RESUMO
Objective: To investigate the effect of omeprazole on plasma concentration, efficacy and adverse reactions of capecitabine in patients with colon cancer. Methods: Seventy-two patients with colon cancer treated with capecitabine were analysed retrospective. The patients treated with capecitabine combined with omeprazole were identified as experimental group and the capecitabine treatment alone as control group.The differences of blood concentration and the side effects of capecitabine between these two groups were compared. Results: The plasma concentration of 5-Fluorouracilum in experimental group was (126.25±50.59) µg/ml, without significant difference of (123.09±56.70) µg/ml in control group (P=0.121). The incidence of â ¢ to â £ degree bone marrow suppression, nausea, vomiting, diarrhea and hand-foot syndrome in experimental group were 13.8%, 0%, 0% and 19.4%, respectively. In control group, the incidence of â ¢ to â £ degree bone marrow suppression, nausea, vomiting, diarrhea and the hand-foot syndrome were 11.1%, 0%, 0% and 19.4%, respectively, without significant difference of experimental group (P>0.05). The incidence of acid reflux and heartburn in the control group was 72.2%, significantly higher than 44.4% of the experimental group (P<0.05). The objective response rate (ORR) and progression-free survival time (PFS) in these two groups were 30.6% and 33.3%, and 8.0 month and 8.5 month, respectively, without significant difference (P>0.05). Conclusion: The intravenous omeprazole attenuates reflux and heartburn of colon cancer patients treated with capecitabine, without affecting its plasma concentration and side effects and has no impact on the PFS of these patients.
Assuntos
Capecitabina/efeitos adversos , Capecitabina/sangue , Neoplasias do Colo/tratamento farmacológico , Omeprazol/efeitos adversos , Omeprazol/sangue , Protocolos de Quimioterapia Combinada Antineoplásica , Capecitabina/uso terapêutico , China/epidemiologia , Neoplasias do Colo/mortalidade , Intervalo Livre de Doença , Fluoruracila/administração & dosagem , Refluxo Gastroesofágico/induzido quimicamente , Refluxo Gastroesofágico/epidemiologia , Azia/induzido quimicamente , Azia/epidemiologia , Humanos , Omeprazol/uso terapêutico , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Osteopontin (OPN) plays an important role in the metastasis and recurrence of tumors after resection of hepatocellular carcinoma (HCC). In this study, the down-regulation effect on OPN expression in HCC cells of RNA interference (RNAi) molecules designed to target different segments of OPN was investigated to identify a more effective site for OPN knockdown. Specific small interfering RNAs (siRNAs A, B, and C) of OPN were synthesized and transfected into an HCC cell line (HEP-G2; representing the OPNi-A, OPNi-B, and OPNi-C groups). Fluorescent quantitative polymerase chain reaction and immunohistochemical methods were used to detect the mRNA and protein expression of OPN before and after RNAi. Results showed that after transfection, the fluorescence intensity of the OPNi-A group was greater than those of the OPNi-B and OPNi-C groups. After 48 h of transfection, the ΔCT values of OPN mRNA expression in the OPNi-A-C groups increased from 8.31 ± 1.58, 8.78 ± 1.49, and 8.25 ± 1.51 to 12.14 ± 1.43, 10.22 ± 1.97, and 10.48 ± 1.88, respectively (P < 0.05), and the OPN protein levels (immunohistochemistry scores) decreased from 6.44 ± 1.67, 5.43 ± 2.05, and 5.45 ± 2.52 to 2.84 ± 1.52, 4.43 ± 1.65, and 3.95 ± 1.43 points, respectively. These results indicated that RNAi based on different segments of the OPN gene had different down-regulatory effects on OPN expression. Synthesis of targeted siRNA aimed at specific OPN segments might have important significance for dealing with the invasiveness and metastasis of HCC cells.
