Glucosinolates metabolites in plasma, milk and thyroid of gestating and lactating ewes
; ; et al
The effects of high level of rapeseed meal in the diet on the concentration of antinutritional factors (glucosinolates metabolites) in blood plasma, milk and thyroid were studied in 90 ewes. From the ... [more ▼]
The effects of high level of rapeseed meal in the diet on the concentration of antinutritional factors (glucosinolates metabolites) in blood plasma, milk and thyroid were studied in 90 ewes. From the 100th day of gestation, ewes bearing two foetuses were divided into three groups and were fed with pasture hay ad libitum and 500 g/d of diet containing 0 or 40% rapeseed meal obtained from either Apex or Synergy variety. During the 47 first days of lactation, 1200 g/d of the same meal were given. Thereafter, during 3 weeks, the ewes were only fed with hay. Blood and milk samples were taken fortnightly for the determination of SCN- and 5-vinyl-1,3- oxazolidine-2-thione (5-VOT) concentrations. One ewe from each group was slaughtered at the end of rapeseed meal distribution and another one three weeks later for thyroid analyses. SCN- and 5-VOT concentrations in blood plasma increased significantly (P<0.05) and regularly until one month of rapeseed supplementation to the withdrawal of rapeseed in the diet. One to three weeks after the end of rapeseed meal distribution, the SCN- and 5-VOT plasma concentrations came back at the basal level. Some changes were also observed for SCN- and 5-VOT contents in milk. The results indicated a great capacity of the ewes to excrete SCN- and 5-VOT by the milk. A 5-VOT accumulation was observed in the thyroid according to the level of progoitrin in the diet, but no SCN- accumulation. The 5-VOT concentration in thyroid of the ewes fed during three weeks with hay came back to zero. The thyroid analysis showed the reversible aspect of the thyroid hypertrophy due to 5-VOT accumulation. [less ▲]Detailed reference viewed: 77 (2 ULg)
Les glucosinolates, leur dosage.
Wathelet, Jean-Paul ; ; et al
in Revue de l’Agriculture = Landbouwtijdschrift (1986), 39
Mis en évidence depuis le siècle dernier,les glucosinolates sont présents dans toutes les espèces végétales appartenant à la famille des crucifères (Lerin, 1980). lls se dégradent facilement sous I'action ... [more ▼]
Mis en évidence depuis le siècle dernier,les glucosinolates sont présents dans toutes les espèces végétales appartenant à la famille des crucifères (Lerin, 1980). lls se dégradent facilement sous I'action de la myrosinase en isothiocyanates (lTC), vinyl-thio-oxazolidones (VOT), nitriles, thiocyanates, amines ...Ces produits de dégradation sont physiologiquement actifs. Dans le domaine de l'alimentation humaine, ils contribuent à la flaveur de différentes plantes comme les choux, les radis et au goût particulier du raifort et de la moutarde (Mc Gregor et al., 1975). Initialement présents dans le parenchyme des graines de colza, ils subsistent dans les tourteaux obtenus après extraction de l'huile et provoquent des effets toxiques chez les animaux d'élevage. Ceci limite I'utilisation des tourteaux de colza notamment pour les animaux à croissance rapide comme le porc et les volailles. En vue de valoriser au mieux le colza, plante riche en matière grasse (40 à 46 o/ol (Godin et al., 1971) présentant une composition en acides aminés très équilibrée (tableau 1) et un pourcentage de protéines variant entre 22 et 24 o/o (Diem et al., 1975), il est impératif d'une part de diminuer le taux en glucosinolates par sélection (Robbelen et al., 1980) et d'autre oart de les doser avec orécision. Cet article a pour objet de mieux faire connaître les glucosinolates et de faire une mise au point quant à leur dosage. [less ▲]Detailed reference viewed: 131 (13 ULg)
Glucotoxicite et lipotoxicite, deux complices impliques dans le cercle vicieux du diabete de type 2.
