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The role of the duodenum in adaptive changes in sucrose digestion in the small intestine of chicks.

In two experimental series in situ applying perfusion technique, and in vitro, the role of the duodenum in adaptation of sucrose digestion was investigated in the proximal, medial and distal parts of the chick small intestine. No adaptive changes occurred in hydrolysis and carbohydrate transport if the pancreo-duodenal complex was isolated from the lower parts. It is suggested that on feeding with sucrose, factors arise in the duodenal mucosa causing adaptive changes in sucrase activity of the small intestine.

Animals↗

Ascending responses induced by transmural nerve stimulation in the cat duodenum.

Electromyographic responses of the cat duodenum were recorded in vitro up to 5 cm oral to the site of transmural nerve stimulation. Repetitive stimulation induced ascending cholinergic and non-cholinergic excitatory responses characterized by an increase in the slow wave amplitude and spiking activity. Ascending inhibitory responses were also recorded and were characterized by a suppression of the spiking activity and a decrease in the slow wave amplitude. The ascending cholinergic excitatory response was abolished by atropine. The non-cholinergic excitatory and inhibitory responses both disappeared in the presence of tetrodotoxin.

Animals↗

Electron microscopic study on S-100 protein-immunoreactive cells in the guinea pig duodenum, with special reference to the interstitial cells of Cajal.

S-100 protein-immunoreactive cells were studied in the nervous system of the guinea pig duodenum by pre-embedding immunoelectron microscopic cytochemistry. Immunoreactivity of S-100 protein was found diffusely in the cytoplasm of enteroglial cells in the ganglia, nerve strands and autonomic ground plexus. There were fibroblast-like cells containing no S-100 protein immunoreactivity around the ganglia and nerve bundles. Relationship between the fibroblast-like cells and the interstitial cells of Cajal was discussed.

Animals↗

Determination on functional basis of presynaptic alpha 2-adrenoceptor subtypes in guinea-pig duodenum.

The effects of several alpha 2-adrenoceptor agonists and antagonists were examined on the cholinergic twitch contractions evoked by electrical field stimulation of guinea-pig duodenum. Oxymetazoline, xylazine, noradrenaline, alpha-methyl-noradrenaline or medetomidine (0.01-30 microM) were nearly equieffective in inhibiting duodenal twitch responses. The effects of xylazine were competitively counteracted by antagonists tested (0.03-10 microM) with the following order of potency: RX 821002 = idazoxan > rauwolscine = yohimbine = BRL 44408 >> prazosin = ARC 239 = BRL 41992. According to the current classification, it is suggested that alpha 2-heteroadrenoceptors involved in the modulation of duodenal cholinergic neurotransmission belong to the alpha ZD subtype.

Adrenergic alpha-2 Receptor Agonists↗

Histochemical alterations in the duodenum of goats experimentally infected with Paramphistomum cervi.

Certain histochemical alterations in the different tunics of duodenum in kids were studied 20, 40, 60 and 80 days post-infection (DPI) with Paramphistomum cervi and the results compared with those of uninfected kids. There was a general reduction of polysaccharide complex substances and glycogen at 20 DPI. A marked decrease in polysaccharide complex substances and glycogen at 20 DPI. A marked decrease in polysaccharide complex substances and glycogen was especially discernible in the Brunner's gland and muscularis mucosa 20 DPI. Thereafter, these substances gradually increased and at 80 DPI this decrease was fully replenished. A slight reduction in mucin and protein content of the infected duodenal goblet cells was noticed at 20 DPI. It is suggested that juvenile P. cervi utilize host-tissue polysaccharide complex substances and glycogen for their growth and development during duodenal migration.

Animals↗

Studies on the role of transferrin and endocytosis in the uptake of Fe3+ from Fe-nitrilotriacetate by mouse duodenum.

