The effect of weight reduction on antioxidant enzymes and their association with dietary intake of vitamins A, C and E / Efeito da redução de peso sobre as enzimas antioxidantes e associação destas com a ingestão de vitaminas A, C e E

Objective Our goal was to assess the effects of weight loss on antioxidant enzymes of red blood cells and it’s relation with vitamins A, E and C intake in 30 obese women. Subjects and methods General information, anthropometric measurements, 3-day food recall, and fasting blood samples were collected from 30 obese women at the beginning of the study and after 3 months intervention. Weight loss was set at about 10% of their weight before the intervention. Results Glutathione reductase and catalase activities showed a significant increase (P < 0.01) after weight reduction, but no significant changes were seen in the superoxide dismutase and glutathione peroxidase activities. There was a positive linear correlation between daily vitamin C intake with superoxide dismutase enzyme after intervention (P = 0.004, r = 0.507). There was a negative linear correlation between vitamin E intake and glutathione peroxidase activity before intervention (P = 0.005, r = -0.5). A negative correlation was found between daily vitamin A intake and glutathione reductase enzyme before and after intervention (r = -0.385, r = -0.397, P < 0.05) respectively. No significant correlation was observed between vitamins A, C, E amounts and catalase activity. Conclusions Ten percent weight reduction can have a significant role in increasing antioxidant enzymes activities, especially glutathione reductase, and catalase enzymes in obese women. However, it is important to take into consideration a balanced amount of certain nutrients while administering a diet with limited energy. .

Objetivo Nosso objetivo foi avaliar os efeitos da perda de peso sobre as enzimas antioxidantes de eritrócitos, e a relação destas com a ingestão das vitaminas A, E e C. Sujeitos e métodos Foram coletadas informações gerais e medidas antropométricas, registro alimentar de três dias e amostras de sangue em jejum de 30 mulheres obesas no início do estudo e depois de três meses da intervenção. A perda de peso determinada antes da intervenção foi de 10% do peso. Resultados As atividades da glutationa redutase e da catalase mostraram aumento significativo (P < 0,01) depois da perda de peso, mas não houve mudanças significativas nas atividades da superóxido dismutase e da glutationa peroxidase. Foi observada uma correlação linear positiva entre a ingestão diária de vitamina C e a enzima superóxido dismutase após a intervenção (P = 0,004, r = 0,507). Houve uma correlação linear negativa entre a ingestão de vitamina E e a atividade da glutationa peroxidase antes da intervenção (P = 0,005, r = -0,5). Foi observada uma correlação negativa entre a ingestão diária de vitamina A e a enzima glutationa redutase antes e depois da intervenção (r = -0,385, r = -0,397, P < 0,05), respectivamente. Não foram observadas correlações significativas entre as vitaminas A, C, E e os níveis e a atividade da catalase. Conclusões Uma redução de 10% no peso pode ter um papel significativo no aumento da atividade das enzimas antioxidantes, especialmente na glutationa redutase e catalase em mulheres obesas. Entretanto, é importante levar em consideração uma ingestão equilibrada de certos nutrientes ao se recomendar uma dieta com níveis de energia restritos. .

Representações sociais de educação em saúde em tempos de AIDS / Social representations of health education in a time of AIDS / Representaciones sociales de educación para la salud en la era del SIDA

Estudo qualitativo e descritivo, cujo objetivo foi identificar e analisar as representações sociais de educação em saúde à pessoa vivendo com HIV entre profissionais de saúde. Os cenários foram três serviços de atenção à DST/HIV/AIDS, em Belém-PA, Brasil, e 37 profissionais de saúde participaram da pesquisa. A coleta de dados deu-se em 2012-2013 por meio de entrevista em profundidade; a análise utilizou o software Alceste 4.10. Com base no conjunto dos resultados foi possível vislumbrar que a educação em saúde pode ser compreendida a partir de categorias: a configuração do agir educativo; as condições sine qua non: educação no trabalho e estrutura da unidade; o processo pedagógico. Conclui-se que as representações sociais configuram-se como orientação-informação para precaução-prevenção e revelam-se no movimento do agir persistente ao emergente, o que suscita uma educação em saúde permanente para se chegar à integralidade nos serviços.

