Hombres con diabetes mellitus tipo 2: autoeficacia y factores psicológicos que influyen en el autocuidado / Type 2 diabetes mellitus among men: psychological factors influencing self-care efficacy / Homens com diabetes mellitus tipo 2: autoeficácia e fatores psicológicos que influem no autocuidado

Resumen Introducción: La prevalencia global de diabetes mellitus tipo 2 (DMT2) en los hombres es alta. Para el tratamiento de la enfermedad el hombre debe realizar acciones de autocuidado, por lo que es importante conocer factores relacionados con su cumplimiento. Objetivo: Identificar la relación entre variables demográficas, clínicas, la angustia, la depresión, la autoeficacia y su influencia sobre el autocuidado en hombres con DMT2. Métodos: Estudio transversal y correlacional, en una muestra de 96 hombres con DMT2, usuarios de 13 centros de salud. Los instrumentos utilizados fueron el cuestionario de acciones de cuidado en diabetes, la escala Self-Efficacy for Diabetes, la escala depresión (CES-D) y la escala angustia por diabetes (DDS). Resultados: El autocuidado se correlacionó de manera positiva con la autoeficacia y negativamente con la angustia por diabetes. Las variables que explicaron el autocuidado con el 47.7% de varianza fueron: la autoeficacia (β = .39), el consumo de alcohol (β = -.29), las horas sentado/parado (β= -.27), el tiempo de diagnóstico (β= -.22) y la edad (β =.18). Discusión: Los hombres tuvieron un bajo autocuidado y mantienen conductas de riesgo, lo cual puede atribuirse a sus creencias, estilo de vida o al tipo de trabajo que desempeñan. Conclusiones: Los resultados ofrecen evidencia sobre factores que influyen en el autocuidado de hombres con DMT2, que pueden orientar a los profesionales de enfermería en la atención del paciente. Se sugiere realizar investigaciones de enfermería en hombres, que contribuyan a mejorar la autoeficacia y el autocuidado.

Abstract Introduction: The global prevalence of type 2 diabetes mellitus among men is high; and these patients need to follow self-care routines. Therefore, knowing the factors which can affect their level of compliance is an important issue for nursing. Objective: To identify the relationship between demographic and clinical variables such as anguish and depression, and self-care efficacy in men suffering from type 2 diabetes mellitus. Methods: This a transversal and correlational study on a sample of 96 men with type 2 diabetes mellitus who were registered in 13 health centers. The instruments used were the Questionnaire of Actions of Care in Diabetes, the Self-Efficacy for Diabetes Scale (SED), the Mexico Center of Epidemiological Studies of Depression Scale (CES-D), and the Diabetes Distress Scale (DDS). Results: Self-care was positively correlated to self-efficacy, and negatively correlated to diabetes-related anguish and depression. Variables which accounted for 47.7% of the self-care variance were: self-efficacy (β = .39), alcohol consumption (β = -.29), number of hours sitting or standing (β= -.27), years of being diagnosed (β= -.22), and age (β =.18). Discussion: The sample demonstrated a low level of diabetes self-care which included risky behaviors. This attitude could be a result of the patients' beliefs, lifestyles, and/or type of job. Conclusions: The findings provide evidence on the factors which can influence self-care among men with type 2 diabetes. These results can orient nursing professionals while providing patient attention. Further related studies are suggested in order to help improve efficacy in type 2 diabetes self-care.

Resumo Introdução: A prevalência global de diabetes mellitus tipo 2 (DMT2) nos homens é alta. Para o tratamento da doença o homem deve realizar ações de autocuidado, pelo que é importante conhecer fatores relacionados com sua conformidade. Objetivo: Identificar a relação entre variáveis demográficas, clínicas, a angustia, a depressão, a autoeficácia e sua influência sobre o autocuidado em homens com DMT2. Métodos: Estudo transversal e correlacional, em uma amostra de 96 homens com DMT2, usuários de 13 centros de saúde. Os instrumentos utilizados foram o questionário de ações de cuidado em diabetes, a escala Self-Efficacy for Diabetes, a escala depressão (CES-D) e a escala angustia por diabetes (DDS). Resultados: O autocuidado correlacionou-se de maneira positiva com a autoeficácia e negativamente com a angustia por diabetes. As variáveis que explicaram o autocuidado com o 47.7% de variância foram: a autoeficácia (β = .39), o consumo de álcool (β = -.29), as horas sentado/parado (β= -.27), o tempo de diagnóstico (β= -.22) e a idade (β =.18). Discussão: Os homens tiveram um baixo autocuidado e mantém condutas de risco, o qual pode atribuir-se a suas crenças, estilo de vida ou ao tipo de trabalho que desempenham. Conclusões: Os resultados oferecem evidência sobre fatores que influem no autocuidado de homens com DMT2, que podem orientar aos profissionais de enfermagem na atenção do paciente. Sugere-se realizar pesquisas de enfermagem em homens, que contribuam a melhorar a autoeficácia e o autocuidado.

