Effects of copper sulphate concentrations during in vitro maturation of bovine oocytes

• Autores: Picco, Sebastian Julio; Rosa, Diana Esther; Anchordoquy, Juan Patricio; Anchordoquy, Juan Mateo; Seoane, Analia Isabel; Mattioli, Guillermo Alberto; Furnus, Cecilia Cristina
• Año de publicación: 2012
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: COPPER; DNA INTEGRITY; GLUTATHIONE (GSH); IN VITRO MATURATION; OOCYTE; OOCYTE METABOLISM
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

The objectives were to evaluate: 1) copper (Cu) concentrations in plasma and follicular fluid (FF) from cattle ovaries; 2) the effects of supplemental Cu during in vitro maturation (IVM) on DNA damage of cumulus cells and glutathione (GSH) content in oocytes and cumulus cells; and 3) supplementary Cu during IVM on subsequent embryo development. Copper concentrations in heifer plasma (116 ± 27.1 μg/dL Cu) were similar (P > 0.05) to concentrations in FF from large (90 ± 20.4 μg/dL Cu) and small (82 ± 22.1 μg/dL Cu) ovarian follicles in these heifers. The DNA damage in cumulus cells decreased with supplemental Cu concentrations of 4 and 6 μg/mL (P < 0.01) in the IVM medium (mean ± SEM index of DNA damage was: 200.0 ± 27.6, 127.6 ± 6.0, 46.4 ± 4.8, and 51.1 ± 6.0 for supplementation with 0, 2, 4, and 6 μg/mL Cu respectively). Total GSH concentrations increased following supplementation with 4 μg/mL Cu (4.7 ± 0.4 pmol in oocytes and 0.4 ± 0.04 nmol/10 6 cumulus cells) and 6 μg/mL Cu (5.0 ± 0.5 pmol in oocytes and 0.5 ± 0.05 nmol/10 6 cumulus cells, P < 0.01) compared with the other classes. Cleavage rates were similar (P ≥ 0.05) when Cu was added to the IVM medium at any concentration (65.1 ± 2.0, 66.6 ± 1.6, 72.0 ± 2.1, and 70.7 ± 2.1 for Cu concentrations of 0, 2, 4, and 6 μg/mL). Percentages of matured oocytes that developed to the blastocyst stage were 18.7 ± 0.6, 26.4 ± 0.03, and 29.0 ± 1.7% for 0, 2, and 4 μg/mL Cu, and was highest (33.2 ± 1.6 %) in oocytes matured with 6 μg/mL Cu (P > 0.01). There was an increase (P > 0.05) in mean cell number per blastocyst obtained from oocytes matured with 4 and 6 μg/mL Cu relative to 0 Cu (IVM alone) and 2 μg/mL Cu. In conclusion, Cu concentrations in the FF and plasma of heifers were similar. Adding copper during oocyte maturation significantly increased both intracellular GSH content and DNA integrity of cumulus cells. Since embryo development was responsive to copper supplementation, we inferred that optimal embryo development to the blastocyst stage was partially dependent on the presence of adequate Cu concentrations during IVM.
Fil: Picco, Sebastian Julio. Universidad Nacional de La Plata; Argentina. Instituto de Genética Veterinaria Ingeniero Fernando Noel Dulout (conicet- Universidad Nacional de la Plata); Argentina
Fil: Rosa, Diana Esther. Universidad Nacional de La Plata; Argentina
Fil: Anchordoquy, Juan Patricio. Universidad Nacional de La Plata; Argentina. Instituto de Genética Veterinaria Ingeniero Fernando Noel Dulout (conicet- Universidad Nacional de la Plata); Argentina
Fil: Anchordoquy, Juan Mateo. Universidad Nacional de La Plata; Argentina. Instituto de Genética Veterinaria Ingeniero Fernando Noel Dulout (conicet- Universidad Nacional de la Plata); Argentina
Fil: Seoane, Analia Isabel. Instituto de Genética Veterinaria Ingeniero Fernando Noel Dulout (conicet- Universidad Nacional de la Plata); Argentina
Fil: Mattioli, Guillermo Alberto. Universidad Nacional de La Plata; Argentina
Fil: Furnus, Cecilia Cristina. Instituto de Genética Veterinaria Ingeniero Fernando Noel Dulout (conicet- Universidad Nacional de la Plata); Argentina. Universidad Nacional de La Plata; Argentina