RESUMO
The treatment of monoclonal Ig deposition disease (MIDD) is controversial and not standardized. We report our experience with high dose melphalan and auto-SCT (HDM/auto-SCT) in seven patients with MIDD associated with underlying Durie-Salmon stage IB multiple myeloma, including five with light chain deposition disease, one with light and heavy chain deposition disease and one with light chain crystal deposition disease. The median age of these patients was 50 years; six of them were male subjects. A monoclonal kappa-light chain was detected by Serum Free Light Chain Assay in all seven. The patients received melphalan 140 mg/m(2) followed by auto-SCT. All patients are alive and six remain in hematologic CR with a median follow up of 23.6 months (7.9-69.8 months). Renal function has improved compared to pre-HDSM/auto-SCT in five patients--two of whom had a renal transplant and became dialysis independent--remained stable in one and worsened in one leading to hemodialysis despite hematologic CR. Our results corroborate previous experience with HDM/auto-SCT in MIDD and argue in favor of kidney transplantation in patients who achieve hematologic CR after HDM/auto-SCT. Although this approach appears effective, multi-center studies are needed to define the optimal treatment for patients with MIDD.
Assuntos
Anticorpos Monoclonais , Imunoglobulina G , Melfalan/administração & dosagem , Mieloma Múltiplo/terapia , Agonistas Mieloablativos/administração & dosagem , Transplante de Células-Tronco , Condicionamento Pré-Transplante , Adulto , Anticorpos Monoclonais/metabolismo , Feminino , Humanos , Imunoglobulina G/metabolismo , Cadeias Pesadas de Imunoglobulinas/metabolismo , Cadeias kappa de Imunoglobulina/metabolismo , Rim/metabolismo , Rim/patologia , Transplante de Rim , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Indução de Remissão , Transplante AutólogoRESUMO
Autologous stem cell transplantation (SCT) with high-dose melphalan (HDM, 200 mg/m2) is the most effective therapy for multiple myeloma. To determine the feasibility of combining carmustine (300 mg/m2) with HDM, we enrolled 49 patients with previously treated Durie-Salmon stage II/III myeloma (32M/17W, median age 53) on a phase I/II trial involving escalating doses of melphalan (160, 180, 200 mg/m2). The median beta2-microglobulin was 2.5 (0-9.3); marrow karyotypes were normal in 88%. The phase I dose-limiting toxicity was > or =grade 2 pulmonary toxicity 2 months post-SCT. Other endpoints were response rate and progression-free survival (PFS). HDM was safely escalated to 200 mg/m2; treatment-related mortality was 2% and > or =grade 2 pulmonary toxicity 10%. The complete (CR) and near complete (nCR) response rate was 49%. With a median post-SCT follow-up of 2.9 years, the PFS and overall survival (OS) post-SCT were 2.3 and 4.7 years. PFS for those with CR or nCR was 3.1 years while for those with stable disease (SD) it was 1.3 years (P=0.06). We conclude that carmustine can be combined with HDM for myeloma with minimal pulmonary toxicity and a high response rate.
