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PubMed1983

Properties of the inhibitory junction potentials recorded from smooth muscle cells of the guinea-pig duodenum.

Inhibitory junction potentials (IJPs) in response to single or repetitive stimulation were recorded intracellularly from smooth muscles of the guinea-pig duodenum. The amplitude of the IJP was dependent on the stimulus intensity and duration. The hyperpolarization of up to 30 mV was evoked by a single pulse. The mean values of the latency, the fall time, the rate of hyperpolarization, the half decay time and the time constant for decay of the IJPs evoked by 0.3 msec stimulation were 67 msec, 130 msec, 86 mV/sec, 156 msec and 194 msec, respectively. The latency and the half decay time were slightly decreased by changes in the stimulus intensity and duration. When repetitive stimulation was applied at low frequencies, successive IJPs were evoked but their amplitudes were decreased gradually. The maximum amplitude of the hyperpolarization was increased with increasing the frequency of stimulation over than 10 Hz. The spike activity due to rebound excitation was potentiated at high frequency. Over 90% of the cells exhibited only the IJP without atropinization. The excitatory junction potentials and the complex type in response to a brief pulse were recorded from a few cells. These results suggest the predominant nonadrenergic inhibition on the duodenal smooth muscles.

Action Potentials↗
PubMed1984

Effects of ATP, its related nucleotides and VIP on the inhibitory potentials in the smooth muscle cells of the guinea-pig duodenum.

Non-adrenergic inhibitory potentials (i.p.'s) were recorded from the smooth muscle cells of the guinea-pig duodenum following field stimulation. ATP, ADP and AMP increased the membrane potential of the cell and decreased the amplitude and the rate of hyperpolarization of the i.p. The amplitudes of the maximum hyperpolarization due to a repeated stimulation and the post-stimulus depolarization were reduced by ATP and AMP. Methylxanthine could not inhibit the i.p. while apamin reversibly decreased the amplitudes of the i.p. and the post-stimulus depolarization. The latency and the time to peak were prolonged by apamin. Biphasic effect of quinidine on the i.p. was obtained. The amplitude and the rate of hyperpolarization of the i.p. were decreased at 10-4 g/ml of quinidine. The amplitudes of the maximum hyperpolarization by repetitive stimulation and the post-stimulus depolarization were decreased by quinidine. The membrane potential of the cell was not affected by VIP. The amplitude and the other parameters of the i.p. were not changed in the used concentration of VIP. Trypsin reduced the membrane potential of the cell but not changed the parameters of the i.p. The membrane was slightly depolarized by the treatment with papain while no significant changes on the i.p. were observed in papain. The obtained results suggest that ATP, its related substances and VIP do not contribute to the non-adrenergic inhibitory neurotransmission.

Adenosine Diphosphate↗
PubMed1998

The effect of short-term octreotide administration on the histologic structure of stomach, duodenum, jejunum, colon, liver and gallbladder in an experimental pancreatitis model.

It is known that long-term administration of octreotide leads to changes in the histology of intraabdominal organs and plasma biochemical values. The purpose of the present study was to evaluate the histological effect of short-term octreotide administration on digestive organs in the experimentally induced pancreatitis by ligating pancreatic duct. The sham operation was performed on 20 rabbits in Groups 1 and 2. Acute pancreatitis was induced by pancreatic duct ligation in 20 rabbits in Groups 3 and 4. Octreotide was administered subcutaneously to the rabbits in Groups 2 and 4 at a dosage of 10 microg/kg/day for 7 days. The animals were sacrificed at the end of day 7, blood and tissue samples were collected. There was no histological changes in the stomach, duodenum, gallbladder, or small and large intestines of those group which received octreotide, while hepatic bile duct proliferation, bile duct epithelium proliferation, periportal inflammation and venous stasis were observed in liver histology. In conclusion, one-week octreotide administration in this experimental acute pancreatitis model was not associated with pathologic changes in digestive organs except liver.

Administration, Cutaneous↗
PubMed1993

Heterogeneity of motilin-immunoreactive cells in the duodenum and pyloric region of several avian species.