Addition of iron-binding proteins (human serum transferrin, mouse serum transferrin, human lactoferrin) to the luminal fluid in tied-off segments of mouse intestine in vivo led to reduced 59Fe3+ absorption from 59Fe3+-nitrilotriacetate when compared to 59Fe3+-nitrilotriacetate alone. Assay of transferrin in luminal fluid from tied segments revealed only trace amounts of immunoreactivity. The levels of luminal transferrin are unaltered in chronic hypoxia where iron absorption is significantly enhanced. Studies in vitro revealed that NH4Cl, dansylcadavarine, para-chloromercuribenzoate and trinitrobenzenesulphonate have no effect on initial 59Fe3+ uptake rates from 59Fe3+-nitrilotriacetate, while N-ethylmaleimide (1 mM) caused a 40% inhibition. In vivo 59Fe3+ uptake was unaffected by preincubation of tied-off segments with colchicine (5 mM) for up to 2 h. These results suggest that receptor-mediated endocytosis of transferrin is not a significant mechanism in the uptake of luminal Fe3+ by mouse duodenum.

Animals↗

Effect of lateral hypothalamic area lesions on serotonin-containing epithelial cells in rat duodenum.

The aphagic effect of lateral hypothalamic area (LHA) lesions induced by kainic acid injection on serotonin (5HT)-containing epithelial cells in rat duodenum was studied in comparison with food deprived rats. The densities of 5HT cells were evaluated by quantitative morphometry using fluorescent histochemical longitudinal sections. The levels of 5HT/mg tissue were determined by HPLC on acid extracts of isolated villous epithelium. Body and duodenal weight losses, as well as duodenal mucosal atrophy, were comparable in the two groups of starved animals, i.e., one is food deprived and the other is lesioned animals. The numbers of 5HT cells in these starved groups were similar to those in controls so that the densities were increased. The 5HT/mg tissue in food-deprived animals was similar to that in controls but significantly higher in the LHA-lesioned group. These results are interpreted in terms of a possible central regulatory mechanism that is intact in the food-deprived animals but destroyed in the lesioned animals.

Animals↗

Cadmium-induced changes in the histoenzymatic activity in liver, kidney and duodenum of pregnant rats.

Cadmium was administered in drinking water at a concentration of 50 ppm to female Wistar rats for 5 months before mating, and then continued during gestation. The histochemical evaluation revealed a relative decrease in succinic dehydrogenase (SDH) and Mg+2-stimulated ATPase activities in duodenum, liver and kidney in the exposed rats. It is suggested that the resulting decrease in metabolic efficiency in maternal organs would be expected to exert an indirect, inhibitive effect on maternal-fetal transfer of nutrients, as reflected by fetal growth retardation.

Adenosine Triphosphatases↗

Aluminum absorption by rat duodenum: further evidence of energy-dependent uptake.

Duodenums of intact anaesthetised rats have been perfused with saline-bicarbonate buffer (pH 8.5), containing AlCl3, across a range of concentrations 0-300 microM. A linear relation between rate of uptake and perfusate Al concentration was found. The clearance of Al from the lumen was also studied with the mean perfusate concentration of 60 microM, in the presence of certain inhibitors. The clearance was significantly reduced by NaCN(1 mM) or dinitrophenol (0.1 mM) in the perfusate, and by prior perfusion with vanadate (10 microM) in saline. No effect was observed after colchicine (25 micrograms) was administered i.v. 3 h before perfusion, but vincristine (10 micrograms) given similarly reduced clearance significantly. Verapamil (25 micrograms/ml) in the perfusate caused a small, just significant, reduction in clearance. These data further characterise duodenal absorption of Al under physiological conditions and suggest that energy-dependent transport plays an important role in its uptake. Calcium channels may provide an additional entry site.

Aluminum↗

Blood appearance of rat alkaline phosphatase originating from the duodenum in vitro.

