阴道毛滴虫代谢产物体外对精子活力的影响

目的 :研究阴道毛滴虫代谢产物体外对人精子活力的影响。　方法 :阴道毛滴虫体外培养 ,除去虫体 ,留取培养液 ,稀释成三个浓度 ;将 10例正常生育男性的优化精子分为等体积的 4份 ,组成以下 4组 :A组加入未培养滴虫的空白培养液 ,B ,C ,D组依次加入前述浓度梯度的培养液 (1.2× 10 9/L、6× 10 8/L、1.2× 10 8/L) ,分别于 30s、1、2、4和 6h时采用计算机辅助精子分析系统 (CASA)分析精子运动参数。　结果 :阴道毛滴虫浓度在 6× 10 8/L以上时 ,精子的活率和活力与对照组相比都显著降低 (P <0 .0 5 ) ,并呈浓度依赖性和时间依赖性。　结论 :阴道毛滴虫代谢产物体外能抑制精子活力 ,可能是造成不孕不育的原因之一。     

输精管逆向注射30%乙醇引起大鼠精子活力低下的实验研究

目的:探讨输精管逆向注射30%乙醇至附睾导致大鼠精子活力低下的原因以及机制。方法:40只雄性SD大鼠随机分为注射组(n=15)、假手术对照组(n=15)和正常对照组(n=10),注射组在输精管靠近附睾2 cm处用1 m l注射器注射30%乙醇0.5 m l;假手术组只在输精管管壁相同部位用注射针刺一小孔;对照组未作任何处置。术后1个月,比较3组大鼠精子活力,苏木精-伊红(HE)染色观察输精管管壁的变化,检测附睾组织匀浆中白细胞介素6(IL-6)、γ干扰素(IFN-γ)和肉碱的含量变化。结果:1个月后,注射组的精子活动率为(30±14)%,假手术组(64±11)%,正常组为(68±9)%。注射组精子活力明显降低,与假手术对照组和正常对照组比较差异有极显著性(P<0.01)。IL-6、IFN-γ含量注射组分别为(772.7±211.0)、(350.7±39.0)pg/m l,假手术组分别为(308.5±121.0)、(172.2±61.0)pg/m l,正常对照组分别为(287.8±143.0)、(163.8±21.0)pg/m l,注射组显著高于假手术组和对照组(P<0.05)。注射组肉碱含量[(491.1±48.0)mol/L]显著低于假手术组[(664.6±45.0)mol/L]和对照组[(605.5±99.0)mol/L],P均<0.05。结论:输精管逆向注射低浓度乙醇能干扰附睾中的精子成熟环境,并激活生殖系统的免疫细胞分泌细胞因子,导致精子活力低下。     

不同生精功能障碍无精子症患者行ICSI后胚胎发育潜能的研究

目的:分析不同生精功能障碍的无精子症患者行ICSI后其胚胎发育潜能。方法:149例患者分为生精功能正常组,轻度、中度和重度生精功能障碍组,采用经皮附睾精子抽吸术(PESA)或经皮睾丸精子抽吸术(TESA)抽取不同生精功能障碍患者的精子行ICSI,记录和分析胚胎的正常受精率、卵裂率、优良胚胎形成率以及妊娠率。结果:PESA与TESA组比较,正常受精率(%)为74.9±19.6 vs 66.3±22.7(P>0.05),卵裂率(%)为96.7±8.6 vs 92.8±19.8(P>0.05),优良胚胎率(%)为43.5±26.2 vs 35.0±29.4(P>0.05)以及妊娠率(%)为44.0 vs 52.0(P>0.05),均无统计学差异。生精功能障碍从正常组到重度组的正常受精率(%)变化依次为77.8±18.4、68.4±18.5、73.5±19.8、51.4±27.9,其中轻度生精功能障碍与正常生精组有差异(P<0.05),重度生精功能障碍组与其他各组有统计学差异(P<0.05);胚胎卵裂率(%)变化依次为96.7±9.2、96.5±15.0、93.9±12.1、93.7±11.1,各组无统计学差异;优良胚胎率(%)变化依次为47.1±25.8、40.3±27.6、36.2±23.1、15.0±24.6,重度生精障碍组与其他各组有统计学差异(P<0.05);妊娠率(%)依次为54.8%、50.0%、13.6%、10.0%,有统计学差异(P<0.05)。结论:采用PESA或TESA行ICSI在正常受精率,卵裂率,优良胚胎率以及妊娠率上较均无明显差异。随着患者生精障碍程度的加重,受精率、优良胚胎率以及妊娠率均显著下降,而卵裂率却无明显区别。     

