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1.
Acta Chir Belg ; 111(2): 103-6, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21618859

RESUMO

We report 2 cases of necrotizing fasciitis following stripping of the long saphenous vein and phlebectomy of varicose collateral vessels. The first one concerns a 42-year-old man who presented with a left thigh postoperative infection, evolving despite oral antibiotic therapy. Urgent surgical exploration proved an extensive necrosis consistent with necrotizing fasciitis. Wide excision of the necrotic tissue was performed. Under intravenous antibiotic therapy, local wound care and hyperbaric oxygen therapy, the patient's condition improved. The second case concerns a 60-year-old man with cardio-vascular disease and diabetes. He was transferred in our institution 7 days after surgery for an infection in the right thigh and septic shock. Immediate surgical exploration showed extensive necrotizing fasciitis of the thigh, popliteal fossa and latero-posterior compartments of the leg. Muscle necrosis of the right leg was also observed. A right supra-condylar amputation was performed. The patient improved under antibiotherapy and hyperbaric oxygen therapy.


Assuntos
Fasciite Necrosante/cirurgia , Procedimentos Cirúrgicos Vasculares/efeitos adversos , Adulto , Amputação Cirúrgica , Antibacterianos/administração & dosagem , Angiopatias Diabéticas/cirurgia , Fasciite Necrosante/diagnóstico , Fasciite Necrosante/etiologia , Humanos , Oxigenoterapia Hiperbárica , Masculino , Pessoa de Meia-Idade , Doença Arterial Periférica/cirurgia , Complicações Pós-Operatórias/cirurgia , Varizes/cirurgia
2.
J Cell Biol ; 108(2): 441-53, 1989 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2645299

RESUMO

The gastric parietal (oxyntic) cell is presented as a model for studying the dynamic assembly of the skeletal infrastructure of cell membranes. A monoclonal antibody directed to a 95-kD antigen of acid-secreting membranes of rat parietal cells was characterized as a tracer of the membrane movement occurring under physiological stimuli. The membrane rearrangement was followed by immunocytochemistry both at the light and electron microscopic level on semithin and thin frozen sections from resting and stimulated rat gastric mucosa. Double labeling experiments demonstrated that a specific and massive mobilization of actin, and to a lesser extent of spectrin (fodrin), was involved in this process. In the resting state, actin and spectrin were mostly localized beneath the membranes of all cells of the gastric gland, whereas the bulk of acid-secreting membranes appeared diffusely distributed in the cytoplasmic space of parietal cells without any apparent connection with cytoskeletal proteins. In stimulated cells, both acid-secreting material and actin (or spectrin) extensively colocalized at the secretory apical surface of parietal cells, reflecting that acid-secreting membranes were now exposed at the lumen of the secretory canaliculus and that this insertion was stabilized by cortical proteins. The data are compatible with a model depicting the membrane movement occurring in parietal cells as an apically oriented insertion of activated secretory membranes from an intracellular storage pool. The observed redistribution of actin and spectrin argues for a direct control by gastric acid secretagogues of the dynamic equilibrium existing between nonassembled (or preassembled) and assembled forms of cytoskeletal proteins.


Assuntos
Actinas/metabolismo , Membrana Celular/fisiologia , Citoesqueleto/fisiologia , Ácido Gástrico/metabolismo , Células Parietais Gástricas/ultraestrutura , Espectrina/metabolismo , Animais , Anticorpos Monoclonais , Membrana Celular/ultraestrutura , Citoesqueleto/ultraestrutura , Imunofluorescência , Imuno-Histoquímica , Microscopia Eletrônica , Ratos , Ratos Endogâmicos
3.
Acta Chir Belg ; 109(1): 106-8, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19341209

RESUMO

We report the case of a 74-year-old man who presented an acute haemoperitoneum further to the rupture of the cystic artery. The bleeding was successfully controlled using embolization. This procedure was complicated by ischaemic necrosis and perforation of the gall-bladder requiring laparoscopic cholecystectomy. Spontaneous rupture of intra-abdominal arteries is a rare event. This usually occurs in abnormal arteries, presenting pseudo-aneurysm or, weakened by arterial hypertension, diabetes or corticotherapy. In the case of a cystic artery rupture, embolization can be safely done as long as the arterial anastomotic network with hepatic parenchyma is sufficient to supply the gall-bladder.


