RESUMO
BACKGROUND: The immune system is particularly sensitive to stress. Although acute stress generally has positive effects, chronic stress typically provokes immunosuppression. The elucidation of the mechanisms involved in immunosuppression are of interest for the design of therapeutic approaches to avoid the appearance of stress disorders. This study aimed to investigate chronic stress-induced alterations on lymphocyte subset distribution and percentages. The experiments were performed with C57BL/6 mice subjected to chronic immobilization stress. RESULTS: Stress caused a marked increase in apoptosis inside the thymus, and a reduction in the total number of thymocytes. Furthermore, the proportion of immature thymocytes declined significantly suggesting that the increased apoptosis mainly affected cells of immature phenotype. In blood, the total number of lymphocytes diminished but not all lymphocyte populations showed the same tendency: while the relative proportion of B cells declined slightly, the relative proportion of circulating CD3+ cells, and particularly some T cell subsets showing an immature phenotype (CD3+PNA+), increased under stress. The spleen and lymph nodes show a marked reduction in cellularity, but the relative proportion of T cells increased, while no change or only a slight reduction was observed in the relative proportion of B cells. Similarly, the relative proportion of T cells increased in bone marrow. CONCLUSIONS: Detailed data on the alterations of lymphoid cell subsets occurring under immobilization stress, both in the bloodstream and in different lymphoid tissues, are obtained. In general, T cells are more affected than B cells and, in particular, a marked increase in the percentage of a subset of circulating PNA+CD3+ T cells is observed.
Assuntos
Subpopulações de Linfócitos/classificação , Estresse Fisiológico/imunologia , Animais , Células Sanguíneas/citologia , Células Sanguíneas/imunologia , Células da Medula Óssea/citologia , Células da Medula Óssea/imunologia , Imobilização , Linfonodos/citologia , Linfonodos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Baço/citologia , Baço/imunologia , Subpopulações de Linfócitos T/classificação , Timo/citologia , Timo/imunologiaRESUMO
C57BL/6 and Balb C male and female mice of various ages were stressed by immobilization for 1 h/day (1, 2, 3, 5, 8, 11 or 14 consecutive days). The animals were then killed for determination of total body weight and the weights of the thymus, spleen and axillary lymph nodes. In addition, the total number of cells in the thymus and the proportion of lymphoid cells in the bone marrow cell population was defined. The effects of stress were modulated by age, sex and strain. Stress-induced involution of the thymus was generally more pronounced in older animals, while for the spleen was the opposite. Involution of the thymus was higher in males than in females, but there were no marked differences between the sexes in the response of the spleen. In general C57BL/6 mice were more sensitive to stress than Balb C mice. However, for the involution induced by stress on lymph nodes there were not a clear trend with age, sex or strain. In male and female mice of all ages and both strains, stress led to statistically significant reductions in the absolute number of cells inside the thymus and spleen and in the proportion of lymphoid cells in the bone marrow.
Assuntos
Envelhecimento/imunologia , Medula Óssea/fisiologia , Sistema Imunitário/fisiologia , Caracteres Sexuais , Estresse Fisiológico/imunologia , Animais , Peso Corporal/fisiologia , Medula Óssea/imunologia , Células da Medula Óssea/imunologia , Feminino , Linfonodos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Especificidade da Espécie , Baço/citologia , Baço/imunologia , Timo/citologia , Timo/imunologiaRESUMO
1 In this study, we investigated whether serotonin could regulate the in vitro activity of phagocytosis through 5-hydroxytryptamine or serotonin (5-HT(1A)) receptors. 2 Mouse peritoneal macrophages were cultured with serotonin and the activity of phagocytosis was assessed by the uptake of zymosan and latex particles added to the culture media. Specific binding of [(3)H]8-OH-DPAT and immunohistochemistry using an affinity-purified anti-5-HT(1A)-receptor antibody were assayed in the macrophages. In addition, we took advantage of the availability of pharmacological inhibitors of nuclear factor-kappaB (NF-kappaB) to explore its role in the regulation of the 5-HT(1A) receptor. 3 Serotonin increased the in vitro activity of phagocytosis in a dose-dependent manner. The 5-HT(1A) receptor agonist (+/-)-8-hydroxy-2-(di-n-propyl-amino)-tetralin (R(+)-8-OH-DPAT) reproduced these effects. Serotonin- or R(+)-8-OH-DPAT-induced increases in phagocytosis were blocked by the 5-HT(1A) receptor antagonist WAY100635 and the NF-kappaB inhibitor pyrrolidinedithiocarbamate. Moreover, mouse peritoneal macrophages expressed specific binding sites for [(3)H]8-OH-DPAT when cultivated in the presence of zymosan or latex beads. Immunohistochemistry confirmed the expression of the 5-HT(1A) receptor protein in the macrophages. 4 These results show that serotonin can upregulate the activity of peritoneal macrophages through 5-HT(1A) receptors.
