Effects of Vitamin K1 Supplementation on the Risk Factors to the Stroke and on Memory in Spontaneously Hypertensive Rats Stroke Prone (SHR-sp)

A number of risk factors have been associated to the stroke and many strategies have been proposed in order to control them as well. Vitamin K has been largely found in brain, which suggests a possible function at that tissue. This study aimed to evaluate the potential of this vitamin on the prevention of risk factors to stroke and on cognitive function on SHRSP rats. Twelve SHRSP males, 15 weeks old, were divided into two groups (n= 6 each), receiving the vehicle-coconut oil (control group) or 40 μg of phylloquinone (treated group) during 28 days. Biological parameters, systolic blood pressure and lipid profile were evaluated. Both groups were submitted to the neurological tasks. The data was treated by Student's t test and ANOVA one-way test being P<0.05 considered significant. The phylloquinone supplementation showed a statistically significant reduction in the treated group of all parameters of lipid profile and systolic blood pressure when compared to the control group. Neurological evaluation indicated a statistically significant improvement in the performance of long term memory tests in the treated group, without similar findings in the evaluation of short memory. In sum, phylloquinone supplementation was shown to modulated lipid profile and protect neuronal suffering in this model.

Effects of alpha-tocopherol associated with lovastatin on brain tissue and memory function in SHRSPs.

Strokes are preceded by oxidative stress and inflammation, two processes linked to atherosclerosis and hypertension. Statins have been widely employed to control atherosclerosis; however, there could be neurological implications to its use­including cognitive impairment. Thus,we aimed to determine whether alpha-tocopherol is capable of reversing the neurological side effects of statins and enhancing its anti-inflammatory properties. To assess these effects, 15-week-old stroke-prone spontaneously hypertensive rats (SHRSPs) were divided into four groups (n = 6, each): alpha-tocopherol (AT), lovastatin (LoV), alpha-tocopherol + lovastatin (AT + LoV), and control (C).We administered 120 IU of alpha-tocopherol diluted in 0.1 ml of coconut oil,whereas the dose of lovastatin was administered at a ratio of 1 mg/kg of rat body weight. The control group received 0.1 ml coconut oil. All animals received the treatments via orogastric gavage.We assessed body weight, diuresis, food and water intake, oxidative stress (malondialdehyde levels), the total cellular injury marker (lactate dehydrogenase), short and long-term memory, cognition, and histopathological changes in the hippocampus. The results demonstrated that lovastatin treatment did not negatively affect the memory of our animal model. In fact, the animals treated with AT and LoV showed improvement in memory and cognition. Additionally, both treatments decrease lactate dehydrogenase and oxidative stress levels. Furthermore, our study also demonstrated hippocampal tissue preservation in the treated groups.

The effects of supraphysiological supplementation of ß-carotene in spontaneously hypertensive rats (SHR and SHR-sp).

OBJECTIVE: To investigate the effect of administration of supraphysiological ß carotene on biological, laboratory and histological parameters of spontaneously hypertensive rats prone to stroke (SHR-sp). METHODS: we used 36 male rats divided into three groups, each containing 12 rats of the types Wistar SHR and SHR-sp, subdivided into six control animals and six animals treated with supraphysiological doses of ß carotene for two ten-week periods, interspersed by a one-week interruption. We carried out daily physical examination and blood pressure assessment. We collected blood for measurement of serum malondialdehyde; the liver and carotid arteries were subsequently harvested for histological examination. RESULTS: there was a temporary change in the color of hair, a significant decrease (p <0.0001) in blood pressure (20 mg ß carotene supplementation) and serum levels of malondialdehyde (p<0.05) and increased amount of elastic fibers in the carotid wall of SHR and SHR-sp. CONCLUSION: ß carotene supraphysiological supplementation caused no toxic effects, showed positive response in the modulation of blood pressure and lower serum malondialdehyde. No significant morphological changes were observed in the groups studied, except for an increase in the number of elastic fibers in the carotid muscular layer, suggesting elastosis in SHR and SHR-sp.