Assuntos
Antineoplásicos Alquilantes/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carmustina/administração & dosagem , Melfalan/administração & dosagem , Mieloma Múltiplo/terapia , Transplante de Células-Tronco de Sangue Periférico , Adulto , Idoso , Antineoplásicos Alquilantes/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carmustina/efeitos adversos , Terapia Combinada , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Humanos , Pneumopatias/induzido quimicamente , Masculino , Melfalan/efeitos adversos , Pessoa de Meia-Idade , Mieloma Múltiplo/tratamento farmacológico , Recidiva , Análise de Sobrevida , Transplante AutólogoRESUMO
During the last 10 years, three European phase II studies were performed to investigate the treatment of elderly patients with myelodysplastic syndrome (MDS) with low-dose 5-aza-2'-deoxycytidine (decitabine, DAC). All these European trial data were reviewed on the basis of the International Prognostic Scoring System (IPSS) risk criteria and the response criteria as recently published by an international working group. To investigate the results in a larger cohort of patients and to determine risk factors, all data were pooled with some observations from the PCH 95-06 US phase II study. The response rate in the 177 patients evaluated (median age 70 years) was 49%. The median response duration was 36 weeks, and the median survival was 15 months. Analysis of the data according to sex, age, French-American-British classification, percentage of blasts in the bone marrow, IPSS risk group, lactate dehydrogenase and cytogenetics did not reveal any factor predictive of response. Overall, 69% of patients benefited, including those with stable disease during therapy. Response duration was significantly shorter with increasing risk (according to the IPSS classification). Haemoglobin level and neutrophil count showed an inverse correlation to the IPSS classification. Univariate analysis showed a significantly inferior survival for elderly patients (>75 years of age) and for those with high levels of serum lactate dehydrogenase (LDH) (more than two times the normal values). Patients with high-risk cytogenetic abnormalities according to the IPSS risk criteria showed better overall survival than those with intermediate-risk abnormalities. When analysed according to the IPSS risk classification, high-risk patients had worse survival prospects following decitabine therapy than those with intermediate risk; however, compared to the originally reported IPPS outcomes for high-risk patients, they probably showed better survival. During the treatment period, 18% of the patients progressed towards acute leukaemia. Decitabine showed a rather low toxicity profile in this elderly patient group. In conclusion, low-dose decitabine is an active drug for the treatment of MDS patients, even for those older than 75 years with bad prognostic characteristics.
Assuntos
Azacitidina/análogos & derivados , Metilases de Modificação do DNA/antagonistas & inibidores , Epigênese Genética/efeitos dos fármacos , Síndromes Mielodisplásicas/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Azacitidina/uso terapêutico , Decitabina , Europa (Continente) , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/genética , Indução de RemissãoRESUMO
Multiple myeloma (MM) is an incurable hematologic malignancy for which autologous hematopoietic stem cell transplantation (HCT) is a standard therapy. The optimal method of stem cell mobilization is not defined. We evaluated intravenous melphalan (60 mg/m2), the most effective agent for MM, and G-CSF (10 microg/kg/day) for mobilization. End points were safety, adequacy of CD34+ collections, MM response, and contamination of stem cell components (SCC). In total, 32 patients were mobilized. There were no deaths or significant bleeding episodes; 14 patients (44%) required hospitalization for neutropenic fever. Median days of grade 3 or 4 neutropenia or thrombocytopenia were 7 (2-20) and 8 (3-17). Median mobilization days, CD34+ cells/kg and total leukaphereses were 16 (12-30), 12.1 million (2.6-52.8), and 2 (1-5) respectively. Four patients (12.5 %) failed to achieve the target of 4 million CD34+ cells/kg in five leukaphereses. Reduction in myeloma was seen in 11 patients (34%) with 3 (9%) achieving complete response; 15 (47%) maintained prior responses. Estimated MM contamination per SCC (N=48) was 0.0009% (range 0-0.1) and 0.21 x 10(4) cells per kg (range 0-41.2). Increased contamination was associated with increased patient age. This strategy for mobilization is feasible, frequently requires hospitalization and transfusion, and controls disease in most patients.
