Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Gynecol Oncol ; 152(2): 235-242, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30466805

RESUMO

OBJECTIVE: Surgical assessment of residual tumor provides the strongest prognostic information in advanced ovarian cancer (AOC), with the best outcome observed after complete resection. Postoperative radiological assessment before initiation of chemotherapy can supplement the information obtained by surgical assessment; however, it may also reveal conflicting findings. METHODS: Patients with AOC enrolled in the AGO-OVAR 12 trial underwent baseline imaging before the first chemotherapy cycle. The findings from surgical and radiologic assessment for disease extend were compared. Additionally, an integrated approach was assessed. RESULTS: Complete data from all 3 assessment methods were available for 1345 patients. Of 689 patients with complete resection, tumor was observed in 28% and 22% of patients undergoing radiologic and integrated assessment, respectively. Patients with surgical- radiological and surgical-integrated concordant findings showed a 5-year overall survival (5Y-OS) of 72% and 71%, whereas patients with surgical-radiological and surgical-integrated discordant results showed inferior 5Y-OS of 47% and 49%, respectively. Patients with surgically assessed residual disease had a 5-YOS of 37%. The interval between surgery and baseline assessment was independently associated with discordance between assessment methods, which might reflect early tumor regrowth. CONCLUSIONS: Baseline tumor assessment before chemotherapy provides information that stratifies patients with complete resection into different prognostic groups. Integrating the data from different assessment methods might lead to improved definitions of prognostic groups. Further investigation to determine if earlier initiation of chemotherapy after debulking surgery could increase survival of patients with early tumor regrowth is warranted.


Assuntos
Carcinoma Epitelial do Ovário/patologia , Carcinoma Epitelial do Ovário/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carboplatina/administração & dosagem , Carcinoma Epitelial do Ovário/tratamento farmacológico , Carcinoma Epitelial do Ovário/mortalidade , Método Duplo-Cego , Feminino , Humanos , Indóis/administração & dosagem , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasia Residual/patologia , Paclitaxel/administração & dosagem , Prognóstico , Adulto Jovem
2.
Br J Cancer ; 107(2): 280-6, 2012 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-22699824

RESUMO

BACKGROUND: BI 2536, a novel Polo-like kinase 1 inhibitor, was assessed in patients with unresectable advanced exocrine adenocarcinoma of the pancreas. METHODS: The study employed a two-stage design. Randomised first-line patients received BI 2536 200 mg on day 1 (n=43) or 60 mg on days 1-3 (n=43) every 21 days. Recruitment of second-line patients was planned for a second stage dependent on an interim analysis demonstrating ≥ 2 responses in the first 18 evaluable patients following 12 weeks of treatment and/or tumour control ≥ 12 weeks in 5 patients per schedule. Primary end point was objective response rate (ORR). RESULTS: By independent review, ORR was 2.3% (all partial) and 24.4% had stable disease as confirmed best response. The second stage was not initiated. Median overall and progression-free survivals were 149 (95% confidence interval (CI), 91-307) and 46 days (95% CI, 44-56). Most common drug-related adverse events were neutropenia (37.2%), leukopenia (29.1%), fatigue (29.1%) and nausea (22.1%); most common grade 3/4-related events were neutropenia (36.0%), leukopenia (27.9%) and thrombocytopenia (8.1%). CONCLUSION: Given the low ORR and poor survival, further development of BI 2536 monotherapy is not warranted in this population.


Assuntos
Adenocarcinoma/tratamento farmacológico , Proteínas de Ciclo Celular/antagonistas & inibidores , Neoplasias Pancreáticas/tratamento farmacológico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Pteridinas/uso terapêutico , Adenocarcinoma/enzimologia , Adenocarcinoma/metabolismo , Idoso , Proteínas de Ciclo Celular/metabolismo , Estudos de Coortes , Intervalos de Confiança , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/enzimologia , Neoplasias Pancreáticas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Pteridinas/efeitos adversos , Pteridinas/farmacocinética , Quinase 1 Polo-Like
3.
Langenbecks Arch Surg ; 391(2): 157-60, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16465554