Effect of Cytomegalovirus Infection on Survival of Older Kidney Transplant Patients (D+/R+): Impact of Valganciclovir Prophylaxis Versus Preemptive Therapy.

BACKGROUND: Kidney transplant patients with D+/R+ serology can be treated with either prophylaxis or preemptive valganciclovir. The older transplant population suffers severe immunosenescence, especially patients with latent cytomegalovirus (CMV) infection (R+). They are more likely to develop indirect CMV effects. Likewise, many patients have significant cardiovascular comorbidity, which makes them more sensitive to these indirect effects. The aim of this study was to evaluate the incidence of CMV viremia and indirect effects on survival, comparing prophylaxis (V) against preemptive (P) valganciclovir in an older kidney transplant population. METHODS: We analyzed the data of 233 recipients from 2002 (age, >55 years; D+/R+) with ≥6 months of follow-up. The patients were divided into 2 groups: 167 (71.7%) in the V group and 66 (28.3%) in the P group. RESULTS: The incidence of CMV infection in the P group was 32% versus 6% in V group. Patients with CMV viremia showed worse survival values than patients without viremia (log rank P = .031). Five-year survivals were 74% vs 88%, respectively. Cox regression showed that the adjusted effect of CMV infection on overall survival was a significant risk (hazard ratio [HR], 2.07; 95% CI, 1.003-4.29). Patients with CMV viremia showed worse cardiovascular survival than patients without viremia, with 5-year survivals of 79% vs 94%. Cox regression showed that the adjusted effect of CMV infection was a significant risk (HR, 2.62). CONCLUSIONS: CMV infection has a detrimental effect on the survival of older patients. Valganciclovir prophylaxis induces a protective effect against CMV infection and could improve survival of older patients with cardiovascular comorbidities.

Evaluation of the supplementation of a feed additive as a potential protector against the adverse effects of 2. 5 ppm T-2 toxin on growing broiler chickens / Avaliação da suplementação de um aditivo alimentar como um protetor potencial contra os efeitos adversos de 2, 5ppm de toxina T-2 em frangos em crescimento

A trial was conducted to evaluate a feed additive containing epoxidase activity from a bacterium (Mycofix-S) as a potential protection against the adverse effects of 2.5 ppm dietary T-2 toxin in male growing broiler chickens. A total of 144 one-day-old Ross 308 male chicks were individually wing-banded and allotted into each of the four experimental groups. Group 1: negative control, no T-2 toxin or additive; group 2: Mycofix-S, 2.5 g/kg; group 3: positive control, 2.5 ppm T-2 toxin; group 4: 2.5 ppm T-2 toxin + 2.5 g/kg Mycofix-S. Feed and water were provided ad libitum for 28 days (days 1 to 28 of age). Each experimental treatment was replicated 6 times, with 6 birds per replicate pen. Response variables included performance parameters, serum activity of alkaline phosphatase (ALP) and amylase, relative weight of selected organs and histology of the upper digestive system. T-2 toxin at 2.5 ppm significantly (P = 0.016) decreased the 28-day body weight gain and cumulative feed intake without affecting feed conversion. The feed additive counteracted these adverse effects. Serum enzyme activities were not significantly (P>0.05) affected for the four experimental groups but when data from the groups receiving T-2 toxin was pooled and compared against the pooled data from groups without the toxin a significant decrease in amylase activity was observed in chickens receiving T-2 toxin. The histological examination of the upper digestive system revealed lesions in mouth, esophagus, proventriculus, gizzard and duodenum in the chickens fed T-2 toxin without the additive. Chickens fed T-2 toxin plus the additive showed lesions in the same tissues except in the duodenum. The results of the present study show that the addition of 2.5 g/kg of the feed additive tested protects against adverse effects on performance and also the integrity of the duodenal mucosa.(AU)