The effects of supraphysiological supplementation of b-carotene in spontaneously hypertensive rats (SHR and SHR-sp) / Efeitos da suplementação suprafisiológica de b-caroteno em ratos espontaneamente hipertensos (SHR e SHR-sp)

Objective: to investigate the effect of administration of supraphysiological âcaroteno on biological parameters (ectoscopy and blood pressure), laboratory (malondialdehyde) and histological (liver and carotid arteries) of spontaneously hypertensive rats prone to stroke (SHR-sp). Methods: we used 36 male rats were divided into three groups, each containing 12 rats Wistar, SHR and SHR-sp, subdivided into six control animals and six animals treated with supraphysiological doses of âcaroteno for two periods of ten weeks interspersed with one week interruption. In the experiment were assessed daily physical examination and blood pressure (plethysmography). At sacrifice, blood was collected for measurement of serum malondialdehyde, liver and carotid arteries for histological examination. Results: temporary change in color of the fur, decreased significantly (p<0.0001) blood pressure (20mg supplementation âcaroteno) and serum levels of malondialdehyde (p<0.05) and increased amount of elastic fibers in the carotid wall of SHR and SHR-sp. Conclusion: supplementation of supraphysiological âcaroteno caused no toxic effects, showed positive response in the modulation of blood pressure and lower serum malondialdehyde. No significant morphological changes were found in both groups, except an increase in the number of elastic fibers in the muscle layer carotid suggesting elastosis in SHR and SHR-sp. .

Objetivo: investigar o efeito da administração suprafisiológica de bcaroteno sobre parâmetros biológicos, laboratoriais e histológicos dos ratos espontaneamente hipertensos com tendência ao acidente vascular encefálico (SHR-sp). Métodos: utilizaram-se 36 ratos machos, distribuídos em três grupos, contendo cada um dos 12 ratos das linhagens Wistar, SHR e SHR-sp, subdivididos em seis animais controle e seis animais tratados com doses suprafisiológicas de âcaroteno por dois períodos de dez semanas, intercalados por uma semana de interrupção. No experimento foram avaliados diariamente o exame físico e a pressão arterial. Foi coletado sangue para dosagem sérica de malondialdeído; o fígado e as artérias carótidas para exame histológico. Resultados: alteração provisória na coloração dos pelos, diminuição significativa (p<0,0001) da pressão arterial (suplementação de 20mg de bcaroteno) e dos níveis séricos de malondialdeído (p<0,05) e aumento da quantidade de fibras elásticas na parede carotídea dos ratos SHR e SHR-sp. Conclusão: A suplementação suprafisiológica de bcaroteno não causou efeitos tóxicos, apresentou resposta positiva na modulação da pressão arterial e diminuição na concentração sérica de malondialdeído. Não foram encontradas alterações morfológicas significativas nos grupos estudados, exceto um aumento no número de fibras elásticas da camada muscular carotídea sugerindo elastose nos ratos SHR e SHR-sp. .

Alpha-tocopherol in the brain tissue preservation of stroke-prone spontaneously hypertensive rats.

Oxidative stress has an important role in neuronal damage during cerebral ischemia and can lead to cognitive and behavioral impairment. Alpha-tocopherol, a powerful antioxidant, may be able to preserve neuronal tissue and circumvent neurological deficits. Thus, this study aimed to investigate the influence of alpha-tocopherol in the preservation of brain tissue and the maintenance of memory formation in stroke-prone spontaneously hypertensive rats (SHRSP). To achieve this aim, twenty-four 15-week-old male SHRSP rats were separated into the following four groups (n = 6 each) that received different treatments over a 4-week period: the alpha-tocopherol group, the control group, the L-NAME group, and the L-NAME + alpha-tocopherol group. We evaluated the physiological parameters (body weight, diuresis, and food and water intake), an oxidative stress marker (malondialdehyde levels), and neurological responses (the Morris Water Maze and Novel Objects Recognition tests). Afterwards, the brains were removed for histopathological analysis and quantification of the number of cells in the hippocampus. Statistically, the alpha-tocopherol group demonstrated better results when compared to all groups. The data indicated a reduction in oxidative stress and the preservation of neurological responses in groups treated with alpha-tocopherol. In contrast, the L-NAME group exhibited increased malondialdehyde levels, impairment of neurological responses, and several hippocampus tissue injuries. The others groups exhibited nerve tissue changes that were restricted to the glial nodes. No significant alterations were observed in the physiologic parameters. Based on these findings, we suggest that alpha-tocopherol can prevent stroke, preserve the structure of the hippocampus, and maintain both memory and cognition functions.

Effects of Emerita brasiliensis flour supplementation on normotensive (Wistar) and spontaneously hypertensive rats (SHR)

Several studies characterize the connection of overweight and obesity with chronic diseases. Therefore, new alternatives are being studied for controlling hypertension, such as chitin and chitosan fibers, commonly found on crustacean's carapace like Emerita brasiliensis. Rats from two different strains were divided into control and supplemented groups (n=6). The Wistar strain experiment started with a 14-days baseline period, followed by supplementation of E.brasiliensis flour added to the diet in the doses of 5, 10 and 20%, for a 14-days period each. With the optimal dose of 20%, the study was undertaken with SHR rats, starting with a 7-days baseline period, followed by three weeks of supplementation. Data were evaluated using one-way ANOVA and p<0.05 was significant. There was a clinical reduction of systolic blood pressure on Wistar rats, but only SHR rats showed a significant reduction of systolicblood pressure and total cholesterol, LDL-cho with an increase of HDL-cho. Those findings were not related to body weight changes but, instead they were associated to E. brasiliensis flour effect on serum lipid profile. This study showed that this flour could be an alternative for controlling the hypertension and hypercholesterolemia.