人输卵管细胞对精子存活的影响

目的 :研究人输卵管细胞对精子存活的影响。方法 :人精子与人输卵管细胞进行体外共培养 ,并以 Earle' s平衡盐液培养的精子作为对照。每日观察精子存活情况 ,并以伊红染色检测精子的存活率。结果 :在共培养组 ,人精子存活时间明显高于对照组 ( P<0 .0 1 )。共培养组精子在 9、2 4、48h的存活率分别为 ( 90 .82± 1 .94) %、( 71 .46± 6.1 9) %、( 46.64± 5.59) % ;高于对照组相应时间的存活率 ( 83 .55± 5.3 6) %、( 46.46± 4.59) %、( 1 8.3 6± 4.1 1 ) % ,差异显著 ( P均 <0 .0 1 )。结论 :人输卵管细胞及其培养液能延长精子的存活时间。     

解偶联蛋白2参与人类精子抗氧化损伤的研究

目的:人类精子对氧化应激非常敏感,解偶联蛋白2(UCP2)存在于多种组织内,通过控制细胞内活性氧(ROS)水平,参与细胞抗氧化应激损伤。本研究通过观察精子UCP2表达对精子膜脂类过氧化物水平和活力的影响,探讨精子的抗氧化机制。方法:应用计算机辅助精液分析对97份精液参数检测,根据a+b级精子百分率分为4组,Ⅰ组25例:a+b级精子>50%;Ⅱ组24例:a+b级精子25%～50%;Ⅲ组24例:a+b级精子10%～25%;Ⅳ组24例:a+b级精子<10%。应用RT-PCR检测精子UCP2mRNA的表达;同时测定精子悬液中膜脂类过氧化反应产物丙二醛(MDA)含量。结果:4组精子UCP2mRNA表达水平分别为1.51±0.24、1.28±0.15、1.17±0.20、0.69±0.18,MDA含量分别为(14.66±2.55)、(16.00±2.09)、(17.44±1.40)、(21.20±3.50)nmol/108精子。UCP2mRNA表达与MDA含量呈负相关(r=-0.633,P<0.01),精子活力较低组UCP2表达显著下降(P<0.01),MDA含量显著升高(P<0.05)。结论:精子内存在UCP2-ROS调节系统,UCP2参与精子氧化还原调节,在精子抗氧化应激中起重要作用。     

3种精子计数池在计算机辅助精液分析系统中的质量评价

目的:应用计算机辅助精液分析(CASA)系统对3种常用精子计数池进行比较,评价其在精子密度及活力分析方面的差异。方法:用浓度为(20±5)×106/ml乳胶珠溶液模拟精液样本,以Makler计数池、Leja计数池、Microcell计数池3种精子计数池作为精液分析工具,每组测定30次,以CASA系统对其密度进行分析并统计均值(x±s)和变异系数(CV);同时收集54例门诊患者精液标本用3种精子计数池分别进行活力分析,计算各组计数池前向运动精子百分率及活动精子百分率。结果:Makler计数池、Leja计数池、Microcell计数池等3种精子计数池的密度均值和变异系数分别为(25.90±3.97)、(18.74±1.62)、(20.35±2.55)×106/ml和15.31%、8.64%、12.54%。3种精子计数池密度均值间均存在明显的差异(P<0.05);Makler计数池、Leja计数池、Microcell计数池3种精子计数池的前向运动精子百分率和活动精子百分率分别为(46.54±17.09)%、(30.65±14.88)%、(30.49±13.21)%和(59.75±16.12)%、(46.76±14.11)%、(43.11±14.02)%。Makler计数池的分析结果均明显高于Leja计数池、Microcell计数池(P<0.05),而Leja计数池与Microcell计数池比较则无明显差异(P>0.05)。结论:不同类型的精子计数池得到的密度结果会存在明显的差异,在进行精子活力分析时,Makler计数池获得的结果会较Leja计数池与Microcell计数池的结果偏高。     