Assuntos
Ducto Cístico/irrigação sanguínea , Hemoperitônio/etiologia , Artéria Hepática , Idoso , Embolização Terapêutica , Vesícula Biliar/irrigação sanguínea , Vesícula Biliar/patologia , Artéria Hepática/diagnóstico por imagem , Humanos , Isquemia/patologia , Masculino , Necrose , Peritonite/etiologia , Radiografia , Ruptura Espontânea
4.
Rev Med Brux ; 30(1): 47-51, 2009.
Artigo em Francês | MEDLINE | ID: mdl-19353942

RESUMO

We report the case of a 15-year old girl presenting with a gastric fullness sensation. The biological examination showed iron deficiency anaemia and elevation of the pancreatic enzymes. At endoscopy, a huge trichobezoar is found in the stomach. The endoscopic removal is impossible due to the compacity of the mass. Surgical resection is therefore performed. The postoperative course is uneventful and the biologic anomalies are rapidly corrected. A throughout anamnesis revealed a trichotillomania with trichophagia, this behavioural trouble found its origin in a familial conflict.


Assuntos
Anemia Ferropriva/etiologia , Bezoares/complicações , Transtornos da Alimentação e da Ingestão de Alimentos/diagnóstico , Pancreatite/etiologia , Gastropatias/complicações , Adolescente , Bezoares/diagnóstico por imagem , Bezoares/patologia , Bezoares/cirurgia , Conflito Psicológico , Família , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Feminino , Humanos , Gastropatias/diagnóstico por imagem , Gastropatias/patologia , Gastropatias/cirurgia , Tomografia Computadorizada por Raios X
5.
Eur J Pediatr Surg ; 17(2): 136-8, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17503310

RESUMO

We report the case of a newborn presenting with a pediculated mass arising from the anal margin. Antenatal sonogram and magnetic resonance imaging were unable to diagnose the precise nature of the lesion. Sacrococcygeal teratoma, an enterogenous cyst, a polyp, a prolapse or other perineal tumors were all proposed as possible entities. At birth, no other anatomic anomaly than this homogenous 2 cm para-anal lesion was seen. Excision of the mass was performed under general anesthesia. The postoperative histological exam showed mature fat cells. Reviewing the literature, there have been few previously reported cases of congenital perineal lipoma. It is a rare, benign and easy-to-treat condition that can be evocated by morphological sonography or magnetic resonance imaging (MRI).


Assuntos
Lipoma/congênito , Lipoma/diagnóstico , Humanos , Recém-Nascido , Lipoma/cirurgia , Espectroscopia de Ressonância Magnética , Masculino , Períneo
6.
Acta Chir Belg ; 107(4): 429-31, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17966540

RESUMO

We report a case of foetal urinary bladder rupture due to posterior urethral valves. A megacystis was diagnosed in a male foetus during routine second trimester ultrasound examination. The diagnosis of bladder rupture was made as, one week later, the bladder became undetectable with the appearance of ascites. During the follow-up, no oligohydramnios developed and intercurrent ascites resolved spontaneously. There are three described mechanisms releasing bladder hyperpressure: bladder diverticles, unilateral vesicoureteral reflux and bladder rupture. In this case, another mechanism might be involved: a patent urachus. The urethral valves were resected and no other surgical treatment was needed. The renal function remained normal. No long-term vesical follow-up of this pathology is available in the literature.


Assuntos
Doenças Fetais/cirurgia , Ruptura Espontânea/embriologia , Ruptura Espontânea/cirurgia , Uretra/anormalidades , Uretra/cirurgia , Doenças da Bexiga Urinária/embriologia , Doenças da Bexiga Urinária/cirurgia , Adulto , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Gravidez , Complicações na Gravidez , Urodinâmica
7.
Hepatogastroenterology ; 53(67): 86-8, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16506382

RESUMO

BACKGROUND/AIMS: Surgical treatment of gastroesophageal reflux disease has become common practice. These operations are known to fail in about 10%, the need for re-intervention approximates 5%. Re-fundoplications are feasible laparoscopically but are technically demanding. METHODOLOGY: For the present paper, we reviewed retrospectively the 10 patients that, in our practice, needed a re-intervention for failure of a prior fundoplication. The causes were: narrowed passage at wrap level (n=4), intra-thoracic wrap migration (n=3), wrap disruption (n=2) and gastric volvulus (n=1). RESULTS: All 10 patients underwent a re-operation consisting of a confection of a new 360 degrees wrap. All interventions were completed laparoscopically and no major complication occurred. The results of these revised fundoplications were satisfying with complete resolution of reflux and/or dysphagia in all patients but one. This latter patient still needed anti-acid medication for an unexplained persistent reflux. CONCLUSIONS: In our experience, laparoscopic correction of failed fundoplications is technically feasible and associated with low rate of complications and high success rate.