O esgotamento dos profissionais de enfermagem: uma revisão integrativa sobre a síndrome de Burnout em UTI / El esgotamiento de la enfermería profesional: una revisión integradora del síndrome de Burnout en la UTI / The exhaustion of nursing: an integrative review of the Burnout syndrome in ICU

Diagnosticar o conhecimento sobre estresse psicológico gerador da síndrome de burnout (SB) na equipe de enfermagem; verificar a influência da SB na atuação destes profissionais que trabalham em UTI. Métodos: Revisão integrativa realizada nas bases de dados MEDLINE, LILACS, Scielo, Cochrane Library, CINAHL e EMBASE. Resultados: A metodologia descritiva foi a mais utilizada (44,11%). Melhor qualificação profissional significa menor predisposição à SB. Ambientes saudáveis e melhores condições de trabalho refletem na saúde e qualidade da assistência dos profissionais. O trabalho em UTI e SB geram alterações psicológicas e nos níveis de felicidade. São considerados fatores estressores: morte, doação de órgãos, relacionamento com familiares e sofrimento moral. Conclusão: O estresse psicológico na UTI influencia na atuação do profissional de enfermagem, sendo a fonte geradora de conflitos e SB.

El diagnóstico de los conocimientos de estrés psicológico, como un generador del síndrome de burnout (BS) en personal de enfermería, evaluar el efecto de SB en el desempeño de estos profesionales que trabajan en la UCI. Métodos: Una revisión integradora realizada durante tres días consecutivos en la bases de datos MEDLINE, LILACS, SciELO y Cochrane Library, CINAHL y EMBASE. Resultados: La metodología utilizada fue el más descriptivo (44,11%). Mejor calificación significa menos predisposición a la SB. Ambientes saludables y mejores condiciones de trabajo reflejan directamente la salud y la calidad de la atención prestada por los profesionales. La UCI trabajar juntos para generar trastornos psicológicos SB (depresión y ansiedad) y los niveles de felicidad. Los factores de estrés se consideran: las situaciones que implican la muerte, la donación de órganos y la relación con los miembros de la familia. Sufrimiento moral (sensación de estar haciendo lo correcto) es un problema encontrado en el estudio como una posible causa de la SB. Conclusión: El estrés psicológico influye en las actividades de la enfermera de la UCI, siendo la fuente de los conflictos y SB.

Diagnostic of psychological stress knowledge, as a generator of the burnout syndrome (BS) in nursing staff, assess the effect of BS in the performance of these professionals working in ICU. Methods: Integrative review conducted on three consecutive days in the databases: MEDLINE, LILACS, SciELO and Cochrane Library, CINAHL and EMBASE. Results: The descriptive methodology was the most used (44.11%). Best qualification means less predisposition to BS. Healthy Environments and better working conditions directly reflect the health and quality of care provided by professionals. The ICU work together to generate BS psychological disorders (depression and anxiety) and levels of happiness. Stress factors was are consider: situations involving death, organ donation and the relationship with family members. Moral suffering (feeling of doing the right thing) was an issue found in the study as a possible cause of the BS. Conclusion: Psychological stress influence the ICU nurse's activities, being the source of conflicts and BS.

Alpha-tocopherol protects against memory impairment caused by L-NAME and modulates the injury marker and blood coagulant parameters.

Cerebrovascular disease studies have shown similarity between humans and spontaneously hypertensive rats stroke-prone rats in the development of spontaneous stroke and transitory ischemic attacks (TIA). In addition, nitric oxide (NO) suppression by L-arginine methyl ester (L-NAME) can precipitate several vascular diseases including TIA and strokes. On the other hand, alpha-tocopherol (AT) has been associated with beneficial effects on vascular disorders. Four groups were tested to evaluate AT effects on NO inhibition: AT, control (C), AT + L-NAME, and L-NAME. During 4 weeks, all groups had their physiologic parameters evaluated and were submitted to neurological tests. After the sacrifice of the animals, total L-lactate dehydrogenase, fibrinogen levels, and platelet counts were measured. Our results demonstrated improvement in memory function and sensory-motor function of the rats treated with AT. The AT treatment also demonstrated a significant difference on the injury identifier, fibrinogen levels, and platelet count between the treated groups and the L-NAME group. In conclusion, AT reversed damaging L-NAME neurological effects and could be considered as a possible protective agent in neurological diseases.

