Liu Z, Foote R H
Department of Animal Science, Cornell University, Ithaca, NY 14853, USA.
J Dairy Sci. 1998 Jul;81(7):1868-73. doi: 10.3168/jds.S0022-0302(98)75757-1.
Studies were designed to evaluate bull sperm motility and membrane integrity following exposure to Tyrode's solution varying in osmolality from 100 to 1537 mOsm. Congo red and bisbenzimide (HOECHST 33258) stains were used to distinguish between sperm with intact versus disrupted plasma membranes. Sperm motility was subjectively evaluated. No significant differences were found between motile and unstained sperm (sperm with intact membranes) in solutions with nearly physiologic osmolalities between 200 and 300 mOsm. However, in 100- and 150-mOsm solutions, the percentage of motile sperm (5 and 19%), respectively) was lower than the percentage of sperm unstained with Congo red (18 and 35%). With HOECHST 33258 stain, the corresponding values were 7 and 14% versus 26 and 31%. The percentage of motile sperm declined greatly in the 500-mOsm medium, but the proportion of unstained sperm was affected little until the osmotic pressure exceeded 732 mOsm. Partial recovery of motility occurred when sperm were returned to the isotonic medium. This study indicated that the sperm plasma membrane was more resistant to osmotic damage than were the mechanisms responsible for sperm motility. Lack of motility in hypertonic media was not an absolute indicator of cell death, and unstained sperm overestimated sperm viability, which are factors to consider when sperm are being evaluated, especially relative to cryopreservation.
本研究旨在评估公牛精子在暴露于渗透压从100至1537毫渗摩尔的台氏液后的活力和膜完整性。使用刚果红和双苯甲酰亚胺（Hoechst 33258）染色来区分质膜完整与受损的精子。对精子活力进行主观评估。在渗透压接近生理值（200至300毫渗摩尔）的溶液中，活动精子（质膜完整的精子）与未染色精子之间未发现显著差异。然而，在100毫渗摩尔和150毫渗摩尔的溶液中，活动精子的百分比（分别为5%和19%）低于未被刚果红染色的精子百分比（18%和35%）。使用Hoechst 33258染色时，相应的值分别为7%和14%，对比26%和31%。在500毫渗摩尔的培养基中，活动精子的百分比大幅下降，但直到渗透压超过732毫渗摩尔，未染色精子的比例才受到较小影响。当精子回到等渗培养基中时，活力出现部分恢复。本研究表明，精子质膜比负责精子活力的机制更能抵抗渗透损伤。高渗培养基中精子活力的缺乏并非细胞死亡的绝对指标，未染色精子高估了精子活力，这些都是在评估精子时需要考虑的因素，尤其是相对于冷冻保存而言。