Assuntos
Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Recidiva Local de Neoplasia/genética , Osteopontina/biossíntese , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Hepáticas/patologia , Invasividade Neoplásica/genética , Metástase Neoplásica , Recidiva Local de Neoplasia/patologia , Osteopontina/genética , Interferência de RNARESUMO
Objective: To evaluate the clinical application effects of a domestic bone-level implant system for restoring single tooth loss, and provide clinical evidence for the promotion and application of domestic implants. Methods: A prospective, multicenter clinical trial was conducted from April 2018 to January 2020 in three institutions: Department of Oral Implantology, School & Hospital of Stomatology, Wuhan University, Department of Stomatology, The First Affiliated Hospital of Zhejiang University School of Medicine, and Department of Stomatology, The Third Hospital of Hebei Medical University. The trial planned to include 100 patients for single tooth implantation and restoration, followed up for 1 year, to evaluate the implantation success rate and other related outcomes. Results: This study screened a total of 142 patients and ultimately included 100, comprising 43 males and 57 females with age of (47.0±12.2) years. Ninety-eight out of 100 patients completed a one-year follow-up (98.0%), while 2 patients terminated the trial early due to implant loosening (2.0%). After a one-year follow-up, the implants of the 98 patients were all functioning successfully, with a success rate of 98.0% (98/100). The patients were satisfied with the overall restoration effect. Conclusions: This study indicates that the domestic bone-level implant system has achieved favorable short-term clinical outcomes for single-tooth implantation and restoration.
RESUMO
Objective: To analyze the epidemiological and clinical characteristics of imported COVID-19 cases after SARS-CoV-2 vaccination and to provide evidence for the prevention and control of COVID-19. Methods: The imported COVID-19 cases in Chengdu as of April 15, 2021 were divided into the vaccinated group and unvaccinated group according to the history of SARS-CoV-2 vaccination. The epidemiological and clinical data of the cases were collected retrospectively, and the differences in epidemiological and clinical characteristics of the two groups were compared. Laboratory tests consisted of nucleic acid test, clinical index test, serum antibody test and lymphocyte test. Software WPS2019 was used for data management and software R 4.0.3 was used for statistical analysis. Results: A total of 75 COVID-19 cases were included in the analysis, in which 20 had received SARS-CoV-2 vaccination and only 4 with clinical symptoms, 55 patients did not receive SARS-CoV-2 vaccination, and 16 had clinical symptoms. In vaccinated group, the first injection time of vaccination ranged from July to November 2020, and 10 cases received two doses of vaccine simultaneously and 10 cases received two doses of vaccine at intervals of 14-57 days. The intervals between the completion of vaccination and the onset ranged from 87 days to 224 days. The differences in classification and clinical type between the two groups were significant. Significant differences were observed in case classification and clinical type between vaccinated group and unvaccinated group (P<0.05). The vaccinated group had a relatively high proportion of asymptomatic infections (40.00%, 8/20), while mild infections were mainly observed in the unvaccinated group(76.36%,42/55). The differences in Ct values (ORF1ab gene and N gene) at the diagnosis were not significant between vaccinated group and unvaccinated group (P>0.05), similar results were also observed in lymphocyte subtypes, procalcitonin and C-reactive protein level comparisons. Serum amyloid A level was higher in unvaccinated group than in vaccinated group (P<0.05). However, the SARS-CoV-2 related serum antibody of IgM, IgG and total antibody levels were significantly higher in vaccinated group (P<0.05). Conclusions: Risk of infection still exists with SARS-CoV-2 after vaccination, which can facilitate the production of specific serum antibody of IgM and IgG when people are exposed to the virus. It has a certain protective effect on SARS-CoV-2 infected persons. Vaccination can reduce the clinical symptoms and mitigate disease severity.