The response of young and adult rats to the riboflavin supplementation

The aim of this article was to study the response of young and adult rats on the supplementation of diet with riboflavin. Twenty-four young and adult normotensives (Wistar) male rats, subdivided into two groups: treated (10mg riboflavin/Kg of body weight) and control (receiving vehicle) were daily evaluated for physical and behavioural aspects. Systolic blood pressure was determined twice a week and liver toxicity was investigated it the end of treatment. Data were evaluated using one-way ANOVA and p<0.05 was significant. There were no changes on general health aspects of the treated rats; however, the supplementation provoked a significant (p<0.05) systolic blood pressure reduction.

O processo do envelhecimento e alguns transtornos, incluindo hipertensão, foram estreitamente associados ao estresse oxidativo. Em relação à riboflavina (vitamina B2), existe uma possibilidade de que suas propriedades antioxidantes podem contribuir para controlar esse evento. Assim, esse estudo utilizou vinte e quatro ratos machos jovens e velhos normotensos (Wistar), sendo subdivididos em dois grupos: tratado (riboflavina 10 mg / kg de peso corporal) e o controle (recebendo veículo). Foram avaliados diariamente aspectos físicos e comportamentais. A pressão arterial sistólica foi determinada duas vezes por semana e a toxicidade hepática foi investigada no final do tratamento. Os dados foram avaliados usando ANOVA one-way e p <0,05. A suplementação não alterou os aspectos de saúde geral dos ratos tratados, no entanto, a suplementação provocou uma significativa (p <0,05) redução da pressão arterial sistólica.

Effectiveness of B vitamins on the control of hypertension and stroke events of SHRSP rats.

The spontaneously hypertensive stroke-prone rat (SHRSP) is a recognized animal model for the study of severe hypertension and stroke, being characterized by presenting an elevated tissue levels of free radicals. Therefore, this study has the main goal to identify the effect of B vitamins, closely associated to the control of oxidative stress, on SHRSP rats. After 10 days (baseline period), the animals, 18 SHRSP rats at 18 weeks of age, were divided into three groups with six rats treated with riboflavin (B2), six treated with pyridoxine (B6) plus folic acid (B9), and control. Body weight, water and food intake, diuresis, sensory-motor responses, and systolic blood pressure of all the rats were determined daily. Physical aspects of whole body (i.e., distribution and coloring of hair, skin and mucosa, and an eventual presence of bleeding, stains, cracks, or opacification) and behavior were equally monitored. The data were evaluated by ANOVA two-way and p < .05 was considered significant. The supraphysiologic doses did not cause toxic effects. There was a significant decrease of systolic blood pressure, homocysteine, and malondialdehyde (MDA) blood levels in animals under B vitamin supplementation. The treatment also inhibited the neurological signs of an ischemic attack (unbalance, ataxia, and convulsions). The findings reported here suggest that B vitamin therapy was effective for the control of systolic blood pressure and oxidative stress. Hence, it could be thought as one of the alternative therapies to prevent the occurrence of stroke.

Fatores de risco para doenças crônicas não transmissíveis no Brasil: uma revisão sistemática / Risk Factors for Chronic non Communicable Diseases in Brazil: a Systematic Review / Factores de riesgo para enfermedades crónicas no transmisibles en Brasil: una revisión sistemática

No Brasil, devido às mudanças nos perfis demográfico, epidemiológico e nutricional da população e ao controleconseguido em um número de enfermidades transmissíveis, vêm observando-se, nas últimas décadas, uma inversãodo perfil epidemiológico com redução das doenças infecciosas e o aumento significativo da prevalência das doençascrônicas não transmissíveis (DCNTs). Essa mudança justifica o estudo dos fatores de risco e determinantes sociaisdas doenças crônico-degenerativas no país. O presente trabalho teve por objetivo conhecer a prevalência daexposição da população aos principais fatores de risco para o desenvolvimento de DCNTs no Brasil. Foi realizadauma revisão sistemática dos artigos publicados na literatura científica, a partir das bases de dados on-line Lilacs eMedline, entre 2003 e 2008, em português. As prevalências variaram conforme os critérios utilizados e ascaracterísticas das populações estudadas, sendo obtidos os seguintes valores mínimo e máximo para cada um dosfatores de risco estudados: tabagismo 8,7% a 28,8%, uso abusivo de álcool 0,1% a 37,7%, excesso de peso 1,5%a 49,0%, obesidade 9,4% a 17,6%, sedentarismo 20,1% a 43,1%, hipertensão arterial 5,3% a 34,0%, diabetesmellitus 2,7% a 7,8%. A variação no grau de exposição da população aos fatores de risco presentes nos diversosestudos aponta para a necessidade de padronização dos instrumentos de medida, a fim de que os resultadosobtidos nas diferentes localidades possam ser comparados. Além disso, as altas prevalências observadas em algumasáreas indicam a necessidade de intervenções imediatas por meio da implementação de estratégias de prevenção epromoção da saúde dirigidas à redução da exposição da população brasileira aos fatores associados ao risco dedesenvolvimento das DCNTs.