Foi realizado um experimento com o objetivo de avaliar um aditivo alimentar contendo atividade de epoxidase de uma bactéria (Mycofix-S) como proteção potencial contra os efeitos adversos de uma dieta com 2,5ppm de toxina T-2 em frangos de corte machos. Um total de 144 pintos machos Ross 308 de um dia de idade foram marcados na asa individualmente e alocados em um de quatro grupos experimentais: grupo 1: controle negativo, sem toxina T-2 ou aditivo; grupo 2: 2,5g/kg de Mycofix-S; grupo 3: controle positivo, 2,5ppm de toxina T-2; grupo 4: 2,5ppm de toxina T-2 + 2,5g/kg de Mycofix-S. Alimento e água foram fornecidos ad libitum por 28 dias (dias um a 28 de idade). Cada tratamento experimental foi replicado seis vezes, com seis pintos por gaiola de replicação. As variáveis de resposta incluíram parâmetros de desempenho, atividade sérica de fosfatase alcalina (ALP) e amilase, peso relativo de órgãos selecionados e histologia do sistema digestivo superior. A toxina T-2 a 2,5ppm diminuiu significativamente (P = 0.016) o ganho de peso corporal aos 28 dias e o consumo de alimento acumulado, sem afetar a conversão alimentar. O aditivo diminuiu os efeitos adversos. As atividades séricas das enzimas não foram afetadas significativamente (P>0.05) nos quatro grupos experimentais, porém, quando os dados dos grupos que receberam a toxina T-2 foram combinados e comparados com o pool de dados dos grupos sem toxina, foi observado um decréscimo significativo da atividade de amilase nos frangos que receberam a toxina T-2. O exame histológico do sistema digestivo superior revelou lesões em boca, esôfago, pró-ventrículo, moela e duodeno nos frangos alimentados com toxina T-2 sem aditivo. Frangos alimentados com toxina T-2 mais aditivo mostraram lesões nos mesmos tecidos, exceto no duodeno. Os resultados do presente estudo mostram que a adição de 2,5g/kg do aditivo alimentar testado protege contra os efeitos adversos sobre o desempenho e a integridade da mucosa duodenal.(AU)

Sobrecarga y Burnout en cuidadores informales del adulto mayor / Overload and Burnout among aged informal caregivers / Sobrecarga e Burnout com cuidadores informais do idoso

Objetivo: Conocer las condiciones personales, de sobrecarga y su relación con el Síndrome de Burnout en el cuidador informal del adulto mayor. Método: Estudio correlacional y transversal. Muestreo no probabilístico, por conveniencia. Muestra: 52 cuidadores informales de ancianos de ambos sexos. Se utilizó cédula de datos personales, la escala de Zarit y el cuestionario Maslach Burnout Inventory. El procesamiento de datos se realizó con el Statistical Package for the Social Sciences versión 20. Resultados: La media de edad de los cuidadores fue de 44 años, 58% están casados, 50% tienen escolaridad media superior, 45% son hijos de los seniles (35% son las hijas), el 27% trabajan como profesionistas, 73% tienen de 1 a 6 años cuidando al anciano; 42% dedica de 6-15 horas a su cuidado; 58% padece sobrecarga, con significancia (r = 0.442, p = 001) con las horas diarias dedicadas al cuidado. El Síndrome de Burnout mostró bajo riesgo en todas las dimensiones: Agotamiento Emocional 67%, Deshumanización 80% y Realización Personal 73%, aunque más del 20% lo padece en alguna dimensión. Conclusiones: La sobrecarga y el síndrome de Burnout en los cuidadores familiares se encontraron bajos. El factor relacionado con la sobrecarga y él Burnout fue el tiempo diario dedicado al cuidado. Con base en los resultados, se propone establecer programas preventivos de entrenamiento acerca del cuidado dirigidos a familiares de ancianos; con el fin de contribuir al bienestar de los cuidadores.

Objective: To explore the personal conditions associated with work overload and the Syndrome of Burnout among aged informal caregivers. Method: Correlational and transversal study using by-convenience not-probabilistic sampling. Sample: 52 aged informal caregivers of both sexes. A personal data form, the Zarit scale, and the Maslach Burnout Inventory questionnaire were all used. Data were processed with the Statistical Package for the Social Sciences version 20. Results: The care providers average age was 44 years old, 58% reported being married, 50% said they had a mid-high level education, 45% were sons of the elderly (35% were daughters), 27% said they worked as professionals, 73% stated they had a 1- 6 year-experience taking care of elders, 42% said that they usually devote between 6 and 15 hours daily to their care activities, and 58% turned out to be suffering from a work overload (r = .442, p=.001). A low Burnout Syndrome risk was found in all the corresponding dimensions: Emotional Fatigue 67%, Dehumanization 80%, and Personal Accomplishment 73%, though more than 20% of the respondents were shown to be suffering from the syndrome in at least one dimension. Conclusions: Work overloads and the Burnout Syndrome among the aged family caregivers were found to be low. An important factor associated with the work overload and the Burnout Syndrome was the time per day devoted to the care. Based on the results, it is suggested to establish preventive training programs related to caring and aimed at the aged family caregivers with the objective of contributing to the wellbeing of these specific caregivers.