Scheen, André ; Paquot, Nicolas ; Lefebvre, Pierre
in Revue Médicale de Liège (1999), 54(6), 535-8
Type 2 diabetes mellitus is a dynamic disease whose natural history is characterized by a progressive aggravation leading to a progressively severe hyperglycaemia, which generally requires a more complex ... [more ▼]
Type 2 diabetes mellitus is a dynamic disease whose natural history is characterized by a progressive aggravation leading to a progressively severe hyperglycaemia, which generally requires a more complex therapy as time progresses. Such an evolution results from a vicious circle where both glucotoxicity and lipotoxicity contribute to reduce insulin secretion and the action of insulin on cell glucose metabolism. These new concepts are able to modify the strategies of prevention and treatment of type 2 diabetes. [less ▲]Detailed reference viewed: 97 (0 ULg)
The gluon condensate in the chiral phase transition
; Jaminon, Martine
in Fried, H. M.; Mueller, B. (Eds.) QCD Vacuum Structure (1993)Detailed reference viewed: 21 (2 ULg)
Gluonic content of the scalar meson nonet in a scaled effective Lagrangian
Jaminon, Martine ;
in Nuclear Physics A (1997), 619
A scaled SU(3) Nambu-Jona-Lasinio Lagrangian is used to compute the mass of the nine scalar mesons in the vacuum and the mass of the glueball. This chiral model provides a gluonic content to the scalar ... [more ▼]
A scaled SU(3) Nambu-Jona-Lasinio Lagrangian is used to compute the mass of the nine scalar mesons in the vacuum and the mass of the glueball. This chiral model provides a gluonic content to the scalar mesons as well as a quark content to the glueball. It is shown that a suitable choice of the vacuum gluon condensate allows reproduction of the experimental masses of the scalar mesons except for K*0(1430). This choice corresponds to a weak coupling between the gluon and quark condensates, giving f0(1500) or fJ(1710) which is nearly a pure glueball. [less ▲]Detailed reference viewed: 11 (1 ULg)
Glutamate controls brain estrogen synthesis during sexual interactions
de Bournonville, Catherine ; ; et al
Poster (2014, November 17)
Besides their long-lasting effects mediated by a modulation of gene transcription, brain-derived estrogens can rapidly regulate (within minutes) reproductive behaviors. In vitro, the activity of aromatase ... [more ▼]
Besides their long-lasting effects mediated by a modulation of gene transcription, brain-derived estrogens can rapidly regulate (within minutes) reproductive behaviors. In vitro, the activity of aromatase (AA), the enzyme responsible for the conversion of androgens into estrogens, is also regulated on a similar short time-scale, via phosphorylation of the enzyme resulting from changes in neuronal activity or glutamate release. Acute changes in AA have been documented ex vivo in specific brain regions following exposure to social or stressful stimuli but the mechanism underlying these regulations is not known. To investigate whether glutamate is implicated in these rapid changes in AA, male quail received a unilateral injection of kainate in the medial preoptic nucleus (POM). The left and right preoptic areas were collected 20 min later and assayed separately by the tritiated water technique for AA. As shown previously in preoptic explants maintained in vitro, AA was downregulated in the kainate-injected hemisphere as compared to the non-injected side. To determine whether the decline in AA detected in the POM after a sexual interaction could be mediated by an increased release of glutamate in this region, extracellular glutamate concentration was measured by in vivo microdialysis with a probe implanted in the POM of sexually mature males. Dialysate was collected every 3 minutes over three periods of 15 min when the male was (1) alone, (2) allowed to freely copulate with a female and (3) alone again. A transient rise in extracellular glutamate concentration was observed specifically and immediately after the expression of cloacal contact movements, when semen is transferred to the female. Glutamate returned to a basal level after the female was removed. Together, these results indicate that the mechanism of acute regulation of aromatase activity by glutamate identified in vitro is potentially responsible for the acute regulation of the enzyme observed in vivo following copulation. As rapid changes in brain estrogen synthesis and its actions are apparently related to the control of sexual motivation rather than sexual performance, follow up experiments should now determine whether the release of glutamate in the POM occurs in parallel with an increase in motivation or follows the termination of the copulatory sequence. [less ▲]Detailed reference viewed: 72 (3 ULg)
Glutathione S-transferase isoenzymes in the two-spot ladybird, Adalia bipunctata (Coleoptera: Coccinellidae).