RESUMO

BACKGROUND: Abdominal gas gangrene caused by clostridia species is rare and usually associated with organ perforation, immune suppression, or advanced malignoma. CASE REPORT: A 61-year-old man was admitted with severe back pain 1 day after uncomplicated colonoscopic polypectomy. With the exception of preexisting minor depression, the patient had been previously in excellent health. The computed tomography scan showed retroperitoneal emphysema in the left psoas muscle. During exploratory laparotomy, a spreading retroperitoneal phlegmon with pneumoretroperitoneum and a secondary peritonitis were found. A macroscopic perforation of the gut, particularly at the polypectomy sites was excluded. After the operation, the patient evolved in a septic shock condition and had pulmonary failure. Before hyperbaric oxygen therapy could be employed, the patient died. The autopsy showed a massive gas gangrene of the retroperitoneum caused by Clostridium perfringens, but no macroscopic bowel perforation was detected. RESULTS: This is the first report of a case of gas gangrene after uncomplicated polypectomy without macroscopic perforation in an otherwise healthy individual. A microperforation due to mucosal defect after polypectomy was most likely the entry point for the bacteria. CONCLUSION: We conclude that clostridial myonecrosis should be considered in unclear abdominal infections, even if the patient's history is not typical as in the present case.


Assuntos
Clostridium perfringens , Doenças do Colo/etiologia , Pólipos do Colo/cirurgia , Colonoscopia/efeitos adversos , Gangrena Gasosa/diagnóstico , Perfuração Intestinal/etiologia , Doenças do Colo/cirurgia , Evolução Fatal , Gangrena Gasosa/microbiologia , Gangrena Gasosa/terapia , Humanos , Perfuração Intestinal/cirurgia , Masculino , Pessoa de Meia-Idade , Espaço Retroperitoneal , Choque Séptico/etiologia , Choque Séptico/terapia , Tomografia Computadorizada por Raios X
6.
Gut ; 51(2): 155-63, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12117872

RESUMO

BACKGROUND AND AIMS: Mucosal flattening and epithelial cell apoptosis are typical features of T cell induced inflammatory diseases of the bowel, such as coeliac disease and graft versus host disease. Mice injected with a T cell activating anti-CD3 antibody develop a severe diarrhoeal illness. We describe the histological features of this enteropathy and define the effector mechanisms involved in T cell induced mucosal injury in this in vivo model. METHODS: Wild-type and genetically modified mice were injected with the anti-CD3 antibody 3C11 (50 microg). Changes in the murine intestine were characterised by light microscopy analysis and terminal uridine nick-end labelling (TUNEL) assay. The role of perforin, Fas/Fas ligand (FasL), tumour necrosis factor alpha (TNF-alpha), and interferon gamma (IFN-gamma) in T cell induced mucosal damage was assessed using selected immunodeficient mouse strains. RESULTS: T cell activation caused severe damage, including small intestinal mucosal flattening and apoptosis of crypt epithelial cells. Mucosal damage was unaltered in anti-CD3 treated mice lacking IFN-gamma, Fas, or TNF-alpha receptors. In mice lacking TNF-alpha receptors and Fas (TNF-R1xR2 lpr/lpr strain), enterocyte apoptosis was diminished but there was no significant reduction in tissue damage. Apoptosis and mucosal injury were significantly reduced in perforin knockout mice. Abrogation of both FasL and perforin (perforin KOxgld mice) further significantly reduced tissue damage and apoptotic bodies. CONCLUSIONS: T cell induced mucosal injury is mediated by the combined effect of multiple pathways but predominantly by perforin. The redundancy of the mechanisms of tissue damage will have significant impact on therapeutic strategies aimed at specific and targeted inhibition of inflammatory processes.


Assuntos
Mucosa Intestinal/imunologia , Glicoproteínas de Membrana/fisiologia , Linfócitos T/imunologia , Fator de Necrose Tumoral alfa/fisiologia , Animais , Anticorpos Monoclonais/farmacologia , Antígenos CD/genética , Apoptose , Complexo CD3/imunologia , Epitélio/patologia , Proteína Ligante Fas , Marcação In Situ das Extremidades Cortadas , Interferon gama/genética , Mucosa Intestinal/patologia , Intestino Delgado/imunologia , Ativação Linfocitária , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos SCID , Modelos Animais , Perforina , Proteínas Citotóxicas Formadoras de Poros , Receptores do Fator de Necrose Tumoral/genética , Receptores Tipo I de Fatores de Necrose Tumoral , Receptores Tipo II do Fator de Necrose Tumoral , Fator de Necrose Tumoral alfa/genética
7.
J Mol Endocrinol ; 28(2): 99-110, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11932207

