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1.
Public Health Nutr ; 23(16): 3028-3044, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32758320

RESUMEN

OBJECTIVE: To define a generic diet to protect human health and food system sustainability based on three dimensions: animal:plant ratio, degree of food processing and food diversity. DESIGN/SETTING: The percentages of maximum animal and ultra-processed energy content were evaluated from scientific papers (Web of Science database) and reports from international scientific institutions. Then, a weekly French standard diet, including these percentages and food diversity (≥42 different foods), was designed to calculate adequacy to nutritional needs. RESULTS: Based on traditional and scientifically based healthy diets, and on foresight scenarios for sustainable diets at horizon 2050, a median daily animal energy content intake of 15 % was found to be protective towards both human health and environment. Based on epidemiological studies associating ultra-processed energy consumption with increased overweight/obesity risk, a precautionary threshold of approximately 15 % ultra-processed energy content was observed. The French diet allows addressing all nutritional needs and other nutritional indicators such as maximum salt and simple sugar consumption, α-linolenic acid:linoleic acid ratio and essential amino acids. This diet was named the '3V rule' for Végétal (plant), Vrai (real) and Varié (varied, if possible organic, local and seasonal). This generic diet can be adapted according to regional traditions and environmental characteristics. Excluding only one dimension of it would threaten both health and food system sustainability. CONCLUSIONS: Tending towards a 3V-based diet, while respecting local constraints, should allow preserving human health, environment (greenhouse gas emissions, pollution, deforestation, etc.), small farmers, animal welfare and biodiversity, culinary traditions and socioeconomics (including an alleviation of public health cost).


Asunto(s)
Dieta , Salud Global , Animales , Dieta Saludable , Abastecimiento de Alimentos , Humanos , Valor Nutritivo
2.
Med Hypotheses ; 82(2): 181-6, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24355424

RESUMEN

The study of micronutrient and phytochemical (MaP, i.e., non-energy nutrients) bioavailability has been mainly studied through a reductionist and pharmacological approach. This has led to associate one health effect to one MaP. However, human interventional studies have given conflicting and disappointing results about MaP supplementation. This is because the health effect is the result of the synergetic action of numerous MaPs supplied by foods and/or diets at nutritional doses. A food is not a drug. Therefore, there is a need for more holistic approach to study MaP bioavailability, then their health effect to achieve general recommendations. This paper aims to hypothesize for such a paradigm shift in this topic and to lay new foundations for research in MaP bioavailability.


Asunto(s)
Micronutrientes/farmacocinética , Fitoquímicos/farmacocinética , Disponibilidad Biológica , Suplementos Dietéticos , Alimentos , Humanos , Inflamación , Intestinos/microbiología , Cinética , Modelos Teóricos , Ciencias de la Nutrición/normas
3.
Br J Pharmacol ; 165(8): 2620-34, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21827451

RESUMEN

BACKGROUND AND PURPOSE: To evaluate the hypothesis that activation of somatodendritic 5-HT(1A) autoreceptors in the dorsal raphe nucleus (DRN) produces the anti-emetic/anti-nausea effects of cannabidiol (CBD), a primary non-psychoactive cannabinoid found in cannabis. EXPERIMENTAL APPROACH: The potential of systemic and intra-DRN administration of 5-HT(1A) receptor antagonists, WAY100135 or WAY100635, to prevent the anti-emetic effect of CBD in shrews (Suncus murinus) and the anti-nausea-like effects of CBD (conditioned gaping) in rats were evaluated. Also, the ability of intra-DRN administration of CBD to produce anti-nausea-like effects (and reversal by systemic WAY100635) was assessed. In vitro studies evaluated the potential of CBD to directly target 5-HT(1A) receptors and to modify the ability of the 5-HT(1A) agonist, 8-OH-DPAT, to stimulate [(35) S]GTPγS binding in rat brainstem membranes. KEY RESULTS: CBD suppressed nicotine-, lithium chloride (LiCl)- and cisplatin (20 mg·kg(-1) , but not 40 mg·kg(-1) )-induced vomiting in the S. murinus and LiCl-induced conditioned gaping in rats. Anti-emetic and anti-nausea-like effects of CBD were suppressed by WAY100135 and the latter by WAY100635. When administered to the DRN: (i) WAY100635 reversed anti-nausea-like effects of systemic CBD, and (ii) CBD suppressed nausea-like effects, an effect that was reversed by systemic WAY100635. CBD also displayed significant potency (in a bell-shaped dose-response curve) at enhancing the ability of 8-OH-DPAT to stimulate [(35) S]GTPγS binding to rat brainstem membranes in vitro. Systemically administered CBD and 8-OH-DPAT synergistically suppressed LiCl-induced conditioned gaping. CONCLUSIONS AND IMPLICATIONS: These results suggest that CBD produced its anti-emetic/anti-nausea effects by indirect activation of the somatodendritic 5-HT(1A) autoreceptors in the DRN. LINKED ARTICLES: This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7.