This is a qualitative and descriptive study, which aimed at identifying and analyzing social representations of health education to HIV patients among health professionals. The setting included three healthcare DST/HIV/AIDS services in Belém-PA, Brazil, and 37 health professionals participated in the study. Data collection was conducted in 2012-2013 on the basis of in-depth interviews and analysis was made on Alceste 4.0 software. Final results indicated that health education can be comprehended in light of categories: educational action; sine qua non: education and training at work, and unit structure; teaching-learning process. Conclusions show that social representations are set as guidance-information for precaution-prevention and that they come forth along continuous and emerging action flow, bringing about permanent health education to ensure healthcare services in full.

Estudio cualitativo y descriptivo, que objetivó identificar y analizar las representaciones sociales de educación en salud a la persona viviendo con HIV entre profesionales de salud. Los escenarios fueron tres servicios de atendimiento al DST/HIV/ SIDA, en Belém-PA, Brasil, y 37 profesionales de salud participaran del estudio. La colecta de datos se dio en 2012-2013, por medio de entrevista en profundidad y el análisis utilizo el software Alceste 4.10. Con base en el conjunto de los resultados fue posible vislumbrar que la educación en salud puede ser comprendida a partir de categorías: la configuración del acto educativo; las condiciones sine qua non: educación en el trabajo y estructura de la unidad; el proceso pedagógico. Se concluye que las representaciones sociales se configuran como orientación-información para precaución-prevención y se revelan en el movimiento del acto persistente al emergente, lo que suscita una educación en salud permanente para llegarse a la integralidad en los servicios.

Total antioxidant capacity in Eales’ disease, uveitis & cataract.

Background & objectives: The human system possesses antioxidants that act harmoniously to neutralize the harmful oxidants. This study was aimed to evaluate the serum total antioxidant capacity (TAC) as a single parameter in Eales’ disease (ED) and in an acute inflammatory condition such as uveitis and in cataract which is chronic, compared to healthy controls. Methods: The TAC assay was done spectrophotometrically in the serum of Eales’ disease cases (n=20) as well as in other ocular pathologies involving oxidative stress namely, uveitis and cataract (n=20 each). The oxidative stress measured in terms of TBARS, was correlated with the TAC. Individual antioxidants namely vitamin C, E and glutathione were also estimated and correlated with TAC. Results: TAC was found to be significantly lower in Eales’ disease with active vasculitis (0.28 ± 0.09 mM, P<0.001), Eales’ disease with healed vasculitis (0.67 ± 0.09 mM), uveitis (0.46 ± 0.09 mM, P<0.001) and cataract (0.53 ± 0.1 mM, P=0.001) compared to the healthy controls, with a TAC level of 0.77 ± 0.09 mM. The TAC was found to correlate positively with vitamin E levels (P=0.05), GSH (P=0.02) but not with vitamin C, as seen in ED cases. In ED cases supplemented with vitamin E and C, there was a significant increase in the TAC level (P=0.02). Interpretation & conclusions: The TAC measurement provided a comprehensive assay for establishing a link between the antioxidant capacity and the risk of disease as well as monitoring antioxidant therapy. This method is a good substitute for assay of individual antioxidants as it clearly gives the status of the oxidative stress in the disease process.

Vitamina E e gravidez / Vitamin E and pregnancy

A vitamina E é considerada um antioxidante biológico por manter a integridade das membranas celulares.Em adultos saudáveis a deficiência de vitamina E é raramente observada.Deficiências de vitamina E podem ser vistas em crianças prematuras ou de baixo peso e naqueles com dificuldades na absorção de gorduras.A suplementação de vitamina E na gravidez é desnecessária e somente deve ser realizada em casos raríssimos.

Suplementación con vitamina E, benéfica o dañina? / Is vitamin-E supplementation beneficial or harmful?