Immunohistochemical characterizations of motilin-immunoreactive cells were examined in gastric and duodenal mucosae of nine species of birds from seven orders using five different region-specific motilin antisera. Motilin-immunoreactive cells appeared as open-type cells in the mucosal epithelium and showed varying immunoreactivities to antisera used in all the birds examined except for the cormorant and penguin, which did not show any kinds of immunoreactivity to motilin. Motilin-immunoreactive cells of the emu duodenum were detected by all the motilin-antisera used. The present results suggest that there is a wide range of heterogeneity between motilin molecules among avian species, or perhaps alternatively the existence of a family of motilin-like peptide. Furthermore, the present results should prove useful for a molecular biological study on the evolution of avian motilin.

Animals↗
PubMed1994

Schwannoma of the duodenum causing melena.

A rare case of duodenal schwannoma is reported. A 69-year-old man was admitted for evaluation of melena. Endoscopy and hypotonic duodenography showed a submucosal tumor in the third part of the duodenum. Biopsy findings were suggestive of leiomyosarcoma, therefore pancreatoduodenectomy was performed. Hematoxylin-eosin staining of the resected specimen showed interlacing bundles of spindle-shaped cells with palisading nuclei. Immunohistochemical staining showed positivity for S-100 protein and neuron-specific enolase, but desmin was negative, thus a diagnosis of schwannoma was made. Schwannoma is often difficult to distinguish from leiomyogenic tumors by standard staining, but immunohistochemical staining proved useful in this case.

Aged↗
PubMed1984

Effects of 4-aminopyridine on the non-adrenergic inhibitory neurotransmission in the guinea-pig duodenum.

The effects of 4-aminopyridine (4-AP) on the non-adrenergic inhibitory potential (i.p.) in the longitudinal and circular smooth muscle cells of the guinea-pig duodenum were investigated using intracellular microelectrodes. The membrane potential of both smooth muscles was decreased by 4-AP and the amplitude of the evoked i.p.s. was increased. In a low-calcium solution (0.25 mM), the amplitude of the i.p.s. was reduced but the additional application of 4-AP increased the amplitude. In the 4-AP containing low-calcium solution, the i.p. was inhibited by verapamil and EGTA. The inhibitory effect of verapamil on the i.p. evoked in a low-calcium solution was less in the presence of 4-AP than that in its absence. In a high-calcium solution (5 mM), the amplitude of the i.p. increased and the additional application of 4-AP enhanced the i.p. further. The amplitude of the i.p. elicited in high-potassium solutions was not changed by 4-AP. The i.p. was not potentiated by 2-aminopyridine or 2,5-diaminopyridine. Tetraethylammonium ions enhanced the amplitude of the i.p. at low concentration but decreased it in high concentration. In a few longitudinal smooth muscle cells, the evoked excitatory potential (e.p.) was observed. Potentiation of the e.p. by 4-AP was completely blocked by atropine. From the results obtained, it is suggested that the release of the non-adrenergic inhibitory neurotransmitter is increased by 4-AP due to increase calcium influx in the nerve terminals. The release of the cholinergic excitatory neurotransmitter seems to be increased by 4-AP.

4-Aminopyridine↗
PubMed1985

Effects of neurotensin on the non-adrenergic inhibitory neurotransmission in the guinea-pig duodenum.

The effects of neurotensin on the non-adrenergic inhibitory neurotransmission in the guinea-pig duodenum were investigated. The resting membrane potential of the duodenal smooth muscle cells was reduced by neurotensin at the concentration of 3 X 10(-8) M or more. The amplitude of the non-adrenergic inhibitory potentials was decreased by neurotensin (1-3 X 10(-8) M). In the Ca2+-free solution, the amplitude of the inhibitory potentials was also decreased. The increased amplitude of the non-adrenergic inhibitory potentials evoked in the high calcium solution (Ca2+, 5 mM) was decreased by neurotensin (10(-8) M). Neither atropine (1.4 X 10(-6) M) nor propranolol (3.4 X 10(-6) M) blocked the inhibitory action of neurotensin (10(-8) M) on the inhibitory potential. The frequency of the spontaneous action potentials of the duodenal smooth muscle cells was strongly increased with accompanying depolarization by neurotensin 8 X 10(-8) M. The tonic contraction of the duodenal smooth muscles was produced by neurotensin (3-8 X 10(-8) M). The results obtained suggest that neurotensin relates to the non-adrenergic inhibitory pathway in the control mechanism on intestinal motility.

Action Potentials↗
PubMed1987

The position and mobility of the duodenum in children.

