RESUMO
OBJECTIVE: To determine incidence, progression, and regression rates for abnormal cervical cytology and their correlates among women with HIV. METHODS: In a multicenter prospective cohort study conducted October 1, 1994, through September 30, 1999 at university, public, and private medical centers and clinics, 1639 HIV-seropositive and 452 seronegative women were evaluated every 6 months for up to 5 years using history, cervical cytology, T-cell subsets, and quantitative plasma HIV RNA. Human papillomavirus (HPV) typing at baseline was determined by polymerase chain reaction. Cytology was read using the Bethesda system, with any smear showing at least atypia considered abnormal. Poisson regression identified factors associated with incident cytologic abnormalities whereas logistic regression identified those associated with progression and regression after an abnormality. RESULTS: At least one abnormal smear was found during all of follow-up among 73.0% of HIV-seropositive patients and 42.3% of seronegatives (p <.001). Only 5.9% of seropositives ever developed high-grade lesions, and the proportion with high-grade findings did not rise over time. Incidence of atypical squamous cells of uncertain significance (ASCUS) or more severe lesions among HIV-seropositive patients and seronegative patients was 26.4 and 11.0/100 woman-years (rate ratio [RR], 2.4; 95% confidence interval [CI], 1.9-3.0), whereas that of at least low-grade squamous intraepithelial lesions (SIL) was 8.9 and 2.2/100 (RR, 4.0; CI, 2.6-6.1). HIV status, detection of the presence of human papillomavirus (HPV), CD4 lymphocyte count, and HIV RNA level predicted incidence of abnormal cytology (p <.05); HPV detection and HIV RNA level predicted progression (p <.01); and HPV detection, CD4 lymphocyte count, and HIV RNA level predicted regression (p <.001). Rates of incidence, progression, and regression of abnormal cytology did not differ between HIV seronegative women and seropositive women with CD4 lymphocyte counts >200/mm(3) and HIV RNA levels <4000/ml of similar HPV status. CONCLUSIONS: Although HIV infected women were at high risk for abnormal cytology, high-grade changes were uncommon. HIV status, HPV detection, CD4 lymphocyte count, and HIV RNA level predicted the incidence of cervical cytologic abnormalities. Progression was significantly increased only among the most immunosuppressed women, while regression was significantly reduced in all HIV seropositive women except those with the best controlled HIV disease.
Assuntos
Infecções por HIV/complicações , Infecções por Papillomavirus/epidemiologia , Infecções Tumorais por Vírus/epidemiologia , Doenças do Colo do Útero/epidemiologia , Displasia do Colo do Útero/epidemiologia , Esfregaço Vaginal , Adulto , Contagem de Linfócito CD4 , Estudos de Coortes , Progressão da Doença , Feminino , HIV-1/isolamento & purificação , Humanos , Incidência , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/diagnóstico , Vigilância da População , Prognóstico , Estudos Prospectivos , RNA Viral/sangue , Fatores de Risco , Infecções Tumorais por Vírus/complicações , Infecções Tumorais por Vírus/diagnóstico , Doenças do Colo do Útero/diagnóstico , Displasia do Colo do Útero/complicações , Displasia do Colo do Útero/diagnósticoRESUMO
In this study, we describe a novel adoptive transfer protocol to study acute lung injury in the rat. We show that bronchoalveolar lavage (BAL) cells isolated from rats 5 h after intratracheal administration of lipopolysaccharide (LPS) induce a lung injury when transferred to normal control recipient rats. This lung injury is characterized by increased alveolar-arterial oxygen difference and extravasation of Evans blue dye (EBD) into lungs of recipient rats. Recipient rats receiving similar numbers of donor cells isolated from healthy rats do not show adverse changes in the alveolar-arterial oxygen difference or in extravasation of EBD. The adoptive transfer-induced lung injury is associated with increased numbers of neutrophils in the BAL, the levels of which are similar to the numbers observed in BAL cells isolated from rats treated for 5 h with LPS. As an indicator of BAL cell activation, donor BAL cell inducible nitric oxide synthase (iNOS) expression was compared with BAL cell iNOS expression 48 h after adoptive transfer. BAL cells isolated 5 h after LPS administration expressed iNOS immediately after isolation. In contrast, BAL cells isolated 48 h after adoptive transfer did not express iNOS immediately after isolation but expressed iNOS following a 24-h ex vivo culture. These findings indicate that the activation state of donor BAL cells differs from BAL cells isolated 48 h after adoptive transfer, suggesting that donor BAL cells may stimulate migration of new inflammatory cells into the recipient rats lungs.