上游处理前后正常形态精子百分率与体外受精-胚胎移植结局的关系

目的:探讨取卵当日上游处理前后精子形态与体外受精-胚胎移植(IVF-ET)治疗结局的关系。方法:选取因单纯输卵管因素不孕而拟行IVF-ET治疗的夫妇94对。使用Kruger标准评价取卵当日上游处理前后的精子形态。以正常精子形态百分率10%为界,分别将上游处理前后的精子分成两组:B1组上游处理前正常形态≥10%,B2组<10%;A1组上游处理后正常形态≥10%,A2组<10%。分别比较B1和B2组以及A1和A2组的IVF-ET治疗结局。结果:上游处理前,B1组的受精率、卵裂率、优质胚胎率、妊娠率和胚胎种植率分别为(72.90±4.23)%、(95.20±2.61)%、(23.35±5.19)%、39.58%、18.35%;B2组分别为(71.33±5.10)%、(95.71±2.88)%、(20.18±6.15)%、41.86%、21.28%;各项指标两组之间差异均无统计学意义(P>0.05)。上游处理后,A1组受精率、卵裂率、优质胚胎率、妊娠率、胚胎种植率分别为(72.72±3.35)%、(95.64±2.04)%、(24.39±4.57)%、50.00%、23.87%;A2组分别为(70.27±8.82)%、(94.82±4.94)%、(13.45±7.39)%、9.52%、6.25%;两组之间受精率及卵裂率差别无统计学意义(P>0.05),但A1组的优质胚胎率、妊娠率及种植率明显高于A2组(P<0.05)。结论:取卵当日经上游处理后的正常精子形态百分率对IVF-ET结局有较好的预测价值。     

TEKT4蛋白在特发性弱精子症患者精子中的表达

目的:探讨TEKT4蛋白在特发性弱精子症发生机制中的作用。方法:采用非连续密度梯度离心分离和纯化特发性弱精子症患者和正常男性精子,采用RT-PCR和Western印迹方法,从mRNA和蛋白水平检测TEKT4的表达及其差异。结果:RT-PCR结果表明,TEKT4 mRNA在特发性弱精子症患者精子中的表达水平与正常男性相比显著降低(0.59±0.13 vs 0.75±0.15,t=4.325,P<0.05);Western印迹结果与RT-PCR结果一致,TEKT4蛋白在特发性弱精子症患者精子中的表达水平与正常男性相比亦显著降低(0.48±0.14 vs 0.69±0.13,t=5.939,P<0.05)。结论:特发性弱精子症患者精子中TEKT4表达水平显著降低,可能是导致弱精子症发生的重要环节之一。     