Assuntos
Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Mobilização de Células-Tronco Hematopoéticas/métodos , Transplante de Células-Tronco Hematopoéticas/métodos , Melfalan/administração & dosagem , Mieloma Múltiplo/terapia , Adulto , Fatores Etários , Idoso , Feminino , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Leucaférese/métodos , Masculino , Melfalan/toxicidade , Pessoa de Meia-Idade , Mieloma Múltiplo/complicações , Células Neoplásicas Circulantes/efeitos dos fármacos , Neutropenia , Transplante Autólogo , Resultado do TratamentoAssuntos
Inibidores Enzimáticos/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Proteína Quinase C/antagonistas & inibidores , Crise Blástica , Inibidores Enzimáticos/efeitos adversos , Humanos , Leucemia Mieloide Aguda/patologia , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Tirosina Quinase 3 Semelhante a fmsRESUMO
BACKGROUND: It has been hypothesized that cigarette smoking among subjects with major depression is a form of self-medication. To explore a possible biological basis for this hypothesis, noradrenergic proteins in the locus coeruleus (LC) were measured in long-term cigarette smokers and in nonsmokers. The LC was studied because elevated amounts of alpha2-adrenoceptors and tyrosine hydroxylase have been observed postmortem in the LCs of subjects with major depression or who commit suicide, and because long-term administration of antidepressant drugs to rats down-regulates these proteins in the LC. METHODS: Postmortem LCs were obtained from long-term cigarette smokers (n=7) and from nonsmokers (n = 9), all of whom lacked diagnoses of major depression. Amounts of tyrosine hydroxylase immunoreactivity and radioligand binding to the norepinephrine transporter, monoamine oxidase A, and alpha2-adrenoceptors were measured. RESULTS: Amounts of tyrosine hydroxylase immunoreactivity and radioligand binding to alpha2-adrenoceptors were significantly lower (approximately 60% and 40%, respectively) along the axis of the LCs of long-term smokers compared with nonsmokers. Smoking had no statistically significant effects on binding to monoamine oxidase A or to the norepinephrine transporter. CONCLUSION: This is the first demonstration that cigarette smoking affects noradrenergic proteins in the LC. The direction of these changes is opposite to that observed when comparing subjects who have major depression with normal controls and the same as that produced by long-term antidepressant treatment in animals. If the present observations reflect long-term effects of smoking on premortem noradrenergic biochemistry, smoking-induced changes in LC biochemistry may strengthen the smoking habit among subjects with major depression.
Assuntos
Locus Cerúleo/química , Fumar/efeitos adversos , Simportadores , Antidepressivos/farmacologia , Autorradiografia , Western Blotting , Proteínas de Transporte/análise , Proteínas de Transporte/metabolismo , Transtorno Depressivo/tratamento farmacológico , Transtorno Depressivo/metabolismo , Transtorno Depressivo/psicologia , Feminino , Humanos , Locus Cerúleo/enzimologia , Masculino , Proteínas da Membrana Plasmática de Transporte de Norepinefrina , Fumar/metabolismo , Tirosina 3-Mono-Oxigenase/análise , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
In this paper, we review research utilizing postmortem brain tissue in order to investigate the potential neuropathology of the noradrenergic system in psychiatric disorders. The postmortem tissue approach to the study of the noradrenergic system has been used primarily in investigations of the biology of suicide and depression. Findings from postmortem studies provide data generally consistent with the hypothesis that a norepinephrine deficiency exists in depression, and possibly in the victims of suicide. However, postmortem studies do not presently provide irrefutable evidence of noradrenergic neuropathology. Technical shortcomings, issues of reproducibility, and the strengths of postmortem research are reviewed. More rigorously performed postmortem research is needed to aid researchers in pinpointing specific neuropathologies associated with psychiatric disease.
RESUMO
In this study, we developed an immuno-autoradiographic method to obtain quantitative estimates of tyrosine hydroxylase (TH) protein in tissue sections from post-mortem human brain. Protein from tissue sections containing the locus coeruleus (LC) was directly transferred to a polyvinylidene fluoride (PVDF) membrane. Immunoreactive TH on PVDF membranes was identified with optimized concentrations of TH antibody followed by application of [125I]labeled secondary antibody. Quantities of TH on autoradiograms were estimated by comparing optical densities of transferred immunoblots to a calibrated standard curve produced with purified recombinant TH dotted onto the same PVDF membranes. Amounts of TH-immunoreactivity in the LC were proportional to the thickness of tissue sections up to 15 micrometer. However, the amounts of total protein, as measured by Ponceau S staining, were linearly related to section thicknesses up to 30 micrometer. Comparisons of quantities of immunoreactive TH in the LC using this method to amounts determined using traditional Western blotting, in which LC tissue was punched from adjacent sections from the same subject, showed a positive correlation (r(2)=0.99, P<0.01). Using the transfer immunoblot method, an uneven distribution of TH protein was observed along the rostrocaudal axis of the human LC (P<0.01). This method may provide a sensitive and useful tool for the study of the role of human TH expression in the pathophysiology of psychiatric disease.
