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PubMed2006

Immunohistochemical study on distribution of endocrine cells in gastrointestinal tract of flower fish (Pseudophoxinus antalyae).

AIM: To detect distribution and relative frequency of endocrine cells in gastrointestinal tract of flower fish (Pseudophoxinus antalyae). METHODS: The intestinal tract of flower fish was divided into four portions from proximal to distal; the enlarged area after oesophagus and anterior, middle and posterior intestine. Immunohistochemical method using the peroxidase anti-peroxidase complex was employed. All antisera between four portions of flower fish were compared using ANOVA. RESULTS: Eleven types of gut endocrine cells were determined; they were immunoreactive for calcitonin gene related peptide, substance P, vasoactive intestinal peptide, bombesin, somatostatin-14, secretin, TrkA, TrkB, TrkC, neurotensin, neuropeptide Y, which were found in almost all portions of the gastrointestinal tract. CONCLUSION: The regional distribution and relative frequency of immunoreactive cells in the flower fish, Pseudophoxinus antalyae, are essentially similar to those of other fish.

Animals↗

PubMed2006

Morphology and motor function of the gastrointestinal tract examined with endosonography.

Endosonography is a useful tool for studying the morphology and motor function of the gastrointestinal tract. Intraluminal ultrasonography is the common denomination of ultrasound examinations using intracorporal transducers which are inserted into the GI tract. Thus, the visceral wall and adjacent structures can be imaged in detail. This review describes the usefulness of endosonography in gastroenterology, in particular with respect to studies of the biomechanical and motor function of the gastrointestinal tract. New techniques such as 3-D EUS, elastography and strain rate imaging are discussed.

Biomechanical Phenomena↗

PubMed2004

In vivo and in vitro study of the influence of the anticholinesterase drug galantamine on motor and evacuative functions of rat gastrointestinal tract.

Galantamine is efficacious for vascular dementia and Alzheimer's disease. Its application leads to some negative gastrointestinal side effects. The present study observes galantamine-induced influence on gastrointestinal motility of rats and its effects on isolated gastrointestinal smooth muscles. The gastrointestinal tract was studied by X-ray contrast examination. Functional disturbances were observed: hypertonia, increased stomach and ileal peristalsis activity, accelerated intestinal passage. In vitro, the drug caused tonic contractions in smooth muscle preparations and increased the gastric and ileal phasic amplitude. The jejunal smooth muscle strips demonstrated an opposite tendency. The reactions were a result of the interaction of galantamine-accumulated endogenic acetycholine with M- and N-acetylcholine receptors. The tonic effects were influenced in varying degree by atropine and ipratropium, whereas the phasic by atropine, ipratropium, hexametonium and methysergide. In conclusion, the in vitro effects registered satisfactorily explain in vivo examined galantamine-induced changes in the gastrointestinal tract of the treated rats and can be considered as main cause for development of such changes.

Animals↗

PubMed2006

Assessment and prevention of gastrointestinal toxicity of non-steroidal anti-inflammatory drugs.

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for analgesic, anti-inflammatory and, in the case of aspirin, for anti-thrombotic actions. The serious gastrointestinal side-effects associated with these drugs are of concern and pose a significant obstacle to their use. This review discusses the pathogenic mechanisms by which the conventional acidic NSAIDs induce gastrointestinal toxicity, with particular emphasis on non-prostaglandin effects. Methods of assessment of NSAID-induced enteropathy are reviewed, with particular emphasis on the use of functional measurement of NSAID-induced changes in the gastrointestinal tract. The advances in our knowledge of the pathogenesis of these effects have resulted in the development of a range of novel NSAIDs. Where functional assessment of the effects of NSAIDs has been employed, it appears to be more useful as an indicator of early-stage changes rather than a predictor of the effects of long-term NSAID exposure. Successful pharmaceutical strategies now offer considerable promise for reducing the severity of NSAID damage to the gastrointestinal tract. The utility of intestinal permeability measurements for selection and assessment of these strategies is discussed.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2000

Distribution and inducibility by 3-methylcholanthrene of family 1 UDP-glucuronosyltransferases in the rat gastrointestinal tract.