Assuntos
Refluxo Gastroesofágico/cirurgia , Laparoscopia , Adulto , Idoso , Procedimentos Cirúrgicos do Sistema Digestório , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reoperação , Estudos Retrospectivos , Falha de Tratamento
8.
Biochim Biophys Acta ; 720(1): 7-16, 1982 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-6174156

RESUMO

The effects of glucagon, gastric inhibitory peptide (GIP) and somatostatin on the generation of cyclic AMP have been studied under basal and histamine- or secretin-stimulated conditions in tubular gastric glands isolated by means of EDTA from the rat fundus and antrum. Four types of cell could be identified by electron microscopy; namely, parietal, mucous, peptic and some endocrine cells with a good morphological preservation of the cellular topography as seen in the intact mucosa. Immunoreactive somatostatin was found in antral glands (210 +/- 16 ng/g cell, wet wt., n = 9) as well as in fundic glands, but in smaller concentration (50 +/- 8 ng/g cell, wet wt., n = 9). (1) In rat fundic glands, glucagon, in supraphysiologic doses (3 . 10(-9) -5 . 10(-7) M), raised cyclic AMP levels 46 times above the basal. At maximally effective doses, combination of glucagon plus histamine was not additive whereas glucagon and secretin stimulations resulted in an additive response. Somatostatin (10(-10) -10(-7) M) inhibited both glucagon- and histamine-induced cyclic AMP production, whereas cimetidine specifically blocked the histaminergic stimulation. (2) In the same conditions, 10(-6)M glucagon produced a marginal effect (4-fold increase) in rat antrum, whereas GIP (10(-9) -10(-6)M) was unable to induce a significant rise of cyclic AMP production in either fundic or antral glands, or to prevent cyclic AMP production stimulated by histamine. (3) The present data do not support the view that circulating glucagon or GIP may regulate gastric secretion directly by a cyclic AMP-dependent mechanism in rat gastric glands and raise the possibility that gastric somatostatin may be the final mediator of the inhibitory actions of these hormones on acid secretion. (4) It is proposed that pancreatic glucagon acts through a receptor-cyclic AMP system which is specific for the bioactive peptide enteroglucagon ('oxyntomodulin'), probably in rat parietal cells.


Assuntos
AMP Cíclico/metabolismo , Polipeptídeo Inibidor Gástrico/farmacologia , Mucosa Gástrica/metabolismo , Hormônios Gastrointestinais/farmacologia , Glucagon/farmacologia , Somatostatina/farmacologia , 1-Metil-3-Isobutilxantina/farmacologia , Animais , Cinética , Masculino , Microscopia Eletrônica , Ratos , Ratos Endogâmicos , Estômago/citologia , Estômago/efeitos dos fármacos
9.
Biochim Biophys Acta ; 630(3): 433-41, 1980 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-6249385

RESUMO

The effects of secretin and vasointestinal peptide (VIP) on the production of cyclic AMP have been studied in gastric glands isolated by means of EDTA from rat fundic and antral mucosa. (1) In gastric fundus, secretin and VIP caused a time- and temperature-dependent stimulation of cyclic AMP production that was maximal when the test agents were incubated for 60 min at 20 degrees C in the presence of 0.5 mM 3-isobutyl-1-methylxanthine as a phosphodiesterase inhibitor. The dose-response curve was monophasic for both peptides, the production of cyclic AMP being sensitive to 10(-10) M secretin and to 5 . 10(-8) M VIP. Half-maximal stimulation was obtained with 2.9 10(-9) M secretin or 2 . 10(-7) M VIP and the maximal stimulation represented a 21-fold and a 19-fold increase above control for secretin and VIP, respectively. Histamine also stimulated cyclic AMP production, with a Km of about 5 . 10(-4) M. No additive effect on cyclic AMP production was oberved when secretin and VIP were simultaneously added at maximally active concentrations, while an additive effect was observed when secretin and histamine were added together. (2) In gastric antrum, the characteristics of the secretin- and VIP-stimulated cyclic AMP production were similar to those observed in gastric fundus. Histamine nevertheless failed to stimulate the formation of cyclic AMP in antral mucosa. (3) These data demonstrate the existence of a cyclic AMP system highly sensitive to secretin in gastric glands isolated from the rat fundus and antrum and suggest that VIP operates through this system. (4) It is proposed that the pepsinogen- and/or mucous-secreting cells are implicated in the regulation of cyclic AMP production by secretin in gastric glands of the rat.