In Brazil, due to changes in population demographic, epidemiological and nutritional profiles as well as thecontrol achieved in a number of communicable diseases, in recent decades an inversion in the epidemiologicalprofile, with a decrease in infectious diseases and a surge in the prevalence of Non Communicable Diseases(NCDs). There is therefore a need to study social determinants and risk factors for chronic and degenerativediseases in the country. The present study intended to assess the prevalence of exposure to major risk factors forNCDs of the Brazilian population. Systematic review of articles in Portuguese published between 2003 to 2008in the scientific literature, identified through the online databases Latin American and Caribbean Health SciencesLiterature (Lilacs) and International Health Sciences Literature (Medline) was done. Prevalence of risk factorexposure varied according to defined criteria and characteristics of the studied population. The following minimumand maximum prevalence values for each studied risk factor were found: smoking 8.7% to 28.8%, alcoholabuse 0.1% to 37.7%, excess weight 1.5% to 49.0%, obesity 9.4% to 17.6%, physical inactivity 20.1% to43.1%, hypertension 5.3% to 34.0%, and diabetes mellitus 2.7% to 7.8%. Variation in the degree of exposureto risk factors for NCDs in the population identified in the various studies points out the need to standardizemeasurement tools so that results from different sites can be compared. Moreover, the high prevalence ofexposure to risk factors observed in some regions suggests that immediate responses by means of implementingstrategies for prevention and healthcare promotion are necessary to reduce the Brazilian population exposure torisk factors associated to chronic diseases development.

En Brasil, debido a cambios en los perfiles demográficos, epidemiológicos y nutricionales de la población y alcontrol logrado en una serie de enfermedades transmisibles, se ha observado en las últimas décadas un cambiodel perfil epidemiológico de la reducción de las enfermedades infecciosas y lo aumento significativo en laprevalencia de las enfermedades crónicas no transmisibles (ECNT). Este cambio justifica lo estudio de losfactores de riesgo y determinantes sociales de las enfermedades crónico-degenerativas en el país. Este trabajotuvo como objetivo conocer la prevalencia de la exposición de la población a los principales factores de riesgopara el desarrollo de las ECNT en Brasil. Se realizó una revisión sistemática de los artículos publicados en laliteratura científica, a partir de las bases de datos online Lilacs y Medline, entre 2003 y 2008, en portugués. Lastasas de prevalencia variaron según los criterios utilizados y las características de las poblaciones estudiadas, yse obtuvo los siguientes valores mínimos y máximos para cada uno de los factores de riesgo analizados: consumode tabaco 8,7% a 28,8%, abuso de alcohol 0,1% a 37,7%, sobrepeso 1,5% a 49,0%, obesidad 9,4% al 17,6%,sedentarismo 20,1% a 43,1%, hipertensión arterial 5,3% a 34, 0%, diabetes mellitus 2,7% a 7,8%. La variaciónen el grado de exposición de la población a los factores de riesgo presentes en los diversos estudios apunta parala necesidad de la estandarización de los instrumentos de medición, de modo que los resultados obtenidos en lasdiferentes localidades se puedan comparar. Además, la alta prevalencia observada en algunas zonas indica lanecesidad de intervención inmediata a través de la aplicación de estrategias de prevención y promoción de lasalud, dirigidas a reducir la exposición de la población brasileña a los factores asociados al riesgo del desarrollode las ECNT.

Medidas antropométricas e acidente vascular encefálico / Anthropometric measures and stroke

