Effects of pentoxifylline on the histological and ultra-structural features of vitrified mouse ovarian tissue: An experimental study

Background: Vitrification is a process that can be used to preserve gonads in the healthy and natural status. Oxidative stress is one of the disadvantages of vitrification. Pentoxifylline (PTX) is an antioxidant that can reduce reactive oxidative stress effects. Objective: We aimed to investigate the effects of PTX on histological and ultra-structural features of vitrified and non-vitrified mouse ovarian tissue. Materials and Methods: Twenty-five adult female Balb-C mice were randomly and equally divided into control group: the ovaries did not receive any treatment; experimental 1 and 2: the vitrified ovaries were incubated in phosphate buffer solution and bovine serum albumin without and with PTX, respectively, for 30 min; sham 1 and 2: the non-vitrified ovaries were incubated in phosphate buffer solution and bovine serum albumin and were incubated without and with PTX, respectively for 30 min. The right and left ovaries in all of the groups were evaluated using light and transmission electron microscopy, respectively. Results: The histological and ultra-structural features of vitrified ovaries were seriously damaged. There was non-uniformed germinal epithelium and tunica albuginea, degenerated granulosa cells and stromal cells, puffy basement membrane and irregular thickness of zona pellucida, as well as a pyknotic nucleus and bubbly and segmented ooplasmic in the follicles. Also, ovarian tissues were damaged by the PTX in the non-vitrified ovaries. Conclusion: Vitrification can damage the histological and ultra-structural features of the ovary in mouse models. PTX as an antioxidant, with concentration of 1.8 mM could not prevent and restore these damages and had no adequate effects on the vitrified ovarian tissues.