Assuntos
AMP Cíclico/metabolismo , Mucosa Gástrica/metabolismo , Secretina/farmacologia , Animais , Histamina/metabolismo , Masculino , Inibidores de Fosfodiesterase/metabolismo , Antro Pilórico/metabolismo , Ratos , Estômago/efeitos dos fármacos , Peptídeo Intestinal Vasoativo/farmacologia
10.
Biochim Biophys Acta ; 1095(3): 249-54, 1991 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-1683568

RESUMO

We studied the effects of oxyntomodulin (OXM), of its C-terminal (19-37) fragment (OXM (19-37)) and of glucagon (GLU) on somatostatin release, cyclic AMP accumulation and inositol phosphate turnover in somatostatin-secreting RIN T3 cells in culture. Rapid changes in cellular free Ca2+ were also measured using fura-2. Carbachol was used as a control test agent for the parameters involving the inositol phosphate/Ca2+ cascade. OXM, GLU and OXM (19-37) were all able to stimulate somatostatin release with relative ED50 of approx. 1, 22 and 45, respectively. OXM and GLU stimulated cyclic AMP levels with relative ED50 of approx. 1 and 30, respectively, whereas OXM (19-37) was totally ineffective on this parameter. In contrast to carbachol, none of the peptides significantly modified the inositol phosphate turnover or induced rapid changes in cellular free Ca2+. We conclude that the RIN T3 cells contain a receptor-cyclic AMP system similar to that found in gastric mucosa and that this system is linked to somatostatin release. Another receptor-second messenger mechanism linked to somatostatin release is triggered by the (19-37) fragment. This mechanism is not the inositol phosphate/Ca2+ cascade triggered in the same cells by cholinergic agents.


Assuntos
Peptídeos Semelhantes ao Glucagon/farmacologia , Insulinoma/metabolismo , Somatostatina/metabolismo , Animais , Cálcio/metabolismo , Carbacol/farmacologia , AMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Glucagon/farmacologia , Peptídeos Semelhantes ao Glucagon/química , Técnicas In Vitro , Fosfatos de Inositol/metabolismo , Oxintomodulina , Fragmentos de Peptídeos/farmacologia , Ratos , Taxa Secretória/efeitos dos fármacos , Somatostatina/biossíntese , Fatores de Tempo , Células Tumorais Cultivadas
11.
Diabetes ; 48(9): 1873-6, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10480622

RESUMO

Human alpha-endosulfine is an endogenous regulator of the beta-cell K(ATP) channels. The recombinant alpha-endosulfine inhibits sulfonylurea binding to beta-cell membranes, reduces cloned K(ATP) channel currents, and stimulates insulin secretion from beta-cells. These properties led us to study the human ENSA gene that encodes alpha-endosulfine. Here, we describe the isolation, the partial characterization, and the chromosomal localization of the ENSA gene. The ENSA gene appears to be a 1.8-kb-long sequence that contains the transcription initiation site located 528 bp upstream of the initiation codon. The ENSA gene is intronless, and a single copy gene seems to be present in the genome. Finally, the ENSA gene co-localizes on human chromosome 14 (14q24.3-q31) with a locus for susceptibility to type 1 diabetes called IDDM11; thus, the ENSA gene represents an IDDM11 candidate.


Assuntos
Trifosfato de Adenosina/farmacologia , Proteínas de Drosophila , Ilhotas Pancreáticas/metabolismo , Peptídeos/genética , Canais de Potássio/efeitos dos fármacos , Sequência de Aminoácidos , Mapeamento Cromossômico , Clonagem Molecular , Código Genético , Humanos , Peptídeos e Proteínas de Sinalização Intercelular , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Canais de Potássio/metabolismo
12.
Eur J Cell Biol ; 61(1): 150-9, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8223700

RESUMO

A set of monoclonal antibodies directed against various gastric markers was produced in order to study the developmental expression of the gastric mucosa. A previously described monoclonal antibody, mab 146.14, labeled the proton pump (H+, K+) ATPase specifically located in gastric parietal cells. Mabs 15.1 and 121.17 revealed the mucus of mucous neck cells and mucous surface cells, respectively. By addition, mab 81.1 was directed against a cell surface membrane protein antigen composed of a major 31 kDa component (called GEP31). Our study mainly focused on the characterization of GEP31. This protein was typically located in the gastrointestinal epithelial tract (stomach, small intestine, colon). Moreover, interesting features were observed during the study of the early ontogenesis of the gastric mucosa. The 31 kDa protein was detected at the onset of gland formation (day 18), and a gradual increase in expression of the protein could be observed between day 18 and day 19. Furthermore, a comparative study of the expression of different terminal differentiation markers of gastric epithelial cells ((H+, K+) ATPase, mucins) during the early period of ontogenesis revealed that GEP31 could be detected well before the appearance of these markers. To our knowledge, GEP31 thus appears as the earliest expressed specific cell surface epithelial gastric antigen described to date. Furthermore, the partial N-terminal amino acid sequence of GEP31 was determined and revealed that it is not a known protein.