Objetivo: Conhecer as condições pessoais, de sobrecarga e sua relação com a síndrome de Burnout no cuidador informal do idoso. Método: Estudo correlacional e transversal. Amostragem não probabilística por conveniência. Amostra: 52 cuidadores informais de idosos de ambos os sexos. Utilizou-se a cédula de dados pessoais, a escala de Zarit e o questionário Maslach Burnout Inventory. O processamento de dados realizou-se com o Statistical Package for the Social Sciences versão 20. Resultados: A média de idade dos cuidadores foi de 44 anos, 58% são casados, 50% são de escolaridade de ensino médio, 45% são filhos dos idosos (35% são as filhas), 27% trabalham como profissionais, 73% cuidam o idoso de 1 a 6 anos, 42% dedica ao cuidado de 6 a 15 horas, 58% padece de sobrecarga com significância (r=.442, p=001) pelo cuidado dedicado diariamente. A síndrome de Burnout mostrou um risco baixo em todas as dimensões: esgotamento emocional 67%, desumanização 80% e realização pessoal 73%, ainda que mais do 20% padeça em alguma dimensão. Conclusões: A sobrecarga e a síndrome de Burnout nos cuidadores familiares encontram-se baixos. O fator relacionado com a sobrecarga e o Burnout foi pelo cuidado dedicado diariamente. Com base nos resultados, propõem-se estabelecer programas preventivos de treino em volta do cuidado dirigido a familiares de idosos, com o fim de contribuir para o bem-estar dos cuidadores.

Sequencing of the new HLA-B*44:150 allele suggests recombination between B*44:02:01:01 and B*07:02:01 alleles.

B*44:150 was identical to B*44:02:01:01 except at the 3'-end region of exon 3, where a B*07-specific sequence was identified.

Perfil sociodemográfico y de intereses profesionales de los estudiantes de licenciatura en enfermería / Socio-demographic profile and professional interests of students of Bachelor's degree in nursing

Introducción: Aunque en los servicios de salud a nivel mundial existe deficiencia de personal de enfermería, en América Latina el índice de deserción en las escuelas de enfermería es elevado; esta problemática recae en trabajadores en ejercicio quienes deben brindar cuidado enfermero en situaciones de cansancio y estrés. La problemática lleva a pensar que no existen características adecuadas en los estudiantes que ingresan para cursar favorablemente la carrera. Objetivo: Determinar las características sociodemográficas, económicas, familiares, de antecedentes escolares e intereses profesionales de estudiantes que ingresan a estudiar la carrera de Enfermería. Suponemos una relación entre deserción e intereses u objetivos que guiaron a alumnos en la selección de carrera, sus características socio-económicas-familiares y del plantel que provienen. Metodología: Estudio transversal y descriptivo, se consideró el 100% de las cédulas de tutoría aplicadas a estudiantes de Enfermería que ingresaron entre 2001 y 2006. Los datos sociodemográficos, económicos y familiares se obtuvieron por medio de preguntas abiertas o cerradas, para clasificar nivel socioeconómico se utilizó la propuesta de Sigmarket, los intereses profesionales se evaluaron a partir de una escala tipo likert. Resultados: El perfil obtenido mostró una población joven, predominantemente solteros, que no realizan trabajo remunerado, dependen económicamente de sus padres, de condiciones socioeconómicas precarias, sus intereses están orientados hacia la obtención de conocimientos y aspectos de carácter social Conclusiones: Fue importante identificar una tendencia, aunque no significativa estadísticamente, de permanencia en mayor medida de los alumnos con condiciones sociales más precarias, y aquellos cuyos intereses de orden social se ubican en el nivel más alto.