Assuntos
Macrófagos Peritoneais/fisiologia , Fagocitose/fisiologia , Receptor 5-HT1A de Serotonina/biossíntese , Serotonina/fisiologia , 8-Hidroxi-2-(di-n-propilamino)tetralina/metabolismo , 8-Hidroxi-2-(di-n-propilamino)tetralina/farmacologia , Animais , Sítios de Ligação , Relação Dose-Resposta a Droga , Técnicas In Vitro , Látex , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Fagocitose/efeitos dos fármacos , Piperazinas/farmacologia , Piridinas/farmacologia , Serotonina/farmacologia , Agonistas do Receptor 5-HT1 de Serotonina , Antagonistas do Receptor 5-HT1 de Serotonina , Regulação para Cima , ZimosanRESUMO
Mice exposed to surgical stress induced by laparotomy and treated with chronic alprazolam (0.5-2 mg/kg) showed a dose-dependent reduction in stress-induced suppression of the natural killer (NK) cell activity. These immunoenhancing effects of alprazolam were more intense when it administered before the surgery was performed.
Assuntos
Alprazolam/farmacologia , Células Matadoras Naturais/efeitos dos fármacos , Estresse Fisiológico/imunologia , Animais , Formação de Anticorpos/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células Matadoras Naturais/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Estresse Fisiológico/tratamento farmacológico , Estresse Fisiológico/etiologia , Procedimentos Cirúrgicos Operatórios/efeitos adversosRESUMO
Mice exposed to a chronic auditory stressor and treated with nefazodone (10 mg/kg/day s.c.), showed a reduction in stress-induced suppression of thymus and spleen cellularity, and in peripheral T-Iymphocyte population. The in vitro blastogenic response of spleen lymphoid cells to mitogen concanavalin A, the in vitro and in vivo activity of phagocytosis, both measured using the zymosan and carbon clearance tests, respectively, were also assessed and nefazodone was found to partially reverse the inhibitory effect of stress on those parameters. Nefazodone did not significantly affect those parameters in unstressed mice. In conclusion, this report provides evidence on the immunoprotective effects of this novel antidepressant drug against the adverse effects of stress in mice.
Assuntos
Imunidade/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos , Triazóis/farmacologia , Animais , Antidepressivos/farmacologia , Concanavalina A/farmacologia , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Norepinefrina/metabolismo , Fagocitose/efeitos dos fármacos , Piperazinas , Serotonina/metabolismo , Antagonistas da Serotonina/farmacologia , Baço/patologia , Estresse Fisiológico/imunologia , Estresse Fisiológico/patologia , Linfócitos T/imunologia , Timo/patologiaRESUMO
Experiments were conducted to evaluate the effects of amphetamine (0. 4 mg/kg) on the development of autochthonous tumors induced by the Moloney sarcoma virus (MSV) in Balb/c female mice. Enhancement of MSV-induced tumor incidence and tumor growth was observed, together with a delay in the usual prompt regression of the tumors, when mice were daily injected with amphetamine for 3 days after MSV-inoculation. However, no effects of amphetamine on tumor development were observed when it was administered during the 3 days before tumor inoculation.
