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2.
Euro Surveill ; 19(50): 20991, 2014 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-25597540

RESUMO

An outbreak of Legionnaires' disease with 334 confirmed cases was identified on 7 November 2014 in Vila Franca de Xira, Portugal and declared controlled by 21 November. Epidemiological, environmental and microbiological analysis identified industrial wet cooling systems to be the probable source of infection. Preliminary results from sequence-based typing of clinical specimens and environmental isolates confirmed this link. A series of meteorological phenomena are likely to have contributed to the scale of this outbreak.


Assuntos
Ar Condicionado , Surtos de Doenças , Legionella pneumophila/isolamento & purificação , Doença dos Legionários/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/prevenção & controle , Feminino , Humanos , Doença dos Legionários/diagnóstico , Doença dos Legionários/microbiologia , Masculino , Pessoa de Meia-Idade , Portugal/epidemiologia , Fatores de Risco , Sorotipagem , Microbiologia da Água , Adulto Jovem
3.
Euro Surveill ; 15(13)2010 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-20394709

RESUMO

The experience reported in an earlier Eurosurveillance issue on a fast method to evaluate the impact of the 2003 heatwave on mortality in Portugal, generated a daily mortality surveillance system (VDM) that has been operating ever since jointly with the Portuguese Heat Health Watch Warning System. This work describes the VDM system and how it evolved to become an automated system operating year-round, and shows briefly its potential using mortality data from January 2006 to June 2009 collected by the system itself. The new system has important advantages such as: rapid information acquisition, completeness (the entire population is included), lightness (very little information is exchanged, date of death, age, sex, place of death registration). It allows rapid detection of impacts (within five days) and allows a quick preliminary quantification of impacts that usually took several years to be done. These characteristics make this system a powerful tool for public health action. The VDM system also represents an example of inter-institutional cooperation, bringing together organisations from two different ministries, Health and Justice, aiming at improving knowledge about the mortality in the population.


Assuntos
Mortalidade/tendências , Vigilância da População/métodos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Temperatura Alta/efeitos adversos , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Portugal/epidemiologia , Fatores de Tempo , Adulto Jovem
4.
Euro Surveill ; 14(18)2009 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-19422778

RESUMO

The aim of this study was to estimate the excess mortality associated with the influenza activity registered in Portugal between week 49 of 2008 and week 5 of 2009. For this purpose available mortality data from the Portuguese Daily Mortality Monitoring (VDM) System was used. Several estimates of excess deaths associated with the recent recorded influenza activity were determined through statistical modelling (cyclic regression) for the total population and disaggregated by gender and age group. The results show that the impact of the 2008-9 influenza season was 1,961 excess deaths, with approximately 82% of these occurring in the age group of 75 years and older.


Assuntos
Surtos de Doenças/estatística & dados numéricos , Influenza Humana/mortalidade , Estações do Ano , Humanos , Incidência , Vigilância da População , Portugal/epidemiologia , Medição de Risco/métodos , Fatores de Risco , Análise de Sobrevida , Taxa de Sobrevida
5.
Euro Surveill ; 10(7): 150-3, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16088048

RESUMO

During the first two weeks of August 2003, Portugal was affected by a severe heat wave. Following the identification in Portugal of the influence of heat waves on mortality in 1981 and 1991 (estimated excess of about 1900 and 1000 deaths respectively), the Observatorio Nacional de Saude (ONSA) - Instituto Nacional de Saude Dr. Ricardo Jorge, together with the Vigilancia Previsao e Informacao - Instituto de Meteorologia, created a surveillance system called iCARO, which has been in operation since 1999. iCARO identifies heat waves with potential influence on mortality [1]. Before the end of the 2003 heat wave, ONSA had produced a preliminary estimate of its effect on mortality. The results based on daily number of deaths from 1 June to 12 August 2003 were presented within 4 working days. Data was gathered from 31 National Civil registrars, covering the district capitals of all 18 districts of mainland Portugal, and representing approximately 40% of the mainland's mortality. The number of deaths registered in the period 30 July to 12 August was compared with the ones registered during 3 comparison periods: (in July): 1-14 July, 1-28 July, and 15-28 July). 15-28 July, the period best resembling the heat wave in time and characteristics, produced an estimation of 37.7% higher mortality rate then the value expected under normal temperature conditions. From this value, an estimate of 1316 death excess was obtained for mainland Portugal. The main purpose of this article is to present the method used to identify and assess the occurrence of an effect (excess mortality) during the heat wave of summer 2003.


