Prochowska Sylwia, Niżański Wojciech, Partyka Agnieszka
Department of Reproduction and Clinic of Farm Animals, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland.
Department of Reproduction and Clinic of Farm Animals, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland.
Theriogenology. 2017 Jan 15;88:43-49. doi: 10.1016/j.theriogenology.2016.09.045. Epub 2016 Oct 3.
The aim of this study was to examine apoptotic markers in fresh and frozen-thawed feline spermatozoa collected via urethral catheterization and epididymal slicing. Caspase activation, DNA fragmentation, and phosphatidylserine externalization were evaluated using flow cytometry in sperm cells from both sources before and after cryopreservation. The study revealed no differences between urethral and epididymal spermatozoa, both in fresh and frozen-thawed samples. The level of apoptotic changes in sperm cells in fresh feline semen was low: 0.8 ± 0.8% of live urethral and 0.4 ± 0.4% of live epididymal spermatozoa showed active caspases; 1.6 ± 0.9% and 2.1 ± 1.9%, respectively, showed DNA fragmentation; and 0.3 ± 0.2% and 1.0 ± 1.3%, respectively, showed phosphatidylserine externalization. In both types of sperm cells, cryopreservation did not induce a significant increase in caspase activation (urethral: from 3.9 ± 3.2% to 7.5 ± 5.0%; epididymal: from 4.7 ± 2.9% to 11.7 ± 8.5%). In urethral spermatozoa, phosphatidylserine externalization in live cells was significantly (P < 0.05) increased after thawing (from 0.3 ± 0.2% to 2.7 ± 2.5%). This increase was not noted for epididymal spermatozoa (from 1.0 ± 1.3% to 1.7 ± 1.3%). No significant changes in DNA fragmentation were observed (2.1 ± 0.8% and 1.7 ± 1.0%). In conclusion, both urethral and epididymal feline spermatozoa showed equally low levels of apoptotic-like changes. Hence, apoptotic alterations seem to play only a minor role, if any, in urethral and epididymal feline spermatozoa. The deterioration of sperm quality after freezing and thawing is more likely connected with direct damage to the cells than to activation of apoptotic processes.
本研究旨在检测经尿道导管插入术和附睾切片采集的新鲜及冻融猫精子中的凋亡标志物。在冷冻保存前后，使用流式细胞术评估了来自这两种来源的精子细胞中的半胱天冬酶激活、DNA片段化和磷脂酰丝氨酸外化情况。研究发现，在新鲜和冻融样本中，尿道精子和附睾精子之间均无差异。新鲜猫精液中精子细胞的凋亡变化水平较低：活的尿道精子中有0.8±0.8%、活的附睾精子中有0.4±0.4%显示半胱天冬酶活性；分别有1.6±0.9%和2.1±1.9%显示DNA片段化；分别有0.3±0.2%和1.0±1.3%显示磷脂酰丝氨酸外化。在两种类型的精子细胞中，冷冻保存均未导致半胱天冬酶激活显著增加（尿道精子：从3.9±3.2%增至7.5±5.0%；附睾精子：从4.7±2.9%增至11.7±8.5%）。在尿道精子中，解冻后活细胞中的磷脂酰丝氨酸外化显著增加（P<0.05）（从0.3±0.2%增至2.7±2.5%）。附睾精子未观察到这种增加（从1.0±1.3%增至1.7±1.3%）。未观察到DNA片段化有显著变化（分别为2.1±0.8%和1.7±1.0%）。总之，尿道和附睾猫精子的凋亡样变化水平均同样较低。因此，凋亡改变在尿道和附睾猫精子中似乎只起很小的作用（如果有作用的话）。冷冻和解冻后精子质量的下降更可能与细胞的直接损伤有关，而非与凋亡过程的激活有关。
