The profile of ovarian tissue of female Sprague-Dawley rats (Rattus norvegicus L.) after vitrification using ethylene glycol and egg yolk as cryoprotectant

Abstract

Vitrification has been widely used to preserve ovarian tissue. However, an efficient method with minimal damaging effect towards the tissue has not been established, yet. Accordingly, the combination method among intra- and extracellular cryoprotectant was conducted in this study. The aim of the research is to evaluate combination of ethylene glycol (EG) as intracellular cryoprotectant with egg yolk as extracellular cryoprotectant in reducing coldshock effect on ovarian tissue vitrification after 48 hours. Twenty one samples of twelve week-old female Sprague-Dawley rats are used in this study. Ovarian samples (n = 21) were washed in saline to clear excessive blood and were weighed. Samples for control groups (n = 3) were immediately fixated. Control treatment groups (n = 9) plunged into cryotube filled with 3.75 %, 7.5 % and 15 % of EG solution, respectively, while treatment groups (n = 9) were 3.75 %, 7.5 % and 15 % of egg yolk+EG solution, respectively. All samples were then frozen in liquid nitrogen (- 196 °C). After 48 hours, the samples were thawed and weighed. The result shown that based on Anova test there were no significant different (p<0.05) in weight of ovarian tissue before and after vitrification. In conclusion, vitrification using a combination of ethylene glycol (EG) and egg yolk may have significant impact in preventing coldshock in the ovary.