UDP-Glucuronosyltransferases (UGT) catalyze the glucuronidation of a broad spectrum of endobiotic and xenobiotic substrates. The resulting glucuronides are more hydrophilic, facilitating renal and biliary excretion. Apart from hepatic glucuronidation, high rates of gastrointestinal glucuronidation have been observed. The aim of this study was to characterize the expression of family 1 UGTs (UGT1A) in liver, kidney, and all parts of the rat gastrointestinal tract by reverse transcription polymerase reaction (RT-PCR), Northern blot, and xenobiotic induction experiments. RT-PCR experiments were performed with primers specific for all known rat UGT1A mRNAs. UGT1A1, UGT1A6, and UGT1A7 were expressed in liver, kidney, and the gastrointestinal tract. UGT1A5 transcripts were detected in liver, but not in kidney or gastrointestinal tissue. In contrast, UGT1A2 and UGT1A3 were not expressed in liver or kidney, but were detected in intestine. Low levels of UGT1A3 were detectable in duodenum and jejunum. UGT1A2 was abundantly expressed in the small intestine; expression levels in the stomach and the large intestine were low. Quantitative evaluation of RNA levels by Northern blot revealed expression in gradients, with highest UGT1A mRNA levels in duodenum and decreasing levels in the small and large intestine. Only UGT1A6 was expressed at high levels in the rectum. Rats treated with 3-methylcholanthrene (3-MC) displayed a 10-fold induction of hepatic UGT1A6 and UGT1A7 mRNAs. In gastric tissues and in intestine, induction was 4-fold and 2-fold, respectively. In contrast to the constitutive expression of UGT1A7 in kidney, UGT1A6 was inducible in the liver. Effects of 3-MC on UGT1A1 expression revealed downregulation in the liver and highly variable effects in duodenum and stomach. This study demonstrates tissue-specific expression and tissue-specific induction patterns in rat liver, kidney, and gastrointestinal tract, which may represent the physiological basis of tissue-specific glucuronidation in rats.

Animals↗

PubMed1999

Cloning, expression and functional role of a nociceptin/orphanin FQ receptor in the porcine gastrointestinal tract.

The heptadecapeptide nociceptin/orphanin FQ is the cognate ligand for the opioid receptor-like orphanin FQ (OFQ) receptor, a member of the G protein-coupled receptor superfamily. The gastrointestinal tract is a major site of opioid action, and preliminary evidence suggests that an OFQ receptor may be expressed in rat small intestine. We addressed the hypothesis that this receptor is expressed in the gastrointestinal tract of the pig, a model for the human digestive system. A 1205-bp cDNA was isolated from porcine forebrain which contained the 370 amino acid open reading frame encoding the OFQ receptor. The receptor mRNA is likely to arise from a single gene, as determined by Southern blotting of porcine genomic DNA restriction digests using a porcine OFQ receptor cDNA probe. A semi-nested reverse transcriptase-polymerase chain reaction survey of receptor mRNA indicates that it is expressed in the porcine cerebral cortex and kidney, and along the length of the gastrointestinal tract. OFQ decreased initial contractile responses of porcine ileal smooth muscle strips to trains of electrical field stimulation with an IC50 value of 1.3 nM; its effects were resistant to the opioid antagonist, naloxone. The peptide, at concentrations > or =3 nM, also attenuated Isc elevations evoked by electrical transmural stimulation of mucosa-submucosa sheets from porcine ileum. The actions of OFQ appeared to differ from those previously reported for opioid receptor agonists in these tissue preparations. These results indicate that an OFQ receptor is expressed in the porcine intestine which modulates the neural control of intestinal smooth muscle contractility and mucosal transport.

Amino Acid Sequence↗

PubMed1987

Stromal tumors of the gastrointestinal tract: myogenic or neurogenic?

Because of the recent controversy over the histogenesis of gastrointestinal stromal tumors, 170 gastrointestinal tract tumors appearing to be of smooth muscle type with routine stains were studied immunohistochemically. Five percent were positive for S-100 ("neural") protein. These findings are compared with several recent studies. We conclude that only a small minority of gastrointestinal tract stromal tumors are neurogenic and that most are probably of smooth muscle type.

