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1.
Acta Chir Belg ; 111(2): 103-6, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21618859

RESUMEN

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.


Asunto(s)
Fascitis Necrotizante/cirugía , Procedimientos Quirúrgicos Vasculares/efectos adversos , Adulto , Amputación Quirúrgica , Antibacterianos/administración & dosificación , Angiopatías Diabéticas/cirugía , Fascitis Necrotizante/diagnóstico , Fascitis Necrotizante/etiología , Humanos , Oxigenoterapia Hiperbárica , Masculino , Persona de Mediana Edad , Enfermedad Arterial Periférica/cirugía , Complicaciones Posoperatorias/cirugía , Várices/cirugía
2.
Br J Pharmacol ; 161(4): 799-814, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20860660

RESUMEN

BACKGROUND AND PURPOSE: Quercetin lowers plasma glucose, normalizes glucose tolerance tests and preserves pancreatic ß-cell integrity in diabetic rats. However, its mechanism of action has never been explored in insulin-secreting ß-cells. Using the INS-1 ß-cell line, the effects of quercetin were determined on glucose- or glibenclamide-induced insulin secretion and on ß-cell dysfunctions induced by hydrogen peroxide (H(2)O(2)). These effects were analysed along with the activation of the extracellular signal-regulated kinase (ERK)1/2 pathway. N-acetyl-L-cysteine (NAC) and resveratrol, two antioxidants also known to exhibit some anti-diabetic properties, were used for comparison. EXPERIMENTAL APPROACH: Insulin release was quantified by the homogeneous time resolved fluorescence method and ERK1/2 activation tested by Western blot experiments. Cell viability was estimated by the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT) colorimetric assay. KEY RESULTS Quercetin (20 µmol·L(-1)) potentiated both glucose (8.3 mmol·L(-1))- and glibenclamide (0.01 µmol·L(-1))-induced insulin secretion and ERK1/2 phosphorylation. The ERK1/2 (but not the protein kinase A) signalling pathway played a crucial role in the potentiation of glucose-induced insulin secretion by quercetin. In addition, quercetin (20 µmol·L(-1)), protected ß-cell function and viability against oxidative damage induced by 50 µmol·L(-1) H(2)O(2) and induced a major phosphorylation of ERK1/2. In the same conditions, resveratrol or NAC were ineffective. CONCLUSION AND IMPLICATIONS: Quercetin potentiated glucose and glibenclamide-induced insulin secretion and protected ß-cells against oxidative damage. Our study suggested that ERK1/2 played a major role in those effects. The potential of quercetin in preventing ß-cell dysfunction associated with diabetes deserves further investigation.


Asunto(s)
Antioxidantes/farmacología , Células Secretoras de Insulina/efectos de los fármacos , Insulina/metabolismo , Quercetina/farmacología , Acetilcisteína/farmacología , Animales , Línea Celular , Glucosa/metabolismo , Gliburida/farmacología , Peróxido de Hidrógeno/toxicidad , Hipoglucemiantes/farmacología , Secreción de Insulina , Células Secretoras de Insulina/metabolismo , Masculino , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Estrés Oxidativo/efectos de los fármacos , Fosforilación/efectos de los fármacos , Ratas , Ratas Wistar , Resveratrol , Transducción de Señal/efectos de los fármacos , Estilbenos/farmacología
3.
Acta Chir Belg ; 109(1): 106-8, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19341209

RESUMEN

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.


Asunto(s)
Conducto Cístico/irrigación sanguínea , Hemoperitoneo/etiología , Arteria Hepática , Anciano , Embolización Terapéutica , Vesícula Biliar/irrigación sanguínea , Vesícula Biliar/patología , Arteria Hepática/diagnóstico por imagen , Humanos , Isquemia/patología , Masculino , Necrosis , Peritonitis/etiología , Radiografía , Rotura Espontánea
4.
Rev Med Brux ; 30(1): 47-51, 2009.
Artículo en Francés | MEDLINE | ID: mdl-19353942

RESUMEN

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.