Assuntos
Vacinas contra COVID-19/administração & dosagem , COVID-19 , Anticorpos Antivirais/sangue , COVID-19/epidemiologia , China/epidemiologia , Humanos , Estudos Retrospectivos , VacinaçãoRESUMO
Chronic exposure to arsenic causes health problems, including peripheral neuropathy. Oxidative stress is one of the mechanisms underlying arsenic-induced neurotoxicity. For this report, we studied the protective effect of N-acetylcysteine (NAC) on arsenic-induced oxidative injury in dorsal root ganglion (DRG) explants. After 24-h incubation, NAC concentration-dependently attenuated arsenite-induced depletion in glutathione (GSH) content and increases in the ratio of oxidized GSH/reduced GSH (GSSG/GSH ratio) in DRG explants. Furthermore, NAC inhibited arsenite-induced elevation in the expression of stress proteins, such as heat shock protein 70 and heme oxygenase 1, as well as arsenite-induced phosphorylation of p38 mitogen-activated protein kinase. Incubation with NAC ameliorated arsenite-induced apoptosis by abolishing both mitochondrial and endoplasmic reticulum (ER) pathways. In the mitochondrial pathway, NAC attenuated arsenite-induced elevation in Bcl-2 level and cytosolic cytochrome c, as well as arsenite-induced reduction in procaspase-3 levels. In the ER pathway, NAC suppressed arsenite-induced increases in activating transcription factor 6 and C/EBP homologous protein in the nuclear fraction. Furthermore, arsenite-induced reductions in procaspase-12 and elevation in BIP and caspase-12, an ER-specific enzyme, were prevented after NAC incubation. Taken together, our results demonstrate that NAC is neuroprotective against arsenite-induced oxidative injury in DRG explants. Furthermore, NAC inhibits arsenite-induced toxicity by inhibiting ER and mitochondrion activation. Our data indicate that NAC is potentially therapeutic for arsenite-induced peripheral neuropathy.
Assuntos
Acetilcisteína/farmacologia , Arsenitos/efeitos adversos , Sequestradores de Radicais Livres/farmacologia , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/lesões , Estresse Oxidativo/efeitos dos fármacos , Fator 6 Ativador da Transcrição , Animais , Caspases/metabolismo , Relação Dose-Resposta a Droga , Gânglios Espinais/patologia , Glutationa , Proteínas de Choque Térmico HSP70 , Masculino , Técnicas de Cultura de Órgãos , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2 , Ratos , Ratos Sprague-DawleyRESUMO
Studies of photoelectron count autocorrelation function of light scattered from suspensions of thick filaments of Limulus telson muscle and scallop striated adductor muscle reveal that Ca2+ can activate cross-bridge motions of these isolated filaments. By treating suspensions of activated filaments with phenylmethylsulfonyl fluoride (PMSF), we can suppress active cross-bridge motions but not affect the Ca2+-dependent ATPase activity.
Assuntos
Citoesqueleto/efeitos dos fármacos , Contração Muscular/efeitos dos fármacos , Miosinas/antagonistas & inibidores , Fluoreto de Fenilmetilsulfonil/farmacologia , Sulfonas/farmacologia , Adenosina Trifosfatases/metabolismo , Animais , Caranguejos Ferradura , Moluscos , Movimento (Física)RESUMO
In freshly dispersed guinea pig taenia coli myocytes the activity of the large conductance Ca(2+)-activated K+ channel (maxi-K+ channel) predominates. The open probability (Po) of this channel is increased by micromolar concentrations of the beta-adrenergic agonist isoproterenol (ISO). Low concentrations of cholera toxin (CTX, 1 pM) and guanosine 5'-O-2-thiodiphosphate (GDP beta S, 0.5 mM) suppress the ISO-induced increase of Po. Higher concentrations of CTX (e.g., 0.5 nM) as well as forskolin and dibutyryl cAMP increase the Po. 1,9-Dideoxyforskolin, the forskolin analogue, which lacks the adenylate cyclase-stimulating effect, does not. A specific protein kinase A inhibitor (Wiptide), applied intracellularly via diffusion from the patch electrode, suppresses the ISO-induced increase of whole-cell outward K+ current during step depolarization. In contrast, intracellularly applied protein kinase C (19-36), a specific protein kinase C inhibitor, has no effect on the whole-cell current. TMB-8, an inhibitor of intracellular calcium mobilization, does not affect either the whole-cell outward K+ current during step depolarization or the Po. These observations show that ISO increases the Po of the maxi-K+ channels in the guinea pig taenia coli myocytes through the G protein-adenylate cyclase-protein kinase A system.