金黄地鼠腹侧前列腺来源蛋白结合精子表面的实验研究

目的:探讨前列腺分泌蛋白是否可结合于精子表面。方法:以金黄地鼠作为研究对象,应用间接免疫荧光和亲和素标记的蛋白转印方法检测前列腺分泌蛋白是否可结合于精子。制备的抗前列腺粗提取物多克隆抗体,间接免疫荧光技术检测体外与前列腺分泌物孵育的附睾精子,以及体内分别与含前列腺及去除前列腺雄鼠交配后收集的子宫腔内和输卵管腔内精子的前列腺成分抗原。前列腺提取物经电泳分离转膜后和生物素标记附睾精子膜蛋白作用,测定在体外前列腺分泌蛋白能否与附睾精子膜结合。实验分为对照组、附属性腺全去组、腹侧前列腺组、去除腹侧前列腺组。结果:前列腺抗原成分的免疫反应局限在精子体中部表面,而精子头、颈部未见阳性反应。在体外(80±5)%附睾精子与前列腺分泌蛋白结合,在体内与对照组雄鼠交配后收集的子宫腔内精子与前列腺分泌蛋白结合精子阳性率为(30.0±4.6)%,与去除腹侧前列腺组(3.6±1.4)%比较差异有显著性(P<0.01),在体内与对照组雄鼠交配后收集的输卵管腔内精子与前列腺分泌蛋白结合精子阳性率为(16.0±3.6)%,与去除腹侧前列腺组精子(3.2±1.4)%比较差异有显著性(P<0.01)。前列腺分泌蛋白的电泳印记膜与生物素标记附睾精子膜蛋白孵育后显色分析结果可见5条阳性反应带。结论:金黄地鼠的前列腺分泌蛋白可结合于精子体中部表面,前列腺分泌蛋白中至少有5个组分可与精子膜蛋白结合。     

膜联蛋白5对人精子膜及DNA完整性的影响

目的:研究膜联蛋白5(Annexin5)对人精子细胞膜及DNA完整性的影响。方法:①精子膜完整性测定:按精子浓度>20×106/ml;活率>60%选取标准收集精液标本53份,分为3组,实验组为47.5μl精液中加入2.5μl10-6mol/L的Annexin5;阴性对照组为47.5μl精液标本中加入2.5μl1mol/L的Tris-HCl(pH8.0,25℃);空白对照组为47.5μl精液标本中加入2.5μl0.01mol/L的PBS(pH7.4),作用20min后,通过精子低渗肿胀试验(HOS)检测精子膜的完整性。②DNA完整性测定:同方法①,3组实验标本作用20min后,每份标本加入2.5μl0.02mol/L的H2O2,作用60min,通过吖啶橙(AO)荧光染色检测精子核DNA的完整性。结果:An-nexin5处理20min后低渗肿胀精子百分率与空白对照组及阴性对照组比较均具有极显著差异[(66.17±12.02)%vs(58.13±13.08)%,P<0.01;(66.17±12.02)%vs(59.94±11.91)%,P<0.01];空白对照组与阴性对照组比较无显著性差异。加入H2O2后,Annexin5组的DNA碎片指数与空白对照组及阴性对照组比较均具有极显著差异[(6.39±1.07)%vs(11.16±1.16)%,P<0.01;(6.39±1.07)%vs(10.86±1.05)%,P<0.01],空白对照组与阴性对照组比较无显著性差异。结论:Annexin5蛋白能在体外提高低渗肿胀精子百分率,对精子膜的完整性具有保护作用,同时对HO作用引起的精子核DNA破坏起保护作用。     

影响胚胎培养液pH及CO2平衡的因素探讨

目的探讨胚胎培养液在CO2平衡及使用过程中pH的动态变化特性。方法应用血气分析仪检测人输卵管液（HTF）培养液在CO2平衡过程中不同时间、CO2浓度、液量、加油厚度以及失去CO2支持后的二氧化碳分压（PCO2）和pH的变化。结果胚胎培养液添加10％合成血清代用品（SSS）后,[HCO3^-]降低2．19mmol／L,pH降低0．022.1．0ml培养液CO2完全平衡时间为5h,加油后延长至15h,培养液经5．0％CO2完全平衡的最终pH为7．270-7．280。培养液液面越高平衡效果越差,≥6．0ml培养液CO2平衡15h后pH尚未稳定。CO2浓度由5．0％提高到6．0％,培养液pH降低0．060。培养液加油越厚其平衡效果越差,矿物油预先经过CO2平衡能明显提高平衡效果。失去CO：支持的无油培养液在静止状况下pH稳定时间为23min,而加油培养液的pH稳定时间超过60min。结论胚胎培养液CO2平衡宜采用适量多管和≥15h的过夜平衡方法;失去CO2支持的无油平衡培养液的操作时间应尽量短,而加油培养液可稍延长;应尽量减少培养液的加油厚度,使用预先CO2平衡的矿物油能明显提高平衡效果;应实测培养液pH来客观评价CO2平衡效果或CO2气体质量,选择适宜的CO2气体浓度、平衡方式和平衡时间。     