Introduction: Although it exists a deficiency in nursing staff at a global level in health services, in Latin America the rate of dropout in nursing schools is high; this problem lies over workers who must provide nurse care in situations of fatigue and stress. The problem leads us to think there are no appropriate characteristics for students to successful fulfill their career. Objective: to determine the socio demographic, economic and family characteristics, school background and professional interests of students entering nursing. We assume an existing relationship between dropout, the interests or goals that guided students in the selection of the career in nursing, the socio-economic-family characteristics and the institution of origin. Methodology: cross-sectional and descriptive study that considered the 10000% of admission interviews made to incoming nursing students from 200001 to 200006. The socio-demographic, economical and familiar data were obtained from closed and openended questions; the Sigmarket proposal was used for the classification of the socioeconomic level, the professional interests were evaluate from a likert scale. Results; the obtained profile showed a young population, mainly single, that doesn't have a paid job and depends from their parents economically, from a low socio-economic conditions, their interests are focus towards the acquisition of knowledge and aspects of social nature. Conclusions: it was important to identify a mayor tendency, although not statistically significant, of continuing the career from part of the students with lower social conditions and those whose social interests are located in the highest level.

Pros y contras percibidos de la actividad física realizada por adultos mayores / Perceived pros and cons of physical activity by older adults

INTRODUCCION: La práctica de actividad física regular es una de las prioridades en salud pública para incrementar el bienestar y la calidad de vida especialmente en la tercera edad. Esta práctica depende de varios factores entre otros las experiencias previas de la conducta y la valoración de las ventajas y desventajas que tiene su realización. Propósito: Conocer los pros (ventajas) y Contras (desventajas) percibidos del ejercicio físico en adultos mayores. METODOLOGÍA: En este estudio se utilizó el balance decisional (Prochaska y Di Clemente1997). Se aplicó la aproximación cualitativa con muestreo teórico y análisis de contenido en una muestra de 15 participantes. Resultados: Estos mostraron tres categorías: Pros de la actividad física construida a partir de las subcategorías: mejorar la salud física y emocional e incrementar las relaciones interpersonales. La segunda categoría: Contras se construyó a partir de las subcategorías ambientales ocupaciones enfermedades y ser cuidadores de otras personas y una tercer categoría identificada se construyó con las razones para realizar la actividad física. CONCLUSIONES: Los pros y contras señalados por los participantes pueden ser la clave para el diseño de estrategias de programas de salud encaminados a incluir la actividad física en el adulto mayor.

Introduction: The practice of regular physical activity is one of the priorities in public Health to increase the well-being and the quality of life especially in the third age. This practice depends on several factors, among others the previous experiences of the conduct and evaluation of the advantages and disadvantages upon achievement. Purpose: Acknowledge pros and cons detected on physical exercise on older adults. Methodology: In this study the decisional balance (Prochaska and Di Clemente,1997) was used. The qualitive approach was applied by theoretical sampling and analysis of content sampling 15 participants. Results: They showed this categories: Pros of the physi cal activity, built from the subcategories: To improve the physical and emotional health and to increase the interpersonal relations. The second category, cons was formed from environmental Subcategories: Occupations, diseases and to carers of others persons and a third Identified category was the reasons of physical activity. Conclusions: The pros and cons distinguished by the participants can be the key for the strategic health programs design aimed to include physical activity on major adults.

Noninvasive recovery and detection of possum Trichosurus vulpecula DNA from bitten bait interference devices (WaxTags).

The brushtail possum is a major agricultural and ecological pest in New Zealand. A novel noninvasive DNA sampling tool for detecting its presence (WaxTags, or WT) was tested. DNA was recovered from saliva left on WT, and two lengths (407 bp and 648 bp) of the cytochrome c oxidase I (COI) barcoding region were amplified by polymerase chain reaction (PCR). PCR products were considered (+) when a DNA band was clearly visible by electrophoresis. Different factors that might affect PCR (+) were investigated with captive possums: (i) both extraction protocols of the QIAGEN DNeasy Blood and Tissue Kit, (ii) effect of an overnight or longer delay of up to 3 weeks before DNA extraction on both COI amplicons, and (iii) effect of the individual, order and magnitude of the bite. Extraction protocols were not significantly different. The effect of the overnight delay was not significant, and amplification of the short amplicon was significantly higher (100%) than for the long fragment (48%). After a two or 3-week delay, the short amplicon had 94% and 56% PCR (+), success rates, respectively. Individual, order and magnitude of a bite had no significant effect. The delay trial was repeated with WT from the wild, for which PCR (+) rate of the short amplicon was 63%, regardless of freshness. Four microsatellites were amplified from captive WT samples. We conclude that DNA from saliva traces can be recovered from WT, a potential new tool for noninvasive monitoring of possums and other wildlife.