Assuntos
Cálcio/farmacologia , Colo/fisiologia , Isoproterenol/farmacologia , Músculos/fisiologia , Canais de Potássio/fisiologia , Transdução de Sinais/fisiologia , Adenilil Ciclases/fisiologia , Alcaloides/farmacologia , Animais , Bucladesina/farmacologia , Cálcio/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Toxina da Cólera/farmacologia , Colforsina/farmacologia , Colo/citologia , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , Proteínas de Ligação ao GTP/fisiologia , Ácido Gálico/análogos & derivados , Ácido Gálico/farmacologia , Guanosina Difosfato/análogos & derivados , Guanosina Difosfato/farmacologia , Cobaias , Potenciais da Membrana/fisiologia , Músculos/citologia , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/farmacologia , Estaurosporina , Tionucleotídeos/farmacologiaRESUMO
Photoelectron count autocorrelation function of light scattered by Limulus thick myofilament suspensions was measured as a function of scattering angle in the relaxed, activated and rerelaxed states. By using the cumulants method of data analysis, the average linewidth over large ranges of KL (up to 120), has been calculated with K and L being, respectively, the magnitude of the momentum transfer vector and the length of the myofilament. We have observed a dramatic increase in the average linewidth denoting the presence of additional high frequency components for the myofilament suspension on the activated state. By confirming our results on the size of the myofilaments from electron micrographs, we are able to attribute the high frequency (kHz) components to the "correlated" cross-bridge motions, representing, to our knowledge, the first direct experimental evidence of such movements in isolated thick myofilament suspensions.
Assuntos
Citoesqueleto/ultraestrutura , Caranguejos Ferradura/ultraestrutura , Músculos/ultraestrutura , Animais , Biometria , Luz , Microscopia Eletrônica , Modelos Biológicos , Contração Muscular , Relaxamento Muscular , Espalhamento de RadiaçãoRESUMO
OBJECTIVE: In the present study, the outcomes of childhood leukemia treated with haplo-HSCT using parent as donor were evaluated and the risk factors for survival were identified. PATIENTS AND METHODS: 111 consecutive cases from March 2002 to March 2012 in our center were analyzed. The median age of patients was 10 (3-14) years old. All patients received unmanipulated combined marrow and peripheral blood stem cells for transplant after conditioning with busulfan and cyclophosphamide (Cy)/Cy and total body irradiation (TBI) plus antithymocyte globulin (ATG). RESULTS: Durable hematopoietic reconstitution was seen in 98% of recipients. Engraftment failure occurred in 3 cases including 2 cases of father to daughter transplants. One-hundred-day transplant-related mortality (TRM) was only 4.5%. The cumulative incidences of grade II to IV acute graft-versus-host disease (aGvHD) and chronic GvHD (cGvHD) were 47.6% and 28.3%, respectively. With the median follow-up of 32 (12-134) months, 2-year and 5-year overall survival (OS) rates for all patients were 82.1% and 79.2%, respectively. Five-year OS rates for patients in early, intermediate and advanced disease were 84.0%, 81.0%, and 57.1%, respectively (p = 0.08). Five-year OS of transplants in father to son, father to daughter, mother to son, and mother to daughter were was 88.1%, 57.1%, 70.6%, and 82.6%, respectively (p = 0.08). CONCLUSIONS: Under current protocol, children with leukemia tolerate haplo-HSCT from their parent very well with lower TRM, less cGvHD, and better OS compared with our published data. Pre-transplant disease status and donor- recipient relationship and the recipient age have significant impact on survival.
Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Leucemia/terapia , Pais , Doadores de Tecidos , Condicionamento Pré-Transplante/métodos , Adolescente , Soro Antilinfocitário/uso terapêutico , Bussulfano/uso terapêutico , Criança , Pré-Escolar , Ciclofosfamida/uso terapêutico , Feminino , Doença Enxerto-Hospedeiro/diagnóstico , Doença Enxerto-Hospedeiro/prevenção & controle , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Leucemia/diagnóstico , Masculino , Resultado do Tratamento , Irradiação Corporal Total/métodosRESUMO
Accumulation of transition metals has been suggested to be responsible for the deteriorated nigrostriatal dopaminergic system in Parkinson's patients. In the present study, the mechanism underlying the zinc-induced neurotoxicity was investigated in the nigrostriatal dopaminergic system in vivo. Our 6-methoxy-8-paratoluene sulfonamide quinoline fluorescence study showed zinc translocation in the infused nigral cells after intranigral infusion of zinc. Furthermore, lipid peroxidation in the zinc-infused substantia nigra was consistently elevated 4 h to 7 d after the infusion. At the same time, an abrupt increase in cytosolic cytochrome c content in the infused substantia nigra was observed 4 h after zinc infusion and gradually decreased to basal levels 7 d after infusion. Both TUNEL-positive neurons and DNA fragmentation, indicatives of apoptosis, were detected in the zinc-infused substantia nigra. Furthermore, striatal dopamine content was reduced 7 d after the infusion. In attempt to prevent zinc-induced neurotoxicity, vitamin D3 was systemically administered. Zinc-induced increases in lipid peroxidation and cytosolic cytochrome c in the infused substantia nigra were prevented by this treatment. Moreover, zinc-induced reduction in striatal dopamine content was attenuated after vitamin D3 treatment. Our in vivo data suggest that zinc-induced oxidative stress may result in apoptosis followed by reduced dopaminergic function in the nigrostriatal dopaminergic system. Furthermore, vitamin D3 prevented zinc-induced oxidative injuries in the rat brain.
Assuntos
Apoptose/efeitos dos fármacos , Colecalciferol/farmacologia , Fármacos Neuroprotetores/farmacologia , Substância Negra/efeitos dos fármacos , Substância Negra/patologia , Zinco/farmacologia , Animais , Cromatografia Líquida de Alta Pressão , Citocromos c/metabolismo , Dopamina/metabolismo , Marcação In Situ das Extremidades Cortadas , Peroxidação de Lipídeos , Masculino , Neurônios/citologia , Oxirredução , Estresse Oxidativo , Ratos , Ratos Sprague-Dawley , Substância Negra/metabolismoRESUMO
We present a proof that the mean open (and closed) times of the individual channels in a multichannel record can be found in a model-independent fashion. As the results are model independent, they can be derived by assuming the simplest model for all the channels, namely that they all have the basic CLOSED in equilibrium with OPEN scheme. In particular, the method can be applied to patches where the channel population is heterogenous with respect to open probability. Multichannel simulations are performed to test the limits of applicability of this method to restricted amounts of data. One conclusion is that increasing the number of channels does not substantially reduce the errors in estimating the mean times, in spite of the 'increased information' present. We also prove the general applicability of the algorithm of Fenwick et al. (1982) in estimating the mean times without knowledge of the number of channels present, and discuss its limitations. An illustration using experimental data is also given.
Assuntos
Eletrofisiologia/instrumentação , Algoritmos , Cinética , Modelos BiológicosRESUMO
Two prepubertal sisters of American Indian origin developed osteosarcoma at 8 and 12 years of age. This familial occurrence, tumor onset prior to puberty, unusual tumor location in one who also had short stature, and ethnic background all suggest an inborn predisposition to bone cancer rather than a chance occurrence. Rearrangements involving chromosomes #13 and #14 were found in both the surviving proband and mother. Comparison of the arm ratio and prometaphase G-banding patterns of the rearranged chromosomes suggests either deletion of band 14q11.2 or pericentric inversion (with breakpoints at 13q12 and 14q11.2) in the proband's rearranged chromosome, but not in her mother's. Her mother, who had no malignancy, had a typical Robertsonian translocation [t(13;14)(p11;q11)]. Three previously reported children with chromosomal abnormalities developed osteosarcoma at unusually young ages, younger even than in reported sibships with osteosarcoma. The most frequently detected cytogenetic abnormalities in sarcoma tumor cells involve chromosomes #13 and #14. In addition, some cases of bilateral retinoblastoma and familial unilateral retinoblastoma, which are known to be at increased risk for osteosarcoma, are associated with tiny deletions on chromosome #13. Thus, there may be a causal relationship between constitutional loss or rearrangement of genetic material at these breakpoints on chromosomes #13 or #14 and development of osteosarcoma in this family that is similar to that seen in patients with small constitutional chromosomal deletions who develop Wilms' tumor and retinoblastoma.