Effect of different incubation conditions on phosphatidylserine externalization and motion parameters of purified fractions of highly motile human spermatozoa

The objective of this study was to assess the temporal effects of sperm incubation at body temperature with various amounts of human serum albumin (HSA) on motion parameters and phosphatidylserine externalization, an expression of membrane integrity. Purified sperm populations were prepared by discontinuous gradient separation, incubated at 37 degrees C in 3 different culture conditions (human tubal fluid [HTF] alone, HTF plus 0.3% HSA, and HTF plus 3% HSA) and evaluated at 0, 1, 3, 6, and 24 hours. Annexin V binding was used to monitor membrane translocation of phosphatidylserine and a computer-assisted semen analyzer was used to evaluate motion parameters. All incubation conditions led to a time-dependent, significant decline in sperm motion parameters and an increase in exposure of phosphatidylserine (annexin V+, live cells) to the outer leaflet of the plasma membrane in both patients and donors. Patients had a higher degree of motility loss and externalization of phosphatidylserine than donors. The decline in the percentage of normal cells (annexin V-, live) was greater in HTF alone up to 6 hours, and the decline in the percentages of motile and rapid sperm were greater in HTF alone throughout 24 hours when compared with HSA supplementation. We conclude that prolonged incubation of purified populations of highly motile human spermatozoa at body temperature was associated with significant motility loss and membrane changes as revealed by phosphatidylserine translocation. A higher concentration of HSA resulted in a relative protective effect against such impairments, particularly during the first 6 hours of incubation. Under the experimental conditions tested, significant differences were observed between infertile men and fertile controls.     

Comparison of the effects on penetration capacity of human spermatozoa between using Ham's F-10 medium and a medium based on the composition of human tubal fluid

The penetration ability of human spermatozoa on zona-free hamster ovum when using Ham's F-10 (HF-10) medium was compared with that when using a medium based on the composition of human tubal fluid. Forty semen specimens were each divided into two aliquots; one aliquot was washed with and incubated in HF-10 medium and the other in HTF medium. The penetration rate of sperm with motility between 30 to 60 percent was significantly increased when HTF medium was used (67.9 +/- 6.9%) compared with the rate when HF-10 medium was used (49.2 +/- 7.3%) (P less than 0.05). This study shows that the ZFHO penetration ability of human spermatozoa with poor motility can be improved by using HTF medium as compared with the use of HF-10 medium.     

Impact of Ca2+ flux inhibitors on acrosome reaction of hamster spermatozoa

Ca(2+) plays a prominent role in the regulation of critical functions of spermatozoa, such as capacitation, acrosome reaction (AR), and fertilization. While there is consensus that Ca(2+) is essential, researchers have reported conflicting results as to what happens to Ca(2+) flux across the sperm membrane during capacitation and AR. The purpose of the present study was to further delineate the function of Ca(2+) channels and their role in sperm capacitation and AR. Epididymides were obtained from healthy adult male hamsters. Spermatozoa were washed with modified Tyrode medium supplemented with 0.3% bovine serum albumin, adjusted to 4.5 x 10(7) motile sperm/mL and incubated in 200-microL droplets for 4 hours at 37 degrees C in the presence of trifluoperazine (TFP), a calmodulin inhibitor, at 25, 50, 100, or 150 nM; verapamil (VP), a Ca(2+) channel inhibitor, at 25, 50, 100, or 150 nM; or nifedipine (NF), a voltage-dependent Ca(2+) channel inhibitor, at 50, 100, 200, or 400 nM. Spermatozoa were assessed for AR by using Coomassie brilliant blue staining techniques. Results indicated that incubation of sperm with Ca(2+) channel inhibitors for 4 hours significantly reduced AR in the study groups (TFP: 88% +/- 2.3%, 65% +/- 2.0%, 60% +/- 2.2%, 54 % +/- 2.2%, respectively; VP: 45% +/- 1.3%, 23 % +/- 1.2%, 12% +/- 1.0%, 8% +/- 0.6%, respectively; and NF: 11% +/- 0.8%, 9% +/- 0.3%, 7.0% +/- 0.1%, 6.0% +/- 0.1%, respectively) compared with control group (95% +/- 3.0%, P < .05). However, increasing the concentrations of TFP and NF did not result in further suppression of AR. In summary, the antagonists of calmodulin and Ca(2+) channel inhibitors suppress sperm AR.     