Asunto(s)
Antieméticos/uso terapéutico , Cannabidiol/uso terapéutico , Núcleos del Rafe/fisiología , Receptor de Serotonina 5-HT1A/fisiología , Agonistas del Receptor de Serotonina 5-HT1/farmacología , Vómitos/tratamiento farmacológico , 8-Hidroxi-2-(di-n-propilamino)tetralin/metabolismo , 8-Hidroxi-2-(di-n-propilamino)tetralin/farmacología , Animales , Conducta Animal/efectos de los fármacos , Cannabis , Femenino , Masculino , Náusea/tratamiento farmacológico , Náusea/fisiopatología , Piperazinas/farmacología , Piridinas/farmacología , Núcleos del Rafe/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Antagonistas del Receptor de Serotonina 5-HT1/farmacología , Musarañas , Vómitos/fisiopatología
4.
J Eur Acad Dermatol Venereol ; 22(1): 94-100, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18181979

RESUMEN

BACKGROUND: In the last two decades, there has been an increasing use of isotretinoin (13-cis-retinoic acid or 13-CRA) for treatment of severe, and recently mild and moderate, acne in Westernized populations. Recent human and animal studies emphasized alterations caused by 13-CRA administration on folate-dependent, one-carbon metabolism. Folate deficiency and subsequent hyperhomocysteinemia increase the risk of degenerative diseases. OBJECTIVES: We determine whether a short-term supplementation with 13-CRA alters folate status and homocysteinemia in young and elderly healthy human subjects. METHODS: Twenty young and 20 elderly (age mean, 26.1 and 65.4 years, respectively) healthy male volunteers were supplemented with approximately 0.5 mg/kg/day of 13-CRA for 28 days. Fasting plasma concentrations of 13-CRA, 5-methyltetrahydrofolate (5-mTHF) as the main circulating form of folate, and homocysteine (Hcy), as well as haematologic parameters and biochemical markers of liver and renal function, were measured at baseline and at the end of supplementation. Statistical analyses were carried out using two-way anova and standard tests. RESULTS: In both groups, isotretinoin supplementation caused a dramatic increase in the circulating concentration of 13-CRA and its derivatives. It also led to significant increases in serum triglyceride (P < 0.0001) and creatinine (P = 0.002) concentrations and gamma-glutamyltranspeptidase activity (P = 0.0001) and decrease in serum level of urea (P = 0.027). However, the latter four parameters remained within normal ranges. These changes were accompanied by a 17.7% and 13.5% decrease in the plasma level of 5-mTHF (P = 0.001) in the young and elderly volunteers, respectively. Supplementation with 13-CRA did not cause significant variations in their plasma Hcy concentration. However, the latter parameter seemed to respond differently in each group of age (P = 0.046). CONCLUSIONS: Our data indicate that a 28-day supplementation with isotretinoin alters the plasma folate in young and old healthy individuals. This stresses the necessity of studying the long-term effects of retinoid therapy on folate status and homocysteinemia in acne patients, given that alteration in the latter parameters is known to increase the risk of degenerative diseases.


