Study: Oocyte cryopreservation is a biologically "realistic objective".

2004 OCT 7 - (NewsRx.com & NewsRx.net) -- Researchers in Italy write that "[o]ocyte cryopreservation would amount to a major breakthrough in reproductive medicine."

"Diverse strategies have been tested to minimize cooling-induced cell injury. Nevertheless, oocytes from various species have shown a particular sensitivity to freezing, due to their unique biological characteristics," said G. Coticchio and colleagues, University of Bologna. "Storage of human mature oocytes with slow freezing has resulted in low survival rates, although recent studies based on modified methods have reported higher success."

And, the researchers noted, "Survival after thawing is not necessarily a guarantee of unaltered viability. Developmental failure at pre- or postimplantation stages may originate from critical perturbations of various cell components, such as the chromosome segregation apparatus, the intracellular calcium signalling system, and the cytoskeleton."

Coticchio and coauthors said, "Germinal vesicle (GV)-stage oocytes have been suggested to be more amenable to freezing. But their use would require efficient in vitro maturation systems, ...