Aunque en estudios de laboratorio se han observado efectos potencialmente benéficos de la vitamina E, los resultados de la evaluación clínica son inconsistentes. Una situación que ha limitado el conocimiento en esta área, es la dificultad para establecer comparaciones entre los diferentes estudios. Existen diferencias entre sujetos, tipos de formulaciones, etapas de la enfermedad, y otros aspectos. El consumo de megadosis de esta vitamina se ha incrementado en muchos países. En estudios recientes se ha informado que además de su capacidad antioxidante, esta vitamina tiene acciones moleculares precisas que influyen sobre la actividad de varias enzimas modulando la expresión de genes y la inducción de apoptosis. Sin embargo, algunos estudios clínicos y metaanálisis han informado que dosis de 400 UI/día o mayores de α-tocoferol, se asocian con aumento del índice de mortalidad. Resulta claro que hasta la fecha no se tiene un conocimiento completo de los efectos de estas sustancias a nivel celular y que existe controversia en los resultados de ensayos clínicos. En el presente trabajo se revisa el conocimiento actual sobre las características de esta vitamina, sus principales efectos benéficos, su toxicidad potencial y se discuten los resultados de algunos metaanálisis recientes en relación al aumento del riesgo de mortalidad.

Even though the beneficial effects of vitamin E have been experimentally observed, some clinical trials failed to verify a consistent benefit. One reason for this situation has been the difficulty to make comparisons among different studies. There are differences due to subjects, chemical forms of vitamin E, stages of the disease and others. The intake of high doses of vitamin E as a supplement has increased in many countries. Novel studies, have informed that vitamin E not only has antioxidant properties but can acts through precise molecular actions interacting with proteins and enzymes and modulating cellular signaling, transcriptional regulation and apoptosis induction. However, some recent clinical and meta analysis studies have found that daily supplementation with vitamin E 400 IU or higher is associated to increased mortality. In conclusion, a complete understanding of vitamin E actions at the cell does not exist yet and the controversy about its clinical effects is still present. This paper offers current knowledge on the characteristics, metabolism, properties, beneficial effect as well as the potential toxicity of vitamin E.

Adição da vitamina E aos alimentos: implicações para os alimentos e para a saúde humana / Adding vitamin E to foods: implications for the foods and for human health

A ingestão de vitamina E em doses acima das estabelecidas pelas Dietary Reference Intake, na forma de alimentos ou suplementos, está relacionada à prevenção de doenças crônicas não transmissíveis, à estimulação do sistema imune e à modulação dos processos degenerativos relacionados ao envelhecimento. Por outro lado, a adição de vitamina E aos alimentos com o intuito de alcançar tais efeitos ainda não é comum, porque não há consenso sobre a dose a ser consumida. Em muitas populações tem sido necessário ingerir alimentos fortificados com vitamina E, para alcançar os níveis recomendados para a ingestão adequada. Este trabalho enfoca o papel da vitamina E como um componente antioxidante utilizado pela indústria alimentícia, como um composto que exerce funções específicas no organismo humano e no alimento e como um importante nutriente que, quando adicionado aos alimentos, é capaz de atuar contra a lipoperoxidação e contribuir para o aumento de sua ingestão, além de poder reduzir os efeitos deletérios dos processos oxidativos que ocorrem no organismo humano, prevenindo as doenças crônicas não transmissíveis.

Taking vitamin E in higher doses than those recommended by the Dietary Reference Intake in foods or supplements helps prevent non-communicable chronic diseases, stimulates the immune system and modulates the degenerative processes associated with aging. On the other hand, the addition of vitamin E to foods to obtain those effects is not common yet because there is no consensus on an ideal dose. Vitamin E has been added to the foods consumed by some populations because their intake used to be below the recommended amount. This study focuses on the role of vitamin E (1) as an antioxidant used by the food industry, (2) as acompound with specific functions in the human body and in foods, (3) as an important nutrient that, when added to foods, is capable of inhibiting lipoperoxidation and increase its intake and (4) as a substance that might be capable of reducing the deleterious effects of the oxidative processes that occur in the human body and therefore helping to prevent non-communicable chronic diseases.