The major source of rat serum alkaline phosphatase (ALP) is well known to be from the intestinal enzyme, but it is still unclear whether it is from the duodenal or the ileal enzyme. The organic origin was investigated by means of two-dimensional electrophoresis. Major isoelectric points and molecular masses for activities of duodenal enzyme treated with both phosphatidylinositol-specific phospholipase C and neuraminidase were identified apparently with those of the major serum enzyme. In organ culture, the normal duodenal enzyme was released in the highest amounts to the culture medium. These results indicate that the major source of serum ALP in adult rats is basically from the duodenal enzyme. On the other hand, lectin affinity chromatography for ALPs showed that the ALP in the medium from culture duodenum and liver had the same complex-type sugar chain as with the ALP in the duodenal tissue. Although the duodenal ALP induced by glucosamine in vitro had the hybrid-type chain, sugar chains of the induced ALP in the culture medium were of the complex type, indicating that medial ALPs possessing the same sugar chain as the native duodenal enzyme, complex type, are mainly released from their tissues in normal conditions.

Alkaline Phosphatase↗

Circulation of estrogens introduced into the rectum or duodenum in pigs.

To determine the absorption and metabolism of 17 beta-estradiol (E2) by the rectum of the pig, 10 mg of crystalline E2 was placed in the rectum of prepubertal gilts in Experiment 1. Blood samples were subsequently obtained from hepatic portal and jugular veins and plasma was assayed for E2, estrone (E1), 17 beta-estradiol-glucuronide (E2G), estrone-glucuronide (E1G) and estrone-sulfate (E1S). Concentrations of E2, E1, E2G, E1G, and E1S rose in the hepatic portal vein within 30 min and remained elevated for several hr. Concentrations of E2 in the hepatic portal vein represented 3% of the total estrogen detected in the hepatic portal vein during the 5 hr sampling period, indicating that most of the E2 was metabolized prior to entering the hepatic portal vein after absorption by the rectal mucosa. Concentrations of E2, E1, E2G, E1G, and E1S rose in the jugular vein and remained elevated for several hr. The rise in E2 and E1 in the jugular vein may have come from E2 and E1 in venous circulation from the rectum that entered the inferior vena cava bypassing the hepatic portal vein and liver. The net result of absorption of E2 from the rectum of gilts was a large rise in unconjugated and conjugated E2 and E1 in the peripheral circulation. In Experiment 2 prepubertal gilts fitted with jugular, hepatic portal, duodenal, and gall bladder catheters were infused into the duodenum with bile from pregnant gilts. Concentrations of E2, E1, E2G, and E1G were determined in gallbladder bile of gilts before infusion and at 470 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Rectal↗

Absorption and metabolism of estrogens from the stomach and duodenum of pigs.

To determine the absorption and metabolism of 17 beta-estradiol (E2) by the stomach and liver of the pig, crystalline E2 was placed in the stomach of prepubertal gilts. Blood samples were subsequently obtained from the hepatic portal and jugular veins and plasma was assayed for E2, estrone (E1), 17 beta-estradiol-glucuronide (E2G), estrone-glucuronide (E1G) and estrone-sulfate (E1S). Concentrations of E2, E1, E2G and E1S rose in the hepatic portal vein within five min and remained elevated for several hr. Concentration of E2 represented only 6% of the total estrogen detected in the hepatic portal vein during the sampling period, indicating that most of the E2 was converted or conjugated prior to entering the hepatic portal vein. The metabolism of E2 presumably occurred in the stomach mucosa because food had been withheld for 26 hr before infusion of E2. Concentrations of E2G, E1G and E1S, but not E2 and E1, rose in the jugular vein and remained elevated for several hr. The lack of a rise in E2 and E1 in the jugular vein indicates that the E2 and E1 from the hepatic portal vein were completely converted and/or removed by the liver. Most of E2 was converted to E1 and then to E1G. The infusion of bile containing normal estrogens from pregnant gilts into the duodenum of prepubertal gilts resulted in a peak of E1G and E2G in the hepatic portal and jugular veins within a few minutes. This was followed in about 180 min by a second sustained rise. The first peak was essentially abolished by extracting E1 and E2 from the bile before infusion. The second peak failed to occur in gilts given antibiotics orally to reduce gut bacteria before infusion of bile.