Asunto(s)
Envejecimiento/sangre , Fármacos Dermatológicos/farmacología , Ácido Fólico/sangre , Isotretinoína/farmacología , Acné Vulgar/tratamiento farmacológico , Adulto , Anciano , Fármacos Dermatológicos/administración & dosificación , Fármacos Dermatológicos/sangre , Suplementos Dietéticos , Homocisteína/sangre , Humanos , Isotretinoína/administración & dosificación , Isotretinoína/sangre , Masculino , Tetrahidrofolatos/sangre
5.
Mech Ageing Dev ; 128(11-12): 594-600, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17916375

RESUMEN

The regulation of cell growth and differentiation and also expression of a number of genes by retinoids are mediated by nuclear retinoid receptors (RARs and/or RXRs). In this study we investigated age-related alteration in both RAR and RXR receptor subtypes gene expression and tissue transglutaminase (tTG) activity before and after supplementation with 13-cis retinoic acid (13cRA) in human peripheral blood mononuclear cells (PBMCs). Healthy men (40) were divided in two groups according to their age (young group: 26.1+/-4.1 years and old group: 65.4+/-3.8 years). Each volunteer received 13cRA (Curacné), 0.5mg/(kgday)) during a period of 4 weeks. We have shown that RXRbeta expression was decreased significantly (p=0.0108) in PBMCs of elderly men when compared to that of young volunteers. Distribution of retinoic acid receptor subtype expression in PBMCs was found in the order: RXRbeta>RARgamma>RXRalpha>RARalpha. The tTG activity in PBMCs reflected a trend to be enhanced after 13-cis retinoic acid supplementation. In conclusion, we demonstrate a significant decrease in the expression of RXRbeta subtype of rexinoid receptors in PBMCs of healthy elderly men. Our data suggest that in healthy elderly men reduction of RXRbeta expression in PBMCs might be a common feature of physiological senescence.


Asunto(s)
Envejecimiento/genética , Suplementos Dietéticos , Isotretinoína/uso terapéutico , Leucocitos Mononucleares/efectos de los fármacos , Receptor beta X Retinoide/genética , Adulto , Factores de Edad , Anciano , Envejecimiento/sangre , Alitretinoína , Senescencia Celular/efectos de los fármacos , Senescencia Celular/genética , Regulación hacia Abajo/efectos de los fármacos , Proteínas de Unión al GTP , Humanos , Isotretinoína/sangre , Isotretinoína/farmacología , Leucocitos Mononucleares/enzimología , Leucocitos Mononucleares/metabolismo , Masculino , Persona de Mediana Edad , Proteína Glutamina Gamma Glutamiltransferasa 2 , ARN Mensajero/sangre , Receptores de Ácido Retinoico/genética , Valores de Referencia , Receptor alfa de Ácido Retinoico , Receptor alfa X Retinoide/genética , Receptor beta X Retinoide/sangre , Factores de Tiempo , Transglutaminasas/sangre , Tretinoina/sangre , Receptor de Ácido Retinoico gamma
6.
Br J Nutr ; 98(4): 691-701, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17475083

RESUMEN

Plant extracts rich in polyphenols (PERP) could represent interesting alternative antioxidants but their use in ruminants needs further investigation since the antioxidant capacity of PERP could be altered by digestive processes. The aim of the study was to investigate the bioavailability and the antioxidant capacity of four PERP (rosemary; grape; citrus; marigold) in ruminants made highly susceptible to lipoperoxidation by a continuous linseed oil infusion (4 % DM) in the duodenum. The PERP were given, as a single acute dose (10 % DM), directly into the rumen of sheep (n 5) and blood was then collected every 3 h over a period of 30 h. Grape was particularly efficient to enhance the plasma total antioxidant status (P < 0.05). Moreover, many new polyphenols were detected in the plasma and the identification of epicatechin in the grape group suggested that, contrary to monogastrics, ruminants can benefit from the antioxidant effect of polymeric proanthocyanidins. Finally, the four PERP tested, and more especially marigold, significantly reduced plasma susceptibility to liperoxidation (mean increase of lag phase: +5.9 min, P < 0.02; mean reduction of oxidation rate: - 1.7 A234/min, P < 0.01). In conclusion, the digestive processes in ruminants do not inhibit the antioxidant properties of PERP in vivo and are beneficial by improving the biological effect of polymeric proanthocyanidins. Further experiments are now necessary to determine the optimum dose of administration and to characterize the bioactive molecules.