Efeito da vitamina E-TPGS hidromiscível sobre as alterações nutricionais e a lesão hepática na colestase crônica: estudo experimental em ratos jovens / The effect of water soluble vitamin E-TPGS on nutritional alterations and hepatic lesions in chronic cholestasis-an experimental study in young rats

A colestase crônica por ligadura e ressecção do ducto biliar em ratos jovens é frequentemente utilizada como modelo experimental de atresia biliar. Na colestase ocorre má absorção de vitamina E com resultante estresse oxidativo. Objetivos: Sendo a vitamina E-TPGS hidromiscível, e portanto absorvível mesmo na colestase, testamos os seus efeitos sobre 35 consequências nutricionais, sobre as alterações do metabolismo lípidico e sobre a lesão hepática da colestase obstrutiva crônica no modelo experimental acima. Métodos: Quarenta ratos machos da raça wister com 21 dias de vida (P21) foram divididos em 4 grupos de 10 animais e submetidos a um dos seguintes tratamentos: 1) LA-ligadura e ressecção do ducto biliar comum e administração diária de água, por gavagem, num volume de 0,02ml por grama de peso do animal; 2) LE-ligadura e ressecção do ducto biliar comum e administração diária, por gavagem, de 25UI/kg num volume de 0,02ml de vitamina E-TPGS por grama de peso do animal de uma solução a 20% de vitamina E-TPGS; 3) SA-operação simulada e administração diária de água, por gavagem, num volume de 0,02ml por grama de peso do animal; 4) SE-operação simulada e administração diária, por gavagem, de 25UI/kg num volume de 0,02ml de vitamina E-TPGS por grama de peso do animal de uma solução a 20% de vitamina E-TPGS. Durante o experimento foi determinado o ganho de peso, a quantidade de ração ingerida, o aproveitamento nutricional (P21 a P49) e balanço nitrogenado (P42 aoP49). No P48, foram submetidos ao teste do tempo de sono após pentobarbital. No P49, foram sacrificados e colhido sangue e órgãos para seguintes determinações: peso fresco, conteúdo de água e gordura da carcaça, fígado e baço, concentrações séricas de colesterol-T, triacilglicerol, LDL-colesterol, VLDL-colesterol, HDL-colesterol, albumina, globulinas totais, vitamina A e E, atividade sérica das aminotransferases (AL T e AST).

Enzymatic and non-enzymatic antioxidants in selected Piper species.

Piper species, commonly used in diet and traditional medicine were assessed for their antioxidant potential. Catalase activity was predominated in Piper longum, followed by Piper cubeba, green pepper, Piper brachystachyum and Piper nigrum. P. nigrum was richest in glutathione peroxidase and glucose-6-phosphate dehydrogenase, green pepper was richest in peroxidase and vitamin C while vitamin E was more in P. longum and P. nigrum. P. brachystachyum and P. longum were rich sources of vitamin A. All the Piper species had GSH content of around 1 to 2 nM/g tissue. The antioxidant components of Piper species constitute a very efficient system in scavenging a wide variety of reactive oxygen species. Antioxidant potential of Piper species was further confirmed by their ability to curtail in vitro lipid peroxidation by around 30-50% with concomitant increase in GSH content.

Intake of Dietary Fat and Vitamin in Relation to Breast Cancer Risk in Korean Women: A Case-Control Study

To investigate association between breast cancer risk and nutrients intake in Korean women, a case-control study was carried out, at Seoul, Korea. Incident cases (n=224) were identified through the cancer biopsy between February 1999 and December 2000 at two University hospitals in Seoul. Hospital-based controls (n=250) were selected from patients in the same hospitals, during the same periods. Food intake was investigated semiquantitative frequency questionnaire (98 items) by trained dietitian. Subjects were asked to indicate the average food intake and vitamin supplement for a 12 months period of 3-yr prior to the base-line phase. In investigation of vitamin supplement use, subjects were asked the average frequency of use, duration, dose and the brand name of vitamin supplement (multivitamins, vitamin A, vitamin C and vitamin E). And nutrients were calorie adjusted by the residuals method. In this study, higher breast cancer risk incidence was not observed with higher intake of total fat and saturated fatty acids, however statistically significant trends with breast cancer incidence for total saturated fatty acids were found (p trend =0.0458). In analyses of vitamins, beta-carotene and vitamin C were significantly associated with decreasing risk of breast cancer. In analyses, results from dietary plus supplement of vitamin was not associated with breast cancer risk in this study. In conclusion, our findings suggest that antioxidant vitamins such as beta-carotene and vitamin C intake could lower the breast cancer risk in Korean women.

Effects of dried fish on antioxidant levels in rat liver.

