption (P less than 0.001). These studies demonstrate distinct site specific variations in intestinal water and electrolyte absorption in both the basal and the meal-stimulated states.

Animals↗
PubMed1977

Intestinal absorption of 47Ca in elderly patients with osteoporosis, Paget's disease and osteomalacia. Effects of calcitonin, oestrogen and vitamin D2.

The intestinal absorption of 47Ca was studied in elderly patients. A standard dose of 10 muCi of 47Ca was given orally. The radioactivity was measured in the plasma, and expressed as percentage of the administered dose per litre plasma. As a control group served 12 patients aged 60-80 years, hospitalized for observation for various reasons, receiving no medical treatment and not suffering from any known metabolic bone diseases or other metabolic pathological conditions. Results of kinetic curves demonstrate in elderly patients a decreased absorption with maximum specific activity in plasma reached at 120 min, when compared to data from the literature referring to a group of young people with a mean age of 35 years. Oestrogen treatment, given as ethinyl oestradiol 10 mug once daily per os for 10 days proved to increase 47Ca absorption as was demonstrated in 2 patients with osteoporosis. The effect of calcitonin (160 MRC units given 45 min before the test) on calcium absorption, in 5 patients with Paget's disease or osteoporosis appears as biphasic: in the first hour depressing calcium absorption and then in the second and third hours increasing the absorption, suggesting a hyperparathyroid state secondary to the calcitonin effect. The vitamin D2 treatment proved to increase calcium absorption.

Aged↗
PubMed1981

Intestinal absorption of nutrients in rats treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

Impairment of active intestinal absorption of glucose and leucine was observed in rats 2-3 wk after oral treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (5 and 100 mg/kg). At the higher dose level used this response was complicated by the effects of severely reduced food consumption. Malabsorption of specific nutrients may help occasion the body wasting seen in many animals after acute exposure to TCDD.

Animals↗
PubMed1991

[Intestinal absorption of insulin with a new telemetric shuttle in dogs].

Telemetric shuttles for the in vivo investigation of the gastrointestinal tract have been available for sometime. We describe herein the use of a new shuttle model whose original features include: a) continuous, real time transmission of its location in the small bowel and accurate measurement of the gut length, b) controlled release of 1 ml of a given substance at any chosen site, allowing detailed investigation of intestinal absorption at different levels of the small bowel under physiological conditions. Small bowel length was measured in dogs using the shuttle and was later compared to the actual small gut length measured in the same animals at laparotomy. The telemetric measurements appeared to closely match the direct operative measurements. Insulin absorption from the canine small bowel was then investigated releasing different dosages of insulin together with the pancreatic enzyme inhibitors Soybean and Aprotinine and a surfactant (5-methoxysalicylate). By adjusting the dose of insulin released, the type of adjuvant substance delivered with it and the site of release in the small bowel, we have been able to precisely define the conditions of insulin absorption. Insulin as such is exclusively absorbed in the ileum when released in doses of 500 IU or higher and mixed with aprotinine. For absorption to take place the solution delivered by the shuttle needs to have the correct pH and natremic concentration.

Animals↗
PubMed1986

[Nutritional status and small intestine absorption].

A high percentage of hospitalized patients are malnourished. By means of biochemical examinations (visceral proteins), anthropometric measurements (body mass, triceps skinfold, arm muscle circumference, creatinine index) and immunological methods (total lymphocyte count in the blood, skin testing with test antigens) it is possible to classify nutritional conditions in severity and kind of malnutrition. 158 patients with chronic inflammatory diseases of the GI-tract and cancer without generalization were studied by means of an exact nutritional assessment and by means of the modified D-xylose test. There was no significant correlation between the degree of malnutrition and the extent of intestinal absorption. Only in 5.7 per cent of malnourished patients existed a malabsorption.

Female↗
PubMed1988

Kinetic mechanism for the intestinal absorption of ofloxacin.

The absorptive behaviour of ofloxacin, a quinolone antibacterial agent, was studied following recirculation in small intestine of both male and female rats, at initial doses ranging from 0.125 to 5 mg mL-1. A saturable Michaelis-Menten process is suggested to explain the intestinal absorption. No significant differences were found in the absorption parameters per metabolic weight unit.

Animals↗
PubMed1989

Passive and carrier-mediated intestinal absorption components of two angiotensin converting enzyme (ACE) inhibitor prodrugs in rats: enalapril and fosinopril.

The intestinal absorption mechanism of two ACE inhibitor prodrugs, enalapril and fosinopril, was investigated in rats using a single-pass perfusion method. A modified boundary layer solution was applied to determine the apparent intestinal wall permeability. The prodrug enalapril is well absorbed from rat jejunum, whereas the parent drug, enalaprilat, is poorly absorbed. The permeability of enalapril is concentration dependent and is decreased by the dipeptide Tyr-Gly and by cephradine but not by the amino acids L-leucine or L-phenylalanine, indicating a nonpassive absorption mechanism via the small peptide carrier-mediated transport system. In contrast, fosinopril is readily absorbed by a concentration-independent mechanism without the involvement of the peptide carrier.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1989

The influence of ascorbic acid and lactose on the interaction of iron with each of cobalt and zinc during intestinal absorption.

The effect of ascorbic acid and lactose on the interaction between iron and each of zinc or copper during intestinal absorption was studied in normal and iron-deficient rats. It was found that addition of cobalt to the iron dose inhibited absorption of iron to 42% in normal rats and to 46.7% in iron deficient ones. The presence of zinc with the iron dose also inhibited absorption of iron to 34.6% in normal rats and to 32.2% in case of the iron deficient ones. The addition of ascorbic acid to the combined dose of Fe + Co enhanced absorption of iron by five times in normal and in iron deficient rats. In case of the combined dose of Fe + Zn the enhancement was four times in normal rats and six times in iron deficient ones. The addition of lactose to the combined dose of either Fe + Co or Fe + Zn corrected the inhibiting action of either cobalt or zinc on iron absorption. Based on these findings, it is recommended that ascorbic acid and lactose be added to therapeutic multimineral preparations.

Animals↗