Introdução: O acidente vascular encefálico (AVE) é uma das maiores causas de morbidade e mortalidade em meios humanos,sendo seu tratamento vinculado com prolongada hospitalização e despesas econômicas elevadas. Dentro deste contexto, destacam-se as medidas antropométricas que podem ser consideradas importantes preditoras destes eventos cerebrovasculares. Objetivo: Investigar, através de revisão de literatura, a correlação entre as medidas antropométricas e o risco de AVE. Materiais e métodos: Foi realizada uma revisão sistemática, utilizando-se as bases de dados eletrônicos Medline, Pubmed e Scielo, reunindo pesquisas num período de 10 anos, entre 1996 e 2006, usando palavras chaves da língua inglesa como stroke, hypertension, body mass index (BMI), waist hip ratio(WHR), procedendo em seguida com a análise crítica dos dados obtidos, apresentando-os por distribuição de freqüência e tabulação. Resultados: Em 53 por cento dos estudos houve correlação positiva entre índice de massa corporal (IMC) e AVE, entretanto em 20 por centodos estudos, esta relação foi negativa. As medidas que descreviam circunferências abdominais apareceram em 47 por cento dos estudos correlacionadas positivamente com risco de AVE, e as dobras cutâneas que apesar de citadas escassamente (13 por cento) tiveram relação positiva coma doença cerebrovascular. Conclusão: Esta revisão reafirmou a correlação positiva entre obesidade abdominal, elevado IMC e dobras cutâneas com risco de AVE. Contudo, autores preconizam a reduçãode peso corpóreo e da circunferência abdominal, através de dietas eatividades físicas, como a melhor forma de prevenir o AVE.

Introduction: Stroke is one of the major causes of morbity and mortality in the mankind. The treatment is associated with long hospitalization and high economic costs. In this context, werestood out the anthropometrics measures that may be consideredan important indicative of these cerebrovascular events. Aim: To investigate, through literature review, the correlation between anthropometrics measures and risk of stroke. Methods: The author scarried out a systematic review, using the bases of electronic data Medline, Pubmed and Scielo of the last 10 years, between 1996 and 2006, using the following key words: stroke, hypertension, bodymass index (BMI), waist hip ration (WHR), proceeding with critical analysis of the obtained data and introducing them by frequency distribution and tabulation. Results: In 53 percent of the studies there is correlation between body mass index (BMI) and stroke, however, in 20 percent of the studies, this correlation was negative. The measures that described abdominal circumferences appeared in 47 percent correlated with risk of stroke, and the skinfolds in spite of scarcely mentioned (13 percent), had positive correlation with the cerebrovascular disease. Conclusion: This review reaffirms the positive correlation between abdominal obesity, BMI and skin folds with risk of stroke. However, authors recommend the reduction of body weight and abdominal circunference, through diets and physical activities, as the best formto prevent stroke.

Neuroproteção mediada pela vitamina D / Neuroprotection mediated by vitamin D

O objetivo do presente estudo foi apresentar os principais tópicos discutidos na literatura quanto à ação da vitamina D sobre o acidente vascular encefálico. São revisados aspectos referentes ao comportamento dessa vitamina sobre os fatores determinantes do acidente vascular encefálico, pois muitas evidências sugerem um efeito neuroprotetor devido à presença de receptores para vitamina D em múltiplas regiões do cérebro. Os resultados da literatura dos últimos 10 anos foram tabelados com as características de cada trabalho. A 1,25 di-hidroxivitamina D3foi escolhida como forma de suplementação dos ensaios analisados. Nenhum estudo em humanos procurou avaliar sua atuação na prevenção da isquemia cerebral, bem como não foi relatado qualquer trabalho envolvendo o modelo experimental de acidente vascular encefálico espontâneo. Apesar dos resultados apontarem para um papel neuroprotetor da vitamina D, os achados ainda são muito incipientes e discordantes quanto aos mecanismos de ação que estariam envolvidos nesse evento. Portanto, verifica-se a importância do desenvolvimento de novas investigações sobre a vitamina D como agente terapêutico nessa patologia.

The aim of the present study was to show the most important topics discussed in the literature about the action of vitamin D and stroke. Aspects related to this vitamin on stroke factors are reviewed, as many evidences suggest a neuroprotector effect due to the presence of vitamin D receptors in several areas of the brain. The results of the literature in the last 10 years were listed in a table with the characteristics of each article. 1,25 dihydroxyvitamin D3 was chosen as the form of supplementation of analyzed works. No study in humans investigated its action on cerebral ischemic prevention and no work that had involved the experimental model of spontaneous stroke was reported. In spite of the results showing a neuroprotector role of vitamin D, the findings are still very slight and in disagreement with mechanisms involved in this event. Therefore, the necessity is observed to develop new researches on vitamin D as a therapeutic agent of this pathology.