Assuntos
Autorradiografia/métodos , Locus Cerúleo/enzimologia , Tirosina 3-Mono-Oxigenase/análise , Western Blotting , Humanos , Técnicas de Imunoadsorção , Locus Cerúleo/citologia , Fatores de TempoRESUMO
The main use of systemic chemotherapy in metastatic melanoma remains palliative. Dacarbazine (dimethyl-1-triazeno imidazole-4-carboxamide [DTIC]) is the standard chemotherapy agent for advanced disease. The combination chemotherapy and biochemotherapy regimens have achieved higher response rates, but have not led to durable remission or improved survival. The field of systemic therapy remains in need of a more effective and less toxic treatment strategy.
Assuntos
Antineoplásicos/uso terapêutico , Melanoma/secundário , Neoplasias Cutâneas/patologia , Antineoplásicos Hormonais/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Dacarbazina/uso terapêutico , Humanos , Imunoterapia , Melanoma/tratamento farmacológico , Terapia Neoadjuvante , Cuidados Paliativos , Indução de Remissão , Taxa de SobrevidaRESUMO
An abnormal expression of noradrenergic proteins (e.g., tyrosine hydroxylase, norepinephrine transporters) in the locus coeruleus has recently been demonstrated in subjects with major depression and/or victims of suicide. Monoamine oxidase A (MAO-A) is a key enzyme in the catabolism of biogenic amines and is expressed in brain noradrenergic neurons. In this study, the binding of [3H]Ro41-1049 to MAO-A was measured by quantitative autoradiography at multiple levels along the rostral-caudal axis of the noradrenergic locus coeruleus from subjects with major depression and age- and postmortem interval-matched control subjects who were psychiatrically normal. [3H]Ro41-1049 binding to MAO-A was unevenly distributed along the axis of the locus coeruleus, paralleling an uneven number of neuromelanin-containing (noradrenergic) neurons throughout the nucleus. Accordingly, there was a significant correlation between the number of neuromelanin-containing neurons per section and the specific binding of [3H]Ro41-1049 at any particular level of the locus coeruleus in control subjects (r(2)=0.25; p<0.001) and in subjects with major depression (r(2)=0.14; p<0. 001). Moderate levels of [3H]Ro41-1049 binding were observed in regions surrounding the locus coeruleus, including the central gray and the dorsal and median raphe nuclei. No significant differences in [3H]Ro41-1049 binding to MAO-A were observed at any level of the locus coeruleus, or raphe nuclei, comparing subjects with major depression to psychiatrically normal control subjects. These findings demonstrate that the pathophysiology of major depression is not likely to involve abnormalities in MAO-A.
Assuntos
Monoaminas Biogênicas/metabolismo , Tronco Encefálico/enzimologia , Transtorno Depressivo/metabolismo , Monoaminoxidase/metabolismo , Adulto , Idoso , Tronco Encefálico/patologia , Feminino , Humanos , Locus Cerúleo/enzimologia , Locus Cerúleo/patologia , Masculino , Pessoa de Meia-Idade , Inibidores da Monoaminoxidase/farmacologia , Ensaio Radioligante , Núcleos da Rafe/enzimologia , Núcleos da Rafe/patologia , Tiazóis/farmacologiaRESUMO
BACKGROUND: Levels of tyrosine hydroxylase (TH) are regulated in the noradrenergic locus coeruleus (LC) in response to changes in the activity of LC neurons and in response to changes in brain levels of norepinephrine. To study the potential role of central noradrenergic neurons in the pathobiology of major depression, TH protein was measured in the LC from postmortem brains of 13 subjects with a diagnosis of major depression and 13 age-matched control subjects having no Axis I psychiatric diagnosis. Most of the major depressive subjects died as a result of suicide. METHODS: Protein from sections cut through multiple rostro-caudal levels of LC was transferred to Immobilon-P membrane, immunoblotted for TH, and quantified autoradiographically. RESULTS: The distribution of TH-immunoreactivity (TH-ir) along the rostro-caudal axis of the LC was uneven and was paralleled by a similar uneven distribution of neuromelanin-containing cells in both major depressive and psychiatrically normal control subjects. Amounts of TH-ir in the rostral, middle and caudal levels of the LC from major depressive subjects were significantly higher than that of matched control subjects. There were no significant differences in the number of noradrenergic cells at any particular level of the LC comparing major depressive subjects to control subjects. CONCLUSIONS: Elevated expression of TH in the LC in major depression implies a premortem overactivity of these neurons, or a deficiency of the cognate transmitter, norepinephrine.
