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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Glucose absorption, water absorption and dipeptide hydrolase activities have been determined in isolated rat small intestine at 1, 3, 5 and 21 days after a single intraperitoneal injection of 5-fluorouracil. 2. Absorption rates and enzyme activities were elevated 1 day after treatment, but were reduced to 40% of control values at 3 and 5 days. Changes were seen regardless of whether absorption was expressed per unit length or per unit dry weight of intestine. 3. There were highly significant positive correlations between glucose or water absorption rates and peptidase activities, especially in proximal jejunum. The most significant correlation was observed between water absorption rate and jejunal L-Leu-Gly hydrolase activity. 4. Malabsorption may account for some of the gastrointestinal side effects associated with treatment with 5-fluorouracil. Enzyme measurements may be useful as an index of intestinal function.
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PMID:Changes in absorptive and peptide hydrolase activities in rat small intestine after administration of 5-fluorouracil. 63 72

We have studied the absorption of 3-methylhistidine (3MH) in vitro and changes in its plasma concentration in preruminant calves after ingestion of milk containing 3MH under normal and malabsorptive conditions. Changes in 3MH concentration were compared to those in lysine, homoarginine (as a component of guanidinated caseine) and xylose, also added to milk. The absorption of 3MH in vitro was dose-dependent and was inhibited by leucine, indicating that 3 MH was transported in the same manner as neutral amino acids. After the ingestion of milk supplying 2.5-20 mumols (3MH)/kg body weight, 3MH increased dose-dependently within 1.75 h and reached maximal levels between 3 and 8 h. Lysine concentration initially parallelled the course of blood 3MH levels but dropped sooner. Homoarginine concentration did not increase until 2-4 h postprandially, probably as a consequence of the time needed for casein degradation. Xylose concentration increased as rapidly as 3MH and lysine concentration. Feeding a diet containing soybean protein for 36 d and administration of neomycine for 5 d to newborn calves induced malabsorption of xylose. However, 3MH absorption and caseine digestion, which increased after homoarginine absorption were not reduced.
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PMID:[Postprandial plasma variations of 3-methylhistidine compared to those of lysine, homoarginine and xylose on the normal conditions and in malabsorption in the suckling calf]. 170 Sep 10

Chylomicron retention disease is characterized by fat malabsorption, hypocholesterolemia, normal fasting triglycerides, and marked intestinal steatosis despite the presence of both plasma and intestinal apoprotein B. The defect remains unknown but presumably involves the synthesis or secretion of chylomicrons. The present investigation examines this hypothesis by studying the biosynthesis of chylomicrons in cultured jejunal explants and by defining the quantitative and qualitative abnormalities of plasma lipids and of circulating lipoproteins. Following 2-3 years of a low fat diet supplemented with medium chain triglycerides, six patients with chylomicron retention disease had significantly higher triglyceride (TG) levels coupled with a decrease in both free (FC) and esterified cholesterol (EC) as well as in essential fatty acids and phospholipids (PL) when compared to healthy controls. The low total plasma cholesterol was largely accounted for by low levels of both low density (LDL) and high density lipoprotein (HDL) cholesterol. VLDL and LDL were characterized by a diminished percentage of CE with an increase of TG while HDL contained relatively more FC as well as PL and less CE. The diameter of VLDL was larger whereas those of LDL and HDL were smaller than in normal controls. Jejunal explants, when incubated with [14C]palmitate, were capable of normal biosynthesis of TG, diglycerides, PL, and CE. These lipids, however, except for PL, were retained in the tissue and could not be secreted into the culture medium. Incubation of intestinal biopsies with [3H]leucine and [14C]mannose resulted in normal protein synthesis and reduced glycosylation. The presence of intestinal apoB-48 was confirmed by immunoblot using 2D8 antibodies. These data suggest that the intestinal defect in this disease results from a disorder of the final assembly of chylomicrons or in the mechanism of their exocytosis.
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PMID:Intestinal apoB synthesis, lipids, and lipoproteins in chylomicron retention disease. 343 59