Assuntos
Transtornos de Estresse por Calor/mortalidade , Temperatura Alta/efeitos adversos , Tempo (Meteorologia) , Métodos Epidemiológicos , Humanos , Portugal/epidemiologia , Estações do Ano
6.
Euro Surveill ; 10(7): 5-6, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29208091

RESUMO

During the first two weeks of August 2003, Portugal was affected by a severe heat wave. Following the identification in Portugal of the influence of heat waves on mortality in 1981 and 1991 (estimated excess of about 1900 and 1000 deaths respectively), the Observatório Nacional de Saúde (ONSA) - Instituto Nacional de Saúde Dr. Ricardo Jorge, together with the Vigilância Previsão e Informação - Instituto de Meteorologia, created a surveillance system called ÍCARO, which has been in operation since 1999. ÍCARO identifies heat waves with potential influence on mortality [1]. Before the end of the 2003 heat wave, ONSA had produced a preliminary estimate of its effect on mortality. The results based on daily number of deaths from 1 June to 12 August 2003 were presented within 4 working days. Data was gathered from 31 National Civil registrars, covering the district capitals of all 18 districts of mainland Portugal, and representing approximately 40% of the mainland's mortality. The number of deaths registered in the period 30 July to 12 August was compared with the ones registered during 3 comparison periods: (in July): 1-14 July, 1-28 July, and 15-28 July). 15-28 July, the period best resembling the heat wave in time and characteristics, produced an estimation of 37.7% higher mortality rate then the value expected under normal temperature conditions. From this value, an estimate of 1316 death excess was obtained for mainland Portugal. The main purpose of this article is to present the method used to identify and assess the occurrence of an effect (excess mortality) during the heat wave of summer 2003.

7.
Teratog Carcinog Mutagen ; 22(3): 195-203, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11948630

RESUMO

Chronic exposure to low frequency (LF) noise and whole-body vibration (WBV) induces both physiological and psychological alterations in man. Recently, we have shown that long-term occupational exposure to LF noise and WBV produces genotoxic effects in man expressed as an increase in sister chromatid exchange (SCE) levels in lymphocytes. The objectives of the present study were to investigate whether the observed effect could be reproduced in a murine model and, if so, which of the agents, LF noise alone or in combination with WBV, would be instrumental in the SCE induction. SCEs were analyzed in spleen lymphocytes of mice exposed to LF noise alone and in combination with WBV for 300 and 600 hr. An effect at the cell cycle kinetics level was also investigated. The results revealed significant increases in the mean SCE number per cell and in the proportion of cells with high frequency of SCEs (HFCs) in lymphocytes of mice submitted to combined noise and WBV over controls. No significant differences were found between single noise-exposed and control mice. A cell cycle delay was observed exclusively in the noise and WBV exposure groups. In conclusion, we demonstrated that, as in exposed workers, prolonged exposure to the combination of LF noise and WBV determines an increase in SCE level in mice while LF noise alone is not effective in SCE induction.


Assuntos
Ruído/efeitos adversos , Troca de Cromátide Irmã , Baço/citologia , Vibração , Animais , Ciclo Celular , Células Cultivadas , Cinética , Linfócitos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Baço/efeitos dos fármacos , Fatores de Tempo
8.
Acta Med Port ; 15(6): 423-7, 2002.
Artigo em Português | MEDLINE | ID: mdl-12680288