Assuntos
Líquido da Lavagem Broncoalveolar/citologia , Lipopolissacarídeos/toxicidade , Pulmão/patologia , Transferência Adotiva , Animais , Linhagem Celular , Transplante de Células , Eosinófilos/patologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Lesão Pulmonar , Macrófagos Alveolares/fisiologia , Macrófagos Alveolares/transplante , Masculino , Camundongos , Neutrófilos/patologia , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase Tipo II , Ratos , Ratos Sprague-DawleyRESUMO
This study reports that quiescent herpes simplex virus (HSV) type 1 genomes, persisting in long-term infected nerve growth factor (NGF) differentiated PC12 cells, were not stimulated by superinfection with a HSV-1. We have previously shown that HSV-1 can establish long term, quiescent infections in NGF differentiated PC12 cells. To determine if virion associated factors or virus induced gene products could trans-activate the quiescent viral genomes, long term infected PC12 cell cultures were superinfected at a high moi (moi of 20) with a recombinant HSV 17alpha47/lacZ that contains the lacZ gene within the alpha 47 locus. Progeny virus and gene expression from the resident 'quiescent' viral genomes were not detected following superinfection with recombinant 17alpha47/lacZ. The failure to stimulate the quiescent genome appears to be related to the inability of the super infecting virus to induce any gene expression from its own genome following entry into the long term NGF treated PC12 cells. Interestingly, both primary and superinfecting viruses could be stimulated from the quiescently infected cultures following cocultivation with inducer cells. These data suggest that (i) HSV genomes in quiescently infected PC12 cells are unable to be stimulated by incoming virion associated factors and (ii) NGF differentiated PC12 cells maintained in tissue culture for longer than 3 weeks became completely refractory to viral gene expression. The possibilities that these results are reflective of populations of neural cells, in vivo in mouse central nervous system, which are completely refractory to virus gene expression, yet accommodating to the maintenance of viral genomes and thus favor 'latency', are discussed.
Assuntos
Herpesvirus Humano 1/fisiologia , Fator de Crescimento Neural/farmacologia , Células PC12/virologia , Latência Viral , Animais , Técnicas de Cocultura , DNA Complementar/análise , DNA Viral/análise , DNA Viral/genética , Expressão Gênica , Herpesvirus Humano 1/genética , Herpesvirus Humano 1/isolamento & purificação , Óperon Lac , Células PC12/efeitos dos fármacos , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ensaio de Placa Viral , Ativação ViralRESUMO
Infants with inherited deficiency of pulmonary surfactant protein (SP) B develop respiratory failure at birth and die without lung transplantation. We examined aspects of surfactant metabolism in lung tissue and lavage fluid acquired at transplantation or postmortem from ten infants born at term with inherited deficiency of SP-B; comparison groups were infants with other forms of chronic lung disease (CLD) and normal infants. In pulse/chase labeling studies with cultured deficient tissue, no immunoprecipitable SP-B was observed and an approximately 6-kD form of SP-C accumulated that was only transiently present in CLD tissue. SP-B messenger RNA (mRNA) was approximately 8% of normal in deficient specimens, and some intact message was observed after, but not before, explant culture. Transcription rates for SP-B, assessed by nuclear run-on assay using probes for sequences both 5' and 3' of the common nonsense mutation (121ins2), were comparable in all lungs examined. The minimal surface tension achieved with lavage surfactant was similarly elevated in both deficient and CLD infants (26-31 mN/m) compared with normal infants (6 mN/m). Both SP-B-deficient and CLD infants had markedly decreased phosphatidylglycerol content of lavage and tissue compared with normal lung, whereas synthetic rates for phospholipids, including phosphatidylglycerol, were normal. We conclude that the mutated SP-B gene is transcribed normally but produces an unstable mRNA and that absence of SP-B protein blocks processing of SP-C. Chronic infant lung disease, of various etiologies, reduces surfactant function and apparently alters phosphatidylglycerol degradation.
