Carotenoids modulate the trade-off between egg production and resistance to oxidative stress in zebra finches

9 pagesInternational audienceThe allocation of resources to reproduction and survival is a central question of studies of life history evolution. Usually, increased allocation to current reproduction is paid in terms of reduced future reproduction and/or decreased survival. However, the proximal mechanisms underlying the cost of reproduction are poorly understood. Recently, it has been shown that increased susceptibility to oxidative stress might be one of such proximate links between reproduction and self-maintenance. Organisms possess a range of antioxidant defenses, including endogenously produced molecules (e.g., enzymes) and compounds ingested with food (e.g., carotenoids). If reproductive effort increases the production of reactive oxygen species, the availability of antioxidant defenses may partly or fully counteract the free-radical damages. One could, therefore, expect that the trade-off between reproduction and oxidative stress is modulated by the availability of antioxidant defenses. We tested this hypothesis in zebra finches. We manipulated reproductive effort by either allowing or preventing pairs to breed. Within each breeding or non-breeding group, the availability of antioxidant compounds was manipulated by supplementing or not supplementing the drinking water with carotenoids. We found that although birds in the breeding and non-breeding groups did not differ in their resistance to oxidative stress (the breakdown of red blood cells submitted to a controlled free-radical attack), one aspect of breeding effort (i.e., the number of eggs laid by birds in both breeding and non-breeding groups) was negatively correlated with resistance to oxidative stress only in birds that did not benefit from a carotenoid-supplemented diet. This result therefore suggests that carotenoid availability can modulate the trade-off between reproduction and resistance to oxidative stress

Long term hemodialysis aggravates lipolytic activity reduction and very low density, low density lipoproteins composition in chronic renal failure patients

<p>Abstract</p> <p>Background</p> <p>Dyslipidemia, particularly hypertriglyceridemia is common in uremia, and represents an independent risk factor for atherosclerosis.</p> <p>Methods</p> <p>To investigate the effects of hemodialysis (HD) duration on very low density lipoprotein (VLDL) and low density lipoprotein (LDL) compositions and lipopolytic activities, 20 patients on 5 to 7 years hemodialysis were followed-up during 9 years. Blood samples were drawn at T0 (beginning of the study), T1 (3 years after initiating study), T2 (6 years after initiating study) and T3 (9 years after initiating study). T0 was taken as reference.</p> <p>Results</p> <p>Triacylglycerols (TG) values were correlated with HD duration (r = 0.70, P < 0.05). An increase of total cholesterol was noted at T2 and T3. Lowered activity was observed for lipoprotein lipase (LPL) (-44%) at T3 and hepatic lipase (HL) (-29%) at T1, (-64%) at T2 and (-73%) at T3. Inverse relationships were found between HD duration and LPL activity (r = -0.63, P < 0.05), and HL activity (r = -0.71, P < 0.01). At T1, T2 and T3, high VLDL-amounts and VLDL-TG and decreased VLDL-phospholipids values were noted. Increased LDL-cholesteryl esters values were noted at T1 and T2 and in LDL-unesterified cholesterol at T2 and T3.</p> <p>Conclusion</p> <p>Despite hemodialysis duration, VLDL-LDL metabolism alterations are aggravated submitting patients to a greater risk of atherosclerosis.</p

A well-oxygenated cells environment may help to fight against protein glycation

Objectives: Normoglycemic Wistar rats’ Glycated Hemoglobin Levels (GHL) showed a time-dependent difference between control groups and those exposed to regular inhalation of peroxidizing extracts of turpentine. These extracts were able to optimize the oxygen permeation at the cellular level during and subsequently to a breathing session. The more the rats breathed turpentine peroxidized vapor, the lower their GHL was. This study was designed to confirm, in ex-vivo blood samples, the impact of peroxidizing extract on the GHL. Materials and Methods: Red blood cells were separated from plasmas by centrifugation. Plasmas were treated by peroxidizing and non-peroxidizing turpentine vapor or untreated (control), then combined with washed red blood cells three hours before evaluation. Glycation of hemoglobin proteins was quantified according to the Habeed’s method. Results: The ex-vivo experiments showed that the peroxidizing terpenes reduced the GHL after a three-hour contact. So did oxidized terpenes. Controls and the volatile component of the expended essential oil showed the opposite results. Conclusion: Optimal oxygenation, especially when facilitated by the peroxidized volatile component of the essential oil of turpentine, can protect organisms (mammals in this study) from protein glycation. Optimizing oxygenation can also reduce the GHL of treated blood samples after three hours of incubation