Francis, Frédéric ; Haubruge, Eric ;
in Archives of Insect Biochemistry and Physiology (2002), 49(3), 158-66
Isoenzymes of glutathione S-transferase (GST) in adult Adalia bipunctata, an aphidophagous predator, were studied. Cytosolic GST activity was studied in each beetle developmental stage. The highest ... [more ▼]
Isoenzymes of glutathione S-transferase (GST) in adult Adalia bipunctata, an aphidophagous predator, were studied. Cytosolic GST activity was studied in each beetle developmental stage. The highest activities towards both 1-chloro-2,4-dinitrobenzene (CDNB) and 2,4-dinitro-1-iodobenzene (DNIB) occurred in adults. The enzyme distribution was investigated in adults. While most of the enzymatic activity was found in the abdomen (40-50 and 34-63% respectively) using several concentrations of both CDNB and DNIB, significant differences were observed for the head and the thorax depending on the substrate. Activities were more abundant in the thorax with DNIB (37-47%) compared to the 13-19% obtained with CDNB. Some GST activity was also detected in the elytra. GSTs were purified by epoxy-activated Sepharose 6B affinity chromatography and applied to an HPLC column to determine the native molecular weight (69 kDa). Three isoenzymes were separated by chromatofocusing at pH ranges 7-4. Three bands with molecular mass from 23 to 26 kDa were visualised on SDS-PAGE. Their isoelectric points were 6.66, 6.36, and 6.21. The substrate specificities and the kinetic parameters (Vm and Km) of the isoenzymes showed large differences depending on the isoenzyme. Arch. [less ▲]Detailed reference viewed: 14 (1 ULg)
Glutathione S-transferases in the adaptation to plant secondary metabolites in the Myzus persicae aphid.
Francis, Frédéric ; ; Haubruge, Eric
in Archives of Insect Biochemistry and Physiology (2005), 58(3), 166-74
Glutathione S-transferases (GST) in insects play an important role in the detoxification of many substances including allelochemicals from plants. Induction of GST activity in Myzus persicae in response ... [more ▼]
Glutathione S-transferases (GST) in insects play an important role in the detoxification of many substances including allelochemicals from plants. Induction of GST activity in Myzus persicae in response to secondary metabolites from Brassica plants was determined using different host plant species and confirmed using artificial diet with pure allelochemicals added. The 2,4-dinitro-1-iodobenzene (DNIB) was found to be a useful substrate for identifying particular GSTs in insects. GSTs from M. persicae were purified using different affinity chromatography columns and related kinetic parameters were calculated. GST isoenzymes were characterised using electrophoretic methods. Although SDS-PAGE results indicated similarity among the purified enzymes from each affinity column, biochemical studies indicated significant differences in kinetic parameters. Finally, the GST pattern of M. persicae was discussed in terms of insect adaptation to the presence of plant secondary substances such as the glucosinolates and the isothiocyanates, from Brassicaceae host plants. [less ▲]Detailed reference viewed: 33 (5 ULg)
Glutathione S-transferases of Aulacorthum solani and Acyrthosiphon pisum: partial purification and characterization.
