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Presence of growth hormone-releasing factor-like immunoreactivity in rat duodenum.

Growth hormone-releasing factor-like immunoreactivity (GRF-LI) was detected in partially purified extracts of rat hypothalamus and duodenum with a highly specific RIA for rat GRF (rGRF). The concentration of rGRF-LI in the rat hypothalamus was 32.5 fmol/mg dry weight (455 fmol or 3.18 ng/region), while the rat duodenum contained 2.15 fmol/mg dry weight (111 fmol or 0.78 ng/region). Partially purified hypothalamic and duodenal extracts exhibited displacement of the tracer parallel to rGRF. GRF-LI levels in all other brain regions (brainstem, cortex) or gastrointestinal tract tissues (forestomach, antrum, ileum, colon, pancreas) measured were close to the detection level of the RIA. rGRF-LI in hypothalamic and duodenal extracts behaved like synthetic rGRF in both gel filtration and reverse-phase HPLC systems. Coelution of rGRF-LI contained in both these tissue extracts with synthetic rGRF suggests that these molecules are similar, if not identical.

Animals↗

Terpinen-4-ol: mechanisms of relaxation on rabbit duodenum.

The effect of terpinen-4-ol was studied on rabbit duodenum in-vitro. Terpinen-4-ol induced relaxation of the basal tonus (IC50 170.2 (95% confidence interval, 175-204) microM) with a maximal relaxant response of 180.4+/-3.9% (n=6) of the contraction induced by 60 mM [K(+)]. The maximal relaxation induced in control conditions was not affected (P>0.05) by pretreatment of the tissues with phentolamine (50 microM) or propranolol (10 microM), N(G) nitro-L-arginine methyl ester (L-NAME; 1 mM), 1H-(1,2,4)oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 100 microM), hexamethonium (1 mM), tetrodotoxin (1 microM), the mixture charybdotoxin-apamin (1 microM), glibenclamide (10 microM), 4-aminopyridine (10 microM) or tetraethyl-ammonium (100 microM). In addition, terpinen-4-ol completely relaxed tissues precontracted with 60 mM [K(+)] solutions (IC50 325.9 (245.1-433.1) microM) and also blocked (IC50 154.7 (117.7-191.7) microM) the phasic component of this contraction. At a concentration of 195 and 650 muM it reduced by 41.3+/-3.4% and 75.4+/-3.1%, respectively the maximal contractile response to Ca(2+) in depolarized duodenum. Terpinen-4-ol completely blocked the component of carbachol-induced contraction, which was resistant to nifedipine (100 microM) pretreatment or to a Ca(2+)-free solution. These data show that terpinen-4-ol relaxes intestinal smooth muscle and suggest that this effect is myogenic in nature and depends on calcium antagonism.

Animals↗

Ontogeny of calbindin-D28K and calbindin-D9K in the mouse kidney, duodenum, cerebellum and placenta.

The appearance of the calcium-binding proteins (CaBP-D28K and CaBP-D9K) in embryonic mice tissues was determined using a sensitive immunohistochemical assay. CaBP-D28K first appears in myenteric nerve plexuses of the duodenum on day E15, in duodenal villus cells on day E16, in Purkinje cells of the cerebellum on day E19, in cells of the mesonephric duct on day E11 and in the metanephric duct on day E12. CaBP-D9K first appears in enterocytes of the duodenum on day E18, in trophoblastic giant cells (TGC) of the placenta on day E10, and in the metanephric duct on day E15. A differential time of appearance and colocalization of the two CaBPs is demonstrated in the embryonic mouse kidney, suggesting either that vitamin D does not control both CaBPs in the foetus or that the vitamin D control is unequal. The early appearance and location of CaBP-D9K in TGCs may suggest that these cells play an important role in transplacental transfer of calcium.

Animals↗

(+/-)-Pindolol acts as a partial agonist at atypical beta-adrenoceptors in the guinea pig duodenum.