Addition of specific metabolites to bovine epididymal cell culture medium enhances survival and motility of cryopreserved sperm

We have developed a cell culture system of bovine epididymal epithelium in which cryopreserved bovine sperm motility was efficiently maintained for many hours. The culture conditions to maintain viable epididymal cells are quite different from conditions normally used to incubate sperm cells. Thus, we have modified a previously described principal cell medium (PCM; Moore et al, 1992) using HEPES as a buffer and supplemented media with myo-inositol, pyruvate, lactate, glycerol, and carnitine to mimic epididymal intraluminal conditions. In the first experiments the effects of PCM and our epididymal cell medium (ECM) on sperm motility were compared in the absence of cells and evaluated by microscopic analysis under a phase contrast microscope or using the Hamilton Thorn Image Analyzer System. Our results showed that motility of cauda epididymal sperm was significantly higher in ECM than in PCM during a 48-hour incubation period when both media were supplemented with 10% fetal bovine serum (FBS). We then replaced FBS with bovine serum albumin (BSA) or no proteins at all to verify if ECM was able to enhance sperm survival. To test this aspect we used frozen-thawed sperm, which survived up to 48 hours when sperm cells were coincubated with epididymal cell monolayers. Hence, PCM, ECM, and different media containing each metabolite of ECM were supplemented with 0.5% BSA to assess motility of thawed sperm after an incubation period of 6 hours. A positive effect on sperm motility was observed in all fresh and unconditioned media containing 1 mM pyruvate. Motion parameters were more efficiently maintained in all conditioned media than in unconditioned media. Our results showed, however, that pyruvate was almost completely oxidized or consumed by epididymal cells during preincubation of culture media. We conclude that motility of frozen-thawed bovine spermatozoa can be improved using a culture medium or a medium conditioned by epididymal cell cultures without carnitine but containing mainly pyruvate, inositol, glycerol, and lactate.     

The effect of serum on motility of human spermatozoa in culture

The motility of spermatozoa was higher at 6-22 h in Ham's F10 culture medium supplemented with 20-30% human serum than with lower proportions of serum or with 1% human serum albumin. Heat treatment (56 degrees C, 1 h), charcoal extraction and dialysis (18,000 molecular weight cut-off) of the serum did not reduce sperm motility suggesting that high molecular weight components are responsible for maintenance of motility. Renewing the medium (Ham's F10 with 30% serum) at 7 h resulted in better sperm motility and velocity at 22 h. At 22 h the pO2, pCO2, pH and sodium concentrations were not different in replenished and control cultures, but the concentration of glucose was higher and that of potassium lower if the medium was changed. These results suggest that addition of 20-30% human serum and renewal of medium at intervals is beneficial for sperm culture and may be of use in in vitro fertilization.     

Oocyte Penetration and Acrosome Reactions of Human Spermatozoa I: Influence of Incubation Time and Medium Composition

Washed sperm suspensions were evaluated for their ability to penetrate zona-free hamster oocytes and to exhibit an acrosome reaction in vitro. The percentage of acrosome reactions (AR%) was found to increase with incubation time and increased bovine serum albumin (BSA) concentration. We also found, however, that a remarkably high number of live, unreacted spermatozoa persisted during prolonged incubation in sperm samples obtained from some fertile men. After 22 hrs incubation, the motility of the spermatozoa was higher when the medium was supplemented with 10% human cord serum instead of 3.0% BSA. Penetration rates in hamster oocytes were not significantly different with 10% serum or 3.0% BSA as medium-supplementation. The addition of human instead of bovine serum albumin did not apparently affect the oocyte penetration rate of the spermatozoa.     