Asunto(s)
Antioxidantes/farmacocinética , Flavonoides/farmacocinética , Peroxidación de Lípido/efectos de los fármacos , Fenoles/farmacocinética , Extractos Vegetales/farmacocinética , Alimentación Animal , Animales , Disponibilidad Biológica , Estrés Oxidativo , Polifenoles , Ovinos , Oveja Doméstica , Resultado del Tratamiento
7.
Free Radic Biol Med ; 29(11): 1129-34, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11121720

RESUMEN

The oxidative modification of low-density lipoprotein cholesterol (LDL) has been implicated in the pathogenesis of atherosclerosis. Copper (Cu) is essential for antioxidant enzymes in vivo and animal studies show that Cu deficiency is accompanied by increased atherogenesis and LDL susceptibility to oxidation. Nevertheless, Cu has been proposed as a pro-oxidant in vivo and is routinely used to induce lipid peroxidation in vitro. Given the dual role of Cu as an in vivo antioxidant and an in vitro pro-oxidant, a multicenter European study (FOODCUE) was instigated to provide data on the biological effects of increased dietary Cu. Four centers, Northern Ireland (coordinator), England, Denmark, and France, using different experimental protocols, examined the effect of Cu supplementation (3 or 6 mg/d) on top of normal Cu dietary intakes or Cu-controlled diets (0.7/1.6/6.0 mg/d), on Cu-mediated and peroxynitrite-initiated LDL oxidation in apparently healthy volunteers. Each center coordinated its own supplementation regimen and all samples were subsequently transported to Northern Ireland where lipid peroxidation analysis was completed. The results from all centers showed that dietary Cu supplementation had no effect on Cu- or peroxynitrite-induced LDL susceptibility to oxidation. These data show that high intakes (up to 6 mg Cu) for extended periods do not promote LDL susceptibility to in vitro-induced oxidation.


Asunto(s)
Cobre/administración & dosificación , Peroxidación de Lípido/efectos de los fármacos , Lipoproteínas LDL/sangre , Adulto , Dinamarca , Dieta , Suplementos Dietéticos , Inglaterra , Femenino , Francia , Radicales Libres , Humanos , Masculino , Persona de Mediana Edad , Nitratos/farmacología , Irlanda del Norte
8.
Br J Nutr ; 83(5): 561-8, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10953681

RESUMEN

There is a lack of agreement on index of Cu status and reliable and sensitive biomarkers are still required. The purpose of this present work was to assess in rats the sensitivity of diamine oxidase (DAO) activity, a recently proposed biomarker, to modifications in dietary Cu intake in comparison with other plasma biomarkers of Cu status. We also evaluated the effect of Cu dietary level on Cu and Zn intestinal absorption. Results showed that plasma Cu and plasma caeruloplasmin were significantly decreased at day 8 compared with the control group (7.4 mg Cu/kg diet) while DAO activity was significantly decreased at day 12 of the deficient diet (0.61 mg Cu/kg diet). Cu supplementation (35 mg Cu/kg diet) had no effect on any of the studied biomarkers of Cu status. In Cu-deficient rats plasma Cu and DAO activities were normalized 4 d after return to the control diet while caeruloplasmin was normalized later, at day 11. Apparent absorption values (%) of total Cu or 65Cu isotope were significantly increased in the Cu-deficient rats compared with the other groups and similar in the control and the Cu-supplemented groups. The urinary excretion of total Cu or 65Cu isotope were increased in the Cu-supplemented group compared with the other two groups. Both apparent absorption and urinary excretion of total Zn or 67Zn isotope remained unchanged in the three experimental groups. In conclusion, DAO activity seemed to be less sensitive to Cu deficiency than plasma Cu or caeruloplasmin concentrations. The present study also showed a significant increase in Cu intestinal absorption with dietary Cu restriction but no decrease with Cu supplementation in the rat.