Biological response of spontaneously hypertensive rats to the streptozotocin administration

Foi estudada a sensibilidade de ratos espontaneamente hipertensos (SHR) adultos ao efeito diabetogênico da estreptozotocina (STZ). Os animais foram subdivididos em grupos: controle (tampão citrato), 40mg/kg ou 50mg/kg de estreptozotocina, sendo analisados parâmetros biológicos gerais, pressão arterial sistólica, níveis sanguíneos de glicose e insulina. Ambas as doses foram capazes de induzir hiperglicemia acima de 300mg/dl, entretanto a dose de 50mg/kg provocou efeitos fisiológicos mais pronunciados no peso corpóereo, diurese, ingestão hídrica e de ração. Não houve alteração da pressão arterial sistéolica em qualquer dose. Nossos achados sugerem que SHRs não necessitam de doses de estreptozotocina acima de 40 mg/kg com para produzir diabetes, provavelmente porque essa cepa é muito mais sensível do que ratos normotensos. A estreptozotocina pode ser a droga de escolha para induzir diabetes sem provocar alterações na pressão arterial, permitindo o uso desse modelo experimental nos estudos da hipertensão induzida pelo diabetes.

Dieta hipercalórica agrava a hipertensão arterial em ratos espontaneamente hipertensos / High-calorie and high-fat diet increases arterial hypertension in spontaneously hypertensive rats

A obesidade é uma desordem metabólica de etiologia complexa, ligada a fatores genéticos, dieta, metabolismo e atividade física, sendo a incidência de hipertensão arterial uma de suas conseqüências mais importantes. Este estudo investiga o efeito da dieta hipercalórica e hiperlipídica na pressão arterial sistólica de ratos espontaneamente hipertensos (SHR). Machos SHR (n=12) com 5 semanas de idade e peso variando de 88g a 90g mantidos em gaiolas metabólicas em biotério com condições controladas, foram subdivididos em dois grupos após período basal. Um grupo (n=6) recebendo dieta padrão (349kcal/100g) e outro (n=6) recebendo dieta hipercalórica e hiperlipídica (486kcal/100g). Foram avaliados o peso corpóreo, consumo de ração e pressão arterial sistólica dos animais. O período de ensaio durou 8 semanas. Os dados foram analisados pelo teste t-student. O grupo que recebeu dieta hiperlipídica e hipercalórica teve um ganho ponderal 2 vezes maior do que o grupo com ração padrão. A pressão sistólica inicial de 150?4mmHg do grupo com a dieta suplementada alcançou 181?7mmHg, superando os valores médios para ratos SHR nessa faixa etária. O uso da dieta hipercalórica foi eficaz para a indução da obesidade. Nossos resultados confirmam o agravamento do quadro de hipertensão por dieta hipercalórica e hiperlipídica e a influência dos componentes dessa dieta nesse processo, independentemente da quantidade de ração consumida.

Efeito da suplementação de beta-caroteno na pressão arterial de ratos / Effect of beta-carotene supplementation on the blood pressure of rats

OBJETIVO: Investigar se a suplementação com doses suprafisiológicas de beta-caroteno exerce efeito positivo no controle da hipertensão arterial, e detectar possíveis efeitos adversos dessa suplementação. MÉTODOS: Ratos espontaneamente hipertensos (n=12) e normotensos (n=12) com 20 semanas, foram submetidos a um período basal de 10 dias, e subdivididos em 4 grupos de 6 animais, suplementados com beta-caroteno em três diferentes doses: 2,5mg, 3,75mg e 5,0mg por animal, via gavagem orogástrica diária, durante 14 dias para cada dose, intercaladas por um período de wash-out de 7 dias; os grupos controle receberam apenas o veículo (óleo de coco). Foram ainda submetidos à avaliação ectoscópica para possível detecção de efeitos tóxicos ou interação entre nutrientes, e à análise dos parâmetros biológicos; a pressão sistólica foi aferida por pletismografia duas vezes na semana, em dias alternados. Após o período de suplementação os animais foram sacrificados, e tiveram o peso do fígado determinado pelo método de Scherle. RESULTADOS: A administração de beta-caroteno não levou a alterações dos parâmetros biológicos dos animais, assim como não foi detectado efeito tóxico. Quanto à pressão arterial sistólica, as duas linhagens apresentaram redução significante (p<0,05), sendo a maior redução observada durante administração da terceira dose. O peso médio do fígado foi de 7,25 (desvio-padrão 3,2) gramas, e a relação média do peso do órgão/média do peso corpóreo igual a 0,0192 para o grupo dos hipertensos. CONCLUSÃO: A suplementação de beta-caroteno tem efeito positivo tanto no controle quanto na prevenção da hipertensão arterial de ratos. A relação peso do fígado/peso corpóreo apresentou-se dentro dos padrões de normalidade.