Mouse embryo growth in different culture media: selection of a medium for quality control cross-testing of human in vitro fertilization conditions

A total of 2070 two-cell mouse embryos were recovered from 89 superovulated female hybrid mice. Six different culture media were tested. The various media supported mouse embryo development as follows (percentage mean +/- SD, n = 10): Hopp and Pitts medium (H&P) 87 +/- 5 Dulbecco's modified; Eagle's medium supplemented with 10% (volume/volume, v/v) fetal bovine serum (DMEM) 80 +/- 4; Ham's F-10 +/- 15.0% (v/v) human fetal cord serum (hFCS) 79 +/- 3; Whittingham's T-6 medium (WT-6) 60 +/- 4; Ham's F-10 +/- 7.5% (v/v) hFCS 55 +/- 5; Krebs-Ringer low bicarbonate buffer (KRLBB) 42 +/- 6. In H&P, DMEM, WT-6, and Ham's F-10 medium supplemented with hFCS, the pH was maintained within a narrow range of 7.30-7.45 and adequate level of oxygenation was achieved during 72 h in culture. KRLBB had poor buffering capacity and attained ineffective levels of oxygenation during culture. Superior mouse embryo development from two-cells to morulae and hollow blastocysts occurred in H&P, Ham's F-10 + 15% hFCS, and DMEM. Ham's F-10 medium supplemented with hFCS is routinely checked for its ability to support mouse two-cell embryo development to morulae and blastocysts. This is done in conjunction with H&P medium as the control.     

Serum factors stimulate the motility of human spermatozoa

Motile human sperm were collected from a Percoll gradient and the effects on sperm motility of human serum, various serum fractions, follicular fluid and seminal plasma were assessed. In culture medium alone (RPMI-1640) sperm motility was lost after about 5 h. The addition of male blood serum both enhanced sperm motility and prolonged viability very significantly. Albumin, seminal plasma and follicular fluid all stimulated sperm motility but to a much lesser extent than did blood serum. No difference was noted between male serum or female serum which had been collected during the follicular or luteal phases of hormone-stimulated cycles and which contained high levels of oestradiol. Serum fractions obtained by separation on Sephacryl S-300 column were tested for their ability to enhance sperm motility. The most pronounced effect, much superior to that achieved by the albumin fraction, was obtained by a fraction with a molecular weight of around 200 kD. In conclusion, certain factors in human serum, which are different from albumin, strongly support sperm motility. The high serum concentrations of oestradiol resulting from hormone stimulation for in-vitro fertilization do not invalidate the use of serum from the same patient during sperm preparation, or in the medium used for ovum insemination and culture.     

Lipid transfer activity in human follicular fluid: relation to human sperm capacitation

A potentially important event during sperm capacitation is the loss of sperm membrane cholesterol. Although the exact mechanisms mediating this loss are not known, albumin and high density lipoprotein have been proposed as lipid acceptors. The authors propose that lipid transfer may be involved in capacitation as a specific mediator in the sequence of events leading to sperm membrane cholesterol loss. We present the first direct evidence of lipid transfer activity (LTA) in human follicular fluid (HFF). The redistribution of 14C-cholesteryl ester among human plasma lipoproteins was used as a measure of LTA (% Transfer [%T]). The HFF was fractionated by S-300 gel filtration chromatography and assayed for LTA. Three peaks of activity were consistently eluted from the column. Each peak of LTA also stimulated human sperm to penetrate zona-free hamster oocytes after short capacitating incubations. The peak with highest LTA (12.75 +/- 1.11%T) with an Mr approximately 68,000, gave the greatest stimulation (penetration index, PI: 3.34 +/- 0.96 fold increase above control, n = 4). The HFF also showed a significant dose response for both LTA and PI, whereas bovine serum albumin did not. These results demonstrate the existence of LTA in HFF and suggest that a specific lipid transfer protein may have a role in human sperm capacitation or acrosome reaction.