Factors involved in vitro maturation of carnivore oocytes

In order to sustain complete maturation of Carnivore oocytes, the modifications of the culture environment by: 1) the addition of gonadotropins that modulate the intracellular levels of regulatory molecules; 2) the addition of gonadotropins and thiol compounds that stimulate endogenous system of cell defense; 3) the use of alternative culture systems, have been investigated in the present thesis. The data showed that the presence of gonadotropins in the maturation medium of feline oocytes caused a moderate increase of the intracellular concentration of cAMP, a significant changes in communications between oocyte and surrounding cumulus cells and an increase of the intracellular concentration of glutathione along with meiotic progression. The use of an alternative culture system for in vitro maturation of canine oocytes, i.e. isolated oviduct, combined with the extension of the culture time (two step: isolated oviduct 24h + drop 48h) positively influenced the oocytes survival and their in vitro maturation rates.