Francis, Frédéric ; Haubruge, Eric ; Gaspar, Charles et al
in Comparative Biochemistry & Physiology Part B (2001), 129(1), 165-71
Glutathione S-transferases (GST) play an important role in the detoxification of many substances including allelochemicals from plants. Brassicaceae plants contain glucosinolates and emit volatile ... [more ▼]
Glutathione S-transferases (GST) play an important role in the detoxification of many substances including allelochemicals from plants. Brassicaceae plants contain glucosinolates and emit volatile isothiocyanates which affect the GST system. A comparison of the GST of two aphid species, the generalist Aulacorthum solani found on Brassicaceae and the Fabaceae specialist Acyrthosiphon pisum, was made to try to explain their respective feeding behaviour. Differences of GST were determined among the two aphid species based on purification by affinity chromatography, SDS-PAGE and on kinetic studies. Purification yields using an epoxy-activated Sepharose 6B column were highly different for the two aphid species (18% and 34% for A. solani and A. pisum, respectively). These variations were confirmed by SDS-PAGE. While only a 27-kDa band was observed for A. pisum, two bands of approximately 25-kDa were visualized for the generalist aphid, A. solani. Considering the kinetic results, differences of Km and Vmax were observed following the aphid species when a range of substrates (CDNB and DCNB) and GSH concentrations were tested. Studies on the detoxification enzymes of generalist and specialist herbivores would be undertaken to determine accurately the effect of the host plant on the organisms eating them, particularly in terms of biochemical and ecological advantages. [less ▲]Detailed reference viewed: 20 (1 ULg)
Glutathione-S-transferase pi expression in toxic epidermal necrolysis: a marker of putative oxidative stress in keratinocytes.
Paquet, Philippe ; Pierard, Gérald
in Skin Pharmacology & Physiology (2007), 20(2), 66-70
BACKGROUND: Toxic epidermal necrolysis (TEN) is a dramatic drug-induced emergency related to extensive destruction of the epidermis. There is evidence that its pathomechanism involves impaired ... [more ▼]
BACKGROUND: Toxic epidermal necrolysis (TEN) is a dramatic drug-induced emergency related to extensive destruction of the epidermis. There is evidence that its pathomechanism involves impaired detoxication of xenobiotics. Glutathione-S-transferase pi (GST-pi) is a phase II detoxifying enzyme involved in drug metabolization by human keratinocytes. METHOD: Immunohistochemistry was performed in order to assess the expression of GST-pi in keratinocytes of TEN, other cutaneous adverse drug reactions and bullous pemphigoid. RESULTS: GST-pi was disclosed in the involved epidermis of 16/16 TEN patients. It was present in the cytoplasm of suprabasal keratinocytes. GST-pi was also expressed in the clinically uninvolved skin in a majority (8/12) of TEN patients. By contrast, it was rarely and poorly expressed in the other tested dermatoses. CONCLUSION: The pathomechanism of TEN is not related to an impaired quantitative expression of GST-pi. GST-pi expression is an early event in TEN. As oxidative stress is a major inducer of GST-pi, this mechanism might be involved in TEN. Its GST-pi expression mainly restricted to the suprabasal keratinocytes suggests that the pathomechanisms leading to keratinocyte death in TEN are distinct at different levels of the epidermis. [less ▲]Detailed reference viewed: 33 (2 ULg)
Glycaemic and blood pressure control seems harder to improve than lipid control in type 2 diabetic patients: comparison of two surveys over 5 years in Belgium.
PAQUOT, Nicolas ; ; SCHEEN, André et al
in Diabetologia (2008), 51(suppl 1), 71155Detailed reference viewed: 9 (0 ULg)
Glycaemic control and blood pressure control seems harder to imporve than lipid control in Type 2 Diabetic Patients: Comparison of two Surveys over 5 Years
PAQUOT, Nicolas ; ; SCHEEN, André et al
in Diabetologia (2008), 51(suppl 1), 71Detailed reference viewed: 2 (1 ULg)
Glycation of YAP1 transcription factor by Methylglyoxal, a glycolysis by-product, induces its nuclear accumulation in human breast cancer cells.
Poster (2014, May 19)Detailed reference viewed: 22 (2 ULg)
Glycemic Variability, Hypoglycemia and Organ Failure in the Glucontrol Study
Penning, Sophie ; ; PREISER, Jean-Charles et al
in 10th Belgian Day on Biomedical Engineering (2011)Detailed reference viewed: 22 (3 ULg)
Glycemic Variability, Hypoglycemia and Organ Failure in the Glucontrol Study
Penning, Sophie ; ; PREISER, Jean-Charles et al
Poster (2011, December)Detailed reference viewed: 27 (7 ULg)
Glycémie délocalisée: Entretien avec le Dr Etienne CAVALIER
in Biotribune Magazine (2006), 19(1), 33Detailed reference viewed: 50 (10 ULg)