Asunto(s)
Amina Oxidasa (conteniendo Cobre)/fisiología , Cobre/sangre , Absorción , Amina Oxidasa (conteniendo Cobre)/sangre , Animales , Biomarcadores/sangre , Ceruloplasmina/metabolismo , Cobre/farmacocinética , Suplementos Dietéticos , Absorción Intestinal/fisiología , Isótopos , Masculino , Estado Nutricional/fisiología , Ratas , Ratas Wistar , Sensibilidad y Especificidad , Zinc/fisiología , Isótopos de Zinc
9.
J Agric Food Chem ; 48(5): 1427-33, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10820038

RESUMEN

The objectives of this study were to investigate the effects of dietary fat (6% soy oil or rapeseed oil or tallow) and alpha-tocopheryl acetate supplementation at two levels (30 or 200 ppm) on radical production, measured by ESR spectroscopy, and on lipid and protein oxidation in turkey muscle extracts oxidized by an enzymic system (NADPH, ADP, FeSO(4)/cytochrome P450 reductase). Two muscles were tested: pectoralis major (glycolytic) and sartorius (oxidative) muscles. Radical production measured by ESR was higher in pectoralis major muscle than in sartorius muscle, whereas lipid and protein oxidation was more important in sartorius muscle, showing the importance of the pro-/antioxidant ratio in oxidative processes in muscular cells and of the measurement methodology to appreciate the free radical production. Dietary fat had no effect on the level of ESR signals, whereas feeding of animals with soy oil induced higher oxidation of lipids. Protein oxidation was less sensitive to the nature of the dietary fat than lipid oxidation. Vitamin E supplementation significantly decreased radical production, as measured by ESR spectroscopy. Vitamin E also decreased lipid and protein oxidation, but the effect of vitamin E on protein oxidation was less pronounced than on lipid oxidation.


Asunto(s)
Grasas de la Dieta/administración & dosificación , Metabolismo de los Lípidos , Proteínas Musculares/metabolismo , Vitamina E/administración & dosificación , Animales , Radicales Libres , Masculino , Músculo Esquelético/metabolismo , Oxidación-Reducción , Pavos
10.
Free Radic Biol Med ; 28(3): 324-9, 2000 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-10699742

RESUMEN

A multicenter European study (FoodCue) was undertaken to provide data on the significance of increased dietary copper as a pro-oxidant or antioxidant in vivo. The present work describes the effect of Cu supplementation on (2,2'-azo-bis(2-amidinopropane) hydrochloride (AAPH)-induced red blood cell oxidation in middle-aged people. Double-blinded copper supplementation was achieved in 26 healthy volunteers (50-70 years) with pills containing 3 mg CuSO(4), 3 mg Cu glycine chelate (CuG) and 6 mg CuG. Each 6 week supplementation period was preceded and followed by 6 weeks of washout (WO) on placebo. The results show significant increases in time necessary to achieve 50% hemolysis (LT(50)) after 3CuSO(4) and 6CuG compared with values after WO periods. Cu supplementation did not increase the levels of (Cu,Zn)SOD activity in red blood cells. Resistance to hemolysis was significantly and positively correlated (r =.30, p <.01) with alpha- and beta-carotene content in the plasma. Together, these data suggest that intake of copper as high as 7 mg/d has no pro-oxidant activity and may rather result in protection of red blood cells against oxidation. The decreased oxidizability of red blood cells did not result from increased (Cu,Zn)SOD activity and may occur through other mechanisms such as changes in membrane antioxidant content.


Asunto(s)
Antioxidantes/metabolismo , Sulfato de Cobre/farmacología , Suplementos Dietéticos , Eritrocitos/metabolismo , Vitaminas/sangre , Anciano , Amidinas/farmacología , Carotenoides/sangre , Sulfato de Cobre/administración & dosificación , Método Doble Ciego , Eritrocitos/efectos de los fármacos , Europa (Continente) , Femenino , Hemoglobinas/metabolismo , Humanos , Luteína/sangre , Licopeno , Masculino , Persona de Mediana Edad , Oxidantes/farmacología , Oxidación-Reducción , Caracteres Sexuales , Superóxido Dismutasa/sangre , Vitamina A/sangre , Vitamina E/sangre , beta Caroteno/sangre
11.
Mol Reprod Dev ; 54(4): 362-70, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10542376

RESUMEN

We have previously characterized and cloned a secreted sperm-bound selenium-independent glutathione peroxidase protein (GPX5), the expression of which was found to be restricted to the mouse caput epididymidis. Because of the lack of selenium (Se) in the active site of this enzyme, unlike the other animal GPXs characterized to date, it was suspected that GPX5 does not function in the epididymis as a true glutathione peroxidase in vivo. In the present report, following dietary selenium deprivation which is known to reduce antioxidant defenses and favor oxidative stress in relation with depressed Se-dependent GPX activities, we show that the epididymis is still efficiently protected against increasing peroxidative conditions. In this model, the caput epididymides of selenium-deficient animals showed a limited production of lipid peroxides, a total GPX activity which was not dramatically affected by the shortage in selenium availability and an increase in GPX5 mRNA and protein levels. Altogether, these data strongly suggest that the selenium-independent GPX5 could function as a back-up system for Se-dependent GPXs.


