International Journal of Reproductive Medicine
Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences of Yazd
Vol. 10, No. 3, 2012, pp. 257-264
Bioline Code: rm12037
Full paper language: English
Document type: Research Article
Document available free of charge
International Journal of Reproductive Medicine, Vol. 10, No. 3, 2012, pp. 257-264
© Copyright 2012 - Iranian Journal of Reproductive Medicine
Hydrostatic pressure improves in-vitro maturation of oocytes derived from vitrified-warmed mouse ovaries|
Rashidi, Zahra; Azadbakht, Mehri & Khazaei, Mozafar
Background: Cryopreservation has limited successes and in-vitro maturation is used to improve its results. Hydrostatic pressure (HP) plays an important role in follicular development.
Objective: This study was designed to examine the effects of HP on in-vitro maturation of oocytes and cell death in cumulus cells derived from vitrified-warmed mouse ovaries.
Materials and Methods: Preovulatory follicles were harvested from non-vitrified and vitrified-warmed 6-8 week-old female NMRI mouse ovaries and randomly assigned to following groups: non-vitrified (control), non-vitrified with HP exposure (treatment I), vitrified-warmed (treatment II) and vitrified-warmed with HP exposure (treatment III). The follicles of treatments I and III were subjected to HP (20 mmHg) for 30 min and after that all groups were cultured for 24h and assessed for in-vitro maturation of oocytes. The viability and apoptosis of cumulus cells and oocytes were assessed using supravital nuclear staining and TUNEL assay, respectively.
Results: Oocytes harvested follicles in both control and treatment II had a significantly lower percentage of metaphase II oocytes (MII) than the treatment I and III (23.5±3.1, 15.03±4.6 and 32.7±3.2, 25.5±4.6; respectively) (p<0.05). Viability of the cumulus cells reduced in treatment I, II and III (83.4, 83.3 and 77.7%) compared to control (86.9%), (p<0.05). The apoptotic index in cumulus and oocyte complexes in treatments I and III (10.7±0.8 and 15.3±0.8) was higher than in control and treatment II (6.7±0.5 and 9.7±0.5) (p<0.05).
Conclusion: These results demonstrate that HP had a mild effect on cell death incidence in cumulus cells without any effect on oocyte. However, it can be used as a mechanical force to improve in-vitro maturation of oocytes derived from vitrified-warmed mouse ovaries.
Vitrification, In-vitro maturation, Hydrostatic pressure, Cell death, Mouse.
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