Assuntos
Proteínas Fetais/biossíntese , Células Parietais Gástricas/metabolismo , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais , Antígenos/análise , Diferenciação Celular/fisiologia , Idade Gestacional , Masculino , Proteínas de Membrana/análise , Ratos , Ratos Wistar
13.
Endocrinology ; 123(6): 2782-7, 1988 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3197645

RESUMO

Glucagon-like materials and glucagon have been identified by immunoassay and immunocytochemistry in the mammalian central nervous system. However, the molecular forms relevant to brain glucagon-like immunoreactivity (GLI) have not been precisely defined. In the rat small intestine, more than 90% of GLI is constituted by two peptides: oxyntomodulin (OXM) and glicentin. This work was initiated to characterize and determine the concentrations of these two peptides and glucagon in the rat central nervous system and to compare their relative proportions with those found in the gut. Different regions from the adult rat brain were analyzed by HPLC in association with RIA, using a central glucagon antiserum and an antibody directed toward the C-terminal end of OXM and glicentin. The elution profiles of hypothalamus extracts were constituted by two main peaks, both detected by the two antibodies used and displaying the same retention times as glicentin and OXM, respectively. A third small peak, which coeluted with glucagon, was constantly recorded with the central glucagon antiserum. The percentages of glicentin, OXM, and glucagon in 10 hypothalami were 37 +/- 1%, 55 +/- 1%, and 8 +/- 2%, respectively (n = 8). This distribution was quite similar to that in small intestinal extracts (38 +/- 1%, 59 +/- 1%, and 1.3 +/- 0.1%, respectively; n = 7); however, the peptide concentrations were almost 50-fold greater in intestine than in hypothalamus. In the medulla oblongata, the same peptide ratio was observed, with 10-fold lower concentrations compared to those in hypothalamus. In olfactory bulb, cerebellum, and cortex the concentrations were close the the detection limit, whereas they could be not detected in the pituitary. The combination of HPLC and specific RIAs allowed us to unambiguously characterize OXM and glicentin as the major components of GLI in the rat hypothalamus and medulla oblongata. The same proportion of these two peptides in the central nervous system and the gut indicates that a similar posttranslational processing exists in these rat tissues, another example of the brain-gut axis.


Assuntos
Química Encefálica , Hormônios Gastrointestinais/análise , Peptídeos Semelhantes ao Glucagon/análise , Glucagon/análise , Intestino Delgado/análise , Fragmentos de Peptídeos/análise , Precursores de Proteínas/análise , Animais , Cromatografia Líquida de Alta Pressão , Glicentina , Hipotálamo/análise , Masculino , Bulbo Olfatório/análise , Oxintomodulina , Pâncreas/análise , Radioimunoensaio , Ratos , Ratos Endogâmicos , Distribuição Tecidual
14.
Endocrinology ; 121(2): 704-13, 1987 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3595539