Assuntos
Proteolipídeos/genética , Proteolipídeos/metabolismo , Surfactantes Pulmonares/genética , Surfactantes Pulmonares/metabolismo , Síndrome do Desconforto Respiratório do Recém-Nascido/metabolismo , Acetatos/metabolismo , Acetatos/farmacologia , Western Blotting , Cisteína/farmacocinética , Feto/metabolismo , Expressão Gênica/fisiologia , Genótipo , Humanos , Lactente , Recém-Nascido , Metionina/farmacocinética , Fosfatidilcolinas/metabolismo , Fosfatidilgliceróis/metabolismo , Proteolipídeos/análise , Proteínas Associadas a Surfactantes Pulmonares , Surfactantes Pulmonares/análise , RNA Mensageiro/análise , Radioisótopos de Enxofre , Transcrição Gênica/fisiologia , TrítioRESUMO
Laminins are principal components of basement membranes. Eleven laminin isoforms are known, each a heterotrimer composed of polypeptide chains designated alpha, beta, and gamma. Five alpha chains have been identified to date: alpha1, alpha2, alpha3, alpha4, and alpha5. Recent studies of fetal and adult mouse lung show prominence of alpha3, alpha4, and alpha5 in alveolar tissue, and point to differences in the cellular expression of these alpha chains in the developing alveolus. We examined isolated rat alveolar type II cells and lung fibroblasts for expression of laminins alpha3, alpha4, and alpha5. We found that laminin alpha3 was expressed only by alveolar epithelial cells, that laminin alpha4 was expressed only by lung fibroblasts, and that laminin alpha5 was expressed primarily by alveolar epithelial cells. Metabolic labeling and immunoprecipitation confirmed the production of laminin alpha4 by fibroblasts and laminin alpha5 by alveolar epithelial cells in culture. These studies indicate that different alveolar cell types contribute different laminin alpha chains to the laminin isoforms in alveolar basement membranes. Immunohistochemistry showed colocalization of these laminin alpha chains with the laminin beta1, beta2, and gamma1 chains, indicating the likelihood that laminins 6 to 11 are present in alveolar basement membranes.
Assuntos
Laminina/metabolismo , Alvéolos Pulmonares/metabolismo , Animais , Linhagem Celular Transformada , Fibroblastos/metabolismo , Imuno-Histoquímica , Hibridização In Situ , Laminina/biossíntese , Laminina/genética , Alvéolos Pulmonares/citologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-DawleyRESUMO
OBJECTIVE: To evaluate components of pulmonary surfactant and identify mutations in the surfactant protein B gene (SP-B) of a term infant with severe respiratory distress and chronic lung disease. PATIENT AND TESTING: Respiratory distress developed in an infant delivered at term, and he required extracorporeal bypass support for 2 weeks. Until his unexpected death at 9.5 months, he was ventilator and oxygen dependent and required continual dexamethasone therapy. Tracheobronchial lavage samples were analyzed for content of surfactant proteins (SPs), and DNA from blood samples were sequenced and analyzed by polymerase chain reaction restriction analysis for the presence of SP-B gene mutations. Surfactant lipid composition and function, the contents of SPs and their messenger RNAs (mRNAs), and the immunostaining pattern for SPs were determined in postmortem lung tissue. RESULTS: The lavage sample contained SP-A but not SP-B, and DNA restriction analysis indicated that the patient and his mother were heterozygous for the previously described 121ins2 mutation of SP-B. Postmortem lung tissue contained normal levels of SP-A and its mRNA, a low but detectable level of SP-B, and near normal content of SP-B mRNA. SP-C was abundant on staining, and some 6-kd precursor was present in tissue. A surfactant fraction was deficient in phosphatidylglycerol and was not surface active. On DNA sequencing, a point mutation was found in exon 7 of the patient's SP-B gene allele without the 121ins2 mutation, resulting in a cysteine for arginine substitution, and the father was a carrier for the same mutation. CONCLUSIONS: We describe a patient who is a compound heterozygote with a new mutation and only a partial deficiency of SP-B. Some forms of inherited SP-B deficiency may have low expression of immunoreactive and possibly functional SP-B with milder lung disease and longer survival. These infants may benefit from glucocorticoid therapy and may not develop antibodies to SP-B after either lung transplant or gene therapy.