The agonistic and antagonistic effects of (+/-)-pindolol (1-(1H-indol-4-yloxy)-3-[(1-methylethyl)amino]-2-propanol) were estimated to clarify whether (+/-)-pindolol acts as a partial agonist on atypical beta-adrenoceptors in the guinea pig duodenum. (+/-)-Pindolol induced concentration-dependent relaxation with a pD2 value of 5.10 +/- 0.03 and an intrinsic activity of 0.83 +/- 0.03. However, the relaxations to (+/-)-pindolol were not antagonized by the non-selective beta1- and beta2-adrenoceptor antagonist (+/-)-propranolol (1 microM). In the presence of (+/-)-propranolol (1 microM), the non-selective beta1-, beta2- and beta3-adrenoceptor antagonist (+/-)-bupranolol (30 microM) induced a rightward shift of the concentration-response curves for (+/-)-pindolol (apparent pA2 = 5.41 +/- 0.06). In the presence of (+/-)-propranolol, (+/-)-pindolol (10 microM) weakly but significantly antagonized the relaxant effects to catecholamines ((-)-isoprenaline, (-)-noradrenaline and (-)-adrenaline), a selective beta3-adrenoceptor agonist BRL37344 ((R*,R*)-(+/-)-4-[2-[(2-(3-chlorophenyl)-2-hydroxyethyl) amino]propyl]phenoxyacetic acid sodium salt) and a non-conventional partial beta3-adrenoceptor agonist (+/-)-CGP12177A([4-[3-[(1,1-dimethylethyl)amino]-2-hydroxypropoxy]-1,3-dihydro-2H-benzimidazol-2-one] hydrochloride). These results demonstrate that (+/-)-pindolol possesses both agonistic and antagonistic effects on atypical beta-adrenoceptors in the guinea pig duodenum.

Adrenergic beta-1 Receptor Agonists↗

Pancreatic arteriovenous malformation involving adjacent duodenum with gastrointestinal bleeding: report of a case.

A 54-year-old man was admitted to our hospital with the symptoms of palpitation, dyspnea, and tarry stool. Upper gastroduodenal endoscopy revealed submucosal lesions with vascular ectasia in the second part of the duodenum. Dynamic computed tomography (CT) detected a hypervascular lesion in the pancreatic head and the duodenum. Selective angiography showed proliferation of a vascular network and early filling of the portal vein at the early arterial phase. With a diagnosis of pancreatic arteriovenous malformation (AVM), we performed pylorus-preserving pancreaticoduodenectomy. At laparotomy, localized and meandering vessels were seen on the surface of the head of the pancreas. Histological examination showed dilated tortuous vessels accompanied by severed elastic fibers in the vessel media and blood clot formation. The incidence of pancreatic AVM remains extremely low, and recurrent gastrointestinal bleeding is a frequent complication. To prevent recurrent bleeding and progressive portal hypertension, surgery may be the definitive management of symptomatic AVM.

Arteriovenous Malformations↗

Immunohistochemical detection of metallothionein in liver, duodenum and kidney after dietary copper-overload in rats.

Metallothionein (MT) has been used in immunohistochemical techniques to indicate presence and distribution of heavy metals within biological tissues. This study describes a comparison of the pattern of MT-immunostaining in the liver, duodenum and kidney during dietary copper overload in rats. Sixteen male 10-week-old Wistar rats were randomly allocated into groups of four. Two groups were fed a pelleted diet containing 1,500 mg/kg copper and two control groups received a rodent diet containing 10 mg/kg copper. After 6 weeks samples of liver, kidney and duodenum were collected for immunohistochemistry and histology. An indirect immunoperoxidase technique, using monoclonal antibody E9 against horse MT and polyclonal sera against rabbit MT, was employed. Copper-loaded rats had marked MT-immunoreactivity within the nucleus and cytoplasm of many periportal hepatocytes, renal proximal convoluted tubule epithelial cells, intestinal columnar epithelial cells and Paneth cells. Immunohistochemical staining was similar using either mouse anti-MT polyclonal serum, or monoclonal antibody E9. Hepatocytes surrounding inflammatory foci were positive for MT, supporting the proposed role of this protein in free radical scavenging. The presence of MT in the kidney appears to be associated with renal excretion of copper-metallothionein (Cu-MT) in copper-loaded rats. Paneth cells were easily detected using MT-immunostaining. MT may play a part in absorption of copper from intestinal contents and possible storage as Cu-MT in Paneth cells. The function of Paneth cells remains unknown but the presence of marked MT-immunoreactivity in these cells, observed in copper-loaded rats, suggests their involvement in homeostasis and metabolism of copper.

Animals↗

Effects of chronic administration of either ethanol or pentanol on rat duodenum morphology.