RESUMO

Oxyntomodulin (OXM), an intestinal glucagon-containing peptide extended at its C-terminal end by an octa-peptide, is one of the gut glucagon-like immunoreactants (GLI) or enteroglucagon. The distribution of OXM and glucagon was determined in the gastrointestinal tract and in the plasma of the rat. Reversed-phase HPLC, associated with RRA or RIA, performed with an N-terminally directed glucagon antiserum (GOL), was used. HPLC of intestinal extracts or plasma separated the GOL immunoreactivity into three peaks: two major peaks coeluting with a preparation of rat glicentin (peak I, partially purified from rat intestine) and porcine or rat OXM, respectively, and a smaller peak coeluting with glucagon. The behavior of the three peaks in the analytical systems matched that of glicentin, OXM, and glucagon, respectively, allowing their identification. The concentrations of OXM picomoles per g of tissue) gradually increased from the duodenum (9 +/- 1) to ileum (93 +/- 4), thereafter decreasing in cecum and colon (22 +/- 3). In the gut, OXM, glucagon, and peak I averaged 40%, 1%, and 59% of the total GLI, respectively. OXM was present in significant amounts in the pancreas (18% of GLI) and stomach (27% of GLI), two tissues in which it accounted, together with glucagon, for almost the totality of GLI. In 24 h-fasted rats, plasma concentrations of OXM, glucagon, and peak I, determined after HPLC with GOL antiserum, were 15.1 pM, 8.6 pM, and 12.3 pM, respectively. Two hours after refeeding, both OXM and peak I were significantly increased (P less than 0.05 and P less than 0.02) by a similar factor (2-fold), while glucagon remained unchanged. When the HPLC results were compared with RIA measurement of GLI (GOL antiserum) and glucagon (with a C-terminal glucagon antiserum) in plasma, enteroglucagon (GOL--C-terminal glucagon antiserum immunoreactivities) correlated well with the sum of OXM plus peak I. The combination of HPLC and RRA or RIA allows the unambiguous determination of OXM, glucagon, and glicentin (peak I) in tissues and plasma. In the rat intestine and in the plasma, OXM and glicentin appear roughly in the same ratio and seem to be the major components, if not the totality, of enteroglucagon.


Assuntos
Sistema Digestório/análise , Hormônios Gastrointestinais/análise , Peptídeos Semelhantes ao Glucagon/análise , Glucagon/análise , Animais , Cromatografia Líquida de Alta Pressão , Glucagon/sangue , Peptídeos Semelhantes ao Glucagon/sangue , Intestinos/análise , Masculino , Oxintomodulina , Pâncreas/análise , Proglucagon , Precursores de Proteínas/análise , Radioimunoensaio , Ensaio Radioligante , Ratos , Ratos Endogâmicos , Estômago/análise , Distribuição Tecidual
15.
Endocrinology ; 115(1): 102-5, 1984 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6376068

RESUMO

Oxyntomodulin, a gut peptide recently purified, has been tested in isolated perfused pancreases of normal rats. It was shown to stimulate insulin release monophasically in the presence of a low (6 mM) glucose concentration in the medium. Furthermore, oxyntomodulin potentiated glucose-induced insulin release (10 mM glucose) in a dose-dependent manner, although it was less powerful in this respect than equimolar concentrations of pancreatic glucagon. As oxyntomodulin belongs to the gut glucagon-like immunoreactants which are released during digestion, it is suggested that oxyntomodulin might be one of the factors that could functionally link the gut and the endocrine pancreas and contribute, at least in part, to the regulation of postprandial insulin release.


Assuntos
Hormônios Gastrointestinais/farmacologia , Peptídeos Semelhantes ao Glucagon/farmacologia , Insulina/metabolismo , Pâncreas/metabolismo , Animais , Relação Dose-Resposta a Droga , Glucagon/farmacologia , Técnicas In Vitro , Secreção de Insulina , Cinética , Masculino , Oxintomodulina , Pâncreas/efeitos dos fármacos , Perfusão , Ratos , Ratos Endogâmicos
16.
Endocrinology ; 133(2): 631-8, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8102095

RESUMO

Glucagon-like peptide-1(7-36)amide (tGLP-1), oxyntomodulin (OXM), and glucagon are posttranslational end products of the glucagon gene expressed in intestinal L-cells. In vivo, these peptides are potent inhibitors of gastric acid secretion via several pathways, including stimulation of somatostatin release. We have examined the receptors through which these peptides stimulate somatostatin secretion using the somatostatin-secreting cell line RIN T3. tGLP-1, OXM, and glucagon stimulated somatostatin release and cAMP accumulation in RIN T3 cells to similar maximum levels, with ED50 values close to 0.2, 2, and 50 nM and 0.02, 0.3, and 8 nM, respectively. Binding of [125I]tGLP-1, [125I]OXM, and [125I]glucagon to RIN T3 plasma membranes was inhibited by the three peptides, with relative potencies as follows: tGLP-1 > OXM > glucagon. Whatever the tracer used, the IC50 for tGLP-1 was close to 0.15 nM and was shifted rightward for OXM and glucagon by about 1 and 2-3 orders of magnitude, respectively. Scatchard analyses for the three peptides were compatible with a single class of receptor sites displaying a similar maximal binding close to 2 pmol/mg protein. In the hamster lung fibroblast cell line CCL39 transfected with the receptor for tGLP-1, binding of [125I]tGLP-1 was inhibited by tGLP-1, OXM, and glucagon, with relative potencies close to those obtained with RIN T3 membranes. Chemical cross-linking of [125I]tGLP-1, [125I]OXM, and [125I]glucagon revealed a single band at 63,000 mol wt, the intensity of which was dose-dependently reduced by all three peptides. These data suggest that in the somatostatin-secreting cell line RIN T3, OXM and glucagon stimulate somatostatin release through a tGLP-1-preferring receptor. This suggests that some biological effects, previously described for these peptides, might be due to their interaction with this receptor.