OBJECTIVE: To investigate if supplementation with supraphysiological doses of beta-carotene has a positive effect on controlling hypertension and detect possible adverse effects of this supplementation. METHODS: 20-week-old spontaneously hypertensive rats (n=12) and normotensive rats (n=12) were submitted to a basal period of 10 days, then divided into 4 groups of 6 animals and supplemented daily by orogastric gavage with beta-carotene in 3 different doses: 2.5mg, 3.75mg and 5.0mg/animal during 14 days for each dose that was inserted by a seven day wash-out period; control groups received only coconut oil. Animals were submitted to ectoscopic evaluation to detect possible toxic effects or interaction between nutrients and analysis of biological parameters; systolic blood pressure was measured by plethysmography twice a week on alternate days; after the supplementation period, animals were killed and their livers weighed by the Scherle method. RESULTS: Administration of beta-carotene did not alter the animals' biological parameters or cause any toxic effects. Regarding systolic blood pressure, both lineages showed significant results (p<0.05), with the highest dose presenting the best results. The average liver weight was 7.25 (3.2 standard-deviation) grams, and the relationship between the average liver weight and body weight was 0.0192 for the hypertensive group. CONCLUSION: Beta-carotene supplementation was effective in controlling and preventing hypertension in rats. The relationship between liver weight and body weight was normal.

Effects of decylubiquinone (coenzyme Q10 analog) supplementation on SHRSP.

Decylubiquinone treatment in vitro has demonstrated a potent inhibitor effect on reactive oxidative species production. However, the effectin vivo has not been demonstrated yet. Thus, rats SHRSP male were divided in two groups: treated and controls (n=6, each). The treated group received 10 mg/Kg(-)/body weight of decylubiquinone diluted in coconut oil by oral gavage during four weeks. Control rats just received the vehicle. Body weight, diuresis, food and water intake, systolic blood pressure, total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, blood glucose levels and malondialdehyde were determined. There were a significant (p<0.05) reduction on systolic blood pressure, plasma malondialdehyde, total cholesterol and LDL-cholesterol in the treated group. Additionally, HDL-cholesterol also increased significantly. However, body weight, diuresis, food and water intake, blood glucose levels and triglycerides did not alter after treatment. Thus, decylubiquinone can be a new antihypertensive, hypolipidemic and antioxidant agent on the prevention and treatment of diseases linked to oxidative stress.

Consumo de Camellia sinensis em população de origem oriental e incidência de doenças crônicas / Camellia sinensis consumption by an Asian-Brazilian population and incidence of chronic diseases

Investigar os prováveis benefícios dos hábitos culturais orientais, incluindo o consumo de Camellia sinensis (chá verde) na prevenção de doenças crônicas. Trinta e quatro indivíduos entre 25 e 84 anos, de ambos os sexos, pertencentes à comunidade nipônica do Rio de Janeiro, RJ, foram submetidos a anamnese alimentar e questionário socio-econômico-cultural. Dos indivíduos, 76 por cento consumiam chá verde, sendo que 35 por cento o ingeriam diariamente e 27 por cento esporadicamente. Verificou-se que o consumo regular de álcool era predominante nos não usuários de chá verde, quando comparados com os apreciadores da bebida (50 por cento e 35 por cento, respectivamente, faziam uso de álcool). Não foi observado sedentarismo na amostra. Dos apreciadores do chá, 81 por cento não apresentavam doenças crônicas. Já entre os consumidores, observamos um menor percentual de doenças crônicas, especialmente, de hipertensão, porém sem significância estatística.

Effect of cholecalciferol supplementation on blood glucose in an experimental model of type 2 diabetes mellitus in spontaneously hypertensive rats and Wistar rats.

BACKGROUND: Vitamin D might have an influence on glucose concentrations, due to the presence of VDR receptors on the pancreas. We established an experimental model of type 2 diabetes in spontaneously hypertensive rats (SHR) and Wistar rats in order to investigate the glycemic response. METHODS: SHR males (n=6) and Wistar rats (n=6) weighing approximately 89+/-5.5 g and 123.5+/-6.5 g, respectively, after 7 days of basal period, had the chow pattern substituted (350 kcal/100 g) for a hypercaloric/hyperlipidic (HC/HL) diet (490 kcal/100g) and then injected with 40 mg/kg (SHR) and 20 mg/kg (Wistar) streptozotocin I.P. After the creation of diabetes, the rats suffered daily gavage of cholecalciferol (12.5 microg/kg(-) (1)) for 14 days. The blood glucose was assessed twice a week with a glucometer. The data were analyzed by ANOVA. RESULTS: SHR and Wistar rats fed on a HC/HL diet gained 60 g and 32 g in once week, vs. the basal period, where they only gained 23 g and 13 g, respectively. The cholecalciferol supplementation did not change the glucose concentration in all of the SHR animals. About 40% of the group responded by treatment with reduction of about 60% in glucose concentrations. We did find a 40% of the blood glucose levels in all Wistar rats. CONCLUSIONS: Cholecalciferol is able to reduce blood glucose in this experimental diabetes model.