RESUMO

INTRODUCTION: In recent years, there have been many reports about a possible association between Stressful Life Events (SLE) and the onset of Graves' Disease (GD). Nevertheless, most papers have been criticised and no such association has yet been proven. AIM OF THE STUDY: To assess the possible associations between SLE and the onset of GD. METHODS: Retrospective study of 62 subjects, divided into 2 groups of 31 each, GD (Gp1) and controls (Gp2). The patients in Gp1 had thyroid disease diagnosed within the last 12 months, with clinical and biochemical confirmation. In Gp2, psychopathological and endocrine disturbances had been ruled out. Each 2 group consisted of 9 males (29%) and 22 females (71%). The mean age was 38.48 + 10.9 in Gp1 and 41.1 + 11.8 in Gp2. SLE evaluation (number and impact) was reported for the 12 months preceding the onset of symptoms of thyroid disease. To assess SLE, we used the Life Experiences Survey-LES from Saranson, Johnson and Siegel (1978; 1985). Statistical analysis was done using Mann-Whitney and Kruskal-Wallis tests. RESULTS: Patients with GD had a significantly greater number of SLEs compared to Controls (p < .001). The number and impact of negative SLEs was significantly higher in Gp1 compared to Gp2 (p < .001). There were no significant differences between the groups in terms of the number and impact of both positive and neutral SLEs. DISCUSSION: The findings of this study support that SLEs may contribute to the precipitation of GD. We observed that patients with GD had significantly more negative events and experienced a greater negative impact from them prior to the onset of GD. The association of SLEs with GD is probably related to the association of stress with changes in the immune system, which can play an important role in the aetiology of thyrotoxicosis.


Assuntos
Doença de Graves/etiologia , Estresse Psicológico/complicações , Adulto , Idoso , Coleta de Dados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Doenças da Glândula Tireoide/etiologia , Tireotoxicose/etiologia
9.
Clin Endocrinol (Oxf) ; 55(1): 15-9, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11453947

RESUMO

BACKGROUND: In the last few decades, several studies have suggested a possible association between Stressful Life Events (SLEs) and the onset of Graves' Disease (GD). However, others have criticised this association and it has not yet been possible to prove it unequivocally. At present, we are not aware of studies correlating SLE and non autoimmune thyrotoxicosis. OBJECTIVE: To assess possible associations between SLEs, the onset of GD and the onset of non autoimmune thyrotoxicosis (toxic nodular goitre, TNG). DESIGN: A case-control retrospective study. PATIENTS: This study included 93 subjects, divided into three groups of 31 each: GD, TNG and control (CG). The GD and TNG patients had thyroid disease diagnosed within the last 12 months, with clinical and biochemical confirmation. In the CG, psychopathological and endocrine disturbances had been ruled out. All three groups consisted of nine males (29%) and 22 females (71%). The mean age was 38.4 +/- 10.9 years in the GD group, 48.3 +/- 11.1 years in the TNG group and 41.1 +/- 11.8 years in the CG group. SLEs were evaluated (number and impact) for the 12 months preceding the onset of symptoms of thyroid disease. MEASUREMENTS: SLE occurrences and their impact on each group of cases were measured. To assess SLEs, we used the Life Experiences Survey (LES). Our statistical analysis included descriptive techniques and parametric and/or nonparametric comparative tests. P < 0.01 was considered statistically significant. Odds ratios were also calculated. RESULTS: Patients with GD had a significantly greater number of SLEs compared to the TNG group and the CG (P < 0.001). The number and impact of negative SLEs were significantly higher in GD compared to TNG and CG (P < 0.001). The difference between TNG and CG was not significant (P > 0.01). GD had a higher impact of positive SLEs than TNG (P = 0.004), and no significant differences were found between the GD group and CG. Neutral SLEs were similar in the three groups. CONCLUSIONS: These results suggest that SLEs are a precipitating factor of the onset of GD. We also demonstrated that SLEs do not seem to have any conclusive relationship with the onset of TNG.


Assuntos
Doenças Autoimunes/psicologia , Doença de Graves/psicologia , Acontecimentos que Mudam a Vida , Adulto , Estudos de Casos e Controles , Feminino , Bócio Nodular/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Psicometria , Estudos Retrospectivos , Fatores de Risco , Estresse Psicológico/complicações , Fatores de Tempo
10.
Euro Surveill ; 4(4): 44-47, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12631907

RESUMO

The term leptospirosis describes a group of diseases caused by members of the order Spirochaetales, mainly the species Leptospira interrogans. Infection can be asymptomatic but disease of differing severity and clinical features (often suggestive of menin

11.
Mediators Inflamm ; 8(2): 119-22, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10704150

RESUMO

The effects of chronic mild prenatal stress on leukocyte infiltration into the airways was investigated in rat offspring. The chronic prenatal stress consisted of transitory and variable changes in the rat's living conditions. Offspring at adult age were actively sensitized (day 0) and intratracheally challenged (day 14) with ovalbumin. Bronchoalveolar lavage was performed in the offspring at 48 h after intratracheal challenge with ovalbumin. A significant increase in total leukocyte infiltration was observed in the non-stressed offspring group and this was associated with a marked recruitment of eosinophils without a significant effect on the influx of neutrophils and mononuclear cells. In the prenatal stressed offspring, the counts of both total leukocyte and eosinophils, as well as mononuclear cells, was increased by 50% compared to the non-stressed offspring. We provide here the first experimental evidence that chronic mild unpredictable prenatal stress produces a marked increase in the allergen-induced airway inflammation in the rat offspring.