RESUMO

We investigated the role of hepatocyte growth factor (HGF) in beta-cell growth and its complex intracellular signal transduction pathways. Cell proliferation was measured in the beta-cell line INS-1 using [3H]thymidine incorporation. Activation of mitogenic signaling proteins was assessed using co-immunoprecipitation, immunoblot analysis and specific protein activity inhibitors in proliferation assays. HGF (1 x 375 nM) increased INS-1 cell proliferation in the presence of 3-24 mM glucose up to 45-fold vs unstimulated controls. HGF exceeded the effect of glucose alone (2 x 2-fold at 3 mM glucose and 1 x 7-fold in the presence of 15 mM glucose). The HGF-induced INS-1 cell proliferation was further increased by addition of IGF-I or GH. Stimulation with HGF activated the JAK-2/STAT-5 pathway with a subsequent activation of phosphatidylinositol-3'-kinase (PI3'K). PI3'K activation was necessary for HGF- and glucose-stimulated INS-1 cell proliferation. The effect of PI3'K was mediated via 70 kDa S6 kinase and protein kinase B, which showed maximum activation in the presence of 3-6 mM glucose. Protein kinase C was essential for HGF-induced INS-1 cell proliferation. The HGF effect was also mediated at low glucose concentrations via insulin receptor substrate 4 (IRS-4) whereas other IRS proteins did not show any activation. High glucose concentrations also showed an increased IRS-4/PI3'K binding and therefore activation. In conclusion, beta-cell proliferation is mediated via complex interacting signal transduction pathways. HGF, in contrast to other growth factors, seems to be of importance particularly in the presence of low glucose concentrations and therefore takes a special role in this complex concert.


Assuntos
Glucose/deficiência , Fator de Crescimento de Hepatócito/farmacologia , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Inibidores Enzimáticos/farmacologia , Glucose/metabolismo , Glucose/farmacologia , Hormônio do Crescimento/metabolismo , Hormônio do Crescimento/farmacologia , Fator de Crescimento Insulin-Like I/metabolismo , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Timidina/metabolismo
8.
J Immunol ; 167(5): 2651-6, 2001 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-11509607

RESUMO

The intestinal mucosa normally displays minimal inflammation despite the close proximity between mucosal macrophages and lumenal bacteria. Macrophages interact with bacteria and their products through CD14, a surface receptor involved in the response to LPS, and CD89, the receptor for IgA (FcalphaR). Here we show that resident macrophages isolated from normal human intestine lack CD14 and CD89. The absence of CD14 and CD89 was not due to the isolation procedure or mucosal cell products, but was evident at the transcriptional level, as the macrophages expressed neither CD14- nor CD89-specific mRNAs, but did express Toll-like receptor 2 and 4 transcripts. Consistent with their CD14(-) phenotype, lamina propria macrophages displayed markedly reduced LPS-induced cytokine production and LPS-enhanced phagocytosis. In addition, IgA-enhanced phagocytosis was sharply reduced in lamina propria macrophages. Thus, the absence of CD14 and CD89 on resident intestinal macrophages, due to down-regulated gene transcription, causes down-modulated LPS- and IgA-mediated functions and probably contributes to the low level of inflammation in normal human intestinal mucosa.


Assuntos
Antígenos CD/metabolismo , Proteínas de Drosophila , Mucosa Intestinal/citologia , Mucosa Intestinal/imunologia , Receptores de Lipopolissacarídeos/metabolismo , Macrófagos/imunologia , Receptores Fc/metabolismo , Antígenos CD/genética , Sequência de Bases , Citocinas/biossíntese , Primers do DNA/genética , Regulação para Baixo , Humanos , Imunoglobulina A/metabolismo , Técnicas In Vitro , Jejuno/citologia , Jejuno/imunologia , Receptores de Lipopolissacarídeos/genética , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Fagocitose/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Receptores Fc/genética , Transdução de Sinais , Receptor 2 Toll-Like , Receptores Toll-Like
9.
Ther Umsch ; 56(10): 597-601, 1999 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-10549232

RESUMO

Abdominal complaints during pregnancy are frequent. In most instances, nausea and vomiting are a consequence of pregnancy and are considered indicators of a well-developing pregnancy. The growing uterus and hormonal changes during pregnancy often lead to gastroesophageal reflux and constipation. Serious gastrointestinal diseases such as intestinal obstruction or the exacerbation of a chronic inflammatory bowel disease during pregnancy are rare, but if suspected, often warrant immediate confirmation and aggressive therapy. Unnecessary delays are associated with an increasing mortality and morbidity.