Adolescent↗

PubMed2005

Presence and distribution of ghrelin-immunopositive cells in the chicken gastrointestinal tract.

The presence and distribution patterns of ghrelin, a gastric acylated peptide, were studied in the entire gastrointestinal tract of the chicken (Gallus domesticus) using the peroxidase-antiperoxidase immunohistochemical method, western blot analysis and a specific antibody against the C-terminal region of rat ghrelin. Ghrelin-immunopositive cells were observed in the mucosal layer of all segments examined. The largest numbers of ghrelin-positive cells were located at the base of lobuli of the proventriculus gland, along villi of the intestines and in crypts of the duodenum. Lower numbers of ghrelin-immunostained cells were located in crypts of jejunum and ileum and only few ghrelin-immunostained cells were detected at the base of crypts of the large intestine. Closed and open types of cells were observed in all segments. Western blot analysis confirmed the presence of ghrelin-like protein in the entire chicken gastrointestinal tract. The anatomical distribution patterns and the morphological characteristics of chicken ghrelin-positive cells suggest that they are endocrine cells. Furthermore, it is concluded that ghrelin shows a high degree of preservation during evolution from non-mammalian vertebrates to mammals.

Animals↗

PubMed1992

Nitric oxide synthase immunoactivity and NADPH diaphorase enzyme activity in neurons of the gastrointestinal tract of the toad, Bufo marinus.

The presence of nitric oxide synthase (NOS) was demonstrated immunohistochemically, and NADPH diaphorase was demonstrated by enzyme histochemistry in neurons throughout the gastrointestinal tract of the anuran amphibian, Bufo marinus. Successive staining showed that NOS immunoreactivity and NADPH diaphorase activity occurred in precisely the same subgroup of enteric neurons. Subsequent detailed studies of the distribution of these neurons were made using NADPH diaphorase histochemistry. Numerous reactive nerve cell bodies and fibres were found in the myenteric plexus from the esophagus to the cloaca. A dense innervation of the longitudinal and circular muscle layers occurred throughout the gastrointestinal tract. The lamina muscularis mucosae was only prominent in the stomach, where it was sparsely innervated. Reactive nerve cell bodies were common in the submucosa of the large intestine, less common in the small intestine and extremely rare in the stomach and esophagus. Reactive fibres contributed to subepithelial plexuses in the esophagus, colon, rectum and cloaca. It is concluded that NOS/NADPH diaphorase is conserved amongst vertebrate classes and that NO is a likely neurotransmitter in the toad gastrointestinal tract.

Amino Acid Oxidoreductases↗

PubMed1998

Ultrathin endoscopy in the assessment and treatment of upper and lower gastrointestinal tract strictures.

BACKGROUND: Ultrathin (</= 6 mm diameter) endoscopes have recently been introduced into clinical practice. METHODS: We retrospectively assessed the role of a 6 mm diameter videoendoscope in 15 patients with tight gastrointestinal tract strictures. RESULTS: The ultrathin endoscope was successfully passed through 9 of 12 esophageal strictures not amenable to endoscopy with a standard-diameter endoscope allowing stricture dilatation or nasogastric tube placement in 8 of these. Ultrathin endoscopy was also successful in passing 3 lower gastrointestinal tract strictures caused by Crohn's disease that were impassable using larger-diameter endoscopes. CONCLUSION: Ultrathin endoscopy is potentially useful in the assessment and treatment of some upper and lower gastrointestinal tract strictures.

Adult↗

PubMed1993

Tuberculosis of the gastrointestinal tract and peritoneum.