Assuntos
Neoplasias Ósseas/genética , Aberrações Cromossômicas/genética , Cromossomos Humanos 13-15 , Osteossarcoma/genética , Adolescente , Adulto , Criança , Pré-Escolar , Bandeamento Cromossômico , Transtornos Cromossômicos , Feminino , Humanos , Cariotipagem , Masculino , Pessoa de Meia-Idade , Linhagem , Translocação GenéticaRESUMO
The effects of the mu opioid receptor agonists, morphine and Tyr-D-Ala-Gly-N-methyl-Phe-Gly-ol (DAGO), the delta opioid receptor agonist, Tyr-D-Pen-Gly-Phe-D-penicillamine (DPDPE) and the kappa-opioid receptor agonist, dynorphin A-(1-13) on the whole-cell K+ currents (IK) of cultured mouse DRG neurons and neuroblastoma X DRG neuron hybrid F11 cells were studied. These opioid ligands all elicited dual effects. Low concentrations (< nM) usually elicited a transient increase in IK (within 1 min), followed by a sustained decrease in IK. In contrast, microM concentrations rapidly elicited a sustained increase in IK. After brief treatment with cholera toxin subunit B (CTX-B), the usual sustained decrease in IK evoked by < nM opioid agonists no longer occurred. Low concentrations then elicited only a sustained increase in IK. On the other hand, after chronic treatment with pertussis toxin (PTX), the usual microM opioid-induced increases in IK no longer occurred and more than half of the cells responded with a sustained decrease of IK to microM as well as nM opioids. The results suggest that mu, delta and kappa opioid receptors are each coupled to K+ channels through CTX-B- and PTX-sensitive transduction systems. Both systems have similar threshold concentrations to opioids. Activation of the CTX-B-sensitive opioid receptor/transduction system resulted in a decrease in K+ conductance of the cell which is generally associated with an increase in neuronal excitability. Activation of the other system resulted in an increase in K+ conductance which will, in general, decrease neuronal excitability. The net change in the IK depends upon which effect predominates. The dominance at different opioid concentrations may depend on the relative efficacies of the coupling of these two systems to K+ channels.
Assuntos
Neoplasias Encefálicas/metabolismo , Gânglios Espinais/metabolismo , Neuroblastoma/metabolismo , Canais de Potássio/metabolismo , Receptores Opioides/agonistas , Sequência de Aminoácidos , Animais , Toxina da Cólera/farmacologia , Gânglios Espinais/citologia , Gânglios Espinais/efeitos dos fármacos , Células Híbridas , Camundongos , Dados de Sequência Molecular , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Técnicas de Patch-Clamp , Toxina Pertussis , Canais de Potássio/efeitos dos fármacos , Receptores Opioides delta/agonistas , Receptores Opioides kappa/agonistas , Receptores Opioides mu/agonistas , Transdução de Sinais/efeitos dos fármacos , Células Tumorais Cultivadas , Fatores de Virulência de Bordetella/farmacologiaRESUMO
In a previous study, we showed that microM concentrations of mu or delta opioid agonists increase voltage-dependent outward K+ currents in neuroblastoma x DRG neuron hybrid F11 cells via pertussis toxin-sensitive receptors. The present study demonstrates that much lower concentrations (fM to nM) of these opioids (DAGO and DPDPE) decreased voltage-dependent outward K+ currents during step depolarization. The opioid antagonist, naloxone (3 nM) prevented these decreases in K+ current as did the cholera toxin subunits A or B (ca. 1 nM). Furthermore, the specific mu opioid receptor antagonist, beta-funaltrexamine (5 nM) blocked the decrease by DAGO and the specific delta antagonist, naltrindole (1 nM) blocked that by DPDPE. Acute GM1 ganglioside (1 microM) treatment markedly enhanced the efficacy of opioid-induced decrease in K+ current. After treating the cells with pertussis toxin (1 microgram/ml) for 2 days or more, these opioids decreased the K+ current even when tested at concentrations as high as 1 microM. These results indicate that the decrease in K+ current elicited in F11 cells by low concentrations of mu and delta opioid agonists resembles the opioid-induced prolongation of the action potential duration and decrease in voltage-dependent K+ conductance that occur in DRG neurons in primary cultures. The F11 cell line provides therefore a valuable model system for correlative pharmacologic, electrophysiologic and biochemical analyses of Gs-coupled, GM1 ganglioside-regulated excitatory opioid receptor functions, in addition to G(i)/G(o)-coupled inhibitory receptor functions, in sensory neurons.