Asunto(s)
Epidídimo/enzimología , Glutatión Peroxidasa/metabolismo , Selenio/deficiencia , Selenio/metabolismo , Hormonas Testiculares , Animales , Antioxidantes/metabolismo , Northern Blotting , Glutatión Peroxidasa/genética , Riñón/enzimología , Peroxidación de Lípido , Hígado/enzimología , Masculino , Ratones , ARN Mensajero/análisis
13.
Clin Chim Acta ; 284(1): 31-43, 1999 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-10437641

RESUMEN

Oxidative stress is currently suggested as a mechanism underlying diabetes. The present study was designed to evaluate the oxidative stress related parameters in streptozotocin-induced diabetes in rats using different complementary approaches: susceptibility to in vitro oxidation (lipid peroxidation induction in liver homogenate, red blood cells hemolysis), blood antioxidant status (total antioxidant capacity by two approaches), and plasma isoprostane measurement, a new marker of lipid peroxidation in vivo. We have shown that induced liver thiobarbituric acid reactive substances increased after 4 weeks of diabetes, in spite of increased liver vitamin E content. Red blood cells hemolysis was significantly delayed after 4 weeks of diabetes. Plasma antioxidant capacity (AOC) tended to increase after 4 weeks of diabetes and was correlated with plasma vitamin E levels. Total antioxidant activity (TAA) significantly decreased after 1 week and a significant correlation was observed with plasma albumin levels. Plasma isoprostane (8-epiprostaglandinF2alpha) concentrations were not modified significantly 1 week or 4 weeks after the induction of diabetes. Levels of vitamin E in the diet and changes in its distribution among the body seems to play an important role in the development of oxidative stress during diabetes and its consequences.


Asunto(s)
Antioxidantes/metabolismo , Diabetes Mellitus Experimental/metabolismo , Peroxidación de Lípido , Animales , Ácido Araquidónico/sangre , Diabetes Mellitus Experimental/sangre , Dinoprost/análogos & derivados , Dinoprost/sangre , Hemólisis , Hígado/metabolismo , Masculino , Estrés Oxidativo , Ratas , Ratas Wistar , Estreptozocina , Triglicéridos/metabolismo
14.
Biochim Biophys Acta ; 1453(1): 35-40, 1999 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-9989243

RESUMEN

Magnesium (Mg) plays an essential role in fundamental cellular reactions and the importance of the immuno-inflammatory processes in the pathology of Mg deficiency has been recently reconsidered. The purpose of the present study was to assess the effect of different stages of Mg deficiency on endotoxin response and tumor necrosis factor-alpha (TNF alpha) production. Weaning male Wistar rats were pair fed either a Mg-deficient or a control diet. At day 7, lipopolysaccharide (LPS) induced no lethal effects in control rats but resulted in 70% mortality in Mg-deficient rats within 3 h. The vulnerability of Mg-deficient rats to LPS was associated with higher TNF alpha plasma values. Mg-deficient animals that received magnesium supplementation before endotoxin challenge had significantly increased survival. At day 2, control and Mg-deficient rats were also subjected to endotoxin challenge with or without magnesium pre-treatment. A significant increase in TNF alpha plasma level was observed in Mg-deficient rats compared to rats fed the control diet. Mg-deficient rats that received magnesium replacement therapy before endotoxin challenge had significantly lower TNF alpha plasma values than those receiving saline before endotoxin. Thus, the results of this experiment suggest that the activated or primed state of immune cells is an early event occurring in Mg deficiency.


