Hunter R H, Petersen H H, Greve T
Department of Clinical Studies-Reproduction, Royal Veterinary and Agricultural University, Copenhagen, Denmark.
Mol Reprod Dev. 1999 Nov;54(3):283-91. doi: 10.1002/(SICI)1098-2795(199911)54:3<283::AID-MRD9>3.0.CO;2-T.
As a means of determining whether ovarian follicular fluid reaches the functional sperm reservoir in the caudal isthmus of the Fallopian tube shortly after ovulation, 0.01-0.02 ml aliquots of whole or steroid-free follicular fluid were introduced into the distal extremity of the isthmus within 1 hr before ovulation. Eggs were recovered during a second intervention 4 hr 45 min-6 hr 10 min after treatment and examined by phase-contrast microscopy for the normality of fertilisation. In a separate experiment, 0.01-0.02 ml aliquots of 10 microM calcium ionophore solution were introduced into the same site in comparable animals. Sixty-nine fertilised eggs were recovered from 12 fallopian tubes treated with whole follicular fluid, of which 24 (34.8%) were polyspermic. The 12 contralateral control tubes (PBS-treated) yielded 47 fertilised eggs, of which only one (2.1%) was polyspermic (P < 0.001). Steroid-free aliquots of the same follicular fluid introduced bilaterally into eight fallopian tubes (4 animals) resulted in recovery of 59 fertilised eggs, of which only one (1.7%) was polyspermic. Treatment with ionophore solution yielded a 41.6% incidence of polyspermy (10 of 24 eggs from four tubes) compared with 3.8% polyspermy (1 egg) from the control tubes (P < 0.01). Dispermy was the principal form of polyspermy. The numbers of accessory spermatozoa on/in the zona pellucida were increased by the experimental treatment. Follicular fluid passing down the fallopian tube ampulla at ovulation was therefore considered not to be the physiological stimulus for an initial, tightly-controlled release of spermatozoa from epithelial binding in the caudal isthmus. Indeed, because such sperm activation commences shortly before ovulation, a locally transmitted ovarian programming with relatively high concentrations of follicular hormones remains the favoured model. Although pre-ovulatory progesterone is considered to be the coordinating steroid of increasing influence in these pre-fertilisation events, its effects are proposed to be modulated in the endosalpinx by mobilisation of Ca2+ ions into a discrete population of bound spermatozoa. Results of the steroid-free follicular fluid and calcium ionophore treatments stand in support.
为了确定排卵后不久卵巢卵泡液是否会到达输卵管峡部尾端的功能性精子储存库，在排卵前1小时内，将0.01 - 0.02毫升的全卵泡液或无类固醇卵泡液等分试样注入峡部远端。在处理后4小时45分钟至6小时10分钟的第二次干预期间回收卵子，并通过相差显微镜检查受精的正常情况。在另一个实验中，将0.01 - 0.02毫升10微摩尔钙离子载体溶液等分试样注入可比动物的同一部位。从12根用全卵泡液处理的输卵管中回收了69枚受精卵，其中24枚（34.8%）为多精受精。12根对侧对照管（用PBS处理）产生了47枚受精卵，其中只有1枚（2.1%）为多精受精（P < 0.001）。将同样的无类固醇卵泡液等分试样双侧注入8根输卵管（4只动物）后回收了59枚受精卵，其中只有1枚（1.7%）为多精受精。用离子载体溶液处理导致多精受精发生率为41.6%（来自4根输卵管的24枚卵子中有10枚），而对照管的多精受精率为3.8%（1枚卵子）（P < 0.01）。双精受精是多精受精的主要形式。实验处理增加了透明带上/内的附属精子数量。因此，排卵时通过输卵管壶腹向下流动的卵泡液被认为不是促使精子从峡部尾端上皮结合处最初严格控制释放的生理刺激因素。实际上，由于这种精子激活在排卵前不久开始，具有相对高浓度卵泡激素的局部传递的卵巢编程仍然是最受青睐的模型。虽然排卵前孕酮被认为是在这些受精前事件中影响力不断增加的协调类固醇，但其作用被认为是通过将钙离子动员到离散的结合精子群体中在内输卵管中受到调节。无类固醇卵泡液和钙离子载体处理的结果支持了这一点。