Short-term feeding studies were carried out to investigate the effect of ingestion of salted dried fish on alterations in tissue lipid peroxidation and modulation of the activities of detoxification enzymes in liver in order to study the induction of oxidative stress. Rats were fed diets with either 5, 10 and 20% dried mackerel for 4 weeks and levels of antioxidants in liver were estimated. The results showed that the fish intake at 10 and 20% dietary level reduced glutathione with a reciprocal increase in thiobarbituric acid reactive substances and a concomitant decrease in antioxidant vitamins A and C contents in liver. A significant decline in the activities of hepatic glutathione peroxidase and glutathione reductase were also observed at these levels of fish consumption. Kidney gamma-glutamyl transpeptidase activity on the other hand was increased abnormally at 20% fish intake. The results suggested that the dried fish consumption at higher concentrations (at 10 and 20%) for a short period caused lowering of the activities of antioxidative enzymes thereby inducing oxidative stress in rat liver.

The Effects of Antioxidants and Nitric Oxide Modulators on Hepatic Ischemic-Reperfusion Injury in Rats

Ischemic-reperfusion injury (IRI) is thought to be caused by oxygen radicals. Nitric oxide (NO) also has been thought to play a key role in IRI. This experiment was designed to evaluate the effects of antioxidants and NO supplement on hepatic IRI. Male Sprague-Dawley rats were divided into five groups: a sham operation group, a group with IRI, and three groups with vitamin C combined with vitamin E (VC&VE), L-arginine and N(G)-nitro-L-arginine (NNLA) injected after IRI. IRI was induced by clamping of the porta hepatis for 30 minutes and then by declamping. To prevent mesenteric blood congestion, a porto-systemic shunt had been made four weeks before the portal clamping. Biochemical assays of TNF-alpha level and NO2- level in the blood, malondialdehyde level, catalase activity and NO synthase activity in the liver tissue were performed. The results were as follows: IRI increased the malondialdehyde level and exhausted the catalase activity remarkably. VC&VE lowered the malondialdehyde levels and protected against catalase exhaustion, but had no significant effect on the NO production. L-arginine had a definite antioxidant effect, which was much weaker than that of VC&VE. In conclusion, antioxidants and a supplement of NO protected the liver tissue against IRI.

study of the relation between vitamin E status and the degree of liver disease in patients with hepatosplenic schistosomiasis

Vitamin E has an antioxidant protective effect against peroxidation in lipid phase in the membranes of most cells. Previous reports have shown diminished vitamin E in some chronic liver disease. This study aimed to assess vitamin E status in patients with hepatosplenic bilharziasis with different degree of liver dysfunction. Assessment of serum alpha, gamma and delta tochopherol, total serum cholesterol, total serum biltrubtn, serum ALT, serum albumin and prothrombin activity were done in 40 patients with hepatosplenic bilharziasis [15 Child s stage A, 13 Child s stage B and 12 Childs stage C], and in 10 healthy control subjects. Serum alpha, gamma and delta tochopherols decreased significantly [P<0.01] in all patient groups when compared to healthy controls. Also serum alpha tochopherol to cholesterol ratio [which is supposed to be a better reflection of vitamin E status] decreased sign [P< 0.01] in all patient groups when compared to healthy control. Serum vitamin E [alpha] and ratio between alpha-tochopherol to cholesterol was correlated significantly with serum cholesterol, plasma prothrombin time, ALT, albumin, bilirubin and Child score. These results indicate that in patients with hepatosplenic bilharziasis, vitamin E status is reduced as evidenced by reduced serum alpha, gamma and delta tochopherols and reduced serum alpha tochopherol to cholesterol ratio. Both are sign correlated with biochemical and clinical findings of the disease

Efeito da vitamina E, da vitamina C e da associacao vitamina E-vitamina C, na sindrome de isquemia-reperfusao, em membro posterior de rato / Effects of vitamin E, the vitamin C and the association of vitamin E-vitamin C, in ischemia-reperfusion syndrome, on the posterior paw of rat