Assuntos
Adrenérgicos/farmacologia , Anfetamina/farmacologia , Vírus do Sarcoma Murino de Moloney , Infecções por Retroviridae/patologia , Sarcoma Experimental/patologia , Infecções Tumorais por Vírus/patologia , Animais , Feminino , Imunidade Celular/efeitos dos fármacos , Injeções Subcutâneas , Camundongos , Camundongos Endogâmicos BALB C , Pré-Medicação , Infecções por Retroviridae/tratamento farmacológico , Sarcoma Experimental/tratamento farmacológico , Infecções Tumorais por Vírus/tratamento farmacológicoRESUMO
Groups of 35-day-old male C57BL/6 mice were stressed 1 hour per day by immobilization for 1, 2, 3, 5, 8, 11 or 14 consecutive days. Control groups were left undisturbed. The animals were then killed and body weight and the weights of the thymus, spleen and axillary lymph nodes determined. Chronic immobilization stress caused involution of the thymus, spleen and lymph nodes to an extent depending on the number of days of stress. The thymus showed the fastest response: thymus weight was significantly lower in stressed animals than in controls by the third day of stress while significant effects on spleen and lymph node weight were not observed until day 5. Fast recovery of lymphoid organ weight was observed after the stress period. The thymus recovered most quickly: control values were re-attained approximately 8 days after cessation of stress, and indeed by day 20 thymus weight was about 12% higher than in normal animals. The spleen and lymph nodes recuperated weight more slowly, re-attaining control values after about 20 days.
Assuntos
Tecido Linfoide/patologia , Estresse Fisiológico/patologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Tamanho do Órgão , Fatores de TempoRESUMO
The effect of immobilization stress on precursor cell migration from bone marrow to the thymus was studied in C57BL/6 mice. The in vitro migration assays, using Nucleopore chambers, showed that precursor cell migration to thymus supernatants was strongly inhibited in stressed animals. This inhibition of migration seemed to be cell-associated what can explain the thymic involution observed in mice under stress conditions. The migration of precursor cells from bone marrow may be one of the mechanisms by which the thymus gland is involuted by stress.
Assuntos
Células da Medula Óssea , Imobilização , Timo/citologia , Animais , Animais Recém-Nascidos , Movimento Celular , Células Cultivadas , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Experiments were conducted to evaluate the effects of chronic buspirone (1 mg/kg/day) on the influenza A (PR-8/34) virus specific immune injury in CD-1 mice exposed to a chronic auditory stressor. Treatment with buspirone resulted in a decrease of the stress-induced increase of virus titers and pulmonary vascular permeability as well as in a reduction of the mortality of mice.
Assuntos
Buspirona/farmacologia , Vírus da Influenza A/crescimento & desenvolvimento , Infecções por Orthomyxoviridae/imunologia , Estresse Fisiológico/complicações , Animais , Permeabilidade Capilar , Imunidade Inata/efeitos dos fármacos , Pulmão/virologia , Masculino , Camundongos , Infecções por Orthomyxoviridae/complicações , Infecções por Orthomyxoviridae/virologia , Alvéolos Pulmonares/irrigação sanguínea , Distribuição AleatóriaRESUMO
Several experiments were conducted to evaluate the effects of chronic amphetamine on the influenza A (PR-8/34) virus specific immune injury in CD-1 mice. Treatment with amphetamine resulted in a significant increase of lung virus titers and pulmonary vascular permeability. Amphetamine also increased the lethality of infected mice.
Assuntos
Anfetamina/farmacologia , Infecções por Orthomyxoviridae/tratamento farmacológico , Orthomyxoviridae/efeitos dos fármacos , Animais , Pulmão/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos , Orthomyxoviridae/patogenicidade , Distribuição AleatóriaRESUMO
Mice exposed to a chronic auditory stressor and treated with fluoxetine (5 mg/kg) showed a reduction in stress-induced suppression of thymus and spleen cellularity, and in peripheral T lymphocyte population. The blastogenic response of spleen lymphoid cells and the delayed type hypersensitivity response (DTH) to sheep red blood cells (SRBC) were also assessed and fluoxetine was found to partially reverse the inhibitory effect of stress on both parameters.
Assuntos
Contagem de Células/efeitos dos fármacos , Fluoxetina/farmacologia , Terapia de Imunossupressão , Estresse Fisiológico/tratamento farmacológico , Linfócitos T/efeitos dos fármacos , Animais , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Baço/efeitos dos fármacos , Timo/efeitos dos fármacosRESUMO
Mice injected with amphetamine showed a dose-related suppression of the natural killer cell activity. The capacity of T-cells to generate cytotoxic T-lymphocytes (CTL) in mixed lymphocyte cultures and in vivo was also assayed and amphetamine was found to inhibit CTL responses.
