Kawakami Eiichi, Ohashi Tomoko, Hori Tatsuya, Tsutsui Toshihiko
Department of Reproduction, Nippon Veterinary and Animal Science University, Musashino-shi, Tokyo, Japan.
J Vet Med Sci. 2002 Oct;64(10):867-72. doi: 10.1292/jvms.64.867.
Sperm ejaculated by 8 beagle dogs and the cumuli oophori collected from 3 estrous beagle bitches were co-incubated, and penetration of the sperm into cumuli was observed to investigate the influence of cumuli on homologous sperm. The percentages of hyperactivated sperm and acrosome-reacted sperm were calculated after incubation with homogenized cumuli. The hyaluronic acid content of the incubated cumuli was measured, and hyperactivation and the acrosome reaction of the sperm were evaluated in medium containing hyaluronic acid. The mean percentage of hyperactivated sperm (33.0%) and number (3.0) of sperm that had penetrated a cumulus among sperm incubated for 7 hr were significantly higher than the values for sperm incubated for 0.5 hr (P<0.01). Almost all sperm that had penetrated the cumuli had intact acrosome, as though they were hyperactivated. The percentages of motile sperm (77.3%) and hyperactivated sperm (23.6%) after 2 hr incubation in the medium containing homogenized cumuli were significantly higher than in control medium (P<0.01), but there was no difference between cumulus and control media in the percentages of acrosome-reacted sperm. The hyaluronic acid content of a cumulus increased after 24 hr incubation. After 2 and 4 hr of incubation the percentages of hyperactivated sperm in the medium containing hyaluronic acid were significantly higher than in the control medium (P<0.01). These results suggest that canine hyperactivated sperm with intact acrosome can penetrate homologous cumuli and that the sperm are able to pass through the cumulus because the hyperactivated movement is maintained by hyaluronic acid secreted by the cumulus cells.
将8只比格犬射出的精子与从3只处于发情期的比格母犬采集的卵丘细胞共同孵育，观察精子对卵丘细胞的穿透情况，以研究卵丘细胞对同源精子的影响。与匀浆后的卵丘细胞孵育后，计算超活化精子和顶体反应精子的百分比。测定孵育后卵丘细胞的透明质酸含量，并在含有透明质酸的培养基中评估精子的超活化和顶体反应。孵育7小时的精子中，超活化精子的平均百分比（33.0%）和穿透卵丘细胞的精子数量（3.0）显著高于孵育0.5小时的精子（P<0.01）。几乎所有穿透卵丘细胞的精子顶体都完整，似乎处于超活化状态。在含有匀浆卵丘细胞的培养基中孵育2小时后，活动精子的百分比（77.3%）和超活化精子的百分比（23.6%）显著高于对照培养基（P<0.01），但卵丘细胞培养基和对照培养基中顶体反应精子的百分比没有差异。孵育24小时后，卵丘细胞的透明质酸含量增加。在含有透明质酸的培养基中孵育2小时和4小时后，超活化精子的百分比显著高于对照培养基（P<0.01）。这些结果表明，顶体完整的犬超活化精子能够穿透同源卵丘细胞，并且精子能够穿过卵丘细胞是因为卵丘细胞分泌的透明质酸维持了超活化运动。