Assuntos
Gastroenteropatias/diagnóstico , Gastroenteropatias/terapia , Complicações na Gravidez/diagnóstico , Complicações na Gravidez/terapia , Adulto , Feminino , Refluxo Gastroesofágico/diagnóstico , Refluxo Gastroesofágico/terapia , Fármacos Gastrointestinais/uso terapêutico , Humanos , Doenças Inflamatórias Intestinais/diagnóstico , Doenças Inflamatórias Intestinais/terapia , Úlcera Péptica/diagnóstico , Úlcera Péptica/terapia , Gravidez
10.
Dtsch Med Wochenschr ; 124(42): 1235-8, 1999 Oct 22.
Artigo em Alemão | MEDLINE | ID: mdl-10572532

RESUMO

HISTORY AND FINDINGS: A 17-year old adolescent with chronic constipation developed fecal incontinence with liquid, fetid stool. He had had variable bowel symptoms since early childhood, but not in his infancy. Since several years he had undergone psychotherapeutic treatment for depression due to a familial conflict situation. Abdominal palpation revealed the presence of a large, hard mass in the lower abdomen, measuring about 20 cm in diameter. INVESTIGATIONS: A defecography verified the presence of a huge obstructing fecalith in the rectum, with massive dilation and elongation of the antecedent rectum and colon (megarectum and megacolon). Neither endoscopy nor radiological imaging revealed a narrow bowel segment. In sequential biopsies, no indication of aberrant innervation was found. The recto-anal inhibitory reflex could be elicited. TREATMENT AND COURSE: Restoration of the rectal passage was achieved by manual disimpaction in numerous sessions, supported by repeated rectal enemas. Subsequently, the patient had normal daily bowel movements for a few days. However, he had to be readmitted three weeks later because again a fecalith had formed, measuring 15 cm in diameter. A few days after discharge the patient hat not followed the exhortation to void ad least once per day. After renewed disimpaction he was referred to a psychosomatic clinic. CONCLUSION: Voluntary withholding of defecation can eventuate massive coprostasis and the development of megacolon and megarectum. In theses instances the major complaint may not be constipation but paradoxical diarrhea. A number of conditions have to be excluded before the diagnosis idiopathic megacolon can be confirmed. Treatment ist difficult and often necessitates prolonged and repetitious interventions.


Assuntos
Constipação Intestinal/complicações , Impacção Fecal/diagnóstico , Adolescente , Doença Crônica , Diagnóstico Diferencial , Diarreia/etiologia , Endoscopia , Enema , Impacção Fecal/complicações , Impacção Fecal/terapia , Incontinência Fecal/etiologia , Humanos , Masculino , Megacolo/diagnóstico , Recidiva , Tomografia Computadorizada por Raios X
11.
Am J Physiol ; 276(3): R715-23, 1999 03.
Artigo em Inglês | MEDLINE | ID: mdl-10070131

RESUMO

Specific in vivo T cell activation initiated by treatment with anti-CD3 antibodies leads to diarrhea and structural damage of the intestinal mucosa. In this study, the effect of T cell-induced mucosal damage on jejunal epithelial ion transport, muscle contractility, and neuronal ACh release was assessed in Ussing chambers, organ baths, and a specialized perfusion apparatus, respectively. Time-matched control mice received hamster serum containing irrelevant antibodies. Jejunal segments from anti-CD3-treated mice displayed a significantly elevated epithelial baseline short-circuit current (which indicates increased ion transport) and a concomitant reduction in responsiveness to prosecretory stimuli (nerve stimulation, carbachol, and forskolin). Longitudinal smooth muscle displayed altered spontaneous contractile activity, length-tension relationships, and carbachol-stimulated contraction in tissues excised from mice 20 and 40 h posttreatment. Anti-CD3 treatment did not affect stimulated ACh release from myenteric plexus neurons. We conclude that specific T cell activation via anti-CD3 antibody results in dramatic alterations in jejunal epithelial and smooth muscle function. Such T cell-induced changes in intestinal function may contribute to the symptomatology of T cell-mediated enteropathies, including graft-versus-host disease, celiac disease, and idiopathic inflammatory bowel disease.