Assuntos
Pneumopatias/genética , Proteolipídeos , Surfactantes Pulmonares/deficiência , Alelos , Sequência de Aminoácidos , Líquido da Lavagem Broncoalveolar/química , Doença Crônica , Heterozigoto , Humanos , Imuno-Histoquímica , Recém-Nascido , Pulmão/química , Pulmão/metabolismo , Pulmão/patologia , Pneumopatias/metabolismo , Pneumopatias/patologia , Masculino , Dados de Sequência Molecular , Mutação Puntual , Proteolipídeos/análise , Proteolipídeos/genética , Surfactantes Pulmonares/análise , Surfactantes Pulmonares/genética , RNA Mensageiro/análise , Síndrome do Desconforto Respiratório do Recém-Nascido/genética , Síndrome do Desconforto Respiratório do Recém-Nascido/metabolismo , Síndrome do Desconforto Respiratório do Recém-Nascido/patologia , Mapeamento por RestriçãoRESUMO
An infant with a family history of congenital alveolar proteinosis associated with surfactant protein B (SP-B) deficiency was identified when SP-B was not detected in amniotic fluid obtained at 37, 38, and 40 weeks of gestation. Surfactant replacement with commercially available preparations that contained SP-B was begun soon after delivery. Progressive respiratory failure developed despite continued surfactant replacement, corticosteroid therapy, and extracorporeal membrane oxygenation. The infant died at 54 days of age while awaiting lung transplantation. Surfactant extracted from amniotic fluid, bronchoalveolar lavage fluid, and lung tissue had no phosphatidylglycerol; surface tension was 24 dynes/cm (normal, < 10 dynes/cm) and did not decrease with in vitro addition of exogenous SP-B. Pulmonary vascular permeability measured with positron emission tomography was twice normal. At autopsy the alveolar proteinosis pattern was less prominent than that seen in affected siblings. Immunoreactivity of SP-B was absent in type II cells, but numerous foreign body granulomas with central immunoreactivity for SP-B and surfactant protein C were present. We conclude that exogenous surfactant replacement did not normalize surfactant composition, activity, or pulmonary vascular permeability. These findings suggest that endogenous SP-B synthesis is necessary for mature surfactant metabolism and function.
Assuntos
Doenças Fetais/diagnóstico , Diagnóstico Pré-Natal , Proteolipídeos/uso terapêutico , Proteinose Alveolar Pulmonar/diagnóstico , Proteinose Alveolar Pulmonar/tratamento farmacológico , Surfactantes Pulmonares/deficiência , Surfactantes Pulmonares/uso terapêutico , Líquido Amniótico/química , Líquido da Lavagem Broncoalveolar/química , Permeabilidade Capilar , Dexametasona/uso terapêutico , Evolução Fatal , Granuloma de Corpo Estranho/patologia , Humanos , Doença da Membrana Hialina/tratamento farmacológico , Doença da Membrana Hialina/patologia , Recém-Nascido , Pulmão/irrigação sanguínea , Pulmão/patologia , Masculino , Planejamento de Assistência ao Paciente , Proteolipídeos/análise , Proteinose Alveolar Pulmonar/patologia , Surfactantes Pulmonares/análise , Surfactantes Pulmonares/química , Tomografia Computadorizada de EmissãoRESUMO
Surfactant protein D (SP-D) is a collagenous, surfactant-associated, carbohydrate-binding protein that is synthesized by alveolar type II epithelial cells. To further characterize SP-D, we isolated RNA from adult rat lungs and rat type II cells and translated mRNAs in vitro. [35S]methionine-labeled translation products were precipitated with antibodies to rat SP-D, resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and visualized by fluorography. Immune precipitates of translation reactions for rat lung or rat type II cells demonstrated a single collagenous polypeptide (39.3 kDa) that was smaller than surfactant-associated SP-D (43 kDa, reduced) but larger than the mature secreted form of rat SP-A. This component was not identified in translation reactions of rat liver, gut, brain, mammary gland, or rat L2 cell RNA. There was a fivefold enrichment of SP-D mRNA in freshly isolated type II cells relative to lung; however, the levels of translatable SP-D mRNA decreased rapidly during the first 24 h of cell culture. The SP-D translation product migrated faster than the major cellular form of SP-D but approximately 1 kDa slower than cellular SP-D synthesized in the presence of 2,2'-dipyridyl plus tunicamycin. Translation in the presence of canine pancreatic microsomes gave a single glycosylated, endoglycosidase F-sensitive form (40.6 kDa) and demonstrated cleavage of a small signal peptide. These results indicate that SP-D is a secretory product of differentiated type II epithelial cells and that SP-D is secreted in a mature form that does not undergo further proteolytic processing in vivo.
