Dewire D M, Davis N S, Miller K F, Stowe N T, Thomas A J
Department of Urology, Cleveland Clinic Foundation, Ohio.
J Assist Reprod Genet. 1994 Jan;11(1):42-8. doi: 10.1007/BF02213697.
Having observed that sperm from the chronically obstructed caput epididymis fertilize poorly in vitro, we investigated the effect of partial zona dissection (PZD) on fertilization in a murine model of unilateral proximal epididymal obstruction. Cleavage rates were compared for zona-intact oocytes and PZD oocytes incubated with sperm from the following epididymal segments: the obstructed caput, the contralateral nonobstructed caput, the contralateral cauda, and a sperm-free preparation to control for parthenogenesis.
Unilateral epididymal obstruction resulted in significantly higher sperm counts in the obstructed caput compared to the nonobstructed caput, although there was no difference in motility. Cleavage rates for ova incubated with sperm from the obstructed caput and the nonobstructed caput were uniformly poor and did not differ significantly from those for the sperm-free controls. Cauda sperm fertilized significantly better than all other sperm groups (P < 0.05). Partial zona dissection did not improve cleavage rates in any group.
We conclude that sperm from the chronically obstructed caput epididymis, like sperm from the normal caput, are unable to fertilize ova, and PZD does not enhance this poor fertilizing capacity. Furthermore, the finding that PZD does not improve the fertilizing capacity of the presumably mature cauda sperm in our mouse model suggests that any beneficial effect of PZD may be strain-specific.
观察到慢性梗阻的附睾头精子在体外受精能力较差后，我们在单侧近端附睾梗阻的小鼠模型中研究了部分透明带切除术（PZD）对受精的影响。比较了完整透明带卵母细胞和PZD卵母细胞与来自以下附睾节段的精子共同孵育后的卵裂率：梗阻侧附睾头、对侧未梗阻附睾头、对侧附睾尾，以及无精子制剂以控制孤雌生殖。
单侧附睾梗阻导致梗阻侧附睾头的精子计数显著高于未梗阻侧附睾头，尽管活力没有差异。与梗阻侧附睾头精子和未梗阻侧附睾头精子共同孵育的卵子的卵裂率均很差，与无精子对照组相比无显著差异。附睾尾精子的受精能力明显优于所有其他精子组（P < 0.05）。部分透明带切除术未提高任何组的卵裂率。
我们得出结论，慢性梗阻的附睾头精子与正常附睾头精子一样，无法使卵子受精，且部分透明带切除术不能增强这种较差的受精能力。此外，在我们的小鼠模型中，部分透明带切除术未提高推测为成熟的附睾尾精子的受精能力，这一发现表明部分透明带切除术的任何有益作用可能具有品系特异性。