Assuntos
Transtorno Depressivo Maior/enzimologia , Locus Cerúleo/enzimologia , Suicídio , Tirosina 3-Mono-Oxigenase/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Autorradiografia , Western Blotting , Estudos de Casos e Controles , Feminino , Humanos , Immunoblotting , Masculino , Pessoa de Meia-Idade , Neurônios/enzimologiaRESUMO
The binding of [125I]p-iodoclonidine to alpha-2, and/or [125I]iodopindolol to beta-1 and beta-2 adrenoceptors was measured in right prefrontal cortex (Brodmann's area 10) and right hippocampus from subjects with DSM-III-R diagnoses of major depression (n = 15) or schizophrenia (n = 8) as well as from control subjects (n = 20). No significant differences between study groups were observed in binding to alpha-2 adrenoceptors in any of the six layers of prefrontal cortex or in any of the hippocampal fields. Likewise, there were no significant differences in beta-1 or beta-2 adrenoceptor binding in any of the hippocampal fields between control and major depressive subjects. In contrast, binding to beta-1 adrenoceptors, but not beta-2 adrenoceptors, was significantly lower (-13 to -27%) in most hippocampal fields of schizophrenic subjects as compared to control subjects or to major depressives. Alterations in beta-1 adrenoceptor binding in the hippocampus of schizophrenics provide further evidence for a role of central noradrenergic neurons in the neurochemical pathology of schizophrenia.
Assuntos
Química Encefálica/fisiologia , Transtorno Depressivo/metabolismo , Norepinefrina/metabolismo , Receptores Adrenérgicos/metabolismo , Esquizofrenia/metabolismo , Agonistas alfa-Adrenérgicos , Antagonistas Adrenérgicos beta , Adulto , Marcadores de Afinidade , Idoso , Autorradiografia , Clonidina/análogos & derivados , Feminino , Hipocampo/metabolismo , Humanos , Radioisótopos do Iodo , Masculino , Pessoa de Meia-Idade , Pindolol/análogos & derivados , Córtex Pré-Frontal/metabolismo , SuicídioRESUMO
alpha2C adrenoceptors occur in high density in the striatum, but the functional role of these receptors is uncertain. Mice with targeted inactivation of the alpha2C adrenoceptor gene (Adra2c-/-) and genetically related control mice expressing the wild-type alpha2C adrenoceptor (Adra2c+/+) were used to determine whether striatal alpha2C adrenoceptors modulate adenylyl cyclase activation. In striatal slices from Adra2c+/+ mice, the alpha2 adrenoceptor antagonist RX821002 facilitated forskolin-stimulated cyclic AMP accumulation in a concentration-dependent manner. In contrast, RX821002 had no effect on forskolin-stimulated cAMP accumulation in striatal slices from Adra2c-/- mice or in striatal slices from Adra2c+/+ mice treated with reserpine and alpha-methyl-rho-tyrosine to deplete monoamine neurotransmitters. Given the sparse innervation of the striatum by noradrenergic neurons, the possibility that dopamine can activate the mouse alpha2C adrenoceptor at physiologically relevant concentrations was investigated using normal rat kidney (NRK) cells transfected with the mouse alpha2A or alpha2C adrenoceptor cDNA (NRK-alpha2A or NRK-alpha2C cells). Inhibition of [3H]RX821002 binding by agonists in homogenates of transfected cells revealed an affinity of dopamine for alpha2C adrenoceptors that was higher than the affinity of norepinephrine for its cognate receptor, the alpha2A adrenoceptor. Both norepinephrine and dopamine inhibited forskolin-stimulated cAMP accumulation in intact NRK-alpha2C cells. In NRK-alpha2A cells, norepinephrine facilitated forskolin-stimulated cAMP accumulation, an effect not observed for dopamine. Together, these data demonstrate that the alpha2C adrenoceptor is negatively coupled to adenylyl cyclase and is tonically activated in mouse striatal slices. The endogenous activator of the striatal alpha2C adrenoceptor may be dopamine, as well as norepinephrine.