Gastrointestinal and peritoneal tuberculosis remain common problems in impoverished areas of the world, but is relatively infrequent in the United States. A resurgence of tuberculosis in America since the mid-1980s means that clinicians will continue to see cases. Immigrants and AIDS patients are two population groups at particular risk for abdominal tuberculosis in this country; the urban poor, the elderly, and Indians on reservations are others. The symptoms and signs of GI and peritoneal tuberculosis are nonspecific, and unless a high index of suspicion is maintained, the diagnosis can be missed or delayed resulting in increased morbidity and mortality. Only 15-20% of patients have concomitant active pulmonary tuberculosis. Tuberculous peritonitis needs to be considered in all cases of unexplained exudative ascites. Laparoscopy with directed biopsy currently is the best way to make a rapid specific diagnosis. The measurement of ascites adenosine deaminase levels represents a major diagnostic advance in tuberculous peritonitis, particularly in underdeveloped areas where the affliction is common and laparoscopy may not be available. With greater experience, this testing procedure could also supersede invasive studies in western countries, particularly in high-risk patient groups. The commonest sites of tuberculous involvement of the GI tract are the ileocecal area, the ileum and the colon, although any area of the gut can be involved. If the area of affected gut is within reach of the flexible endoscope, rapid diagnosis may be possible with biopsy (if acid-fast bacilli or caseating granulomas are seen). Not infrequently, the disease is not considered until it is diagnosed at the time of surgery. In countries with a high prevalence of intestinal tuberculosis, a therapeutic trial of antituberculous drugs may be reasonable if the clinical picture is compatible. The diagnosis of tuberculous enteritis can be taken as highly probable if the patient responds to treatment and this is followed by no recurrence. Serologic tests for diagnosing tuberculosis are being improved and evaluated in intestinal tuberculosis. Gastrointestinal and peritoneal tuberculosis are treated with antituberculous drugs. Surgery is reserved for complications or uncertainty in diagnosis. Six-, 9-, and 18- to 24-month regimens are all effective for extrapulmonary tuberculosis. Standard therapy of at least 9 months duration is also effective in most AIDS patients who are started on appropriate treatment in a timely fashion and who are compliant. The potential for multidrug resistance needs to be kept in mind and accounted for.

Humans↗

PubMed1991

Prophylaxis of gastrointestinal tract bleeding with magaldrate in patients admitted to a general hospital ward.

A randomized, placebo-controlled trial was performed to assess the effect of magaldrate (800 mg every 4 h) in reducing the rate of upper gastrointestinal tract bleeding among 100 consecutive patients with severe diseases admitted to a general hospital ward. Upper gastrointestinal tract bleeding occurred in 11 of 48 placebo-treated patients and in only 1 of 52 magaldrate-treated patients (p less than 0.01). Endoscopic examination of these patients showed gastric ulcer (two cases), multiple gastric mucosa ulcerations (nine), and no lesions (one). In three patients who received placebo the hemorrhage was clinically relevant and required transfusion of two or more blood units. Patients with two or more risk factors showed a higher rate of gastrointestinal hemorrhage (p less than 0.05). Respiratory failure and treatment with a high dose of corticosteroids were associated with the highest incidence of bleeding (p less than 0.05 for both). The only adverse reaction associated with magaldrate was a mild and self-limiting diarrhea in two cases. We conclude that patients seriously ill admitted to a general hospital ward should be treated with a prophylactic agent against stress-induced ulcer bleeding. Magaldrate is an effective and safe antacid to prevent gastrointestinal tract bleeding in such patients.

Adult↗

PubMed1998

The organization of serotonin-, dopamine-, and FMRFamide-containing neuronal elements and their possible role in the regulation of spontaneous contraction of the gastrointestinal tract in the snail Helix pomatia.

