Nicholson H D, Parkinson T J, Lapwood K R
Department of Anatomy, University of Bristol, UK.
J Reprod Fertil. 1999 Nov;117(2):299-305. doi: 10.1530/jrf.0.1170299.
This study was performed to determine whether oxytocin or vasopressin affect the transport of spermatozoa from the epididymis of rams in vivo. Under general anaesthesia, cannulae were inserted into each ductus deferens and passed into the cauda epididymis of 24 Oxford Down cross rams and the luminal fluid was collected at 10 min intervals for 2-3 h. Animals were divided into seven groups and received either (i) 2 ml 0.9% saline, (ii) 10 micrograms oxytocin, (iii) 100 micrograms oxytocin, (iv) 100 micrograms oxytocin antagonist, (v) 300 micrograms oxytocin antagonist followed by 100 micrograms oxytocin, (vi) 100 micrograms vasopressin, or (vii) 100 micrograms vasopressin followed by 100 micrograms oxytocin, all by i.v. injection. The mass of fluid and number of spermatozoa in each 10 min sample was measured and the motility of the spermatozoa was assessed. Treatment with saline did not affect the mass or the number of spermatozoa in the fluid collected. Oxytocin at 10 micrograms significantly increased both the output of fluid and the number of spermatozoa by twofold. Oxytocin at 100 micrograms produced a greater increase in both fluid output and the number of spermatozoa within 10 min of administration of the peptide. Treatment with oxytocin antagonist had no immediate effect, but subsequently caused a significant reduction in both fluid output and the number of spermatozoa. Pretreatment with oxytocin antagonist inhibited the stimulatory effect of oxytocin. Vasopressin did not increase the number or concentration of spermatozoa in the fluid and appeared to decrease fluid output. No significant changes in the morphology or motility of the spermatozoa collected was observed in any of the samples. These data demonstrate that oxytocin has specific actions on the epididymis to increase sperm transport. They indicate that local oxytocin may be involved in regulating basal contractility of the cauda epididymidis and that augmentation by the peptide in the peripheral circulation, as occurs around the time of ejaculation, may promote a significant increase in the transport of spermatozoa into the vas deferens and ejaculate.
本研究旨在确定催产素或血管加压素是否会影响体内公羊附睾中精子的运输。在全身麻醉下，将套管插入每条输精管并通入24只牛津多塞特杂交公羊的附睾尾部，每隔10分钟收集一次管腔液，持续2 - 3小时。动物被分为七组，分别接受以下处理：(i) 2毫升0.9%生理盐水，(ii) 10微克催产素，(iii) 100微克催产素，(iv) 100微克催产素拮抗剂，(v) 300微克催产素拮抗剂后再注射100微克催产素，(vi) 100微克血管加压素，或(vii) 100微克血管加压素后再注射100微克催产素，均通过静脉注射。测量每个10分钟样本中的液体量和精子数量，并评估精子的活力。用生理盐水处理对收集到的液体中的精子数量或质量没有影响。10微克的催产素使液体输出量和精子数量显著增加了两倍。100微克的催产素在给药后10分钟内使液体输出量和精子数量有更大幅度的增加。用催产素拮抗剂处理没有立即产生影响，但随后导致液体输出量和精子数量显著减少。用催产素拮抗剂预处理可抑制催产素的刺激作用。血管加压素没有增加液体中精子的数量或浓度，且似乎降低了液体输出量。在任何样本中，收集到的精子的形态或活力均未观察到显著变化。这些数据表明，催产素对附睾有特定作用，可增加精子运输。它们表明局部催产素可能参与调节附睾尾部的基础收缩性，并且在射精前后外周循环中该肽的增加可能促进精子向输精管运输并射精的显著增加。