Assuntos
Adenilil Ciclases/metabolismo , Antagonistas Adrenérgicos alfa/farmacologia , Corpo Estriado/fisiologia , Dopamina/farmacologia , Idazoxano/análogos & derivados , Receptores Adrenérgicos alfa 2/fisiologia , Inibidores de Adenilil Ciclases , Animais , Linhagem Celular , Colforsina/farmacologia , Corpo Estriado/efeitos dos fármacos , Cruzamentos Genéticos , AMP Cíclico/metabolismo , Ativação Enzimática , Homozigoto , Idazoxano/farmacologia , Técnicas In Vitro , Cinética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Norepinefrina/farmacologia , Ratos , Receptores Adrenérgicos alfa 2/deficiência , Receptores Adrenérgicos alfa 2/genética , Proteínas Recombinantes/metabolismo , Reserpina/farmacologia , Transfecção , alfa-Metiltirosina/farmacologiaRESUMO
Treatment of metastatic melanoma with biochemotherapy results in the rapid onset of anemia, requiring blood transfusion in 9 of 13 (69%) patients. Prophylactic use of weekly subcutaneous recombinant epoetin alfa eliminated the need for transfusion in all but 1 of 21 (5%) patients.
Assuntos
Anemia/prevenção & controle , Eritropoetina/uso terapêutico , Hematínicos/uso terapêutico , Melanoma/tratamento farmacológico , Anemia/economia , Anemia/terapia , Transfusão de Sangue/economia , Análise Custo-Benefício , Tratamento Farmacológico/economia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Epoetina alfa , Eritropoetina/economia , Hematínicos/economia , Humanos , Melanoma/economia , Melanoma/patologia , Metástase Neoplásica , Qualidade de Vida , Proteínas RecombinantesRESUMO
The norepinephrine transporter (NET) is a membrane protein responsible for termination of the action of synaptic norepinephrine and is a site of action of many drugs used to treat major depression. The present study determined whether the binding of [3H]nisoxetine to the NET is altered in the locus coeruleus (LC) in major depression, using brain tissue collected postmortem from subjects diagnosed with major depression and from age-matched normal control subjects. Thirteen of the 15 major depressive subjects studied died by suicide. The distribution of [3H]nisoxetine binding along the rostro-caudal axis of the nucleus was uneven and was paralleled by a similar uneven distribution of neuromelanin-containing cells in both major depressives and psychiatrically normal control subjects. The binding of [3H]nisoxetine to NETs in the midcaudal portion of the LC from major depressive subjects was significantly lower than that from age-matched, normal control subjects. The binding of [3H]nisoxetine to NETs in other regions of the LC was similar in major depressives and control subjects. In contrast to reductions in binding to NETs, there were no significant differences in the number of noradrenergic cells at any particular level of the LC between major depressives and normal control subjects. The decreased binding of [3H]nisoxetine to NETs in the LC in major depression may reflect a compensatory downregulation of this transporter protein in response to an insufficient availability of its substrate (norepinephrine) at the synapse.
Assuntos
Proteínas de Transporte/análise , Transtorno Depressivo/metabolismo , Locus Cerúleo/química , Proteínas do Tecido Nervoso/deficiência , Norepinefrina/metabolismo , Simportadores , Adulto , Idoso , Transtorno Depressivo/patologia , Feminino , Fluoxetina/análogos & derivados , Fluoxetina/farmacocinética , Humanos , Locus Cerúleo/patologia , Masculino , Melaninas/análise , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/análise , Proteínas da Membrana Plasmática de Transporte de Norepinefrina , SuicídioRESUMO
The norepinephrine transporter (NET) is a site of action for tricyclic antidepressant drugs and for drugs of abuse such as amphetamine and cocaine. In this study, the binding of [3H]nisoxetine to NETs in the noradrenergic cell group, the locus coeruleus, and the serotonergic cell groups, the dorsal raphe nuclei, was measured autoradiographically in postmortem human brain. [3H]nisoxetine binding was unevenly distributed along the rostral-caudal axis of the locus coeruleus and correlated positively with numbers of neuromelanin-containing (noradrenergic) cells along the axis of the locus coeruleus within individuals. Binding densities of [3H]nisoxetine in dorsal raphe nuclei were similar to that in the locus coeruleus. [3H]nisoxetine binding was unevenly distributed along the entire rostral-caudal extent of the dorsal raphe, with the highest binding occurring in the interfascicular and ventral nuclei. A moderate amount of [3H]nisoxetine binding was also observed in the median raphe nucleus. The specificity of [3H]nisoxetine binding to NETs in monoaminergic nuclei was assessed by measuring the inhibition of its binding by desipramine, imipramine, or citalopram. The order of affinities of these drugs was identical in the locus coeruleus and dorsal and median raphe and was characteristic of binding to NETs (desipramine > imipramine > citalopram). Thus, high levels of NETs and an uneven distribution of NETs occur in the locus coeruleus as well as in the dorsal raphe nuclei of the human.