Asunto(s)
Anemia Ferropénica/etiología , Bezoares/complicaciones , Trastornos de Alimentación y de la Ingestión de Alimentos/diagnóstico , Pancreatitis/etiología , Gastropatías/complicaciones , Adolescente , Bezoares/diagnóstico por imagen , Bezoares/patología , Bezoares/cirugía , Conflicto Psicológico , Familia , Trastornos de Alimentación y de la Ingestión de Alimentos/psicología , Femenino , Humanos , Gastropatías/diagnóstico por imagen , Gastropatías/patología , Gastropatías/cirugía , Tomografía Computarizada por Rayos X
5.
Acta Chir Belg ; 107(4): 429-31, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17966540

RESUMEN

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.


Asunto(s)
Enfermedades Fetales/cirugía , Rotura Espontánea/embriología , Rotura Espontánea/cirugía , Uretra/anomalías , Uretra/cirugía , Enfermedades de la Vejiga Urinaria/embriología , Enfermedades de la Vejiga Urinaria/cirugía , Adulto , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Embarazo , Complicaciones del Embarazo , Urodinámica
6.
Eur J Pediatr Surg ; 17(2): 136-8, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17503310

RESUMEN

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).


Asunto(s)
Lipoma/congénito , Lipoma/diagnóstico , Humanos , Recién Nacido , Lipoma/cirugía , Espectroscopía de Resonancia Magnética , Masculino , Perineo
7.
Hepatogastroenterology ; 53(67): 86-8, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16506382

RESUMEN

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.


Asunto(s)
Reflujo Gastroesofágico/cirugía , Laparoscopía , Adulto , Anciano , Procedimientos Quirúrgicos del Sistema Digestivo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reoperación , Estudios Retrospectivos , Insuficiencia del Tratamiento
9.
Neurogastroenterol Motil ; 16(4): 455-63, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15306001

RESUMEN

Glicentin (GLIC) and oxyntomodulin (OXM or GLIC 33-69) are gut hormones which regulate digestion. They are known to reduce digestive secretions and to delay gastric emptying. Their biological activities on intestinal motility are still unknown. The effect of a systemic GLIC or OXM increase was investigated in rats on the food intake, the postprandial myoelectrical activity of small intestine and the orocaecal transit. An OXM or GLIC i.v. infusion was applied during the 5 min preceding food onset and during the first 15 min of food intake. This determined a three- to fourfold increase of the preprandial OXM-GLIC level. The OXM or GLIC plasma increase did not modify food intake. OXM infusion slowed down gastric emptying when the stomach contained 3/4 of the ingested food (before T 3 h). The quantity of food delivered in jejunum was subsequently smaller (P < 0.05). In the small intestine, the duration of postprandial myoelectrical activity (50-60 min g(-1) of ingested food) was reduced by 70% (P < 0.001) on duodenum or jejunum and by 54% (P < 0.01) on ileum in OXM-treated rats. An interdigestive motility profile was settled and an acceleration of both gastric emptying and transit rate was thereafter evidenced (after T 3 h). GLIC also reduced the duration of the postprandial myoelectrical activity on duodenum and jejunum (65 and 63% respectively, P < 0.05), but was not as efficient as OXM on ileum. In pathological states such as acute adult gastroenteritis, OXM and GLIC exhibit a two- to fivefold increase in their plasma concentrations. The present findings suggest that OXM and GLIC could, in that disease, contribute to exclude pathogens, due to their joined action on gut motility.


Asunto(s)
Ingestión de Alimentos/efectos de los fármacos , Motilidad Gastrointestinal/efectos de los fármacos , Péptidos Similares al Glucagón/farmacología , Glucagón/farmacología , Intestino Delgado/efectos de los fármacos , Fragmentos de Péptidos/farmacología , Precursores de Proteínas/farmacología , Animales , Ingestión de Alimentos/fisiología , Motilidad Gastrointestinal/fisiología , Glicentina , Intestino Delgado/fisiología , Masculino , Oxintomodulina , Ratas , Ratas Wistar
12.
Rev Med Interne ; 25(4): 294-8, 2004 Apr.
Artículo en Francés | MEDLINE | ID: mdl-15050796

