Antioxidant defense capacity of ovarian tissue after vitrification in a metal closed system.

Eloísa T Massignam,Adriana Bos-Mikich,Ágata Dupont,Eduardo Sanguinet,Maitê Ferreira,Nilo Frantz,Fábio Klamt

doi:10.5935/1518-0557.20180044

Abstract

ObjectiveThe present study analyzed the quality of bovine ovarian tissue after vitrification in a metal closed chamber, in terms of putative changes in tissue viability (lactate dehydrogenase -LDH- release), anti-oxidant defenses, and redox parameters caused by cryopreservation.MethodsSmall and large fragmented bovine ovarian tissue specimens were vitrified in a metal chamber. After rewarming, tissue samples were fixed or cultured for 48 hours. Glutathione (GSH), protein sulfhydryl content, Total Radical Trapping Antioxidant Potential (TRAP), and lactate dehydrogenase were analyzed immediately after rewarming and after tissue culture.ResultsNo changes in antioxidant parameters or viability of rewarmed tissue samples were found immediately or 48h after vitrification. The method of vitrification in a metal closed chamber used in this study preserved the quality of bovine ovarian tissue. Furthermore, our data showed that the size of the tissue specimens did not affect post-vitrification biochemical viability parameters.ConclusionsWe believe that the vitrification methodology employed in the present study is safe and effective, and should be evaluated for use in humans.

Highlights

Ovarian tissue cryopreservation is an option for the restoration of hormonal and reproductive function of females facing cancer
Considering that the consequences of cryostorage can only be confirmed over long periods of time, and since it is impossible to guarantee there will never be any cross-contamination, current recommendations support the use of systems in which there is no direct contact between the cryopreserved material and liquid nitrogen (Pomeroy et al, 2010)
Ten to 12 tissue specimens from different ovaries were placed in the bottom of a metal cryovial (Patent no.: BR 20 2013 019739 0); a lid was tightly fastened on the top of the vial and the system was immersed in liquid nitrogen (LN2) for storage from one week to two months (Aquino et al, 2014)

Summary

Introduction

Ovarian tissue cryopreservation is an option for the restoration of hormonal and reproductive function of females facing cancer. Comparative studies have demonstrated that vitrification might more effectively preserve ovarian structure and function (Tokieda et al, 2002; Keros et al, 2009). Most vitrification procedures employ an open system to directly expose the biological material to liquid nitrogen (Sugimoto et al, 2000; Tokieda et al, 2002; Migishima et al, 2003; Almodin et al 2004; Chen et al, 2006; Keros et al, 2009; Isachenko et al, 2009; Sheikhi et al, 2011; Fabbri et al, 2010). Our group has developed a metal chamber in which ovarian tissue specimens are vitrified without direct contact with liquid nitrogen (Aquino et al, 2014). Histological analysis of rewarmed tissue specimens showed well-preserved stroma, primordial, and primary follicles (Marques et al, 2015; Aquino et al, 2014)

Methods

Results

Conclusion