Assuntos
Glicoproteínas/genética , Biossíntese de Proteínas , Alvéolos Pulmonares/metabolismo , Surfactantes Pulmonares/genética , Animais , Sistema Livre de Células , Cães , Epitélio/metabolismo , Glicoproteínas/biossíntese , Masculino , Metionina/metabolismo , Microssomos/metabolismo , Pâncreas/metabolismo , Poli A/genética , Poli A/isolamento & purificação , Processamento de Proteína Pós-Traducional , Alvéolos Pulmonares/citologia , Proteína D Associada a Surfactante Pulmonar , Surfactantes Pulmonares/biossíntese , RNA/isolamento & purificação , RNA Mensageiro/genética , RNA Mensageiro/isolamento & purificação , Ratos , Ratos Endogâmicos , Reticulócitos/metabolismoRESUMO
Pulmonary surfactant replacement has previously been shown to be effective in the human neonatal respiratory distress syndrome. The value of surfactant replacement in models of acute lung injury other than quantitative surfactant deficiency states is, however, uncertain. In this study an acute lung injury model using rats with chronic indwelling arterial catheters, injured with N-nitroso-N-methylurethane (NNNMU), has been developed. The NNNMU injury was found to produce hypoxia, increased mortality, an alveolitis, and alterations in the pulmonary surfactant system. Alterations of surfactant obtained by bronchoalveolar lavage included a reduction in the phospholipid-to-protein ratio, reduced surface activity, and alterations in the relative percentages of the individual phospholipids compared with controls. Treatment of the NNNMU-injured rats with instilled exogenous surfactant (Survanta) improved oxygenation; reduced mortality to control values; and returned the surfactant phospholipid-to-protein ratio, surface activity, and, with the exception of phosphatidylglycerol, the relative percentages of individual surfactant phospholipids to control values.
Assuntos
Pneumopatias/induzido quimicamente , Lesão Pulmonar , Nitrosometiluretano/administração & dosagem , Surfactantes Pulmonares/farmacologia , Uretana/análogos & derivados , Doença Aguda , Animais , Pulmão/efeitos dos fármacos , Surfactantes Pulmonares/administração & dosagem , Ratos , Ratos EndogâmicosRESUMO
We have investigated the production of collagenous proteins by primary cultures of rat lung epithelial cells (type II pneumocytes). Three major bacterial collagenase-sensitive chains were synthesized and secreted into the medium between 12 and 36 h of culture. Two of the chains comigrated on sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis (SDS-PAGE) with radiolabeled type IV procollagen (PC) chains isolated from adult rat lung (Mr = 185,000 and 170,000 after reduction) and were coprecipitated with monospecific antibodies to type IV collagen. Cyanogen bromide (CNBr) peptide maps of the chromatographically purified chains were identical to maps of rat lung type IV PC, and confirmed the identity of these chains as pro alpha 1(IV) and pro alpha 2(IV). Type IV PC was the major high molecular weight collagen in the cell layer, and a fraction of the newly synthesized type IV PC was selectively deposited on the substratum together with newly synthesized fibronectin. Type II cells also secreted a low molecular weight, non-disulfide-bonded, collagenase-sensitive protein (Mr = 19,000, collagen standards; Mr = 26,000, globular standards). The protein coeluted with type IV PC from DEAE-cellulose but was resolved from native type IV on CM-cellulose. The protein was not precipitated with polyclonal antibodies to type IV collagen or rat surfactant apoprotein. These studies further demonstrate the heterogeneity of collagenous macro-molecules synthesized by lung epithelial cells in vitro. We suggest that interactions between pneumocyte-derived fibronectin and type IV procollagen contribute to the formation of the epithelial basement membrane and to the attachment of these cells in normal or injured lung.