RESUMEN

PURPOSE: Rhabdomyolysis and myositis are rare, dose-related complications of statins and fenofibrates. The outcome is favorable as a rule with rapid regression after stopping the responsible drug. Recently, various auto-immune disease with evidence of hypersensitivity to HMG-CoA reductase inhibitors or fibrates drugs have been reported. Less than ten cases of dermatomyositis and polymyositis due to cholesterol-lowering drugs (CLD) have been previously reported. Five more cases polymyositis associated with CLD are reported. METHODS: Symptoms were compatible with diagnosis of polymyositis according to Bohan and Peter and with previous reported criteria for drug-induced myopathy in all cases. None of these patients had previous other connective tissue disorders. RESULTS: Five patients (median age 68 [54-78], female N =4) with CLD treatment (statin N =4, fenofibrates N =1) have developed iatrogenic polymyositis. All of them presented both proximal muscular weakness and increased muscle enzyme levels. One patient had iatrogenic antisynthetase syndrome characterized by mechanic's hand, Raynaud's phenomenon and anti JO1 antibodies. One other had sclerodermic hand oedema. Antinuclear antibodies were positive in 4 cases and muscle biopsy revealed polymyositis infiltrate in 4 cases. CLD treatment was discontinued with partial clinical improvement in 3 cases. Clinical remission was obtained with corticosteroid (N =5) in association with immunosuppresive agents in 3 cases. CONCLUSION: Muscular symptoms in patient with CLD treatment could be the first symptom of a polymyositis revealed or increased by this treatment and must encourage physician with antinuclear antibodies screening especially in case of proximal muscular weakness and increased muscle enzyme levels.


Asunto(s)
Fenofibrato/efectos adversos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/efectos adversos , Hipolipemiantes/efectos adversos , Polimiositis/inducido químicamente , Anciano , Anticuerpos Antinucleares/análisis , Femenino , Fenofibrato/uso terapéutico , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Hipercolesterolemia/tratamiento farmacológico , Hipolipemiantes/uso terapéutico , Masculino , Persona de Mediana Edad
13.
Diabetologia ; 45(5): 703-10, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-12107751

RESUMEN

AIMS/HYPOTHESIS: alpha-Endosulphine, a protein that belongs to the cAMP-regulated-phosphoprotein family, has been reported to modulate insulin secretion in vitro through interaction with the pancreatic beta-cell ATP-sensitive potassium (K(ATP)) channel. In this study, we analysed the tissue distribution of alpha-endosulphine and determined its pancreatic cellular localization. METHODS: Quantitative tissue distribution of alpha-endosulphine was studied by RIA on tissue extracts and cellular/subcellular localization was done using immunocytochemistry, morphometry and western blot analysis. alpha-Endosulphine and somatostatin release from RINT-3 somatostatin-secreting cells was quantified by RIA. RESULTS: alpha-Endosulphine, concentrated particularly in the central nervous system, was also detected in a wide variety of tissues including the pancreas. Immunohistochemistry analysis of adult rat pancreatic sections showed that alpha-endosulphine localized in somatostatin delta cells, where its expression increased during post-natal development. Immunoreactive cells were detected from foetal age E19, and the number of somatostatin cells co-expressing alpha-endosulphine increased with developmental age from E19 until adult. alpha-Endosulphine, highly expressed in the cytoplasm of RINT3 somatostatin-secreting cell line, was recovered in the particulate fraction of RINT3 cell extracts but was not co-secreted with somatostatin. CONCLUSION/INTERPRETATION: alpha-Endosulphine is expressed in all tissues tested including pancreas and is also detected in plasma. Pancreatic alpha-endosulphine is specifically localized in somatostatin delta cells. This cytosolic protein is not co-secreted with somatostatin and could be physically associated with particulate components of the cells. These findings are not in favour of an endocrine/paracrine effect of alpha-endosulphine on the beta-cell K(ATP) channel.