Assuntos
Proteínas de Transporte/metabolismo , Locus Cerúleo/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Núcleos da Rafe/metabolismo , Simportadores , Adulto , Fatores Etários , Idoso , Proteínas de Transporte/efeitos dos fármacos , Feminino , Fluoxetina/análogos & derivados , Fluoxetina/metabolismo , Fluoxetina/farmacologia , Humanos , Locus Cerúleo/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/efeitos dos fármacos , Norepinefrina/antagonistas & inibidores , Proteínas da Membrana Plasmática de Transporte de Norepinefrina , Ligação Proteica , Núcleos da Rafe/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Sinapses/metabolismoRESUMO
The present study examined the effects of acute and repeated administration of three antidepressant drugs (imipramine, citalopram and (+)-oxaprotiline) on the levels of mRNA coding for dopamine D1 and D2 receptors in the rat brain. Quantitive in situ hybridization with 35S-labelled oligonucleotide probes has been utilised. The level of mRNA coding for dopamine D1 receptor (D1 mRNA) is decreased following repeated administration of imipramine, both in the nucleus accumbens and in the striatum. On the other hand, the repeated administration of citalopram, the selective inhibitor of serotonin reuptake, resulted in an increase in the level of D1 mRNA in the striatum and in the core region of nucleus accumbens. A similar tendency, i.e.: an increase in the level of D1 mRNA was observed after repeated administration of (+)-oxaprotiline, a selective inhibitor of noradrenaline reuptake. The level of mRNA coding for dopamine D2 receptors (D2 mRNA) was increased in all the brain regions studied, both after administration of imipramine and citalopram. (+)-Oxaprotiline did not produce any statistically significant changes in the level of D2 mRNA. The results obtained in this study indicate that the levels of mRNA coding for dopamine D1 and D2 receptors are regulated by the antidepressant drugs. The changes concerning the dopamine D2 receptors are more consistent and fit in with the previously described binding and behavioral effects and seem to be important for the mechanism of action of antidepressant drugs.
Assuntos
Antidepressivos/farmacologia , Encéfalo/metabolismo , RNA Mensageiro/metabolismo , Receptores de Dopamina D1/genética , Receptores de Dopamina D2/genética , Inibidores da Captação Adrenérgica/farmacologia , Animais , Citalopram/farmacologia , Imipramina/farmacologia , Masculino , Maprotilina/análogos & derivados , Maprotilina/farmacologia , Norepinefrina/antagonistas & inibidores , Ratos , Ratos Wistar , Inibidores Seletivos de Recaptação de Serotonina/farmacologiaRESUMO
Recent reports of specific topographic patterns of cell loss in the locus coeruleus (LC) in psychiatric and neurologic disorders underscores the need for detailed neurochemical analyses of this cell group. In this study, the anatomical distribution of alpha 2-adrenoceptors and its relationship to the distribution of noradrenergic neurons in the human LC was studied. Quantitative autoradiography was used to assess the binding of [125I]p-iodoclonidine ([125I]PIC) to alpha 2-adrenoceptors coordinately with counts of neuromelanin-containing cells in tissue sections cryocut at 10-13 levels along the rostrocaudal axis of the LC. Pontine brain tissue was obtained postmortem from 7 subjects dying of natural or accidental causes, ranging in age from 26 to 78 years. Both the binding of [125I]PIC and number of neuromelanin-containing cells were differentially distributed along the LC axis (P < 0.01) with almost identical topographical patterns. The highest concentration of binding and the greatest number of neuromelanin-containing cells per section occurred near the middle portion of the nucleus. There was a significant correlation between the number of neuromelanin-containing cells per section and the specific binding of [125I]PIC at any particular level of the LC (r2 = 0.56; P < 0.0001). The highest and lowest amounts of [125I]PIC binding in the LC were observed in the youngest and oldest subjects, respectively, and this trend was parallelled by a significant negative correlation between the number of neuromelanin-containing cells at a given level and age (r2 = 0.85; P < 0.003). The uneven distribution of alpha 2-adrenoceptors in the LC demonstrates the importance of anatomical specificity when performing quantitative studies of LC protein chemistry in psychiatric and neurologic disorders.