[The possibilities of neurocognitive rehabilitation in schizophrenia]. / Posibilidades de rehabilitacion neurocognitiva en la esquizofrenia.

INTRODUCTION: Schizophrenia is a severely disability causing syndrome, what tend to chronically alter living project of great number of young people and its families. It is affected multiple cognitive functions, as executive capacity, explicit memory, working memory or perceptive integration. In the last years, neurocognitive rehabilitation techniques of this functions coming from the experience with brain damage patients has been applied to schizophrenia. DEVELOPMENT: Present work revised: a). cognitive deficits that can be considered as nuclear in the genesis of schizophrenia symptoms and b). recovery or substitution strategies of that deficits, that can be generalized to a better psychosocial functioning of the patient. It is proposed that attention control deficit (ACD), defined as the inadequate assignation of attention recourses during cognitive processing, results in attention processing of redundant information and a lack of attention recourses to process new information. Some explaining models are presented for subjective and perceptive symptoms, language disorders and executive disorders in schizophrenia. Possibilities of neurocognitive rehabilitation in schizophrenia are discussed, especially by the utilisation of implicit learning methods, that don't need attention processing. Some recommendations are made for the implementation of cognitive rehabilitation in the general framework of psychosocial and occupational rehabilitation.

Synergistic interaction of diazepam with 3',5'-cyclic adenosine monophosphate-elevating agents on rat aortic rings.

We investigated the effect of the phosphodiesterase type 4 (PDE4) inhibitory activity of diazepam on the arterial wall. To this purpose, we examined the interaction of diazepam with 3',5'-cyclic adenosine monophosphate (cyclic AMP)-elevating agents on vasodilatation and cyclic AMP levels in rat aortic rings precontracted with phenylephrine. The involvement of benzodiazepine receptors was also studied. Diazepam (5-100 microM) produced a relaxation of this preparation which was neither mimicked by gamma-aminobutyric acid (GABA), nor antagonized by flumazenil and 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxamide (PK 11195), inhibitors of central or peripheral type benzodiazepine receptors, respectively. The diazepam-induced relaxation was potentiated by the presence of isoprenaline (10 nM), forskolin (50 nM) or milrinone (0.1 microM). Furthermore, diazepam increased the enhancement of cyclic AMP levels induced by these three agents in this tissue. Our results demonstrate a functional and biochemical synergistic interaction of diazepam with cyclic AMP-elevating agents on rat aortic rings.

Diazepam increases the hypothalamic-pituitary-adrenocortical (HPA) axis activity by a cyclic AMP-dependent mechanism.

1. Previous studies in this laboratory have shown that diazepam behaves as a phosphodiesterase 4 (PDE 4) inhibitor. It has been reported that PDE-4 inhibitors activate the hypothalamic-pituitary-adrenocortical (HPA) axis in the rat. In the present study we have examined whether activation of the cyclic AMP-dependent protein kinase (PKA) is involved in the effect of diazepam on basal HPA axis activity. 2. Acute systemic administration of diazepam (10 mg kg(-1) i.p.) was found to increase the basal HPA axis activity, increasing the plasma concentrations of corticotrophin (ACTH) and corticosterone 30 min post injection. Diazepam also elevated cyclic AMP content of the hypothalamus. 3. Pretreatment of the animals with dexamethasone (1 mg kg(-1) s.c.) for 3 days completely abolished the effect of diazepam on HPA axis activity. 4. The antagonists of central and peripheral benzodiazepine receptors, flumazenil (10 mg kg(-1) i.p.) and PK 11195 (5 mg kg(-1) i.p.) did not affect the diazepam induced increase of HPA axis activity nor did they have an effect per se. 5. The increase in ACTH and corticosterone levels was significantly reduced by the cyclic AMP-dependent protein kinase (PKA) inhibitor, H-89, given either subcutaneously (5 mg kg(-1) s.c.) or intracerebroventricularly (i.c.v.; 28 microg in 10 microl). 6. The results indicate that diazepam can stimulate basal HPA axis activity in the rat by a cyclic AMP-dependent PKA mediated pathway.

Neurochemical activity of noradrenergic neurons and pituitary-adrenal response after naloxone-induced withdrawal: the role of calcium channels.