The morphology of the rat duodenum after chronic treatment with 15% (v/v) ethanol and 4% (v/v) pentanol was studied. Male Wistar rats of experimental groups were given ethanol and pentanol for 15 weeks with food and fluid freely available. Ethanol-15% and 4% pentanol-fed rats showed a significantly reduced fluid and food intake as compared with control rats. The study of the mucosa indicated that the number of chronic inflammatory infiltrating (mononuclear cells) and goblet cells was higher in the groups of the ethanol- and pentanol-fed rats than in the control group. There was an increase in the thickness of the brush border in pentanol-fed rats. Intervillus adhesion was concurrently observed in the pentanol-fed rats but not in the control or ethanol-fed rats. After ethanol feeding many of the villi developed blebs at the apex of the villus or laterally on its upper half. These blebs generally remained intact. In contrast, after pentanol feeding no bleb formation was appreciated. The intake of ethanol and other short chain alcohols present in alcoholic beverages leads to mainfold disturbances on the rat duodenum. These findings suggest that the chronic ingestion of pentanol seems to promote cellular changes but less important than those observed after chronic ethanol ingestion.

Animals↗

Evidence for the presence of a neutral insulinotrophic peptide in the porcine duodenum.

A crude mixture of thermostable peptides extracted from porcine duodenum was fractionated by electrofocusing. A neutral fraction, different from the basic fractions of GIP, VIP, PHI, and CCK was found to promote insulin secretion when injected in vivo to normal rats. This neutral fraction, extracted from the crude mixture by chromatography, stimulated insulin output from an isolated rat pancreas and enhanced glucose-induced insulin release. The insulinotrophic effect of this partially purified duodeno-jejunal material disappeared following digestion with trypsin. The insulin-releasing activity was found to correspond to a compound of molecular weight higher than that of insulin (i.e. higher than 6000). No GIP-like immunoreactivity was found in this neutral fraction indicating that the active peptide(s) are not GIP related compounds. These observations suggest that porcine duodenum contains and incretin activity different from that of the insulinotrophic factors already reported.

Animals↗

Bird's nest inferior vena caval filter migration into the duodenum: a rare cause of upper gastrointestinal bleeding.

PURPOSE: To report the first case of a potentially catastrophic complication of vena caval interruption with a bird's nest filter. METHODS AND RESULTS: A 55-year-old Saudi patient presented with hypovolemic shock from massive upper gastrointestinal hemorrhage. Endoscopy identified a metallic object penetrating the duodenum. Five years earlier, the patient had a bird's nest vena caval filter inserted for recurrent pulmonary embolism. During emergent laparotomy, a broken filter wire was found projecting into the duodenum, where it had induced three profusely bleeding ulcers. The wire was transected and the ulcers oversewn. A hook projecting from the inferior vena cava (IVC) was also cut flush with the vessel wall, but the IVC was not opened nor the filter replaced. The patient's postoperative course was complicated by deep venous thrombosis, but he recovered and is asymptomatic on warfarin anticoagulation after 1 year. Computed tomography (CT) at 1-year follow-up confirmed no further migration of the filter. CONCLUSION: This event reinforces the need to monitor patients with IVC filters over the long term, preferably using CT scanning, and to consider filter migration as a possible cause of upper gastrointestinal bleeding.

Duodenum↗

Effects of maternal proteic undernutrition on the neurons of the myenteric plexus of the duodenum of rats.

The purpose of this study was to verify the effects of proteic undernutrition on the neurons of the myenteric plexus from the duodenum of Wistar rats. Twenty-four animals at the age of 60 days were divided in four groups, which were named according to the period their mothers received hypoproteic ration (8%). Some segments of duodenum were subjected to histological treatment and stained with hematoxilin-eosin and some were used for whole mount preparations stained with Giemsa. We observed small, medium-sized and large neurons grouped in ganglia of various shapes. It was concluded that the maternal proteic undernutrition does not affect the organization of the myenteric plexus and that animals submitted to undernutrition during gestation and lactation, when normally fed, show neurons with strongly basophilic cytoplasm and larger cellular bodies than those from control animals.

Animals↗

Evaluation of the areas of neuronal cell bodies and nuclei in the myenteric plexus of the duodenum of adult rats.

This study compared the areas of cell body and nucleus profiles of the myenteric neurons in the antimesenteric and intermediate regions of the duodenum of adult rats. Five male rats were used. The duodenum was removed and dissected to whole-mount preparations, which were stained by the Giemsa technique. The areas of cell body and nucleus profiles of 100 neurons, 50 from each region, of each animal, were assessed with image analyser. Based on the global mean+/-SD of the areas of cell body profiles, neurons were labelled as small, medium or large. It was observed that the neurons did not differ significantly in size or incidence between the antimesenteric and intermediate regions. However, the nuclei of the small and medium neurons were significantly smaller in the latter region. It is discussed that the smaller nuclear size could be related to the cell bodies being slightly smaller on this region and to a possible smaller biosynthetic activity which would influence nuclear size.