O possivel efeito da vitamina E, vitamina C e da associacao de ambas foi avaliado na atenuacao das lesoes de reperfusao da pata posterior de ratos, submetida a isquemia total. Foram estudados cinco grupos experimentais: Grupo 1-grupo controle em que nao foi realizada isquemia-reperfusao; grupos 2, 3, 4 e 5 com isquemia-reperfusao, onde um clampe microcirurgico foi colocado na arteria femoral por um periodo de 4 horas, de modo a causar uma isquemia total do membro. Depois, o clampe foi retirado, permitindo a reperfusao por 2 horas. As alteracoes devidas ao processo isquemia-reperfusao e os eventuais efeitos da vitamina E, da vitamina C e da associacao de ambas foram estudados pela avaliacao do grau de edema, tomando-se a medida da circunferencia da pata em 3 momentos: apos a anestesia; ao final da isquemia; e ao final da reperfusao. Os produtos da peroxidacao lipidica das membranas celulares foram...

Altered lipid peroxidation and antioxidant potential in human uterine tumors.

A comparative study of lipid peroxidation and antioxidant potential has been made in human uterus and uterine tumor. Two types of uterine tumor used are: tumor (I), a fibroid which is the commonest benign solid tumor in uterus and tumor (II), an adenomyoma. Tumor microsomes are less susceptible to lipid peroxidation induced by both enzymic (NADPH-ADP-Fe3+ and xanthine-xanthine-oxidase) and non-enzymic (ascorbate-Fe2+) systems except in the case of tumor (II) microsomes when induced with xanthine-xanthine oxidase. Resistance of tumor microsomes to lipid peroxidation is associated with the low content of substrates in the form of polyunsaturated fatty acids (PUFAs), higher level of alpha-tocopherol, reduced glutathione and protein thiols and altered enzymic antioxidant potential (catalase and superoxide dismutase).

Effect of DEHP [di-(2-ethyl hexyl) phthalate] on lipid peroxidation in liver in rats and in primary cultures of rat hepatocytes.

The effect of DEHP [di-(2-ethly hexyl) phthalate] on lipid peroxidation in the liver in rats and in primary cultures of rat hepatocytes incubated with it was studied. The doses of DEHP used in this study corresponded to the low levels of this substance leaching into blood stored in DEHP plasticised PVC bags. Increased activity of superoxide dismutase (SOD) and catalase, increased concentration of malondialdehyde (MDA) and conjugated dienes and decrease in the concentration of glutathione and vitamin E have been observed in the liver of rats administered DEHP. Primary cultures of rat hepatocytes incubated with DEHP also showed increase in the activity of these enzymes, increase in the concentration of MDA and decrease in vitamin E. These results indicate that DEHP promotes lipid peroxidation. Incorporation of vitamin E along with DEHP into the culture medium containing hepatocytes counteracted these effects.

Efeito de uma dose aguda de etanol sobre a peroxidaçäo lipídica em ratos: Açäo da vitamina E / Acute dose of ethanol's effect on lipid peroxidation in rats: action of the vitamin E

A geraçäo de radicais livres é um passo importante na patogênese da injúria hepática associada a ingestäo de etanol. A ingestäo do etanol induz a um aumento naperoxidaçäo lipídica por dois mecanismos: uma maior produçäo de espécies reativas de oxigênio e/ou pela diminuiçäo dos níveis dos antioxidantes endógenos. Este trabalho enfoca a geraçäo de radicais livres em ratos, após a ingestäo de uma dose aguda de etanol, e o papel de diferentes níveis de vitamina E na dieta oferecida aos animais. O objetivo do trabalho foi investigar o efeito de dietas com diferentes concentraçöes de vitamina E (Deficiente, Controle e Suplementada 20 vezes) sobre a peroxidaçäo lipídica plasmática e hepática (medida por SRATB), vitamina E em plasma e fígado e glutationa hepática, em ratos alimentados com as dietas. Os animais receberam uma dose aguda de etanol (5 mg/Kg de peso) ao final do período experimental (4 semanas) e foram sacrificados em cinco períodos distintos: 0, 2, 4, 8 e 24 horas após o etanol...

