Department of Obstetrics and Food Animal Clinic, University of Veterinary Medicine, H-1078 Istvan str. 2, Budapest, Hungary.
Anim Reprod Sci. 2023 Nov;258:107361. doi: 10.1016/j.anireprosci.2023.107361. Epub 2023 Oct 20.
The aim of the present study was to compare the survival and developmental rate of canine isolated preantral follicles (PAFs) after cryopreservation with different methods (closed vs open vitrification). Follicles were isolated from ovaries randomly divided into three groups: fresh control, OPS (open pulled straw) vitrified and cryotube (CT) vitrified. Post-thaw viability of follicles and oocytes was assessed. Fresh and vitrified/thawed PAFs were cultured in 20 µl drops of FSH-supplemented medium for 10 days. Follicular growth, survival rate, estradiol production and ovulation rate were examined. CT method resulted in lower rate of live cells (58.7%) and oocytes (38.8%) than that of fresh ones (83.6% and 64%, respectively) and OPS (80.3% and 79.3%, respectively). Survival rate was similar to fresh follicles in OPS group (98.5% and 95.4%, respectively), while CT decreased the survival to 81.2%. Fresh follicles showed continuous growth, while CT follicles stopped to increase their size after 2 day. In the OPS vitrified follicles, this halting occurred between Day5 and Day10. Fresh follicles showed the highest estradiol production (range: 26.9 - 266.2 pg/ml). Comparing the two vitrified groups, lower estradiol concentration range was measured in the CT group (7.8-48.7 pg/ml vs. 15.4-89.6 pg/ml). Ovulation rate in each group was lowest in the OPS group (1.7% vs 7% and 8.9% in fesh and CT, respectively). Our data show that OPS vitrification provides superior survival rate, in vitro growth and hormonal production to CT. To our knowledge, these are the first results on comparing different cryopreservation protocols on canine isolated preantral follicles.
本研究旨在比较不同方法（封闭与开放玻璃化）对犬分离的原始卵泡（PAF）进行冷冻保存后的存活率和发育率。将从随机分组的卵巢中分离出的卵泡分为三组：新鲜对照组、OPS（开放式拉管）玻璃化组和 Cryotube（CT）玻璃化组。评估冻后卵泡和卵母细胞的活力。将新鲜和冷冻/解冻的 PAF 在补充有 FSH 的 20µl 培养液中培养 10 天。检查卵泡生长、存活率、雌二醇产生和排卵率。CT 法的活细胞率（58.7%）和卵母细胞率（38.8%）低于新鲜组（分别为 83.6%和 64%）和 OPS 组（分别为 80.3%和 79.3%）。OPS 组的存活率与新鲜组相似（分别为 98.5%和 95.4%），而 CT 组则降至 81.2%。新鲜卵泡持续生长，而 CT 卵泡在第 2 天停止增大。在 OPS 玻璃化的卵泡中，这种停止发生在第 5 天至第 10 天之间。新鲜卵泡产生的雌二醇量最高（范围：26.9-266.2pg/ml）。比较两个玻璃化组，CT 组测量到的雌二醇浓度范围较低（7.8-48.7pg/ml 与 15.4-89.6pg/ml）。每个组的排卵率均以 OPS 组最低（分别为 1.7%、7%和 8.9%）。我们的数据表明，OPS 玻璃化法提供了优于 CT 的存活率、体外生长和激素产生。据我们所知，这是首次比较不同的犬分离原始卵泡冷冻保存方案的结果。
