O-9: The Peroxidation Indices during Vitrification of Bovine Ovary

Background: Cryopreservation of ovary for preserving germ cell line is going to be an important issue. However, the physical and chemical stresses during cryopreservation are the most important factors that may influence the post freezing tissue viability and quality. Vitrification is a new approach to bypass the impacts of both stresses for gametes and embryos and it is also suggested for ovary vitrification. The aim of the present study was to evaluate an ovarian conventional vitrification protocol for some oxidative stress indices. Materials and Methods: The bovine ovaries (n=16) were transported to the laboratory in a thermos flask (37°C). The ovaries were cut and the medulla parts were removed. The small pieces of ovarian cortex (1×1×1 mm3) were subjected to vitrification protocol. The ovary pieces were left in the vitrification solution 1 (VS1; Ethylene Glycol (20%) and Glycerol (10) in Holding medium) for 3 minutes followed by VS2 (EG (25%) and Glycerol (25%) and sucrose (0.5M)) for 1 minute. The samples were put on an aluminum foil and immersed in LN. Samples were warmed at least 48 hrs after vitrification in warming solutions (WS) with descending concentrations of sucrose; WS1: 0.5; WS2: 0.25 and WS3: 0.15M sucrose each solution for 5 min and finally samples were left in the holding medium for 10 min and subjected to the biochemical assays for carbonyl proteins, malonyl dialdehyde, and sulfydryl groups. Fresh samples from the ovaries were also analyzed for biochemical parameters as control group. Results: Malonyl dialdehyde (149.8 ± 25.3 and 36.9 ± 6.98 nmol/ mg protein; p<0.0001) and GSH (247.2 ± 34.83 and 219.6 ± 13.44 nmol/mg protein; p=0.0007) were increased in vitrified samples compared to the fresh samples, respectively. However, carbonyl protein was reduced in the vitrified samples compared to the fresh samples (94.7 ± 10.55 and 185.7 ± 25.56 nmol/mg protein; p=0.0014). Conclusion: The results showed that vitrification severely alter the peroxidation indices in an ovary vitrification protocol.