Absorption↗

Effects of Ro 5-4864 and PK 11195 in rat duodenum and vas deferens.

Ro 5-4864 and PK 11195 inhibit in a concentration-dependent manner carbachol-induced contractions in rat duodenum (IC50: 1.56 +/- 0.07 x 10(-5) M and 1.18 +/- 0.07 x 10(-5) M respectively). The antagonism is non-competitive and is not mediated by peripheral-type benzodiazepine receptors. The Ro 5-4864 effect is modulated by the calcium concentration of the Tyrode-Ringer solution. In the presence of 1 mM NaF/10 microM AlCl3, Ro 5-4864 and PK 11195 do not inhibit carbachol-induced contractions. Moreover, Ro 5-4864 and PK 11195 significantly relax AlF(4-)-induced contractions, with IC50 values of 2.01 +/- 0.12 x 10(-5) M and 1.28 +/- 0.11 x 10(-5) M respectively. This effect is also modulated by the calcium concentration of the medium. Pertussis toxin potentiates the antagonist effects of Ro 5-4864 and PK 11195 on carbachol-induced contractions, but cholera toxin does not affect them. Ro 5-4864 and PK 11195 inhibit 45Ca2+ uptake induced by KCl (120 mM) in rat vas deferens, but do not affect either basal 45Ca efflux or noradrenaline-induced 45Ca2+ efflux. Only high doses of PK 11195 (above 5 x 10(-5) M) are able to produce a slight reduction of the accumulation of inositol phosphates induced by methoxamine in rat vas deferens, while Ro 5-4864 has no significant effect. Finally, Ro 5-4864 and PK 11195 reduce calcium influx, but do not seem to be the only mechanism of the antagonistic effect on carbachol-induced contractions. An alteration of other second messengers, probably cyclic monophosphate nucleotides, may be involved.

Animals↗

Transgenic expression of the human Vitamin D receptor (hVDR) in the duodenum of VDR-null mice attenuates the age-dependent decline in calcium absorption.

1,25(OH)(2)D(3) regulates calcium homeostasis through its actions in the intestine, bone, and kidney. These actions are mediated through the VDR. To determine if VDR's actions in the proximal small intestine can sufficiently restore calcium homeostasis, we generated transgenic mice expressing hVDR exclusively in the duodenum of mVDR-null mice by using the adenosine deaminase enhancer (hVDR+/mVDR-null). Unlike wild-type mice, hVDR+/mVDR-null mice express hVDR and VDR target genes only in the proximal small intestine. Despite having functional hVDR in the proximal small intestine, hVDR+/mVDR-null mice were hypocalcaemic when fed a normal rodent diet at weaning, like mVDR-null mice fed the same diet. The hypocalcemia in these mice is prevented if they are given the rescue diet before weaning. However, when 90-day-old rachitic mice were fed a rescue diet, serum calcium improved in hVDR+/mVDR-null mice, but not in mVDR-null mice. In conclusion, transgenic hVDR in the proximal small intestine of hVDR+/mVDR-null mice was transcriptionally active and regulated calcium absorption, but VDR actions elsewhere in the intestine are probably necessary to support adequate calcium homeostasis. In addition, hVDR+/mVDR-null mice responded better to the late rescue diet suggesting that expression of VDR in the proximal small intestine protected the calcium absorbing machinery from age-dependent decline.

Aging↗

Effect of surgery for chronic pancreatitis on pancreatic function: pancreatico-jejunostomy and duodenum-preserving resection of the head of the pancreas.

