Amann R P, Seidel G E, Brink Z A
BioPore Inc., State College, Pennsylvania, USA.
J Androl. 1999 Jan-Feb;20(1):42-6.
We evaluated the effect on fertility of in vitro exposure of thawed frozen bull sperm to synthetic FertPlus peptide prior to artificial insemination (AI). The peptide represented a 60-amino acid sequence within rat prosaposin. Commercial cryopreserved semen was from three Holstein bulls. Onset of estrus in groups of Holstein nulliparous heifers was synchronized via injection of prostaglandin F2-alpha, and heifers were scheduled for AI 8-24 hours after estrus was detected. Semen was thawed, diluted to 2.4 x 10(6) sperm/ml with buffer, and split to provide control and exposed aliquots (0 or 30 microM peptide) that were incubated at 37 degrees C for 10 minutes and then were held at 32 degrees C. The two aliquots of semen then were used on an alternate basis 2-65 minutes later to inseminate females. Each AI (one per female) involved the deposit of approximately 250,000 sperm into each uterine horn. This procedure for AI was used to reduce the pregnancy rate with control semen to below the maximum value for a given bull and to facilitate detection of any beneficial effect of the peptide. For each bull, approximately 32 heifers were inseminated with control semen, and approximately 32 heifers were inseminated with peptide-exposed semen. Pregnancy was evaluated ultrasonically approximately 60 days after AI. After excluding one group of heifers with unusually low fertility, averaged across all animals, a 29% increase in pregnancy rate resulted from exposure of sperm to peptide (P < 0.04; one-tailed chi-square test; means were 48 vs. 62%). Pregnancy rates for the three bulls for control and peptide-exposed semen, respectively, were 42 and 62%, 44 and 64%, and 56 and 61%; means in the first two pairs of values tended to differ (P approximately equal to 0.10). These observations should be confirmed with sperm from other bulls used in a more conventional manner. However, with insemination of a limiting number of cryopreserved sperm, brief exposure of the thawed bull sperm to FertPlus peptide appeared to improve fertility dramatically.
我们评估了在人工授精（AI）前，将解冻后的冷冻公牛精子体外暴露于合成的FertPlus肽对生育力的影响。该肽代表大鼠prosaposin内一段60个氨基酸的序列。商业冷冻保存的精液来自三头荷斯坦公牛。通过注射前列腺素F2-α使荷斯坦未生育小母牛组的发情开始同步，在检测到发情后8 - 24小时安排对小母牛进行人工授精。精液解冻后，用缓冲液稀释至2.4×10⁶精子/毫升，并分成两份，分别作为对照和暴露组（0或30微摩尔肽），在37℃孵育10分钟，然后保持在32℃。两份精液样本在2 - 65分钟后交替用于给母牛授精。每次人工授精（每头母牛一次）向每个子宫角注入约250,000个精子。这种人工授精程序用于将对照精液的妊娠率降低到给定公牛的最大值以下，以便于检测该肽的任何有益效果。对于每头公牛，约32头小母牛用对照精液授精，约32头小母牛用暴露于肽的精液授精。在人工授精后约60天通过超声评估妊娠情况。在排除一组生育力异常低的小母牛后，对所有动物进行平均，精子暴露于肽导致妊娠率提高了29%（P < 0.04；单尾卡方检验；平均值分别为48%和62%）。三头公牛对照精液和暴露于肽的精液的妊娠率分别为42%和62%、44%和64%、56%和61%；前两组值的平均值倾向于有差异（P约等于0.10）。这些观察结果应以更常规方式使用其他公牛的精子进行确认。然而，在使用有限数量的冷冻保存精子进行授精时，解冻后的公牛精子短暂暴露于FertPlus肽似乎能显著提高生育力。