Assuntos
Anfetamina/farmacologia , Imunidade Celular/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Teste de Cultura Mista de Linfócitos , Masculino , Camundongos , Camundongos Endogâmicos , Baço/citologia , Baço/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T Citotóxicos/efeitos dos fármacos , Linfócitos T Citotóxicos/imunologiaRESUMO
Experiments were performed in order to evaluate the effects of fluoxetine, a selective inhibitor of neural serotonin transporter antidepressant, on the development lung metastases in rats subjected to laparotomy and injected (i.v.) with 10(4) Walker 256 (W-256) carcinosarcoma cells. The number of metastatic nodules on the surface of the lungs, as well as the percentage-area of metastases in the frontal section through pulmonary hilus were increased in rats subjected to sham-surgery or laparotomy. Treatment with fluoxetine (5 mg/kg) partially reversed those adverse effects of surgery, but the difference was clearer when it was administered before surgery was performed. Survival periods were also assessed and fluoxetine was found to decrease the lethality of rats exposed to surgery.
Assuntos
Antidepressivos de Segunda Geração/farmacologia , Antineoplásicos/farmacologia , Carcinoma 256 de Walker/tratamento farmacológico , Carcinoma 256 de Walker/secundário , Fluoxetina/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/secundário , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Estresse Fisiológico/complicações , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Animais , Masculino , Transplante de Neoplasias , Ratos , Ratos Sprague-Dawley , Estresse Fisiológico/etiologiaRESUMO
Late-onset drinking is a common problem in elderly people related to stress induced by social isolation. Experiments were performed in order to evaluate the effects of alprazolam, a benzodiazepine agonist anxiolytic, on the free-choice ethanol consumption in aged rats subjected to isolation stress. The animals we offered a two-bottle choice consumption (one of 0.2% saccharin and the other with 10% ethanol/0.2% saccharin) and then exposed to 4 days of isolation stress on an irregular, unpredictable schedule. Stress resulted in significant increase in ethanol consumption. Treatment with alprazolam (1 mg/Kg) partially reversed this adverse effect of stress.
Assuntos
Envelhecimento , Consumo de Bebidas Alcoólicas/tratamento farmacológico , Alcoolismo/tratamento farmacológico , Alprazolam/farmacologia , Ansiolíticos/farmacologia , Isolamento Social , Estresse Psicológico/complicações , Consumo de Bebidas Alcoólicas/psicologia , Alcoolismo/etiologia , Alprazolam/uso terapêutico , Animais , Ansiolíticos/uso terapêutico , Modelos Animais de Doenças , Etanol/metabolismo , Feminino , Ratos , Ratos Sprague-DawleyRESUMO
Several experiments were conducted to evaluate the effects of buspirone, a selective 5-hydroxytryptamine-1A (5-HT1A) anxiolytic, on the immune system of mice exposed to a chronic auditory stressor. Daily injection with 0.5 and 1 mg/kg (intraperitoneally) of buspirone resulted in a dose-dependent reduction in the stress-induced suppression of the natural killer (NK) cell activity and the in vitro and in vivo activity of phagocytosis. Higher doses of buspirone (2.0 mg/kg) showed less robust immunoenhancing effects in stressed mice, and caused a significant suppression of these immune parameters in unstressed mice.
Assuntos
Buspirona/farmacologia , Imunidade/efeitos dos fármacos , Estresse Psicológico/imunologia , Animais , Relação Dose-Resposta a Droga , Técnicas In Vitro , Células Matadoras Naturais/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Ruído/efeitos adversos , Fagocitose/efeitos dos fármacos , Baço/citologia , Baço/efeitos dos fármacosRESUMO
Analysis of restriction fragment length polymorphism (RFLP) profiles of a 464 bp amplicon obtained from the mitochondrial cytochrome b gene was used to differentiate between several different fish species. The method was tested by a collaborative study in which 12 European laboratories participated to ascertain whether the method was reproducible. Each laboratory was required to identify 10 unknown samples by comparison with RFLP profiles from authentic species. From a total of 120 tests performed, unknown samples were correctly identified in 96% of cases. Further work attempting to use the method to analyze mixed and processed fish samples was also performed. In all cases the species contained within mixed samples were correctly identified, indicating the efficacy of the method for detecting fraudulent substitution of fish species in food products.