Assuntos
Peptídeos Semelhantes ao Glucagon/farmacologia , Glucagon/farmacologia , Fragmentos de Peptídeos/farmacologia , Receptores de Glucagon , Somatostatina/metabolismo , Animais , Ligação Competitiva , Northern Blotting , Linhagem Celular , Membrana Celular/metabolismo , Cricetinae , Reagentes de Ligações Cruzadas , AMP Cíclico/biossíntese , Fibroblastos/metabolismo , Glucagon/metabolismo , Peptídeo 1 Semelhante ao Glucagon , Receptor do Peptídeo Semelhante ao Glucagon 1 , Peptídeos Semelhantes ao Glucagon/metabolismo , Oxintomodulina , Fragmentos de Peptídeos/metabolismo , Receptores de Superfície Celular/efeitos dos fármacos , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/fisiologia , Transfecção
17.
Endocrinology ; 130(3): 1263-70, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1371446

RESUMO

Oxyntomodulin (OXM), a glucagon-containing peptide extended at its C-terminal end by an octapeptide, is a potent inhibitor of gastric acid secretion in rat and man. OXM appears to act on gastric mucosa at least partially through a stimulation of gastric somatostatin release. We have investigated the effects of OXM on a somatostatin-secreting cell line (RIN T3) derived from a radiation-induced rat insulinoma and characterized specific binding sites for this peptide. OXM increased somatostatin release with an ED50 of 2.3 nM. OXM also stimulated the cAMP accumulation in intact RIN T3 cells and adenylate cyclase activity in RIN T3 cell membranes with ED50 values of 0.5 and 11 nM, respectively. On these parameters, glucagon was 10-30 times less potent than OXM. Forskolin, isobutylmethylxanthine, and 8-bromo-cAMP mimicked the effect of OXM on somatostatin release. Specific binding for mono-[125I]OXM was dependent upon time and membrane concentration. Binding of mono-[125I]OXM was inhibited by OXM and glucagon in a concentration-dependent manner, with dissociation constants (Kd) of 4.5 and 43 nM, respectively. The nonhydrolyzable analogs of GTP (guanosine 5',3-O-(thio)triphosphate and guanosine 5' (beta,gamma-imino)triphosphate decreased the binding of mono-[125I]OXM to its binding sites. Covalent cross-linking of mono-[125I]OXM or mono-[125I]glucagon to RIN T3 cell membranes followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated a single radiolabeled band at 63,000 mol wt, which differed from that observed after cross-linking with liver plasma membranes (55,000 mol wt). These results demonstrate the presence of specific high affinity binding sites for OXM in a somatostatin-secreting cell line (RIN T3) and their coupling to adenylate cyclase via guanine nucleotide-binding proteins.


Assuntos
Peptídeos Semelhantes ao Glucagon/metabolismo , Insulinoma/metabolismo , Insulinoma/patologia , Somatostatina/metabolismo , 1-Metil-3-Isobutilxantina/farmacologia , 8-Bromo Monofosfato de Adenosina Cíclica/farmacologia , Adenilil Ciclases/metabolismo , Animais , Sítios de Ligação/efeitos dos fármacos , Colforsina/farmacologia , AMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Eletroforese em Gel de Poliacrilamida , Glucagon/farmacologia , Radioisótopos do Iodo , Oxintomodulina , Ratos , Células Tumorais Cultivadas/metabolismo , Células Tumorais Cultivadas/patologia
18.
Endocrinology ; 140(1): 22-8, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9886802