Assuntos
Anticorpos/farmacologia , Complexo CD3/imunologia , Jejuno/efeitos dos fármacos , Jejuno/fisiopatologia , Ativação Linfocitária/fisiologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/fisiologia , Acetilcolina/metabolismo , Animais , Bromodesoxiuridina/metabolismo , Cricetinae , Feminino , Técnicas In Vitro , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/inervação , Mucosa Intestinal/patologia , Mucosa Intestinal/fisiopatologia , Jejuno/inervação , Jejuno/patologia , Linfócitos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Músculo Liso/fisiopatologia , Neurônios/metabolismo , Fator de Necrose Tumoral alfa/biossíntese
12.
Dtsch Med Wochenschr ; 124(3): 39-44, 1999 Jan 22.
Artigo em Alemão | MEDLINE | ID: mdl-9987484

RESUMO

HISTORY AND ADMISSION FINDINGS: A 63-year-old man had for 10 months suffered from marked weight loss, night sweats, diffuse abdominal pain and increased stool frequency. He was admitted to evaluate an ultrasonically abnormal focus in the liver parenchyma and elevated liver function parameters. His sclerae were obviously icteric and he looked under-weight. INVESTIGATIONS: He had a hypochromic microcytic anemia and abnormal liver and pancreatic function tests: total bilirubin 3.11 mg/dl, direct bilirubin 2.21 mg/dl, GOT21U/l, gamma-GT 422 U/l, alkaline phosphatase 1449 U/l, alpha-amylase 481 U/l, lipase 2827 U/l. The serum creatinine level was elevated to 1.47 mg/dl. Computed tomography revealed enlarged liver and spleen as well as an enlargement of intraabdominal lymph nodes, chest radiogram and endoscopic cholangio-pancreatography were unremarkable. Biopsies from the lower duodenum, large intestine, bone marrow and liver showed inflammatory changes with Langhans-type mononuclear granulomas. Together with these findings an increased activity of the angiotensin-converting-enzyme (ACE) indicated sarcoidosis, other causes having been excluded. TREATMENT AND COURSE: All signs and symptoms rapidly improved under prednisolone, and 4 weeks after begin of treatment the biochemical abnormalities had clearly regressed. The raised serum levels of soluble IL-2 receptors and of neopterin, measures of sarcoidosis activity, had decreased. Activity of ACE had fallen. CONCLUSION: Sarcoidosis can present with diverse clinical signs and symptoms. In a case of multi-system disease that cannot be readily classified, sarcoidosis should be included in the differential diagnosis.


Assuntos
Gastroenteropatias/diagnóstico , Sarcoidose/diagnóstico , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/uso terapêutico , Biópsia , Medula Óssea/patologia , Diagnóstico Diferencial , Duodeno/patologia , Seguimentos , Gastroenteropatias/tratamento farmacológico , Gastroenteropatias/patologia , Humanos , Intestino Grosso/patologia , Fígado/patologia , Hepatopatias/diagnóstico , Masculino , Pessoa de Meia-Idade , Prednisolona/administração & dosagem , Prednisolona/uso terapêutico , Sarcoidose/tratamento farmacológico , Sarcoidose/patologia , Fatores de Tempo
13.
Semin Immunol ; 10(1): 69-78, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9529657

RESUMO

In chronic inflammatory bowel disease, self-destructive, exaggerated inflammation seems to occur in the absence of a well defined pathogen. However, epidemiological data strongly suggests that development of disease does not depend on endogenous factors alone. In this review, we summarize how a possible role for microbial factors can be reconciled with the current understanding of etiology and pathogenesis of IBD. The data presented does not support that IBD is an infectious disease nor that it is a self-antigen-specific autoimmune disease, however, recent findings increasingly suggest that tissue damage might be caused by a non-specific autoaggressive inflammation which is driven by common, ubiquitous microbial agents derived from the bacterial flora in the intestinal lumen.