Forty-three control patients (neonate to 17 years old) were studied by upper gastrointestinal series to determine the position of key duodenal landmarks and the mobility of the duodenojejunal flexure with manual displacement. These results were compared with the duodenal positions of 35 children of similar ages with surgically documented malrotation. Nine criteria were identified as a useful means of detecting subtle abnormalities of duodenal position. The normal duodenojejunal flexure was found to be readily displaceable in neonates and could be pushed to the right of the spine in over two-thirds of patients less than 4 months old. Over 4 years of age, mobility was very limited. A mobile duodenum discovered on fluoroscopic examination or by positioning of a transpyloric feeding tube should not be considered indicative of malrotation in infancy.

Adolescent↗
PubMed2000

In vitro effects of erythromycin, lidocaine, and metoclopramide on smooth muscle from the pyloric antrum, proximal portion of the duodenum, and middle portion of the jejunum of horses.

OBJECTIVE: To evaluate effects of erythromycin, lidocaine, and metoclopramide on smooth muscle of the pyloric antrum (PA), proximal portion of the duodenum (PD), and middle portion of the jejunum (MJ) of horses. Sample Population-Strips of smooth muscle from 7 horses. PROCEDURE: Isolated muscle strips were suspended in a bath and attached to isometric force transducers. Once stable spontaneous contractions were observed, agents were added. Isometric stress responses were compared with the amplitude of spontaneous contractions. RESULTS: A single dose of erythromycin to the PA increased contractile amplitude (CA) for the longitudinal smooth muscle (mean +/- SEM, 76+/-16 g/cm2) but decreased CA for circular smooth muscle (-79+/-23 g/cm2). The inhibitory effect was decreased by tetrodotoxin, N(G)-nitro-L-arginine methyl ester, and a vasoactive intestinal peptide antagonist. Erythromycin increased CA for the MJ, which was maximal at 10(-4)M (171+/-36 g/cm2). Lidocaine increased CA for the PD, which was maximal at 10(-4) M (60+/-5 g/cm2). Metoclopramide increased the CA, which was maximal at 10(-4) M for the PA (75+/-26 g/cm2), PD (279+/-33 g/cm2), and MJ (456+/-59 g/cm2). CONCLUSIONS: Regional differences in responses to erythromycin, lidocaine, and metoclopramide were evident in the gastrointestinal tract of horses. Metoclopramide increased CA in all tissues used, whereas erythromycin inhibited CA in circular smooth muscle but stimulated CA in longitudinal smooth muscle from the PA. Inhibition is caused by stimulation of inhibitory nerves and is mediated, in part, by nitric oxide and vasoactive intestinal peptide.

Animals↗
PubMed2001

Quality of tissue specimens obtained endoscopically from the duodenum of dogs and cats.

OBJECTIVE: To evaluate quality of duodenal tissue specimens obtained endoscopically from dogs and cats and submitted to 1 of 2 diagnostic laboratories for evaluation. DESIGN: Case series. SAMPLE POPULATION: Slides from 50 consecutive canine and 50 consecutive feline endoscopically obtained duodenal tissue specimens submitted to laboratory 1 and 49 consecutive canine and 46 consecutive feline specimens submitted to laboratory 2. PROCEDURE: Slides were examined independently by 3 investigators, and each tissue piece on each slide was classified as clearly inadequate, questionable, or clearly adequate on the basis of 4 criteria. An overall score was then assigned to the slide. RESULTS: Slides from laboratory 1 were more likely to be scored as clearly adequate and less likely to be scored as clearly inadequate than slides from laboratory 2. Clearly adequate slides from laboratory 1 had a higher number of clearly adequate pieces of tissue than did clearly adequate slides from laboratory 2. Slides scored as clearly adequate had a higher number of individual tissue pieces than did slides scored as clearly inadequate. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the quality of endoscopically obtained duodenal tissue specimens submitted to laboratories can vary, possibly because of differences in experience of individuals collecting biopsy specimens. Results suggest that at least 8 individual tissue pieces should be submitted when performing endoscopic biopsy of the duodenum in dogs and cats.

Animals↗
PubMed1991

Synaptic connections of extrinsic nerve fibers in the myenteric plexus of the rat duodenum.

In the present study the degeneration of extrinsic nerve fibers was first investigated in the duodenal myenteric plexus after their transection, and subsequently synaptic connections of the extrinsic nerve fibers were observed with their degenerative changes to examine the relationship of the extrinsic nerve fibers with the neuronal circuits in the myenteric plexus. Adult rats were anesthetized with pentobarbital, and the extrinsic nerve fibers running with the coeliac and superior mesenteric arteries were cut at about 2 mm distance from the coeliac ganglia to duodenum. Their duodena were fixed at 6 and 12 hours, and 1, 2, 4, 7 and 11 days after the extrinsic denervation, and their myenteric plexuses were observed with the electron microscope. Then, montages on 22 fields of the myenteric plexuses of 7 days after the denervation were made, and the number of all synapses and degenerated synapses in them was counted in each montage. 1. The degenerated changes of the extrinsic nerve fibers Three types of the degenerated axons were found in stages ranging from 12 hours to 11 days after the extrinsic denervation as follows: 1) Type I appeared mainly at 1 and 2 days. The electron density in the axoplasm decreased, and the synaptic vesicles accumulated in the central area of the axoplasm. 2) Type II appeared, also, at 1 and 2 days. The electron dense material occupied the axoplasm or the myelin-like structure appeared in the slightly swollen axons. 3) Type III appeared in stages from 1 to 11 days. Electron dense bodies appeared in the axoplasm.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Distribution of vinculin in the duodenum of chick embryos: immunohistochemical studies at the light and electron microscopic level.

Studies on the localization of vinculin and actin in the embryonic chick duodenum between the 9th and 13th days of incubation were performed by light and electron microscopy. In the light microscopic studies, vinculin and actin were localized by immuno-fluorescent double staining with anti-vinculin and rhodamine phalloidin for actin. In the electron microscopic studies, the immunocytochemical distribution of vinculin was examined on Lowicryl K4M thin sections with anti-vinculin. Vinculin was prominent near or adjacent to the apical inner membrane of epithelial cells of the previllous ridges in all stages, often located near cell junctions including tight and adherent junctions and the top of microvilli, and weakly in the cytoplasm. Our findings suggested the possible interaction between actin and vinculin in differentiation on the apical side of epithelial cells including the formation of microvilli or terminal webs.

Actins↗
PubMed1977

Malrotation of the duodenum and duodenal ulcer.

In 173 patients with surgically confirmed duodenal ulcer, malrotation of the duodenum (MD) was found in the pre-operative radiographs in a total of 54% without significant differences in the age and sex distribution. As compared with a control group, the frequency of MD was significantly increased in men and in patients over 50 years (Table I). The luminal diameter in the presence of MD was larger in the ulcer patients than in the control group (Table II). Gastric retention at 6 hours after the barium meal was more frequent in ulcer patients with MD than in those with normal duodenal configuration, and in both groups more frequent than in the control group. At a follow-up examination at least 12 months after the operation for duodenal ulcer, a significant tendency to a poorer result was revealed in patients with MD, manifested by persistent or postoperatively developed postcibal pain, fullness, nausea and vomiting (Table III-V), except in patients who had undergone parietal-cell vagotomy without pyloroplasty. The latter observation suggests that, in the presence of MD, preserved pyloric function is of significance in the frequency of subsequent manifest symptoms of this anomaly.

Adolescent↗
PubMed1977

Gastrin in the human fetus. Distribution and molecular forms of gastrin in the antro-pyloric gland area, duodenum and pancreas.

The ontogeny of human fetal gastrin has been investigated by immunocytochemistry and radioimmunochemistry. Gastrin and gastrin cells are shown to appear later in the antral than in the duodenal mucosa. At the ages studied (11--22 weeks of gestation) pancreatic gastrin could not be detected. Gastrin component III was found to predominate in the antrum, whereas component II was quantitatively very important in the duodenum. Circumstantial evidence suggests that fetal gastrin is delivered to the blood, and that it may exert trophic functions in the fetus.

Duodenum↗
PubMed1980

Immunoreactive secretin release following taurocholate perfusions of the cat duodenum.