Asunto(s)
Proteínas de Drosophila , Islotes Pancreáticos/crecimiento & desarrollo , Páncreas/crecimiento & desarrollo , Péptidos/metabolismo , Envejecimiento , Animales , Línea Celular , Regulación del Desarrollo de la Expresión Génica , Edad Gestacional , Insulina/metabolismo , Secreción de Insulina , Péptidos y Proteínas de Señalización Intercelular , Islotes Pancreáticos/embriología , Islotes Pancreáticos/metabolismo , Cinética , Páncreas/embriología , Páncreas/metabolismo , Péptidos/genética , Ratas , Ratas Wistar , Somatostatina
14.
Diabetes Metab ; 28(6 Suppl): 4S7-13, 2002 Dec.
Artículo en Francés | MEDLINE | ID: mdl-12703060

RESUMEN

Insulin secretion from the beta-cells in the islets of Langerhans is mainly regulated by glucose entry via its transporter. The intracellular glucose metabolism induces a rise in ATP/ADP ratio which increases the degree of closure of ATP-sensitive potassium channels (K(ATP) channels), inducing a higher intracellular K+, which, in turn, depolarizes the membrane and opens voltage-sensitive calcium channels. The ensuing Ca2+ entry triggers extrusion of insulin-containing secretory granules and, thus, hormone secretion. The analysis of the structure of the genes encoding K(ATP) channels that are made of four Kir subunits (forming the ionic pore) and four regulatory SUR subunits (that contain the binding site for antidiabetic sulfonylureas) allowed to several subclasses of those ionic channels to be described: Insulin secreting beta cells contain the SUR1/Kir 6.2 complex, while heart and skeletal muscles contain the SUR2A/Kir 6.2 set, vascular smooth muscles (such as those present in coronary arteries) have SUR2B/Kir 6.1 and nonvascular smooth muscle SUR2B/Kir 6.2. The pharmacological specificity of each sulfonylurea depends on the type of SUR protein present in each tissue: most of the second generation sulfonylureas used in diabetic clinics (e.g. glibenclamide, glimepiride) display almost the same affinity for SUR1 SUR2A and SUR2B, leading to possible harmful adverse effects in type 2 diabetic patients with an associated cardiovascular pathology. In contrast, among the second generation sulfonylureas, only gliclazide displays a remarkable specificity towards the beta-cell K(ATP) channels, making this drug particularly safe in all situations, as it does not induce any interference with the cardiovascular system.


Asunto(s)
Insulina/metabolismo , Islotes Pancreáticos/fisiología , Animales , Señalización del Calcio/fisiología , Exocitosis , Gliburida/farmacología , Humanos , Hipoglucemiantes/farmacología , Secreción de Insulina , Islotes Pancreáticos/efectos de los fármacos , Modelos Biológicos , Potasio/fisiología , Canales de Potasio/fisiología , Compuestos de Sulfonilurea/farmacología
15.
Pancreas ; 20(4): 348-60, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10824688

RESUMEN

Glicentin (GLIC), oxyntomodulin (OXM), and peptide YY (PYY) released in blood by ileocolonic L-cells after meals may inhibit pancreatic secretion. Whereas OXM interacts with glucagon and tGLP-1 receptors, OXM 19-37, a biologically active fragment, does not. The purpose of this study was to measure the effect of OXM, OXM 19-37, GLIC, tGLP-1, and PYY on pancreatic secretion stimulated by 2 deoxyglucose (2DG), electrical stimulation of the vagus nerves (VES), acetylcholine and cholecystokinin octapeptide (CCK8) in anesthetized rats. The effect of OXM was also studied in dispersed pancreatic acini. Plasma oxyntomodulin-like immunoreactivity (OLI) was measured by radioimmunoassay after the exogenous infusion of OXM and after an intraduodenal meal. OXM 19-37, infused at doses mimicking postprandial plasma levels of OLI, decreased pancreatic secretion stimulated by 2DG, VES, or CCK8. Similar effects were found with OXM and GLIC. OXM 19-37 did not change the pancreatic stimulation induced by acetylcholine in vivo, or CCK-induced amylase release in isolated acini. Vagotomy completely suppressed the inhibitory effect of OXM 19-37 on CCK8-stimulated pancreatic secretion. PYY inhibited the effect of 2DG, but not that of CCK8, whereas tGLP-1, even in pharmacologic doses, had no effect on stimulated pancreatic secretion. OXM, OXM 19-37, but not tGLP-1, inhibit pancreatic secretion at physiologic doses, through a vagal neural indirect mechanism, different from that used by PYY, and probably through a GLIC-related peptide-specific receptor.