Bol d Air Jacquier® (évaluation des effets biologiques et antiradicalaires de terpènes peroxydés)

Le but du Bol d Air Jacquier® est d assurer une respiration cellulaire équilibrée, quels que soient le degré de pollution, le lieu, l âge, le mode de vie ou les conditions physiologiques de celui qui le respire. Le principe de fonctionnement de l appareil est de fournir un extrait naturel de pin peroxydé (pinènes), sous forme inhalable. Par un jeu chimique de liaisons faibles entre les terpènes, les hémoglobines, et de l oxygène tétravalent, l appareil améliorerait l oxygénation cellulaire. Notre travail bibliographique a consisté à résumer ce qui est connu de l action de l appareil, des terpènes de pins, de l oxygène, ainsi que des causes et conséquences de l hypoxie. Notre travail de recherche a mis en évidence que : le Bol d Air® met à disposition des cellules une quantité accrue d oxygène, - les terpènes de pins sont inhalés, hydroxylés puis excrétés dans les urines, l apport d oxygène par l appareil ne génère pas de stress oxydatif. Que ce soit par des dosages classiques d antiradicalaires ou par les méthodes innovantes (KRL et RESEDA), nous mettons en évidence les capacités du Bol d Air® à induire une protection antiradicalaire, dose-dépendante, qui ne contrarie pas les protections antioxydantes existantes. Ces qualités se retrouvent aussi bien in vivo qu ex vivo. Cette protection passe préférentiellement par la constitution et/ou la protection de réserves antiradicalaires circulantes, particulièrement chez les organismes âgés. Par ailleurs, nous avons pu mettre en évidence une action particulière de l appareil sur le métabolisme reliée à la glutathion réductase, et son action positive sur les hémoglobines glyquées. D autres expérimentations ont permis d affiner les conditions d utilisation du Bol d Air®. Enfin, nous terminons ce mémoire par l examen des nombreuses voies de recherches possibles pour comprendre l impact de l appareil sur les organismes, allant de la lutte contre les cellules immortelles à l aide à l entraînement des sportifs.The aim of the Bol d Air Jacquier® device is to provide a balanced cellular oxygenation, regardless the degree of pollution, place, age, lifestyle or physiological conditions of those who breathes it. It is used to provide a natural extract of peroxidizing terpens (with a majority of pinenes), in gaseous and inhalable form. With several light chemical links between terpens, haemoglobin and tetravalent oxygen, the device would improved cellular oxygenation. Our bibliographical work consisted in summarizing what is known about the device, the terpens oil, oxygen and finally the causes and consequences of hypoxia. Our research work consisted in highlighting that : The Bol d Air Jacquier ® may increase cells oxygenation. Terpens oil are inhaled, hydroxylated and excreted in the urines. Oxygen provided by the device does not generate oxidative stress. On the contrary, whether by conventional antioxidant evaluations or innovative methods (KRL and RESEDA), we demonstrated the ability of the Bol Air® to induce an antioxidant effect, dose-dependent, which does not adversely the antioxidant protections existing. These qualities are found as well in vivo as ex vivo. The way of protection could be the stocking up and/or the protection of circulating antioxidant reserves, especially among elder bodies. In addition, we could highlight a specific action of the Bol d'Air on the metabolism related to glutathione reductase, and its positive action on glycated haemoglobin. Other experiments have enabled us to clarify the conditions of use of the device. Lastly, we finish this paper by examining the many possible axes of research to assess the impact of the device on organisms, ranging from the fight against the immortal cells to the supporting of the training of athletes.DIJON-BU Sciences Economie (212312102) / SudocSudocFranceF

Influence d'un régime carencé en lysine sur la richesse et le taux de synthèse de la lipase et de la phospholipase A2 pancréatiques chez le rat en croissance

International audienc

Influence de la malnutrition protéique sur la synthèse des hydrolases pancréatiques

International audienc

Influence de régimes hyperlipidiques sur les synthèses de 5 hydrolases du suc pancréatique chez le rat en croissance

International audienc

Evaluation du statut antioxydant et du métabolisme lipidique chez le rat spontanément hypertendu (SHR) rendu diabétique de type 2