Assuntos
Alérgenos , Hiper-Reatividade Brônquica/fisiopatologia , Inflamação/fisiopatologia , Complicações na Gravidez/psicologia , Efeitos Tardios da Exposição Pré-Natal , Estresse Psicológico , Animais , Hiper-Reatividade Brônquica/etiologia , Eosinófilos/fisiologia , Feminino , Privação de Alimentos , Abrigo para Animais , Contagem de Leucócitos , Ovalbumina , Gravidez , Ratos , Ratos Wistar , Privação de Água
13.
Am J Hematol ; 57(4): 269-76, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9544969

RESUMO

Beta thalassemia and Hb Lepore heterozygotes included in this study exhibit fetal hemoglobin levels varying from trace quantities to 14% (1.74 g/dl) of total hemoglobin in the adult. In this work, we have examined the correlation of DNA sequence polymorphisms with the observed HbF level. The analysis of polymorphic markers within the beta globin cluster in 39 individuals heterozygous for beta thalassemia or Hb Lepore confirms the previous findings for homozygous beta thalassemia: the presence of both an (AT)9 T5 sequence configuration at position -540 of the beta globin gene and a (C --> T) variation at -158 of the Ggamma globin gene is associated with elevated expression of HbF. However, at least one defective beta globin gene is required to reveal this association. The best evidence is from the study of individuals heterozygous for Hb Lepore with various levels of HbF. In these individuals it was possible to explore the effect of a single (AT)x Ty motif (the other being absent from the rearranged Lepore chromosome) on HbF expression. The presence of the (AT)9 T5 configuration increases HbF level from a median of 0.515 g/dl observed in (AT)7 T7 subjects, to 1.39 g/dl. We confirm the existence of linkage disequilibrium between the (C --> T) variation at -158 of Ggamma gene and the (TG)13 configuration at the second intervening sequence (IVS-2) of Agamma gene and identify two new polymorphisms in this region: (TG)7 (CG)5 (TG)8 linked to haplotype V and (TG)8 (CG)5 (TG)10 linked to haplotype II. This study suggests that two distinct regions of the beta cluster, whether in cis or in trans to each other, can interact to enhance HbF expression when a beta thalassemic determinant is present in heterozigosity.


Assuntos
Hemoglobina Fetal/genética , Globinas/genética , Hemoglobinopatias/genética , Adolescente , Adulto , Idoso , Alelos , Pré-Escolar , Feminino , Regulação da Expressão Gênica , Haplótipos , Hemoglobinas Anormais/genética , Humanos , Masculino , Linhagem , Polimorfismo de Fragmento de Restrição , Talassemia beta/genética
14.
Braz J Med Biol Res ; 30(2): 231-3, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9239309

RESUMO

We investigated the long-lasting effect of peripheral injection of the neuropeptide substance P (SP) and of some N- or C-terminal SP fragments (SPN and SPC, respectively) on retention test performance of avoidance learning. Male Wistar rats (220 to 280 g) were trained in an inhibitory step-down avoidance task and tested 24 h or 21 days later. Immediately after the training trial rats received an intraperitoneal injection of SP (50 micrograms/kg), SPN 1-7 (167 micrograms/kg) or SPC 7-11 (134 micrograms/kg). Control groups were injected with vehicle or SP 5 h after the training trial. The immediate post-training administration of SP and SPN, but not SPC, facilitated avoidance behavior in rats tested 24 h or 21 days later, i.e., the retention test latencies of the SP and SPN groups were significantly longer (P < 0.05, Mann-Whitney U-test) during both training-test intervals. These observations suggest that the memory-enhancing effect of SP is long-lasting and that the amino acid sequence responsible for this effect is encoded by its N-terminal part.


