Holt W V, Morris G J, Coulson G, North R D
Institute of Zoology, Zoological Society of London, England.
J Exp Zool. 1988 Jun;246(3):305-14. doi: 10.1002/jez.1402460310.
Cryoinjury in individual ram spermatozoa was investigated in cells cooled at 10 degrees C/min on a programmable cryomicroscope. In physiological buffer and cryoprotective media, there was a smooth decline in sperm swimming speed with decreasing temperature; cooling in buffer caused a marked decline in the proportion of cells displaying forward progression, especially once the temperature fell below 16 degrees C. Spermatozoa cooled in the presence of rhodamine 123, a mitochondrial-specific dye, showed that abolition of sperm motility by cold shock in buffer was not due to mitochondrial inactivation. Temperature decline through the region of 10 degrees C caused a number of spermatozoa in buffer to undergo a sudden asymmetric bending of the flagellum in the region of the midpiece. Ultrastructural studies suggest that this was caused by an unstable, asymmetric membrane lesion. Spermatozoa cooled in the presence of cryoprotective media showed better recovery of motility after rewarming and failed to exhibit the bending effect described above.
在可编程低温显微镜上，以每分钟10摄氏度的速度冷却细胞，研究了单个公羊精子的冷冻损伤。在生理缓冲液和冷冻保护介质中，随着温度降低，精子游动速度平稳下降；在缓冲液中冷却导致显示向前运动的细胞比例显著下降，尤其是一旦温度降至16摄氏度以下。在存在罗丹明123（一种线粒体特异性染料）的情况下冷却的精子表明，缓冲液中冷休克导致的精子活力丧失并非由于线粒体失活。温度下降到10摄氏度区域时，缓冲液中的许多精子在中段区域的鞭毛会突然发生不对称弯曲。超微结构研究表明，这是由不稳定的不对称膜损伤引起的。在冷冻保护介质存在下冷却的精子在复温后显示出更好的活力恢复，并且未表现出上述弯曲效应。