Asunto(s)
Deficiencia de Magnesio/metabolismo , Factor de Necrosis Tumoral alfa/biosíntesis , Animales , Endotoxinas , Magnesio/sangre , Magnesio/farmacología , Deficiencia de Magnesio/sangre , Deficiencia de Magnesio/inducido químicamente , Masculino , Ratas , Ratas Wistar , Factor de Necrosis Tumoral alfa/análisis
15.
Br J Nutr ; 78(3): 493-500, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9306889

RESUMEN

Since experimental Se deficiency results in a significant increase in plasma cholesterol concentration the present investigation was undertaken to assess further the influence of this deficiency on the expression of proteins involved in hepatic lipid metabolism. Se deficiency was induced by feeding weanling male Wistar rats on a deficient diet for 6 weeks. Hypercholesterolaemia associated with Se deficiency was related to increased 3-hydroxy-3-methylglutaryl-coA (HMG-CoA) reductase (EC 1.1.1.34) activity in liver microsomes as compared with control animals. Hepatic lipoprotein receptor levels (LDL-receptor and HDL-binding proteins, HB1 and HB2) were not significantly affected by Se deficiency, as assessed by immunoblotting. Plasma triacylglycerol concentrations tended to decrease in Se-deficient rats in concert with their reduced post-Triton secretion. There was no significant effect of Se deficiency on the hepatic synthesis of apolipoproteins. These results point to the need for further investigations into the mechanism related to the increased activity of HMG-CoA reductase and the enhanced cholesterogenesis in the liver of Se-deficient rats likely to result from this.


Asunto(s)
Metabolismo de los Lípidos , Hígado/metabolismo , Selenio/deficiencia , Animales , Hidroximetilglutaril-CoA Reductasas/metabolismo , Lipoproteínas/metabolismo , Masculino , Microsomas Hepáticos/enzimología , Ratas , Ratas Wistar , Triglicéridos/sangre , Destete
16.
Br J Nutr ; 76(6): 899-907, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9014658

RESUMEN

The present study examined the effects of Se, vitamin E and combined Se and vitamin E deficiencies in rats on plasma lipid, lipoprotein and apolipoprotein (apo) concentrations. Deficiencies were induced by feeding rats the respective diets for 6 weeks. The study shows that Se deficiency results in increased concentrations of plasma cholesterol and apo E. Both could be explained by an increase in the HDL1 fraction. Vitamin E deficiency alone had no significant effect on plasma lipid, lipoprotein and apo concentrations. Se deficiency in combination with vitamin E deficiency leads to an increase in plasma LDL and apo B concentrations. These results point to the need for further investigations on the mechanism by which Se deficiency affects lipoprotein metabolism.


Asunto(s)
Lipoproteínas/sangre , Selenio/deficiencia , Deficiencia de Vitamina E/sangre , Animales , Apolipoproteínas/sangre , Apolipoproteínas E/metabolismo , Colesterol/sangre , Masculino , Ratas , Ratas Wistar
17.
Clin Chim Acta ; 200(2-3): 201-10, 1991 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-1663845

RESUMEN

The role of sarcolemma and sarcoplasmic reticulum in malignant hyperthermia was studied by the esr technique using the trapezius muscle membrane of both normal and genetically susceptible pigs. Normal and malignant hyperthermia membranes from sarcolemma as well as from sarcoplasmic reticulum did not show significant differences near the polar heads of the phospholipidic bilayer. In contrast, the fluidity and activation energy of normal membranes differed from those in malignant hyperthermia; in both sarcolemma and sarcoplasmic reticulum the mobility of the label was greater than the controls. The presence of halothane was examined, by inducing this disease anesthetically. The drug effect confirmed the above results, i.e. the disease affects mainly the hydrophobic core of the lipid bilayer of both sarcolemma and sarcoplasmic reticulum membranes.


Asunto(s)
Halotano/farmacología , Hipertermia Maligna/fisiopatología , Sarcolema/química , Retículo Sarcoplasmático/química , Porcinos/fisiología , Animales , Modelos Animales de Enfermedad , Espectroscopía de Resonancia por Spin del Electrón , Calor , Hipertermia Inducida , Fluidez de la Membrana/fisiología , Membranas/química , Modelos Químicos , Fosfolípidos/química , Sarcolema/efectos de los fármacos , Retículo Sarcoplasmático/efectos de los fármacos , Propiedades de Superficie , Porcinos/genética
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