The distribution of serotonin-, tyrosine hydroxylase-, and FMRFamide-immunoreactive neuronal elements, as well as the concentrations of serotonin and dopamine in the different parts of the gastrointestinal tract, were studied in the snail Helix pomatia. The sensitivity of the spontaneous contractions of the alimentary tract to serotonin, dopamine, and FMRFamide was also tested. Serotonin-, tyrosine hydroxylase-, and FMRFamide-immunoreactive elements could be demonstrated in each part of the gastrointestinal tract, but they showed different innervation patterns. Serotonin- and tyrosine hydroxylase-immunoreactive elements were dominant in the submucosal layer, whereas FMRFamide-immunoreactive elements were dominant in both the mucosal and submucosal layers. Tyrosine hydroxylase-immunoreactive elements were confined to the longitudinal muscle trabeculae of submucosa, whereas serotonin-immunoreactive elements were distributed throughout the submucosal layer. No serotonin-immunoreactive cell bodies, but only fibers, could be detected in the gastrointestinal tract, and therefore they represent extrinsic elements. Tyrosine hydroxylase- and FMRFamide-immunoreactive cell bodies represent intrinsic elements of the tract. The occurrence and density of the serotonin- and tyrosine hydroxylase-immunoreactive elements showed significant differences in the different parts of the alimentary tract, in accordance with HPLC assays, which revealed a significant frontocaudal decrease in both the serotonin (from 2.11 to 1.21 pM/mg) and dopamine (from 3.28 to 0.52 pM/mg) contents of the different parts of the alimentary tract. Dopamine at 10(-5) M concentration proved to be effective only on the longitudinal muscles by increasing the tone and frequency of contractions, but was ineffective on the circular muscles. Serotonin affected both the longitudinal and circular muscles. Serotonin at 10(-5) M concentration decreased the tone and increased the frequency of low-amplitude contractions of the longitudinal muscles of the esophagus and the gizzard but increased both the tone and frequency of the crop. Serotonin at 10(-9) M concentration slightly decreased the tone and blocked the contractions of the circular muscles in the crop but at 10(-5) M concentration induced contractions of the circular muscles in the gizzard. FMRFamide at 10(-6) M concentration decreased the tone and was shown to block the contractions of both the longitudinal and circular muscles.

Animals↗

PubMed2000

Identification and regional distribution of the dopamine D(1A) receptor in the gastrointestinal tract.

Dopamine (DA) is regarded as an important modulator of enteric function. Recent experiments have suggested that newly cloned DA receptor subtypes are widely expressed in peripheral organs, including the gastrointestinal tract. In the present studies, the D(1A) receptor subtype was identified in rat gut regions through localization of receptor protein by means of light microscopic immunohistochemistry and Western blot analysis and receptor mRNA by RT-PCR and in situ amplification and hybridization (3SR in situ). D(1A) receptor immunoreactivity was shown to have a diverse distribution in the gastrointestinal tract, being present in the gastroesophageal junction, stomach, pylorus, small intestine, and colon. The receptor has a transmural distribution present in both epithelial and muscle layers as well as in blood vessels and lamina propria cells of different gastrointestinal regions. Western blot analysis demonstrated a single 50-kDa band for esophagus, stomach, duodenum, jejunum, and colon. The in situ hybridization signal was localized to the same sites revealed by D(1A) receptor immunoreactivity. RT-PCR revealed an appropriate sized signal in similar regions. This study is the first to identify expression of the central D(1A) receptor throughout the normal mammalian gastrointestinal tract.

Animals↗

PubMed1996

Localization of protein kinase C alpha isoform expression in the human gastrointestinal tract.

Protein kinase C (PKC) includes a family of related proteins which constitutes a major signal transduction pathway. The aim of this study was to determine the localization of the PKC-alpha isoform throughout the human gastrointestinal tract. PKC-alpha expression was also measured and compared between normal and neoplastic colorectal tissue. PKC-alpha mRNA expression was detected in normal human gastrointestinal tract tissue using Northern blot analyses and in situ hybridization. PKC-alpha protein expression was detected in normal gastrointestinal tissue and colorectal neoplasia using Western blot and immunohistochemical analyses. PKC-alpha was expressed throughout the human gastrointestinal tract. Distinct organ and cellular localization was characterized. PKC-alpha mRNA and protein localization were most prevalent in the deep basal layer of the esophageal mucosa. In the stomach, PKC-alpha expression was detected predominately in the cells of the deep glands and surface epithelial cells but less in the mucous neck cells of the gastric pits. In the duodenum and ileum, PKC-alpha mRNA expression was greater in the deeper crypt cells than in the differentiated cells that line the villi. However, immunohistochemistry showed greater expression in the cells of the villi compared to crypt cells. In normal colonic tissue, PKC-alpha mRNA and protein predominated in the cells of the upper crypt and surface epithelial cells. PKC-alpha protein was also prominently expressed in the glands of colorectal adenocarcinoma. There was no quantitative difference in the level of PKC-alpha protein expression between normal and neoplastic colorectal tissue. The specific organ and cellular expression of PKC-alpha suggests separate and distinct functional roles for this PKC isoform throughout the gastrointestinal tissues.