Animals↗

Inhibitory junction potentials of the guinea-pig duodenum in the treatment with catecholamines.

The inhibitory junction potentials (IJPs) in response to single and repetitive stimulation were recorded from the smooth muscle cells of the guinea-pig duodenum intracellularly. In adrenaline and noradrenaline (10(-8)-10(-5) g/ml), the IJP could be evoked in spite of a hyperpolarization of the cell membrane. The amplitude of the IJP was slightly changed in these agents but not abolished. Similar results were obtained in isoprenaline (10(-5) g/ml) and phenylephrine (10(-5) g/ml). The IJPs evoked by single and repetitive stimulation were not blocked by phentolamine (10(-7) g/ml) and propranolol (10(-5) g/ml). In propranolol (10(-7)-10(-5)/g/ml), the membrane was depolarized and the amplitude and the rate of hyperpolarization in the IJP were decreased. The membrane potential was decreased and the amplitude of the IJP was slightly increased in the presence of guanethidine (10(-5) g/ml). The amplitude of the IJP was increased with increasing the concentration of tyramine (10(-6)-10(-5) g/ml). These results suggest that the transmitter released from the intramural inhibitory nerve in the duodenum is nonadrenergic and this type of inhibition seems to be independent from adrenergic inhibition.

Action Potentials↗

Vasoactive intestinal polypeptide stimulates cholecystokinin secretion in perfused rat duodenum.

We examined the effect of vasoactive intestinal polypeptide (VIP) on cholecystokinin (CCK) secretion from the isolated perfused rat duodenum. VIP stimulated CCK secretion mono-phasically in a concentration-dependent manner in concentrations ranging from 10(-9) to 10(-7) M, and 10(-7) M of VIP led to an increment of 82 +/- 25.8 fmole/3 min. The stimulatory effect of VIP on CCK was not inhibited by 10(-5) M atropine. These results suggest that VIP may directly stimulate CCK secretion from the duodenum and work as a non-cholinergic, peptidergic neurotransmitter.

Animals↗

Effect of denervation of the pylorus and transection of the duodenum on acetaminophen absorption in rats; possible mechanism for early delayed gastric emptying after pylorus preserving pancreatoduodenectomy.

Early delayed gastric emptying has been reported as a frequent complication following pylorus preserving pancreatoduodenectomy (PPPD). We investigated the effect of division of the pyloric branch of the vagus nerve and/or transection of the duodenum on gastric emptying using the acetaminophen method in rats to speculate the unknown etiology of early delayed gastric emptying after PPPD. Twenty-four male Wistar rats were divided into the following four groups; Group S, sham operation as controls; Group N, disturbance of neuro-vascular supply to the pylorus; Group D, temporary interference of the duodenal continuity; and Group N+D, with both procedures in Group N and Group D. Gastric emptying was measured using the acetaminophen method at 1, 2, and 4 weeks after operations in each group. No significant difference was observed in Group S at any intervals after the operation. Gastric emptying was prolonged significantly in Group N, Group D and Group N+D compared to Group S until 2 weeks following surgery. Significant delayed gastric emptying was sustained in Group N+D at 4 weeks, although gastric emptying in Group N and Group D was improved by 4 weeks. The results in rodent models suggest that both dissection of the pyloric branch of the vagus and transection of the duodenum might be causative factors of postoperative delayed gastric emptying following PPPD.

Acetaminophen↗

Maternal vitamin D status has no effect on the ontogeny of calcium-binding proteins in the duodenum, kidney and cerebellum of fetal mice.

The effects of vitamin D3 deficiency on the ontogeny of calcium-binding proteins (CaBPs) and the vitamin D receptor in the duodenum, kidney and cerebellum of the mouse were examined. Maternal vitamin D status did not affect the time of appearance of the fetal 28 kDa CaBP (CaBP-D28k) in the cerebellum, kidney and duodenum, and the 9 kDa CaBP (CaBP-D9k) in the intestine and kidney. Vitamin D receptor was undetectable in all fetal tissues, regardless of maternal vitamin D status, at all stages of gestation examined. Thus it appears that maternal vitamin D status does not affect the ontogeny of CaBP-D9k or CaBP-D28k in the mouse fetus. The factors that influence the appearance of calbindins in the fetus are unclear.