Asunto(s)
Péptidos Similares al Glucagón/farmacología , Páncreas/inervación , Páncreas/metabolismo , Animales , Desoxiglucosa/farmacología , Interacciones Farmacológicas , Glicentina , Glucagón/farmacología , Péptido 1 Similar al Glucagón , Péptidos Similares al Glucagón/sangre , Cinética , Masculino , Oxintomodulina , Páncreas/efectos de los fármacos , Fragmentos de Péptidos/sangre , Fragmentos de Péptidos/farmacología , Péptido YY/sangre , Péptido YY/farmacología , Precursores de Proteínas/farmacología , Ratas , Ratas Wistar , Sincalida/farmacología , Nervio Vago/efectos de los fármacos , Nervio Vago/fisiología
16.
Drug News Perspect ; 13(8): 453-62, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12937617

RESUMEN

ATP-dependent potassium (K(ATP)) channels are at a key position in the control of insulin release from pancreatic beta-cells, as they couple the polarity of the cell membrane to the cell metabolism. These channels turn to a closed state when intracellular ATP rises, following an increase in glucose metabolism. These channels are also controlled by sulfonylureas, a class of drugs used in type 2 diabetic patients for triggering insulin secretion. We have obtained evidence of the existence of endogenous equivalents to sulfonylureas in the central nervous system and other K(ATP) channel-containing tissues (including the endocrine pancreas). These molecules, of a peptidic nature, have been called "endosulfines" (for "endogenous sulfonylureas"). In this review, we describe the discovery, isolation and biological features of these molecules--which represent novel regulators of insulin secretion--and the molecular cloning of the large molecular mass form (alpha-endosulfine), and discuss their possible implication in the physiology of beta-cells, as well as in pathology.

17.
Br J Pharmacol ; 128(5): 1021-6, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10556939

RESUMEN

1. The MIN6 cell line derived from in vivo immortalized insulin-secreting pancreatic beta cells was used to study the insulin-releasing capacity and the cellular mode of action of S-22068, a newly synthesized imidazoline compound known for its antidiabetic effect in vivo. 2. S-22068, was able to release insulin from MIN6 cells in a dose-dependent manner with a half-maximal stimulation at 100 micronM. Its efficacy (8 fold over the basal value), which did not differ whatever the glucose concentration (stimulatory or not), was intermediate between that of sulphonylurea and that of efaroxan. 3. Similarly to sulphonylureas and classical imidazolines, S-22068 blocked K(ATP) channels and, in turn, opened nifedipine-sensitive voltage-dependent Ca2+ channels, triggering Ca2+ entry. 4. Similarly to other imidazolines, S-22068 induced a closure of cloned K(ATP) channels injected to Xenopus oocytes by interacting with the pore-forming Kir6.2 moiety. 5. S-22068 did not interact with the sulphonylurea binding site nor with the non-I1 and non-I2 imidazoline site evidenced in the beta cells that is recognized by the imidazoline compounds efaroxan, phentolamine and RX821002. 6. We conclude that S-22068 is a novel imidazoline compound which stimulates insulin release via interaction with an original site present on the Kir6.2 moiety of the beta cell K(ATP) channels.


Asunto(s)
Hipoglucemiantes/farmacología , Imidazoles/farmacología , Insulina/metabolismo , Islotes Pancreáticos/metabolismo , Piperazinas/farmacología , Canales de Potasio de Rectificación Interna , Antagonistas Adrenérgicos alfa/metabolismo , Animales , Calcio/metabolismo , Canales de Calcio/efectos de los fármacos , Canales de Calcio/metabolismo , Línea Celular , Humanos , Idazoxan/análogos & derivados , Idazoxan/metabolismo , Islotes Pancreáticos/efectos de los fármacos , Potenciales de la Membrana/fisiología , Oocitos/efectos de los fármacos , Oocitos/metabolismo , Bloqueadores de los Canales de Potasio , Canales de Potasio/efectos de los fármacos , Ensayo de Unión Radioligante , Receptor de Insulina/efectos de los fármacos , Radioisótopos de Rubidio , Xenopus laevis
18.
Diabetes ; 48(9): 1873-6, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10480622

RESUMEN

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.