Blotting, Western↗

PubMed2003

Delayed 99mTc-labeled erythrocyte scintigraphy in patients with lower gastrointestinal tract hemorrhage: effect of positive findings on clinical management.

RATIONALE AND OBJECTIVES: This study was performed to determine whether the results of delayed technetium 99m (99mTc)-labeled erythrocyte scintigraphy for lower gastrointestinal tract hemorrhage resulted in different clinical management and outcome from that in cases in which the results of initial scintigraphy were negative or equivocal. MATERIALS AND METHODS: The authors retrospectively reviewed all 398 99mTc-labeled erythrocyte scintigraphic studies obtained emergently for lower gastrointestinal tract hemorrhage at their institution between January 1, 1994, and December 7, 2001. Of 67 patients who underwent delayed studies, 37 had positive findings (average delay, 18.4 hours; range, 6-25 hours) and 30 had negative findings (average delay, 20.1 hours; range, 8-26 hours). Clinical management and outcome were compared between these two groups with respect to duration of hospitalization, volume of blood transfusion, mortality, and the percentage who were treated conservatively or referred for angiography, endoscopy, and/or surgery. RESULTS: Patients with positive delayed studies were referred more frequently for angiography than those with negative studies (35% vs 0%, P < .01). There were no significant differences between patients with positive findings and patients with negative findings with respect to mortality (8% vs 0%, P < .32), transfusion requirements (5.6 vs 3.2 units, P < .20), hospitalization (9.5 vs 6.1 days, P < .11), the percentage treated conservatively (35% vs 37%, P < .90), or the percentages referred for endoscopy (49% vs 60%, P < .50) or for surgery (24% vs 17%, P < .64). CONCLUSION: Positive findings at delayed scintigraphy resulted in increased referrals for angiography but had no other effect on clinical course or outcome of lower gastrointestinal tract hemorrhage.

Angiography↗

PubMed1981

Distribution of prostaglandin E2 binding sites in the porcine gastrointestinal tract.

Binding of biologically active 3H-PGE2 to particulate fractions of porcine gastrointestinal mucosa and muscle was investigated. Specific binding activity was detected in the 2500 xg and 30,000 xg sedimentation fractions of mucosa from esophagus, fundus, antrum, duodenum, ileum and colon, as well as in serosal muscle taken from the antrum, ileum, and colon. Optimal binding (greater than 40 fmol/mg protein) was observed in the 30,000 xg fraction of fundic mucosa incubated at pH 5.0. The characteristics of 3H-PGE2 binding were variable in the remainder of the gastrointestinal tract although binding in these tissues was significantly less (0.2 to 15 fmol/mg protein) than that observed in the fundic mucosa. These data suggest that the cellular and/or subcellular site of PG binding is not uniform throughout the gastrointestinal tract. In fundic mucosa removal of the surface epithelial layer by scraping did not significantly alter the total binding activity for PGE. This result suggests that in gastric secretory mucosa optimal binding activity for PGE2 occurs within the gastric pits deep to the surface epithelium.

Animals↗

PubMed1994

Nutritional management of gastrointestinal tract diseases of dogs and cats.

Pharmaceutical agents are often given inappropriate precedence in the treatment of gastrointestinal tract diseases. Nutrients have marked influences on the gastrointestinal tract and manipulation of the diet provides clinicians with a powerful therapeutic strategy to be used alone or concurrently with drug therapy. During acute gastroenteritis a change from the animal's regular food to a diet containing novel protein sources minimizes the likelihood of acquired food allergies to the staple protein components of the diet. "Feeding through" diarrhea, a method used in human infants, has limited applicability in dogs and cats. The ideal diet for chronic small bowel-type diarrhea is highly digestible, gluten-free, hypoallergenic, isosmolar, low in fat and low in lactose. Dietary protein requirements increase in protein-losing enteropathy. Dietary fat is kept to a minimum during gastrointestinal dysfunction because malabsorbed fatty acids and bile acids cause secretory diarrhea. In diseases of the small bowel, it is traditional to use low fiber diets. This recommendation needs revision because the binding and gelling properties of fiber are of potential benefit in the treatment of small bowel diarrhea. High fiber diets are useful in most large bowel diseases. The specific fiber type used markedly influences the clinical result.

Animal Feed↗