Le diabète de type 2 et l'hypertension sont deux facteurs de risque des maladies cardiovasculaires. Par ailleurs, la consommation de glucides simples, et essentiellement de fructose, a augmenté ces dernières décennies, contribuant au développement de ces facteurs de risque. Dans notre étude, la consommation d un régime riche en fructose a induit une hyperglycémie et une hyperinsulinémie conduisant au développement du diabète de type 2, chez des rats SHR. Notre étude a également montré que l association hypertension / diabète de type 2, comparée à l hypertension seule, est liée à une altération du métabolisme lipidique et du statut antioxydant. En effet, les rats SHR diabétiques, en comparaison avec les rats hypertendus, ont développé une hypercholestérolémie et une hypertriglycéridémie, sans modification de la pression artérielle. De plus, le développement du diabète de type 2 a également conduit à l apparition d un stress oxydatif chez les SHR. Ainsi, la consommation exagérée de fructose au cours de l HTA, associée au diabète, contribue à l apparition du syndrome métabolique.Type 2 diabetes and hypertension are both risk factors of cardiovascular diseases. In addition, the consumption of simple sugars, and essentially that of fructose, has increased in the last decades and contributed to the development of these risk factors. In this study, the consumption of a high-fructose diet induced hyperglycemia and hyperinsulinemia leading to the development of type 2 diabetes in SHR rats. Our study has also shown that the association of hypertension and type 2 diabetes, compared with hypertension only, is linked to an alteration of lipid metabolism and antioxidant status. Indeed, diabetic SHR rats, in comparison with hypertensive rats, developed hypercholesterolemia and hypertriglyceridemia, without a change in their blood pressure. The development of type 2 diabetes also induced the appearance of oxidative stress in SHR. In conclusion, excess fructose consumption together with hypertension, associated with diabetes, contributes to the development of the metabolic syndrome.DIJON-BU Sciences Economie (212312102) / SudocSudocFranceF

METABOLISME LIPIDIQUE ET RESISTANCE AU STRESS OXYDATIF CHEZ LE RAT SPONTANEMENT HYPERTENDU (EFFETS DE LA VITAMINE E ET DES ACIDES GRAS POLYINSATURES ALIMENTAIRES)

DIJON-BU Sciences Economie (212312102) / SudocSudocFranceF

AJUGA IVA TREATMENT INCREASES POST-HEPARIN LIPASE ACTIVITY AND DECREASES SERUM AND VLDL-TRIACYLGLYCEROLS IN RATS FED A CHOLESTEROL-RICH DIET

Objective: Hypercholesterolemia is among the most common health problems treated with traditional remedies. The role of lipoprotein lipase in hypercholesterolemia has been the subject of many reviews. We hypothesized that administration of Ajuga iva (Ai) aqueous extract to rats fed a cholesterol-rich diet would induce hypotriglyceridaemia by decreasing lipolytic activity.Methods: Male wistar rats (n=12) were fed on 1% cholesterol-enriched diet for 15d. After this phase, hypercholesterolemic rats (HC) were divided into two groups fed the same diet supplemented or not with Ai for 15d.Results: compared with the HC group, serum triacylglycerols (TG) and unesterified cholesterol (UC) values were respectively 1.4-fold lower and 1.8-fold higher in Ai-HC. VLDL amount (which represented the sum of apolipoproteins (apos)+TG+cholesteryl esters (CE)+UC+phospholipids (PL)), apos, TG and CE contents were, respectively, 2.2-, 2.6-, 4.4-and 1.9-fold lower, whereas that of UC were 1.9-fold higher in Ai-HC. LDL-HDL1-TG value was 1.5-fold lower, and that of PL was 2-fold higher in Ai-HC. The HDL2, amount, TG and UC values were respectively, 2.2-, 8-and 1.2-fold higher and the PL contents were 1.2-fold lower in the Ai-HC. The HDL3, TG, UC and CE values were 3-, 1.6-and 2-fold higher in the Ai-HC group, whereas, PL contents were 1.4-fold lower. Hepatic lipase activity was similar and that of post-heparin lipases was increased by+15% in Ai-HC.Conclusion: cholesterol-enriched diet supplemented with a lyophilised aqueous extract from Ajuga iva induces hypotriglyceridemia concomitantly with decreased VLDL-TG, by stimulating post-heparin lipoprotein lipase activity.Â