Patients undergoing massive small bowel resection for a variety of conditions develop severe nutrient malabsorption which gradually improves through mucosal hyperplasia in the remaining small intestine. Following massive small bowel resection, patients are generally fed elemental diets, often containing high concentrations of medium-chain triglycerides. We evaluated the effect of high percentage medium-chain triglyceride feeding on mucosal adaptation following massive small bowel resection in rats. Twenty 150-g Sprague-Dawley rats were subjected to 60% jejunoileal resection. Another 20 animals received sham operations. One-half of each group were fed a diet containing 83% of the fat as medium-chain triglycerides, the remainder were fed a diet containing 40% medium-chain triglycerides. Animals were pair-fed for 2 wk and subsequently killed. The remaining bowel was removed and unidirectional glucose and leucine uptake were measured using isolated sacs. Mucosal wet weight, protein, and sucrase content were determined. Animals fed medium-chain triglycerides demonstrated decreased mucosal weight in the proximal bowel, decreased mucosal sucrase activity in the proximal bowel, and decreased mucosal leucine uptake in the distal bowel. While medium-chain triglycerides offer an advantage to patients with short bowel syndrome because they are easily absorbed, they may not stimulate the same degree of mucosal adaptation following resection as long-chain triglyceride feedings.
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PMID:Effect of high percentage medium-chain triglyceride diet on mucosal adaptation following massive bowel resection in rats. 644 Oct 12

Blood samples were taken from six overweight women after an overnight fast on three different occasions, before an jejunoileal bypass operation and 1 and 6 months after the operation. The preoperative levels of several plasma free amino acids were significantly elevated, e.g. leucine, isoleucine, valine, lysine, phenylalanine, tyrosine, proline and glutamic acid. One month after the operation all indispensable plasma amino acid concentrations had fallen, in particular the levels of the branched-chain amino acids (BCAA), lysine and tryptophan. Among the dispensable amino acids, plasma tyrosine, arginine and ornithine concentrations were significantly reduced. No further changes of significance were observed in samples taken 5 months later. A close correlation was observed between the plasma levels of retinol-binding protein (RBP) and thyroxine-binding prealbumin (TBPA). One month after the operation the levels of RBP and TBPA had fallen slightly in two subjects and substantially in one subject. A test diet, containing crystalline amino acids, glucose and fat emulsion was given before operation and twice after the operation. Plasma amino acid changes were studied for a period of 2 hours after the meal. The increases in plasma levels following the test meal were lower for many amino acids after the operation. A linear correlation was found between the postprandial increases in BCAA concentrations and the levels of RBP and TBPA. By using complete, carefully defined diets in loading tests, it should be possible to screen for glucose tolerance and amino acid and lipid malabsorption.
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PMID:An oral amino acid loading test before and after intestinal bypass operation for morbid obesity. 713 14

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.
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PMID:Intestinal absorption of nutrients in rats treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). 733 35

Rare instances of symptomatic fat malabsorption have been reported in patients with heterozygous hypobetalipoproteinemia, but with an unclear pathogenesis. An 8-month-old boy with chronic diarrhea and failure to thrive was found to have abnormally low plasma total cholesterol (85 mg/dl), LDL-cholesterol (48 mg/dl), apoB (52 mg/dl), apoA-I (53 mg/dl), and vitamin E (0.22 mg/dl). Decreased plasma LDL-C and apoB were noted in the father (34 and 40 mg/dl, respectively), as well as several other family members. Fasting triglycerides were normal but did not increase normally in response to a fat meal test. Lipoprotein composition showed an abnormal profile of very low density (VLDL, d 1.006 g/ml), low density (LDL, d 1.063 g/ml), and high density (HDL, d 1.21 g/ml) lipoproteins. A fasting jejunal biopsy revealed lipid-laden enterocytes. Electron microscopy of the jejunal biopsy revealed the absence of lipid particles in the intercellular spaces after a fat meal. Jejunal explants cultured with [14C]palmitate and [3H]leucine showed limited synthesis of triglycerides and apolipoproteins (36 and 42% of controls, respectively), whereas the father's results were close to normal. At 1 year of age, improvement in intestinal fat absorption was accompanied by the presence of chylomicrons in the intercellular space, concomitant with the enhanced synthesis of lipids and apoB by jejunal explants. These data provide evidence that heterozygous hypobetalipoproteinemia may present early in life as transient, symptomatic lipid malabsorption. The mechanisms responsible for improved lipid transport despite persistent hypobetalipoproteinemia remain to be established.
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PMID:Variable expression of familial heterozygous hypobetalipoproteinemia: transient malabsorption during infancy. 789 15

