[Morphologic changes in the ovary upon exposure to low temperatures (-196 degrees C) using cryoprotection].

Area of Science:

• Reproductive biology and cryobiology.
• Ovarian tissue cryopreservation and transplantation.

Background:

• Long-term storage of reproductive tissues is crucial for fertility preservation.
• Understanding the effects of deep freezing on ovarian tissue is essential for successful cryopreservation.

Purpose of the Study:

• To investigate the biological effects of deep freezing on ovarian tissue.
• To determine the feasibility of using low temperatures for long-term ovarian tissue storage.

Main Methods:

• Deep freezing of ovarian tissue to -196°C.
• Utilizing polyethylene oxide (molecular weight 400) at a 20% concentration as a cryoprotective agent.
• Controlled cooling rates: 1°C/min to -8°C, then 10°C/min to -196°C.

Main Results:

• Preservation of ovarian functional activity after deep freezing.
• Successful restoration of ovarian function following transplantation of cryopreserved tissue.

Conclusions:

• Deep freezing with optimized cryoprotectants and cooling rates can maintain ovarian viability.
• This technique holds promise for long-term storage and successful transplantation of ovarian tissue.