Effect of genistein enriched diet on the sex steroid endocrinology and the reproductive efficiency of the rainbow trout Oncorhynchus mykiss

National audienc

Effect of genistein enriched diet on the sex steroid endocrinology and the reproductive efficiency of the rainbow trout Oncorhynchus mykiss

National audienc

Effect of genistein enriched diet on the sex steroid endocrinology and the reproductive efficiency of the rainbow trout Oncorhynchus mykiss

International audienceGenistein enriched diets at 500 ppm and 1000 ppm were prepared from a fish meal based diet used as control. Male and female rainbow trout were fed with these diets for one year while they undergo their first sexual development. Testosterone (T), 11-keto-testosterone (11KT), estradiol (E2)and vitellogenin (VTG) were monitored every 1,5 months. Fish were sacrificed at the same periodicity for histological control of the gonad. At the end of the reproductive maturation process, 17α,20β-(OH)2-progesterone (17α,20βP), GTH1 and GTH2 were measured. Reproductive efficiency was assessed on the basis of sperm characteristics (sperm volume, spermatocrit measurements, sperm motility), on oocyte characteristics (oocyte size, layer mass, mass of remaining gonad after spawning). Fertilisation was realised mixing sperm obtained on male fed one defined diet with eggs from females fed on the same diet. Endocrine disruptions were noticed on 17α,20βP GTH1 and GTH2. VTG was increased in a dose response manner in female after natural yolk production. In fish naive to estradiol the effect was also dose-dependant but of much less importance. In male, spermatogenesis was accelerated, while in females, oogenesis was slowed down. Reproductive efficiency was impaired in the 500 ppm fed fish

Experimental determination of conservative and dissipative parts in the tapping mode on a grafted layer: comparison with frequency modulation data

no abstrac

Structural characterization of self-assembled monolayers of organosilanes chemically bonded onto silica wafers by dynamical force microscopy

no abstrac

Structural characterization of self-assembled monolayers of organosilanes chemically bonded onto silica wafers by dynamical force microscopy

no abstrac

Apparition et biosynthèse in-vitro de 11-ketotestotérone chez les femelles vieillissantes d'esturgeon sibérien (Acipenser baeri Brandt)

International audienceHigh levels of 11-ketotestosterone were found (49 to 160 ng ml -1) in plasma of Siberian sturgeon females during the end of their reproductive cycle. These levels were measured either by specific raidioimmunoassay, or both by specific radioimmunoassay and by UV absorption after HPLC (isocratic conditions, 33 % methanol, 26 % acetonitrile, 41 % water).Des niveaux élevés de 11-kétotestotérone (49 à 160 ng ml-1) ont été trouvés dans le plasma des esturgeons femelles de Sibérie à la fin de leur cycle de reproduction. Ces niveaux ont été mesurés soit par dosage radio-immunologique ou à la fois par dosage radio-immunologique et par absorption UV après chromatographie en phase liquide sous haute pression (conditions isocratiques, 33 % de méthanol, 26 % d'acétonitrile, 41 % d'eau

In vitro estrogenic activity of phytoestrogens on liver vitellogenin synthesis in the rainbow trout (Oncorhynchus mykiss)

International audienc

Apparition et biosynthèse in-vitro de 11-ketotestotérone chez les femelles vieillissantes d'esturgeon sibérien (Acipenser baeri Brandt)

International audienceHigh levels of 11-ketotestosterone were found (49 to 160 ng ml -1) in plasma of Siberian sturgeon females during the end of their reproductive cycle. These levels were measured either by specific raidioimmunoassay, or both by specific radioimmunoassay and by UV absorption after HPLC (isocratic conditions, 33 % methanol, 26 % acetonitrile, 41 % water).Des niveaux élevés de 11-kétotestotérone (49 à 160 ng ml-1) ont été trouvés dans le plasma des esturgeons femelles de Sibérie à la fin de leur cycle de reproduction. Ces niveaux ont été mesurés soit par dosage radio-immunologique ou à la fois par dosage radio-immunologique et par absorption UV après chromatographie en phase liquide sous haute pression (conditions isocratiques, 33 % de méthanol, 26 % d'acétonitrile, 41 % d'eau