The influence of the L-type calcium channel antagonist nimodipine on both the activity of noradrenergic neurons projecting to the hypothalamus and the pituitary-adrenal response during morphine tolerance and withdrawal was analysed. Tissue concentration of hypothalamic noradrenaline (NA) and its metabolite 3-methoxy-4-hydroxy-phenylethylen-glycol (MHPG) were determined by high-pressure liquid chromatography. Plasma corticosterone concentration (a marker of pituitary-adrenal activity) was measured by radioimmunoassay. Rats rendered tolerant to morphine decreased hypothalamic MHPG concentration, and reduced hypothalamic NA turnover. Chronic infusion of nimodipine concurrently with morphine prevented the decrease in NA turnover during tolerance. After naloxone administration to tolerant rats we found a striking parallelism between an increased activity of the hypothalamic-pituitary-adrenal axis and an enhanced activity of noradrenergic neurons projecting to the hypothalamus. However, hypothalamic NA turnover and MHPG concentration, both elevated during withdrawal, returned to control levels in rats infused chronically with nimodipine, concomitantly with a reduction of the secretion of corticosterone. Taken together, these data indicate that increased noradrenergic neuronal activity in the hypothalamic nerve terminals is associated with the neuroendocrine morphine withdrawal syndrome and suggest that an up-regulated calcium system might contribute to the activation of these neurons.

Chronic naloxone-induced supersensitivity affects neither tolerance to nor physical dependence on morphine at hypothalamus-pituitary-adrenocortical axis.

This study reports the endocrine effects of chronic mu-blockade induced by naloxone on morphine tolerance and withdrawal at hypothalamus-pituitary-adrenocortical (HPA) axis level. Naloxone (0.5 mg/kg/h) or vehicle (1 microliter/h) were infused s.c. to Sprague-Dawley rats via osmotic minipumps for 7 days, concomitantly with morphine or placebo pellets for 7-8 days. In opiate-naive rats, the mu-preferring opioid agonist morphine (30 mg/kg) increased plasma corticosterone in a partial but significant naloxone-reversible manner. In vehicle-perfused rats, chronic morphine treatment produced tolerance to its neuroendocrine effect, while the development of morphine tolerance was antagonized in the naloxone-treated group. An enhancement of plasma corticosterone levels after acute morphine (30 mg/kg) occurred 24 h after removal of chronic naloxone treatment in vehicle-perfused rats, as a functional index of supersensitivity to the neuroendocrine effects of the mu agonist. By contrast, 24 h after naloxone removal, rats implanted with morphine pellets were significantly less sensitive to acute morphine (tolerance) than its control-placebo group. Substantial elevation of plasma corticosterone, accompanied by motor and behavioural signs, was observed after acute naloxone injection (1 mg/kg) to tolerant rats 24 h after naloxone-pumps removal, which indicates withdrawal. No endocrine, motor or behavioural signs appeared in the naloxone group with pumps in place. These results indicated that morphine desensitizes mu-opioid receptors that were probably upregulated by chronic naloxone in presence of chronic agonist administration, and suggest that opioid tolerance/dependence as well as opioid supersensitivity simultaneously and independently can occur at mu-opioid receptors mediating HPA function.

Catecholaminergic mediation of morphine-induced activation of pituitary-adrenocortical axis in the rat: implication of alpha- and beta-adrenoceptors.

The present study investigates the role of hypothalamic catecholamines in the effects of morphine on hypothalamo-pituitary-adrenocortical (HPA) axis. Acutely administered morphine (30 mg/kg i.p) increased plasma corticosterone and reduced the hypothalamic noradrenaline (NA) content but it did not change either the dopamine (DA) concentration or the ratio DOPAC/DA. After reserpine administration the hypothalamic contents of NA and DA were drastically reduced without changing plasma corticosterone concentrations. The increase in plasma corticosterone induced by morphine was significantly reduced by the pretreatment with reserpine. The alpha 1- and alpha 2-antagonists prazosin and yohimbine, respectively, significantly antagonized the effect of morphine on plasma corticosterone. The beta-antagonist propranolol also significantly attenuated the increase of corticosterone secretion induced by morphine. The results suggest that the action of the opiate on HPA axis activity may be dependent on stimulatory catecholaminergic systems which utilize alpha 1-, alpha 2- and beta-adrenoceptors.

Involvement of kappa-opioid receptor mechanisms in the calcitonin-induced potentiation of opioid effects at the hypothalamus-pituitary-adrenocortical axis.