Assuntos
Doenças Inflamatórias Intestinais/microbiologia , Animais , Doenças Autoimunes/imunologia , Doenças Autoimunes/microbiologia , Doenças Autoimunes/fisiopatologia , Infecções Bacterianas/imunologia , Infecções Bacterianas/microbiologia , Infecções Bacterianas/fisiopatologia , Causalidade , Doença Crônica , Meio Ambiente , Humanos , Inflamação , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/fisiopatologia
14.
J Immunol Methods ; 202(1): 1-11, 1997 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-9075766

RESUMO

Mucosal macrophages play a fundamental role in the regulation of immunological events and inflammation in the small intestine. Because no information is available on normal small intestinal macrophages, we developed a technique for the isolation and purification of jejunal lamina propria macrophages in order to study their phenotype and activity. From sections of normal human jejunum, lamina propria mononuclear cells were isolated by neutral protease digestion and then subjected to counterflow centrifugal elutriation to purify the macrophages. The cells isolated by this procedure contained < 1% CD3+ lymphocytes and displayed the size distribution, morphological features, ultrastructure and phagocytic activity of mononuclear phagocytes. In contrast to blood monocytes, however, mucosal macrophages from the jejunum did not exhibit adherence properties or express CD14, a receptor for the lipopolysaccharide-binding protein. The purification of large numbers of lamina propria macrophages by this procedure offers the opportunity to define the role of this cell in the physiological inflammation characteristic of normal intestinal mucosa and the pathological inflammation associated with small intestinal diseases.


Assuntos
Separação Celular/métodos , Mucosa Intestinal/citologia , Mucosa Intestinal/imunologia , Jejuno/citologia , Jejuno/imunologia , Receptores de Lipopolissacarídeos/análise , Macrófagos/imunologia , Centrifugação , Citometria de Fluxo , Humanos
15.
Naunyn Schmiedebergs Arch Pharmacol ; 347(2): 137-40, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8474534

RESUMO

The effects of agonists and antagonists of 5-hydroxytryptamine (5-HT) receptors on the release of endogenous 5-HT from enterochromaffin cells were studied in the vascularly perfused isolated guinea-pig small intestine. The experiments were done in the presence of tetrodotoxin in order to exclude a neuronally mediated influence on 5-HT release. The 5-HT3 receptor agonist 2-methyl-5-HT increased 5-HT release, and this effect was antagonized by 1 nmol/l tropisetron. Nanomolar concentrations of tropisetron, MDL 72,222 and granisetron decreased 5-HT release. Ondansetron (0.1 and 1 mumol/l) did not modify 5-HT release. 5-Methoxytryptamine, BIMU8 and cisapride concentration-dependently inhibited 5-HT release. BIMU8 was more potent than 5-methoxytryptamine. Micromolar concentrations of tropisetron (1 and 10 mumol/l) enhanced the release, whilst methiothepine (0.1 mumol/l) did not affect the release of 5-HT. The results suggest that enterochromaffin cells of the guinea-pig ileum do not contain 5-HT1 and 5-HT2 receptors, but are endowed with 5-HT3 and 5-HT4 autoreceptors. Activation of the 5-HT3 receptors triggers a positive feedback mechanism leading to an increase of 5-HT release. The 5-HT3 receptors on the enterochromaffin cell differ from neuronal 5-HT3 receptors on guinea-pig myenteric plexus by their high affinity for tropisetron and MDL 72,222, and their very low affinity for ondansetron. Stimulation of 5-HT4 receptors causes inhibition of release; the inhibitory 5-HT4 receptor mechanism appears to predominate.


Assuntos
Intestino Delgado/metabolismo , Receptores de Serotonina/fisiologia , Serotonina/metabolismo , Animais , Células Enterocromafins/efeitos dos fármacos , Células Enterocromafins/metabolismo , Células Enterocromafins/ultraestrutura , Feminino , Cobaias , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/ultraestrutura , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/ultraestrutura , Masculino , Perfusão , Receptores de Serotonina/classificação , Antagonistas da Serotonina/farmacologia , Agonistas do Receptor de Serotonina/farmacologia , Tetrodotoxina/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA