Effect of caffeine treatment before vitrification on MPF and MAPK activity and spontaneous parthenogenetic activation of in vitro matured ovine oocytes.
F Ariu, L Bogliolo, G Leoni, L Falchi, D Bebbere, S M Nieddu, M T Zedda, S Pau, S Ledda
Molecules that stabilize protein kinases may be useful in overcoming the deleterious effects of cryopreservation.To evaluate the effect of caffeine treatment before vitrification of in vitro matured ovine oocytes on the activity of MPF and MAPK as well as the spontaneous parthenogenetic activation after 24 h culture.Oocytes obtained from slaughterhouse sheep ovaries were in vitro matured for 21 h, incubated for 3 h with or without caffeine and then vitrified. After warming, oocytes were processed for the analysis of chromatin configuration and the evaluation of spontaneous parthenogenetic activation (24 h in vitro culture). Fresh in vitro matured oocytes were used as control.Caffeine treatment before vitrification maintained the MPF activity at a level similar to that of fresh oocytes, and reduced the spontaneous parthenogenetic activation in comparison with oocytes that were not-treated with caffeine.Caffeine treatment prolongs the meiotic arrest of vitrified MII oocytes, likely via its action of stabilizing the MPF level.