RESUMO

We have investigated the transduction pathways mediating the contractile effect of two glucagon-containing peptides, glicentin (GLIC) and oxyntomodulin (OXM), on smooth muscle cells isolated from rabbit antrum. Low concentrations of GLIC induced a biphasic and rapid (first phase at 5-8 sec) Ins(1,4,5)P3 production. By comparison, higher concentrations of OXM or OXM(19-37) were required to obtain biphasic time-courses of Ins(1,4,5)P3 production. In a Ca2+ free medium, the first phase of Ins(1,4,5)P3 production induced by GLIC or OXM was maintained, while the second phase disappeared. In saponin-permeabilized cells, all three peptides induced cell contraction with similar efficacies and potencies. Exogenous Ins(1,4,5)P3 mimicked the contractile effect of the peptides and heparin, which inhibits the Ins(1,4,5)P3 binding to its receptor, prevented contraction stimulated by each effector. We conclude that a Ca2+ mobilization from the intracellular stores is essential in the contractile effects of GLIC and OXM. Using the fluo-3 probe, a [Ca2+]i increase was observed in the presence of GLIC, OXM, or OXM(19-37). The three peptides reduced by 30-40% the cAMP content of cells stimulated by forskolin. This effect was pertussis toxin sensitive as demonstrated with OXM(19-37). Our data constitute important clues for the existence in smooth muscle cells of receptor(s) specific for the GLIC/OXM hormones, coupled via G protein(s) to both Ca2+ and cAMP pathways.


Assuntos
AMP Cíclico/fisiologia , Peptídeos Semelhantes ao Glucagon/farmacologia , Glucagon/farmacologia , Músculo Liso/fisiologia , Fragmentos de Peptídeos/farmacologia , Fosfatidilinositóis/fisiologia , Precursores de Proteínas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Cálcio/metabolismo , Carbacol/farmacologia , Colforsina/farmacologia , Glicentina , Peptídeos Semelhantes ao Glucagon/análogos & derivados , Técnicas In Vitro , Inositol 1,4,5-Trifosfato/biossíntese , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Músculo Liso/efeitos dos fármacos , Oxintomodulina , Toxina Pertussis , Antro Pilórico/citologia , Coelhos , Fosfolipases Tipo C/metabolismo , Fatores de Virulência de Bordetella/farmacologia
19.
J Clin Endocrinol Metab ; 74(6): 1405-9, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1592887

RESUMO

The biological specificity of oxyntomodulin toward the gastric mucosa results from its C-terminal octapeptide. A RIA using a specific antibody raised against this region permitted quantification of the whole set of proglucagon-derived peptides that interact with the oxyntomodulin recognition systems, corresponding to the new concept of oxyntomodulin-like-immunoreactivity (OLI). The present report describes the physiological 24-h OLI profile in human plasma (eight men and eight women; mean age, 45 yr; range, 20-77 yr). Blood was withdrawn every hour from 0700-1900 h and every 2 h from 2100-0500 h. A meal-dependent profile was found for circulating OLI, with basal values (60 +/- 7 ng/L) at 0500 h and rises elicited by each food intake. The highest value (136 +/- 21 ng/L) was obtained at 2100 h. Plasma concentrations and diurnal variations of OLI were similar to those of the other intestinal peptides known to exert an endocrine function. The mean circulating OLI values increased with age, whereas no change was noticed according to sex. The inhibitory effect exerted by the peptides of the OLI family on gastric acid secretion, the meal dependence of their plasma concentrations, and the observed synchronism of their diurnal profile with that previously described for somatostatin make them candidates for an enterogastrone action.


Assuntos
Ritmo Circadiano , Peptídeos Semelhantes ao Glucagon/sangue , Fatores Etários , Sequência de Aminoácidos , Feminino , Hormônios Gastrointestinais/química , Peptídeos Semelhantes ao Glucagon/química , Humanos , Masculino , Pessoa de Meia-Idade , Oxintomodulina , Radioimunoensaio/métodos , Homologia de Sequência do Ácido Nucleico
20.
FEBS Lett ; 146(1): 73-8, 1982 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-7140976

RESUMO

A 37 amino acid-peptide has been isolated from porcine jejuno-ileum on the basis of its glucagon-like activity in liver (interaction with glucagon-binding sites and activation of adenylate cyclase) using gel filtration, ion-exchange and high-performance liquid chromatography. Depending on the criteria chosen, this peptide is referred to as either 'bioactive enteroglucagon' (activity in liver), 'oxyntomodulin' (specific action in gastric oxyntic glands) or 'glucagon-37' (chemical structure).


Assuntos
Hormônios Gastrointestinais/isolamento & purificação , Peptídeos Semelhantes ao Glucagon/isolamento & purificação , Músculo Liso/análise , Adenilil Ciclases/metabolismo , Animais , Membrana Celular/metabolismo , Fenômenos Químicos , Química , Íleo/análise , Técnicas In Vitro , Jejuno/análise , Fígado/metabolismo , Oxintomodulina , Ratos , Suínos
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