BACKGROUND: Resection and drainage procedures are performed for chronic pancreatitis. After resection, pancreatic function deteriorates; however, little is known about the effect of drainage procedures. METHODS: Pancreatic function was evaluated prospectively before and after surgery in 27 patients with duodenum-preserving resection of the head of the pancreas (DPRHP), and in 12 patients with pancreatico-jejunostomy (P-JS); 18 patients with chronic pancreatitis served as controls. Results of the 2 groups were not compared because of differences in patient characteristics and indications for surgery. Endpoints were exocrine function (fecal fat excretion, urinary PABA recovery), endocrine function (oral glucose tolerance test, serum C-peptide concentrations), and pancreatic polypeptide secretion. RESULTS: Groups were not different with respect to age and duration of symptoms. Median urinary PABA recovery was not altered significantly after surgery: DPRHP, from 40% to 31%; P-JS, from 52% to 44%; and controls, from 43% to 48%. Median fecal fat also did not change significantly: DPRHP, from 6 to 12 g/24 h; P-JS, from 9 to 5 g/24 h; and controls, from 6 to 7 g/24 h. Although the integrated blood glucose value did not change after DPRHP, the integrated serum C-peptide value decreased after DPRHP (P<.02). After P-JS, the integrated blood glucose value decreased (P<.02), but there was no change in integrated serum C-peptide secretion. Neither integrated blood glucose nor C peptide values were affected in controls. Insulin dependency increased (22% to 33%) after DPRHP. Pancreatic polypeptide secretion decreased only after DPRHP (P=.003). CONCLUSIONS: Surgery for chronic pancreatitis does not influence exocrine pancreatic function after either a drainage (P-JS) or a resection procedure (DPRHP). Clinical endocrine function is not affected after DPRHP but improves after P-JS.

Blood Glucose↗

Duodenum-preserving pancreatic head resection leads to relief of common bile duct stenosis.

BACKGROUND: Common bile duct stenosis (CBDS) is one of the most frequent complications in chronic pancreatitis with inflammatory mass in the head of the pancreas (IMH). METHODS: A total of 474 patients who underwent duodenum-preserving pancreatic head resection (DPPHR) between 1982 and 1998 were reevaluated; 219 patients (46%) with a mean duration of the disease of 45 months had a radiologically proven CBDS. RESULTS: One patient (0.5%) died of septic complications in the early postoperative course, 15 patients (6.8%) had to be reoperated on for complications. A follow-up investigation of 143 patients (92%) revealed a late mortality of 12%; no patient died of biliary complications. Seventy-five percent of the patients were completely free of pain, and 85% of the patients had a constant or even increasing body weight. CONCLUSIONS: The high percentage of pain-free patients with improved physical status and economical rehabilitation demonstrates the improvement of the quality of life after DPPHR for complicated chronic pancreatitis.

Adult↗

[Cystic dystrophy in heterotopic pancreas of the second part of the duodenum. One case of conservative surgical procedure].

Duodenal cystic dystrophy due to ectopic pancreas deposit is an uncommon pathology. Diagnosis is made by modern imaging techniques, mainly endoscopic ultrasound which localizes precisely cysts in duodenal wall. The most frequent clinical symptoms are pain, duodenal obstruction, and weight loss. We report the case of a 40 year-old man with cystic dystrophy of the 2nd part of the duodenum, without chronic pancreatitis, treated by a conservative surgical procedure including segmental duodenal resection. This original approach is an alternative to the Whipple procedure.

Adult↗

Coarse mucosal folds in the duodenum: a twenty-year follow-up.

In a 20-year follow-up of 40 patients with coarse duodenal folds, details were obtained about 34 patients of whom 11 had died. Clinical details were reviewed from the remaining 23 patients, and recent barium meal examinations were reviewed from eight patients. Ten of the 23 surviving patients continued to have recurrent dyspepsia, and the radiological appearance in three of the eight recent barium meals showed that coarse mucosal folds persisted. The clinical course of those with coarse duodenal folds is similar to that of peptic ulcer, with recurrent symptoms in some patients continuing for many years, and in others complicated by development of peptic ulcer. Coarse mucosal folds in the duodenum are usually associated with a high acid secretion and treatment to reduce acid secretion is appropriate in view of the severity of symptoms and risk of ulceration.

Aged↗