The present study was conducted to evaluate the influence of calcitonin on the neuroendocrine effects of both the mu-opioid receptor agonist, morphine, and the selective kappa-opioid receptor agonist, U-50,488H (trans-3,4-dichloro-N-methyl-N-[2-(1- pyrrolidynyl)cyclohexyl]benzeneacetamide methane sulphonate), at the hypothalamus-pituitary-adrenocortical axis in rats. Calcitonin given alone (2.5, 5 or 10 UI/kg i.p.) induced no changes or a slight reduction (20 UI/kg i.p.) in plasma corticosterone, 45 min after its administration. Morphine did not produce any modification in plasma corticosterone at doses of 3 or 10 mg/kg i.p., whereas it produced a significant increase in corticosterone secretion at doses of 20 or 30 mg/kg i.p., 30 min after its administration. Pretreatment with calcitonin (2.5 UI/kg i.p.) 15 min before morphine (3 or 10 mg/kg i.p.) did not modify the effect of the opioid on plasma corticosterone. U-50,488H (0.5, 1, 5 or 15 mg/kg i.p.) induced an increase in the release of corticosterone only at the higher dose, 30 min after injection. Significantly higher plasma corticosterone levels after U-50,488H administration at doses of 0.5, 1 or 5 mg/kg i.p. were observed when calcitonin was administered 15 min before the kappa-opioid receptor agonist. The enhanced responsiveness of the hypothalamus-pituitary-adrenocortical axis to U-50,488H (1 mg/kg i.p.) in animals pretreated with calcitonin, was completely blocked by the selective kappa-opioid receptor antagonist, nor-binaltorphimine, suggesting a role of kappa-opioid receptors in mediating the calcitonin-induced supersensitivity to U-50,488H.(ABSTRACT TRUNCATED AT 250 WORDS)

Lack of involvement of delta-opioid receptor in mediating physical dependence at the hypothalamus-pituitary-adrenocortical (HPA) axis in the rat.

1. In previous studies, we have demonstrated that delta-opioid receptors are involved both in the acute control of hypothalamus-pituitary-adrenocortical (HPA) axis activity and in the development of neuroendocrine opioid tolerance. In the present work we studied whether central delta-opioid receptors play a role in the development of neuroendocrine physical dependence to opioids in the rat. 2. Intracerebroventricular (i.c.v.) administration of the delta-selective agonist DPDPE ([D-Pen2,D-Pen2]enkephalin) produced stimulation of HPA activity, as shown by an increase in corticosterone release. This effect was antagonized by i.c.v. co-administration of ICI 174,864, a selective delta-receptor antagonist, which provide direct evidence that the activation of the HPA axis produced by DPDPE is mediated by central delta-opioid receptor. 3. Chronic pretreatment with i.c.v. DPDPE resulted in tolerance to its neuroendocrine effect. Intracerebroventricular injection of ICI 174,864 to DPDPE-tolerant rats produced neither alteration in corticosterone release nor behaviour signs of dependence. 4. It was concluded that delta-opioid receptors do not play a role in the development of opioid neuroendocrine physical dependence at the HPA axis.

Effects of intracerebroventricular clonidine on the hypothalamic noradrenaline and plasma corticosterone levels of opiate naive rats and after naloxone-induced withdrawal.

The aim of this study was to determine whether hypothalamic noradrenergic neuronal activity contributes to the abstinence-induced hypersecretion of corticosterone during naloxone-induced withdrawal. With this purpose the effects of intracerebroventricular (i.c.v.) clonidine on hypothalamic noradrenaline (NA) and plasma corticosterone were studied in chronically placebo-treated rats (controls) and during naloxone-induced morphine withdrawal. In control rats, clonidine (10 micrograms) significantly increased plasma levels of corticosterone without changing the hypothalamic content of NA. Naloxone (1 mg/kg, s.c.) also increased plasma corticosterone levels and clonidine administered prior to naloxone, antagonized the effect of naloxone on plasma corticosterone. In chronically morphine-treated rats, naloxone treatment induced an increase in plasma corticosterone and reduced the hypothalamic NA content. Clonidine significantly prevented the reduction in the hypothalamic NA, without modifying plasma levels of corticosterone. The results show an interaction between opioid-receptors and alpha 2-adrenoceptors in the hypothalamus, and suggest that mechanisms other than hyperactivity of NA neurons contribute to the hypothalamus-pituitary-adrenocortical (HPA) axis hyperactivity during the opiate withdrawal.