Hori Tatsuya, Ichikawa Mitsue, Kawakami Eiichi, Tsutsui Toshihiko
Department of Reproduction, Nippon Veterinary and Animal Science University, 7-1 Kyonan-cho 1-chome, Musashino-shi, Tokyo 180-8602, Japan.
J Vet Med Sci. 2004 Jan;66(1):37-41. doi: 10.1292/jvms.66.37.
Freeze-storage of epididymal sperm is an important technique for the preservation of gametes in animals, including those becoming extinct. We froze canine sperm recovered from the cauda epididymis and investigated the fertility. The qualities of sperm from the cauda epididymis before freezing were: mean sperm motility, 89.4 +/- 1.6 (SE) %; sperm viability, 89.1 +/- 1.1%; and these were significantly higher than those of sperm from the caput-corpus epididymis (P<0.01, P<0.05). The number of sperm recovered from both cauda epididymides varied among animals: 6.3-122.3 x 10(7), mean 61.5 +/- 10.0 x 10(7). Freezing was used only for sperm recovered from the cauda epididymis. The sperm motility and viability after thawing were 19.5 +/- 2.5% and 53.1 +/- 3.3%, respectively. These were slightly lower than those of frozen-thawed ejaculated sperm, but the differences were not significant. When 2 x 10(8), 3 x 10(8), or 4 x 10 (8) sperm were inseminated in the unilateral uterus, only one animal inseminated with 3 x 10(8) sperm was fertilized (1/16, 6.3%). When 1 x 10(8) sperm were inseminated in the bilateral uterine tubes, one of six animals (16.7%) was fertilized. Therefore, although the qualities of epididymal sperm after thawing were similar to those of ejaculated sperm, the conception rate obtained with frozen-thawed epididymal sperm was low in beagle dogs. It is necessary to investigate the differences in damage between epididymal sperm after thawing and ejaculated sperm and to develop a method for improving the conception rate.
附睾精子的冷冻保存是动物配子保存的一项重要技术，包括那些濒临灭绝的动物。我们冷冻了从附睾尾部回收的犬精子，并研究了其生育能力。冷冻前附睾尾部精子的质量为：平均精子活力89.4±1.6（SE）%；精子存活率89.1±1.1%；这些均显著高于附睾头体部精子（P<0.01，P<0.05）。从双侧附睾尾部回收的精子数量在不同动物之间有所差异：6.3 - 122.3×10⁷，平均61.5±10.0×10⁷。仅对从附睾尾部回收的精子进行冷冻。解冻后精子活力和存活率分别为19.5±2.5%和53.1±3.3%。这些略低于冷冻解冻后的射精精子，但差异不显著。当向单侧子宫内输入2×10⁸、3×10⁸或4×10⁸个精子时，仅一只输入3×10⁸个精子的动物受孕（1/16，6.3%）。当向双侧输卵管内输入1×10⁸个精子时，六只动物中有一只受孕（16.7%）。因此，尽管解冻后附睾精子的质量与射精精子相似，但在比格犬中，冷冻解冻后的附睾精子受孕率较低。有必要研究解冻后附睾精子与射精精子损伤的差异，并开发提高受孕率的方法。