Suplementación de DL-Ó-tocoferol acetato oral en niños con colestasis crónica y déficit de vitamina E / Supplement of Oral DL-Ó-Tocopherol Acetate in children with chronic cholestasis and vitamin E deficit

Objetivo. Determinar la dosis oral suplementaria de dl-Ó-tocoferol acetato para mantener niveles séricos de Ó-tocoferol normales en niños con colestasis crónicas y déficit de vitamina E. Antecedentes. La malabsorción y deficiencia de vitamina E en niños con colestasis crónica se presenta en un 60-70 por ciento, causando un síndrome de degeneración neurológica progresiva entre 18 y 24 meses si no se corrige. La pronta suplementación con vitamina E determina la prevención e irreversibilidad de dicho déficit. Método. Realizamos un estudio prospectivo, longitudinal y comparativo de 60 niños divididos en tres grupos, con déficit de vitamina E y colestasis crónica. Luego de una evaluación inicial y por 15 días, cada grupo recibió suplementación oral con 100 UI, 200 UI y 400 UI diarias de dl-Ó-tocoferol acetato, respectivamente. Fueron monitorizados los niveles séricos de Ó-tocoferol, la función neurológica y los parámetros bioquímicos durante la suplementación. Resultados. Ninguna de las dosis suplementarias orales de dl-Ó-tocoferol acetato administradas por 15 días normalizaron los niveles séricos de Ó-tocoferol (p>0.06). La función neurológica, que no encontraba alterada al inicio del estudio en ninguno de los pacientes, permaneció estable luego de los 15 días, a dosis de 100 UI, 200 UI y 400 UI, a pesar de ser seguro, no mantuvo los niveles séricos normales de Ó-tocoferol en niños con colestasis crónica y déficit de vitamina E

Dietary polyunsaturated fatty acids, and tissue oxidative stress: the effect of d,l-Ó-tocopherol

The effects of feeding young and aged rats with high doses of polyunsaturated fatty acids from marine oil on the susceptibility of erythrocyte membranes to the induction of oxidative stress, on the level of reduced glutathione of different tissues, and on the antioxidant capacity of blood plasma were studied. The protective effect of the supplementation of the oil with d,l-alpha-tocopherol was also assayed. d,l-alpha-Tocopherol supplementation protects erythrocyte membranes from young rats against the induction of oxidative stress, being unable to protect the membranes from the aged ones. The tripeptide glutathione shows a different behavior depending on the tissue. Blood glutathione is not affected by fish oil ingestion and by the d,l- alpha-tocopherol supplementation either in the young or in the aged animals. Liver glutathione is reduced by fish oil feeding in the aged animals only. Brain glutathione is not affected by the fish oil feeding. The supplementation with d,l-alpha-tocopherol restores the hepatic levels of glutathione and increases the brain level of the tripeptide over the controls, this effect being observed for young and the aged rats. The antioxidant capacity of blood plasma in response to the fish oil feeding increases in the young rats only. This capacity is not affected by the suplementation with d,l-alpha-tocopherol. These metabolic changes are ascribed to possible adaptative responses from the animals to the potential risk of oxidative stress induced by fish oil ingestion. We suggest that metabolic risks may be associated with the consumption of high doses of polyunsaturated fatty acids.

Histochemical detection of vitamins D, E and cholesterol in the tailfin rays of the teleost Tilapia rendalli

As nadadeiras dos teleósteos säo constituídas por unidades esqueléticas segmentares denominadas lepidotriquiais ou raios. Essas nadadeiras estäo envolvidas em processos regenerativos: assim, o conhecimento de sua estruturaçäo normal é de fundamental importância tanto para a compreensäo do processo de crescimento como de sua regeneraçäo. Com o objetivo de detectar substâncias lipídicas, as nadadeiras caudais foram fixadas pela formalina contendo bicloreto de cálcio a 3 por cento por 24 horas, à temperatura ambiente. Cortes com 10um de espessura, obtidos em micrótomo de congelaçäo foram submetidos às seguintes reaçöes histoquímicas específicas para lipídios: 1) Permanganato de Potássio Alcalino - Azul de Toluidina, para detecçäo de vitamina D; 2) Acido Perfórmico-Azul de Toluidina, para detecçäo de vitamina E e 3) Acido Peracético-Azul de Toluidina, para detecçäo de colesterol. Os controles para os testes histoquímicos 1, 2 e 3 foram feitos omitindo-se o agente oxidante. Reaçöes positivas obtidas para as reaçöes 1, 2 e 3 demonstraram a presença de vitamina D, E e colesterol nos raios das nadadeiras caudais da espécie Tilapia rendalli