Assuntos
Aprendizagem da Esquiva/efeitos dos fármacos , Memória/efeitos dos fármacos , Substância P/farmacologia , Animais , Masculino , Memória/fisiologia , Ratos , Ratos Wistar
15.
Behav Brain Res ; 83(1-2): 143-5, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9062673

RESUMO

This report summarizes a recent series of experiments dealing with the effect of peripheral (i.p.) administration of SP on the learning of avoidance and habituation tasks. In summary, the results from these studies show that peripheral post-training SP administration in rats enhances memory in a dose- and time-dependent way. The effect of substance P on retention was observed across tasks with different response requirements and in the absence of explicit punishment. The memory-enhancing effects are long-lasting, until 21 days post-training, and are mediated, at least in part, via interactions with the endogenous opioid system. The mnemotropic effects of peripherally administered SP are sensitive to the functional integrity of the vagus, suggesting that the vagus nerve may be one pathway by which systemic SP influences memory storage processes in the brain. Furthermore, the data indicated that these effects seemed to be encoded by different SP sequences, the N-terminal SP1-7, but not the C-terminal hepta- and hexapeptide sequences being responsible for the memory-promoting effects. Taken together, these studies strongly suggest that SP may be considered to have memory-promoting effects.


Assuntos
Memória/efeitos dos fármacos , Substância P/farmacologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Relação Dose-Resposta a Droga , Eletrochoque , Generalização da Resposta/efeitos dos fármacos , Injeções Intraperitoneais , Ratos , Estimulação Química , Substância P/administração & dosagem , Fatores de Tempo , Vagotomia
16.
Braz. j. med. biol. res ; 30(2): 231-3, Feb. 1997. graf
Artigo em Inglês | LILACS | ID: lil-188431

RESUMO

We investigated the long-lasting effect of peripheral injection of the neuropeptide substance P (SP) and of some N- or C-terminal SP fragments (SPN and SPC, respectively) on retention test performance of avoidance learning. Male Wistar rats (220 to 280 g) were trained in an inhibitory step-down avoidance task and tested 24 h or 21 days later. Immediately after the training trial rats received an intraperitoneal injection of SP (50 mug/kg), SPN 1-7 (l67 mug/kg) or SPC 7-11 (l34 mug/kg). Control groups were injected with vehicle or SP 5 h after the training trial. The immediate post-training administration of SP and SPN, but not SPC, facilitated avoidance behavior in rats tested 24 h or 21 days later, i.e., the retention test latencies of the SP and SPN groups were significantly longer (P<0.05, Mann-Whitney U-test) during both training-test intervals. These observations suggest that the memory-enhancing effect of SP is long-lasting and that the amino acid sequence responsible for this effect is encoded by its N-terminal part.


Assuntos
Ratos , Animais , Masculino , Aprendizagem da Esquiva/efeitos dos fármacos , Memória/efeitos dos fármacos , Substância P/farmacologia , Memória/fisiologia , Ratos Wistar
17.
J Neurochem ; 68(1): 233-9, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8978730

RESUMO

The effectiveness of intranasal drug administration to stimulate central neuronal systems is well known from drug addiction and has also been considered as an alternative pharmacokinetic approach to treat brain disorders such as Parkinson's disease. In the present study, the possible neurochemical effects of intranasal administration of the psychostimulants cocaine and amphetamine and of the antiparkinsonian drug L-DOPA were analyzed. By using in vivo microdialysis in the urethane-anesthetized rat, it was found that unilateral intranasal administration of either of the psychostimulants led to huge and rapid increases of extracellular dopamine levels in the neostriatum followed by decreases of its metabolites dihydroxyphenylacetic acid and homovanillic acid. Furthermore, intranasal administration of L-DOPA, but not of the saline vehicle, also led to increased extracellular levels of neostriatal dopamine and to increases of its metabolites. Because the effect of intranasal L-DOPA on neostriatal dopamine was observed only ipsilaterally but not contralaterally to the side of intranasal drug administration, it can be hypothesized that L-DOPA was not effective via passage through the circulation but may have acted through a neuronal or an extraneuronal route. These data provide neurochemical evidence that the intranasal route may not only be efficient in drug abuse, but may also be useful to target the brain therapeutically, as in the case of neurodegenerative brain disorders.