Assuntos
Pulmão/metabolismo , Pró-Colágeno/biossíntese , Animais , Eletroforese em Gel de Poliacrilamida , Células Epiteliais , Epitélio/metabolismo , Hidrólise , Imunoquímica , Pulmão/citologia , Masculino , Mapeamento de Peptídeos , Pró-Colágeno/isolamento & purificação , Ratos , Ratos EndogâmicosRESUMO
Conventional cleavage of linked polypeptide chains by heating in SDS can so alter molecular structure as to interfere with antibody binding, on which both immunoprecipitation and 'western blotting' depend. As an alternative, gentle treatment with acid at room temperature or at 0 degrees C was effective in separating the alpha and beta chains of human MHC Class II glycoprotein dimers and proved superior in terms of preservation of at least one labile epitope on the beta chain.
Assuntos
Eletroforese em Gel de Poliacrilamida , Antígenos HLA/análise , Peptídeos/análise , Testes de Precipitina , Reações Antígeno-Anticorpo , Linhagem Celular , Colódio , Humanos , Concentração de Íons de Hidrogênio , Papel , Peptídeos/imunologia , Dodecilsulfato de Sódio , Temperatura , Fatores de TempoRESUMO
Four mouse monoclonal antibodies to human B cell surface determinants previously described as being directed against Ia like (MHC class II) antigens, have been shown to precipitate Ia alpha and beta chains. Electrophoretic transfer experiments showed one antibody to be directed against Ia alpha chains and two others to be against Ia beta chains. The antibodies were then used to analyse a range of cell types and a large number of lymphoblastoid and lymphoma cell lines. Ia antigens could not be detected on peripheral blood T cells, cord endothelium or T cell lines but their presence was confirmed on activated T cells and peripheral blood non-T cells. There was both qualitative and quantitative variation of Ia like antigen expression on B cell lines, including an apparent genetic polymorphism in alpha chain structure unrelated to DR allotypes and a single instance of a beta chain of abnormally high molecular weight.
Assuntos
Antígenos de Histocompatibilidade Classe II/imunologia , Anticorpos Monoclonais/imunologia , Antígenos de Superfície/imunologia , Linfócitos B/imunologia , Linhagem Celular , Precipitação Química , Eletroforese em Gel de Poliacrilamida , Epitopos/imunologia , Humanos , Peptídeos/análise , Peptídeos/imunologia , Linfócitos T/imunologiaRESUMO
Ia antigens were shown to be present in the cell almost exclusively as mature alpha beta dimers which split into separate alpha and beta chains after boiling in SDS. In contrast metabolically labelling the cells with [35S]methionine resulted in only free alpha and beta chains being labelled. It is concluded that this widely used type of labelling, although useful for studying intermediate synthesis, should not be used for labelling mature cell surface molecules.
Assuntos
Antígenos de Histocompatibilidade Classe II/análise , Precursores de Proteínas/análise , Radioisótopos de Carbono , Linhagem Celular , Eletroforese em Gel de Poliacrilamida/métodos , Genes MHC da Classe II , Humanos , Leucina/metabolismo , Leucemia Linfoide/imunologia , Substâncias Macromoleculares , Metionina/metabolismo , Peso Molecular , Técnica de Diluição de Radioisótopos , Radioisótopos de EnxofreRESUMO
Monoclonal antibodies directed against human Ia alpha- and beta-subunit chains have been used as probes to detect polypeptides carrying recognized antigenic determinants or epitopes following two-dimensional PAGE separation. Approximately 4 sets of components differing in isoelectric point but not in molecular weight are recognized by each antibody. The anti-alpha-chain, McAb, reacts weakly with spots designated as epsilon but neither antibody recognizes Im, Ii or delta determinants under the conditions tested.
Assuntos
Anticorpos Monoclonais/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Linfócitos B/imunologia , Linhagem Celular , Eletroforese em Gel de Poliacrilamida , Epitopos/imunologia , Epitopos/isolamento & purificação , Antígenos de Histocompatibilidade Classe II/isolamento & purificação , Humanos , Técnicas ImunológicasRESUMO
Cyclic 3',5' adenosine monophosphate (cyclic AMP) levels were measured in isolated hepatocytes under several conditions. Following the addition of glucagon cyclic AMP levels increased rapidly with peak values occurring at three minutes. The increase in cyclic AMP was dose dependent. Significant increases were found with 10(-10)M glucagon and a maximum increase of twenty fold was produced by 10(-8) M glucagon. This action of glucagon was augmented by the phosphodiesterase inhibitors, theophylline, SQ 20,009, and papaverine. Treatment of the hepatocytes with trypsin markedly reduced the response to glucagon.