Asunto(s)
Adenosina Trifosfato/farmacología , Proteínas de Drosophila , Islotes Pancreáticos/metabolismo , Péptidos/genética , Canales de Potasio/efectos de los fármacos , Secuencia de Aminoácidos , Mapeo Cromosómico , Clonación Molecular , Código Genético , Humanos , Péptidos y Proteínas de Señalización Intercelular , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Canales de Potasio/metabolismo
19.
Biochem Biophys Res Commun ; 257(3): 766-70, 1999 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-10208857

RESUMEN

The ATP-sensitive K+ channel, an octameric complex of two structurally unrelated types of subunits, SUR1 and Kir6.2, plays a central role in the physiological regulation of insulin secretion. The sulfonylurea glibenclamide, which trigger insulin secretion by blocking the ATP-sensitive K+ channel, interacts with both high and low affinity binding sites present on beta-cells. The high affinity binding site has been localized on SUR1 but the molecular nature of the low affinity site is still uncertain. In this study, we analyzed the pharmacology of glibenclamide in a transformed COS-7 cell line expressing the rat Kir6.2 cDNA and compared with that of the MIN6 beta cell line expressing natively both the Kir6.2 and the SUR1 subunits. Binding studies and Scatchard analysis revealed the presence of a single class of low affinity binding sites for glibenclamide on the COS/Kir6.2 cells with characteristics similar to that observed for the low affinity site of the MIN6 beta cells.


Asunto(s)
Transportadoras de Casetes de Unión a ATP , Gliburida/metabolismo , Islotes Pancreáticos/metabolismo , Canales de Potasio de Rectificación Interna , Canales de Potasio/metabolismo , Animales , Sitios de Unión , Northern Blotting , Células COS , Línea Celular , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Gliclazida/metabolismo , Glipizida/metabolismo , Gliburida/farmacología , Islotes Pancreáticos/citología , Cinética , Orgánulos/metabolismo , Fentolamina/metabolismo , Canales de Potasio/genética , Ratas , Receptores de Droga/genética , Receptores de Droga/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Compuestos de Sulfonilurea/metabolismo , Receptores de Sulfonilureas , Tolbutamida/metabolismo , Transfección
20.
J Biol Chem ; 274(16): 10869-76, 1999 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-10196164

RESUMEN

Using the MIN6 B-cell line, we investigated the hypothesis that miniglucagon, the C-terminal () fragment processed from glucagon and present in pancreatic A cells, modulates insulin release, and we analyzed its cellular mode of action. We show that, at concentrations ranging from 0.01 to 1000 pM, miniglucagon dose-dependently (ID50 = 1 pM) inhibited by 80-100% the insulin release triggered by glucose, glucagon, glucagon-like peptide-1-(7-36) amide (tGLP-1), or glibenclamide, but not that induced by carbachol. Miniglucagon had no significant effects on cellular cAMP levels. The increase in 45Ca2+ uptake induced by depolarizing agents (glucose or extracellular K+), by glucagon, or by the Ca2+channel agonist Bay K-8644 was blocked by miniglucagon at the doses active on insulin release. Electrophysiological experiments indicated that miniglucagon induces membrane hyperpolarization, probably by opening potassium channels, which terminated glucose-induced electrical activity. Pretreatment with pertussis toxin abolished the effects of miniglucagon on insulin release. It is concluded that miniglucagon is a highly potent and efficient inhibitor of insulin release by closing, via hyperpolarization, voltage-dependent Ca2+ channels linked to a pathway involving a pertussis toxin-sensitive G protein.


Asunto(s)
Canales de Calcio/efectos de los fármacos , Glucagón/farmacología , Antagonistas de Insulina/farmacología , Insulina/metabolismo , Fragmentos de Péptidos/farmacología , Calcio/metabolismo , Canales de Calcio/metabolismo , Línea Celular , Agonistas Colinérgicos/farmacología , AMP Cíclico/biosíntesis , Péptido 1 Similar al Glucagón , Péptidos Similares al Glucagón , Glucosa/farmacología , Secreción de Insulina , Transporte Iónico , Islotes Pancreáticos/efectos de los fármacos , Islotes Pancreáticos/metabolismo , Potenciales de la Membrana/efectos de los fármacos , Péptidos/farmacología , Toxina del Pertussis , Factores de Virulencia de Bordetella/farmacología
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