Assuntos
Anfetamina/farmacologia , Cocaína/farmacologia , Corpo Estriado/metabolismo , Agonistas de Dopamina/farmacologia , Dopamina/metabolismo , Levodopa/farmacologia , Administração Intranasal , Animais , Levodopa/análogos & derivados , Masculino , Microdiálise , Ratos , Ratos Wistar , Cloreto de Sódio/farmacologia
18.
Neuroscience ; 64(4): 1045-55, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7538637

RESUMO

The activity of the neurotransmitter dopamine in the nucleus accumbens is considered to be an important element in the central processing of reinforcement. Unilateral administration of the neurokinin substance P into the area of the nucleus basalis magnocellularis of rats was found to be reinforcing, as assessed by the conditioned place preference paradigm. Simultaneous in vivo microdialysis showed that administration of substance P into the area of the nucleus basalis magnocellularis could increase extracellular concentrations of dopamine in the contralateral nucleus accumbens. Only those animals in which the administration of substance P induced this increase in dopamine levels acquired place preference. Furthermore, the changes in extracellular dopamine levels after substance P administration had a bimodal time course with an acute increase (to about 160% of baseline) during the first hour after injection, with a low (to 120-130%) and enduring increase occurring thereafter. Interestingly, during this second increase there were indications for positive correlations with the degree of place preference induced by substance P. Further positive correlations with place preference were found in the levels of the serotonergic metabolite 5-hydroxyindoleacetic acid. In contrast to dopamine, these were observed ipsi- and contralateral to the side of substance P administration. By combining the methods of in vivo microdialysis and conditioned place preference it was shown that the reinforcing effect induced by unilateral substance P injection in the nucleus basalis magnocellularis is related to dopaminergic (and possibly serotonergic) mechanisms in the nucleus accumbens.


Assuntos
Dopamina/metabolismo , Núcleo Accumbens/fisiologia , Substância P/farmacologia , Ácido 3,4-Di-Hidroxifenilacético/metabolismo , Animais , Comportamento Animal , Ácido Hidroxi-Indolacético/metabolismo , Masculino , Microdiálise , Ratos , Fatores de Tempo
19.
Behav Brain Res ; 62(2): 165-9, 1994 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-7524532

RESUMO

The present study determined whether the effects of peripherally administered substance P on memory are mediated via activation of the vagus nerve. Rats were submitted to subdiaphragmatic vagotomy, sham vagotomy or non-operated, and trained in a step-down inhibitory avoidance task and tested 24 h later. Posttraining administration of 50 micrograms/kg of SP facilitated retention performance in non-operated and sham-operated groups. The facilitating effects of 50 micrograms/kg of SP was blocked by vagotomy, although vagotomy did not attenuate the memory-enhancing effects of larger doses (250 and 500 micrograms/kg). These results suggest that the mnemotropic effects of peripherally administered SP are sensitive to the functional integrity of the vagus nerve. Alternatively, the vagus nerve may be one pathway but not the only pathway by which systemic SP influences the memory storage processes in the brain.


Assuntos
Aprendizagem da Esquiva/fisiologia , Rememoração Mental/fisiologia , Inibição Neural/fisiologia , Substância P/fisiologia , Nervo Vago/fisiologia , Animais , Encéfalo/fisiologia , Eletrochoque , Medo/fisiologia , Feminino , Masculino , Ratos , Ratos Wistar , Tempo de Reação/fisiologia , Retenção Psicológica/fisiologia
20.
Behav Brain Res ; 56(1): 101-6, 1993 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-7691075

RESUMO

The present study investigated the effects of post-trial systemic injections of the neurokinin substance P (SP) on inhibitory avoidance learning in rats treated with naloxone before conditioning and/or test trials. Rats were trained in a step-down or uphill inhibitory avoidance task and tested 24 h later. The animals received, 30 min before training and/or testing an i.p. injection of saline or naloxone (Nx) at doses of 0.5; 1.0; 5.0 or 50 mg/kg. Immediately after training they were administered SP 50 micrograms/kg or vehicle. Animals that received Nx both before conditioning and test trials (5.0 and 50 mg/kg), in combination with SP, showed better test performance for the uphill and step-down avoidance then those treated only with SP. Nx administered only before training (5.0 and 50 mg/kg) or before test (0.5 to 50 mg/kg) reduced the effects of SP. These data are discussed in terms of the possibility that Nx produces a state-dependent learning when combined with SP.


Assuntos
Memória/efeitos dos fármacos , Naloxona/farmacologia , Substância P/farmacologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Vasodilatação/efeitos dos fármacos
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