Perfusion of the cat duodenum with sodium taurocholate (TC), 120 mmol/l, at pH 6.1 increased the plasma immunoreactive (IRS) concentration from 2.2 +/- 0.7 pmol/l to 29 +/- 6.1 pmol/l during the first 20 min. This was accompanied by an increased pancreatic secretion of fluid, while the chymotrypsin output showed a "wash-out' phenomenon. TC increased both the bile-acid-dependent and the bile-acid-independent bile secretion. In comparison, HCl, 150 mmol/l, increased IRS from 0.9 +/- 0.5 pmol/l to 41 +/- 15 pmol/l, producing an increase in the pancreatic fluid secretion. However, only a slight increase in the bile-acid-independent bile secretion was found, and the bile-acid-dependent secretion did not change. The effects of TC on the pancreatic secretion were produced at concentrations occurring in cat hepatic bile.

Animals↗
PubMed1981

Sorbin, a peptide contained in porcine upper small intestine which induces the absorption of water and sodium in the rat duodenum.

A fraction increasing water and sodium absorption in rat duodenum was detected in the material obtained at an early stage of purification of the hitherto isolated duodenal hormones. In Wistar rats, duodenal loops were made in situ and filled with a solution containing 0.138 mM NaCl, with 14C PEG and 22Na as markers; the final content was collected after 1 h and the movements of water and Na measured. In contrast to secretin, cholecystokinin, and somatostatin, which induced duodenal secretion, and with pentagastrin, which induced duodenal absorption and stimulated acid secretion, this fraction induced duodenal absorption f Na and water without stimulating acid secretion. The fraction was obtained by chromatography of a concentrate of intestinal peptides in 0.2 M acetic acid on Sephadex G25 (fine), and its active component was found to be methanol-soluble at pH4 and insoluble at pH7.5. It was eluted from carboxymethylcellulose 22 with 0.04 M ammonium bicarbonate and gel filtration of Sephadex G50 *fine), resulting in a tenfold increase in activity. Incubation with chymotrypsin suppressed the biological activity, indicating a peptidic nature. The substance displayed biological and radioimmunological properties distinct from those of the gastrointestinal hormones. Particularly, no cross-reactivity was found with gastrin, prolactin, and angiotensin, which are known to increase intestinal absorption. It therefore seems possible that the activity described is due to a peptide that has as yet not been isolated. The name 'sorbin' is proposed for this active principle.

Animals↗
PubMed1983

Inhibition of pentagastrin-stimulated gastric acid secretion by acid perfusion of the duodenum in chronic gastric fistula rats.

The effect of duodenal acid perfusion on pentagastrin-stimulated gastric acid secretion was studied in Sprague-Dawley rats provided with a chronic gastric fistula, gastroenterostomy, and a 4-cm blind duodenal loop anastomosed to the jejunum. During maximal acid stimulation with intravenous pentagastrin (16 micrograms X kg-1 h-1) the loop was perfused with 0.15 M NaCl or 0.05 M, 0.10 M, or 0.20 M HCl at a rate of 2 ml X h-1. Perfusion with 0.05 M HCl did not significantly alter pentagastrin-stimulated secretion. 0.10 M and 0.20 M HCl reduced the 2-h acid response by 56% and 63%, respectively. Acid secretion returned to control level after cessation of acid perfusion. It is concluded that physiological amounts of HCl in the duodenum inhibits maximal acid secretion stimulated by pentagastrin in rats.

Animals↗
PubMed1983

Secretin release in coeliac disease. Plasma secretin concentration and bicarbonate output to the duodenum after intraduodenal acid infusion in coeliac patients before and after treatment.

Infusion of 40 ml 0.1 mol/l HCl into the duodenum in eight untreated coeliac patients was followed by an increase of the plasma immunoreactive secretin (IRS) concentration from 1.6 +/- 0.2 pmol/l to a peak level of 2.4 +/- 0.3 pmol/l (p less than 0.05). After treatment with a gluten-free diet, the same patients showed an increase from 1.4 +/- 0.3 pmol/l to a peak level of 5.5 +/- 0.9 pmol/l after intraduodenal acid infusion, which was significantly higher than before treatment (p less than 0.01). In control subjects, intraduodenal acid infusion was followed by an increase from 1.4 +/- 0.2 pmol/l to 6.7 +/- 1.1 pmol/l, which was significantly higher than in untreated coeliac disease (p less than 0.01) but did not differ from what was found in treated coeliac patients. Significant differences in pH, volume, or bicarbonate content of the duodenal aspirates or the basal IRS levels were not found.

Adolescent↗