Assuntos
Locus Cerúleo/metabolismo , Receptores Adrenérgicos alfa 2/metabolismo , Adulto , Idoso , Autorradiografia , Clonidina/farmacocinética , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Radioisótopos do Iodo , Locus Cerúleo/citologia , Masculino , Pessoa de Meia-Idade , Ensaio RadioliganteRESUMO
The influence of CGP 37849, a competitive antagonist of NMDA, receptors and desipramine (DMI) on the density of beta-adrenergic receptors in rats exposed to the forced swimming test was investigated. CGP 37849 (10 mg/kg) and DMI (15 mg/kg), given twice to rats (24 h apart), or the forced swimming test alone failed to alter the density of beta-adrenergic receptors in the rat cortex, as tested using [3H]dihydroalprenolol ([3H]DHA). However, in rats injected with CGP 37849 (10 mg/kg) or DMI (15 mg/kg) and exposed to the forced swimming test, it was found that the density of beta-adrenergic receptors in the cortex was decreased. It was also observed that CGP 37849 used in a dose which decreased the density of beta-adrenergic receptors reduced the immobility time in a manner similar to DMI. It is concluded that CGP 37849 may evoke similar adaptive receptor changes as anti-depressant drugs which-in turn-suggests antidepressant-like properties of CGP 37849.
Assuntos
2-Amino-5-fosfonovalerato/análogos & derivados , Antagonistas Adrenérgicos beta/farmacologia , Regulação para Baixo/efeitos dos fármacos , Antagonistas de Aminoácidos Excitatórios/farmacologia , Receptores Adrenérgicos beta/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Estresse Psicológico/fisiopatologia , 2-Amino-5-fosfonovalerato/farmacocinética , 2-Amino-5-fosfonovalerato/farmacologia , Inibidores da Captação Adrenérgica/farmacologia , Antagonistas Adrenérgicos beta/farmacocinética , Animais , Desipramina/farmacologia , Di-Hidroalprenolol , Antagonistas de Aminoácidos Excitatórios/farmacocinética , Masculino , Atividade Motora/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
Chronic sequential exposure to a variety of mild stressors has previously been found to cause an antidepressant-reversible decrease in the consumption of palatable sweet solutions, associated with abnormalities of dopaminergic neurotransmission in the nucleus accumbens. In the present study, 5 weeks of treatment with imipramine (10 mg/kg b.i.d.) reversed the decreased sucrose intake of rats exposed to chronic mild stress. Stress also caused a decrease in D2-receptor binding in the limbic forebrain (but not the striatum), which was completely reversed by imipramine. In nonstressed animals, imipramine decreased D1-receptor binding in both regions. However, in stressed animals, imipramine did not significantly alter D1-receptor binding in either area. Stress alone slightly increased D1-receptor binding, in striatum only. Scatchard analysis showed that all changes in receptor binding resulted from changes in receptor number (Bmax) rather than receptor affinity (KD). The results support the hypothesis that changes in D2-receptor function in the nucleus accumbens are responsible for chronic mild stress-induced anhedonia and its reversal by antidepressant drugs. They do not support the hypothesis that the sensitization of D2-receptors seen following chronic antidepressant treatment is caused by a down-regulation of D1-receptors.