Animals↗

Amylin-immunoreactivity is co-stored in a serotonin cell subpopulation of the vertebrate stomach and duodenum.

Amylin (or islet amyloid polypeptide) is a 37 amino acid peptide originally isolated from amyloid deposits in the pancreas of non-insulin dependent diabetic patients. It has already been immunohistochemically localised within the B and D cells of pancreatic islets and in endocrine cells of the rat and human stomach and duodenum. In this phylogenetic study, a polyclonal antiserum raised against the carboxy-terminal tridecapeptide amide of human amylin was used to demonstrate and examine the distribution of amylin-immunoreactivity in the stomach and duodenum of various vertebrate species. Except for fish, gastrointestinal tracts of all the species studied contained amylin-immunoreactive endocrine cells. They were located chiefly in the lower half portion of the distal gastric body and pyloric glands, and in the lining epithelium of the duodenal villi and crypts. Many cells were elongated, triangular or oval, and had a cytoplasmic process that extended from the cell base along the basement membrane. Others had a bipolar feature that gave them a so-called "open" appearance. Double and triple staining procedures on the same tissue section showed that almost all the amylin-immunoreactive cells present in the gastroduodenal region also co-stored serotonin and chromogranin A, and displayed argyrophilia in Grimelius impregnation. On the other hand, almost all the serotonin-immunoreactive cells of this region co-stored amylin, whereas those in more distal gut regions did not. This finding suggests that those amylin-containing cells correspond to a subtype of gastroduodenal serotonin cells.

Amyloid↗

Cholinergic modulation and effects of dynorphin on the non-adrenergic inhibitory potentials in the guinea-pig duodenum.

Cholinergic modulation and effects of dynorphin on the non-adrenergic non-cholinergic inhibitory potentials (NANC i.p.s) in the longitudinal smooth muscle cells of the guinea-pig duodenum were studied intracellularly. Atropine (1.4 X 10(-7)-1.4 X 10(-5) M) and scopolamine (3.3 X 10(-8)-3.3 X 10(-7) M) increased the amplitude of the evoked i.p.s while physostigmine (3.7 X 10(-7)-3.7 X 10(-6) M) and neostigmine (4.8 X 10(-8) M) decreased it. The frequency of the spontaneous action potentials in the longitudinal smooth muscle cells was increased by dynorphin (6 X 10(-8)-3 X 10(-7) M) without continuous membrane depolarization. The excitatory effect of dynorphin on the spontaneous electrical activity was not blocked by atropine (1.4 X 10(-6) M). Dynorphin (6 X 10(-8)-2.4 X 10(-7) M) increased the amplitude of the i.p.s evoked in the presence of atropine (1.4 X 10(-7)-1.4 X 10(-6) M) and in the propranolol (3.9 X 10(-6) M) solution containing atropine while dynorphin decreased the amplitude of the i.p.s evoked in the absence of atropine. In the high calcium solution containing atropine, the amplitude of the i.p.s increased. Further increase in the amplitude of the i.p.s was observed by additively applied dynorphin. However, the amplitude of the i.p.s evoked in the high calcium solution without atropine was decreased by dynorphin. These results suggest the cholinergic inhibitory modulation on the NANC inhibitory nerves in the guinea-pig duodenum, the non-cholinergic excitatory action of dynorphin on the spontaneous electrical activity of the longitudinal smooth muscle and the excitatory action of dynorphin on the NANC inhibitory nerves in the presence of muscarinic blocking agents.

Action Potentials↗

Venous drainage from the posterior aspect of the pancreatic head and duodenum.

Eighty-three pancreatic head and duodenum specimens, selected from 214 specimens, were dissected minutely to clarify the configurations of the posterior superior pancreaticoduodenal vein (PSPDv) with special reference to its topographical relationship to the common bile duct (CBD) and to whether an artery accompanied the PSPDv. The PSPDv frequently (71.1%) ran postero-inferior to the CBD without the accompaniment of an artery. Moreover, several tributaries draining the second and third portions of the duodenum sometimes (28.9%) joined together without arterial association and formed a stem, the so-called dorsal pancreatic vein. Variations of PSPDv were discussed in relation to the general vascular configuration of the small intestine.

Adult↗