Acute intestinal inflammation was established in rats by intraluminal administration of acetic acid into loops of distal ileum, proximal jejunum or ascending colon. The study included two control groups of intact (untreated) rats and sham-operated (saline-treated) rats for each intestinal segment. A third group of rats received acetic acid. Histological evaluation demonstrated that acetic acid treatment induced a mild inflammatory response. Two days after treatment, zinc absorption was measured using ligated 10-cm loops of each segment in which 65Zn was injected intraluminally. 65Zn absorption by the ileum, jejunum and colon was markedly reduced in those rats in which inflammation was induced by acetic acid. The liver showed the highest uptake of radioisotope, but the relative tissue distribution generally followed the amount of absorption. The surgical procedure itself seemed to reduce zinc absorption. No changes in [3H]leucine absorption were observed between sham-operated and acetic acid-treated controls. There was no significant serosal-->luminal secretion of intramuscularly injected 65Zn in any of the studied segments. Therefore, based upon the data obtained, we conclude that acetic acid-induced intestinal inflammation reduces absorption of zinc by the small and large intestine, and that a surgical procedure (laparotomy) also reduces zinc absorption. The mechanism of this inflammation is such that malabsorption shows some specificity.
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PMID:Malabsorption of zinc in rats with acetic acid-induced enteritis and colitis. 833 9

We prepared corn peptide (CP), a vegetable oligopeptide and tried to discover the effects of its ingestion on facilitating alcohol metabolism in healthy adult men. Ten healthy male volunteers ingested 5 g of CP, wheat peptide (WP), pea peptide (PP), alanine, or leucine 30 min before alcohol intake at a dose of 0.5 g/kg, and blood ethanol and plasma amino acid concentrations were measured during a 2-h observation period after alcohol intake. In subjects who ingested CP, the blood ethanol level was lower than that in the WP, alanine and leucine ingestion groups, but did not decrease as compared to the control when they ingested PP. Similarly there was a difference in the blood ethanol level between alanine and leucine ingestion groups, and leucine ingestion was more effective than alanine against the reduction of the increase in blood ethanol level. On the other hand, there was no significant difference in the plasma concentrations of individual amino acids except alanine, leucine, or lysine after alcohol intake among experimental groups as compared to the control. CP ingestion significantly elevated plasma alanine and leucine rather than other groups during a 2-h observation period. These results suggested that CP may have the effect on the reduction of increase in blood ethanol level after alcohol intake by the marked elevation of plasma alanine and leucine, especially leucine, but neither by the delay of ethanol release from the stomach nor malabsorption of ethanol in the gastrointestinal tracts.
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PMID:The effects of corn peptide ingestion on facilitating alcohol metabolism in healthy men. 933 48

In the present study. we explored the nutritional consequences of cryptosporidiosis. In order to ascertain the direct responsibility of C. parvum for impairment of staturoponderal development observed during the infection in neonatal animals, we investigated the absorption of two major components of the total amino acids in dam's milk (leucine and glutamate) across the ileal mucosa. The infection resulted in significant (47% and 34%, respectively) reductions in leucine and glutamate fluxes (P<0.01). Moreover, the leucine aminopeptidase and alkaline phosphatase activities were reduced in the infected ileal mucosa. Interestingly, the reduction in weight gain, which began at day 6 post-infection (PI), persisted until day 20 PI, although no cryptosporidia were detected in the ileal mucosa after day 12 PI. We thus provide evidence that the malabsorption of amino acids during cryptosporidiosis contributes to impairing the development of neonatal animals, with consequences that persist beyond eradication of the parasite.
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PMID:Impairment of amino-acid absorption in suckling rats infected with Cryptosporidium parvum. 1172 11


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