Assuntos
Toxina da Cólera/farmacologia , Células Híbridas/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Canais de Potássio/efeitos dos fármacos , Receptores Opioides delta/efeitos dos fármacos , Receptores Opioides mu/efeitos dos fármacos , Animais , Ala(2)-MePhe(4)-Gly(5)-Encefalina , D-Penicilina (2,5)-Encefalina , Encefalinas/farmacologia , Gânglios Espinais/citologia , Gânglios Espinais/efeitos dos fármacos , Potenciais da Membrana/efeitos dos fármacos , Neuroblastoma , Toxina Pertussis , Ratos , Fatores de Virulência de Bordetella/farmacologiaRESUMO
Previous studies showed that low concentrations of opioids prolong the calcium-dependent component of the action potential duration (APD) of dorsal root ganglion (DRG) neurons, whereas higher concentrations shorten the APD. In the present study whole-cell voltage-clamp, as well as cell-attached membrane-patch voltage-clamp, recordings demonstrate that application of picomolar to nanomolar concentrations of mu, delta or kappa opioid agonists (DAGO, DPDPE or dynorphin) to DRG neurons in dissociated cell cultures reversibly decreased the activities of voltage-sensitive K+ channels. Pretreatment of DRG neurons with the opioid receptor antagonists, naloxone (30 nM) or diprenorphine (1 nM) prevented mu/delta or kappa opioid-induced decreases in K+ channel activities, respectively. Since opioids added to the bath solution decreased the activities of K+ channels in the membrane patch sealed off by the pipette tip, our results provide strong evidence that some modes of excitatory modulation of the action potential of DRG neurons are mediated by diffusible second messengers. The data are consonant with our previous studies indicating that opioids can elicit excitatory effects on sensory neurons via cholera toxin-sensitive Gs-linked excitatory opioid receptors coupled to cyclic AMP-dependent ionic channels.
Assuntos
Gânglios Espinais/metabolismo , Entorpecentes/farmacologia , Neurônios Aferentes/metabolismo , Canais de Potássio/fisiologia , Potenciais de Ação , Animais , Dinorfinas/farmacologia , Eletrofisiologia , Ala(2)-MePhe(4)-Gly(5)-Encefalina , D-Penicilina (2,5)-Encefalina , Encefalinas/farmacologia , Antagonistas de Entorpecentes , Concentração OsmolarRESUMO
The F11 cell line is a fusion product of cells of mouse neuroblastoma cell line N18TG-2 with embryonic rat dorsal-root ganglion (DRG) neurons. Previous biochemical results suggest that they express mu- and delta-opioid receptors that are negatively coupled to adenylate cyclase. The present study provides direct agonist-binding and electrophysiologic evidence of mu and delta, but not kappa, receptor expression in F11 cells. Radioligand binding assays show that F11 cell membranes bind the mu- and delta-opioid receptor agonists, DAGO and DPDPE with Kd = 4.5 and 4.9 nM and Bmax = 111 and 195 fmol/mg, respectively. Tight-seal patch-clamp recordings of F11 cells after several days in a differentiating culture medium (low serum, cyclic AMP and nerve growth factor) showed that: (i) the outward K+ current during pulsed depolarization in most of these cells was increased by either DAGO or DPDPE, but none were responsive to both opioids or to the kappa-opioid receptor agonist, U-50,488H. The response was blocked by relevant receptor antagonists, naloxone, beta-funaltrexamine or naltrindole; (ii) cells without processes responded neither to DAGO nor to DPDPE; (iii) treatment with pertussis toxin blocked all opioid-induced increases in outward K+ current. The opioid-induced increase in voltage-dependent membrane K+ current in F11 cells resembles the inhibitory effect elicited by mu- and delta-opioid agonists in primary cultures of mouse DRG neurons.