Assuntos
DNA/análise , Peixes/classificação , Carne/análise , Polimorfismo de Fragmento de Restrição , Animais , Impressões Digitais de DNA/métodos , Europa (Continente) , Peixes/genética , Manipulação de Alimentos , Reprodutibilidade dos TestesRESUMO
Identification of 10 salmon species using DNA-based methodology was investigated. Amplification of DNA was carried out using a primer set which amplified a region of the mitochondrial cytochrome b gene. Sequences of PCR-amplified DNA from the salmon species were used to select six restriction enzymes allowing species to be uniquely classified. RFLP patterns generated following analysis with each enzyme were resolved using polyacrylamide gel electrophoresis and visualized by silver staining. Results indicate that it is possible to differentiate between all 10 salmon species and that the technique could be easily adopted by the food industry for analysis of processed salmon products.
Assuntos
Reação em Cadeia da Polimerase/métodos , Polimorfismo de Fragmento de Restrição , Salmonidae/classificação , Animais , Sequência de Bases , Dados de Sequência Molecular , Oncorhynchus/classificação , Oncorhynchus/genética , Oncorhynchus keta/classificação , Oncorhynchus keta/genética , Oncorhynchus kisutch/classificação , Oncorhynchus kisutch/genética , Oncorhynchus mykiss/classificação , Oncorhynchus mykiss/genética , Mapeamento por Restrição , Salmão/classificação , Salmão/genética , Salmonidae/genética , Alinhamento de Sequência , Análise de Sequência de DNA/métodos , Homologia de Sequência do Ácido Nucleico , Truta/classificação , Truta/genéticaRESUMO
Identification of flatfish species using a DNA-based methodology was studied. The polymerase chain reaction was employed to obtain a 464 bp amplicon from mitochondrial cytochrome b gene. The sequences from this fragment belonging to 24 species were analyzed using a genetic distance method, and polymorphic sites were determined. The fragment was found to be highly polymorphic (231 sites), and this permitted the differentiation of most of the species. Phylogenetic tree construction was employed to allow the identification of flatfish species. As a result, each species was grouped in a well-differentiated clade, except for two pairs: Limanda ferruginea and L. limanda, and Solea impar and S. lascaris, which could not be differentiated. On the basis of the sequences obtained, restriction enzymes were selected to provide specific restriction profiles, which allow the differentiation of 21 species of flatfish in a faster and less expensive manner than sequencing. This polymerase chain reaction-restriction fragment length polymorphism methodology (PCR-RFLP) was tested using commercial samples.
Assuntos
Linguados/classificação , Linguados/genética , Animais , Grupo dos Citocromos b/genética , DNA Mitocondrial/análise , DNA Mitocondrial/química , Desoxirribonucleases de Sítio Específico do Tipo II , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNARESUMO
The use of DNA-based methodologies in identification of hake species belonging to the Merluccius genus was shown to be successful. A short fragment of the left hypervariable domain of the mitochondrial control region was amplified, sequenced, and digested from 11 hake species. The hake-specific PCR product, due to its limited size, was obtained in a variety of tissue samples with different levels of DNA concentration and degradation, including sterilized food products. On the basis of this phylogenetically informative 156-bp sequence were selected four restriction enzymes (ApoI, DdeI, DraIII, and MboII) that allow the hake species discrimination. Species identification by phylogenetic analysis of sequences or by PCR-RFLP methodologies is useful in a variety of scenarios including authentication of thermally processed food, detection of food components, and species determination of individuals whose morphological characters are removed.
Assuntos
DNA Mitocondrial/genética , Peixes/genética , Animais , Sequência de Bases , Peixes/classificação , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Homologia de Sequência do Ácido Nucleico , Especificidade da EspécieRESUMO
A rapid and precise method for identifying European hake (Merluccius merluccius) based on TaqMan technology is presented. The method can be applied to fresh, frozen, and processed fish products to detect the fraudulent or unintentional mislabeling of this species. Specific primers and a minor groove binding (MGB) TaqMan probe were designed for this purpose based on partial sequences of the mitochondrial DNA control region. Combinations of primers and probe concentrations that gave the lowest Ct value and the highest final fluorescence value were selected to carry out efficiency, specificity, and cross-reactivity assays. The method was successfully tested on 31 commercial hake samples. A Ct value of about 16 was obtained when Merluccius merluccius was present; however, the fluorescence signal was not detected most of the time (Ct value 40) or presented significantly higher Ct values (38.2 +/- 0.96) for the nonhake species.