Assuntos
Células Híbridas/metabolismo , Neuroblastoma/metabolismo , Neurônios/metabolismo , Canais de Potássio/fisiologia , Receptores Opioides delta/metabolismo , Receptores Opioides mu/metabolismo , Medula Espinal/metabolismo , Animais , Ala(2)-MePhe(4)-Gly(5)-Encefalina , D-Penicilina (2,5)-Encefalina , Encefalinas/metabolismo , Camundongos , Ensaio Radioligante , Ratos , Medula Espinal/citologiaRESUMO
In freshly dispersed taenia coli myocytes of guinea pig, verapamil decreased the whole-cell outward current during depolarization. In aortic myocytes it has the opposite effect. In cell-attached patches, verapamil increased the frequency of opening of the maxi-K+ channel of both taenia coli and aortic myocytes at the expense of the mean open time. In taenia coli myocytes, the greater frequency did not fully compensate for the reduced open time, and the overall open probability of the channel was reduced. In aortic myocytes, the increase in open frequency overwhelmed the effect of the decrease in mean open time. None of the effects could be reproduced with nifedipine or diltiazem in either cell type.
Assuntos
Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Canais de Potássio/efeitos dos fármacos , Verapamil/farmacologia , Animais , Aorta , Cálcio/metabolismo , Separação Celular , Colo , Diltiazem/farmacologia , Eletrofisiologia , Cobaias , Técnicas In Vitro , Músculo Liso/citologia , Músculo Liso/metabolismo , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , Nifedipino/farmacologia , RatosRESUMO
With the patch clamp method we demonstrate a stretch-sensitive Cl- currents as well as stretch-sensitive Cl- channels in a small group (5%,n 117) of cultured human corpus cavernosal muscle cells. The current and the channel activities had the following characteristics: (1) Their equilibrium potentials changed with extracellular Cl- concentration close to that predicted by Nernst equation provided that the relevant channels had high permeability to Cl- but low permeability to acetate ions; (2) They were blocked by mM concentrations of Zn2+; (3) The i-v relation of single channel current was almost linear for holding potentials varied from -70 to +60 mV; and (4) The channels had unitary conductances of approximately 140-170 pS.
Assuntos
Membrana Celular/fisiologia , Canais de Cloreto/fisiologia , Músculo Liso/química , Pênis/química , Acetatos/metabolismo , Fenômenos Biomecânicos , Permeabilidade da Membrana Celular , Células Cultivadas , Cloretos/metabolismo , Cloretos/farmacologia , Condutividade Elétrica , Humanos , Masculino , Músculo Liso/fisiologia , Músculo Liso/ultraestrutura , Pênis/fisiologia , Pênis/ultraestrutura , Estimulação Física , Zinco/farmacologiaRESUMO
We report a case in which malignant melanoma of the vagina showed some MR signal changes after radiotherapy. Before radiotherapy, the tumour had slightly high signal intensity on T(1) weighted images and was enhanced after gadolinium-DTPA administration. After radiotherapy, the signal intensity of the tumour increased conspicuously on both T(1) weighted images and fat suppression T(1) weighted images.