精液凝固蛋白Semenogelin对精子运动抑制机制的研究进展

精液的液化和精子的获能是精子取得向前运动的关键,精液凝固蛋白Semenogelin(Sg)在这个过程中起着至关重要的作用,它们直接参与了精液凝胶的形成,并协同其他一些来源于男性生殖道的蛋白酶类和金属离子等,与精子细胞表面发生作用,参与调控精液液化和精子获能,最终使精子取得向前运动。本文综述了当前Sg对精子活动抑制机制的研究进展。     

不采用冷冻保护剂的玻璃化法与常规冷冻法对人精子冷冻复苏效果的比较

目的比较不采用冷冻保护剂的玻璃化法与常规冷冻法对人精子冷冻复苏的效果。方法将15份上游后的精液标本分别采用常规精子冷冻和不使用冷冻保护剂的冷冻环玻璃化法冷冻,比较精子复苏后的活力、形态及精子膜的完整性三项指标。结果冷冻前、前向活动精子百分率、正常精子形态百分率及精子膜完整率分别为(79±6.42)%、(34±9.36)%和(91±5.18)%;不采用冷冻保护剂的玻璃化法冷冻复苏后,三者分别为(42.20±8.35)%、(31.00±7.63)%和(50.00±9.34)%。常规冷冻法冷冻复苏后,三者分别为(38.00±15.80)%、(30.00±5.24)%和(47.00±13.67)%。冷冻前后前向活动精子百分率和精子膜完整率的差别有统计学意义,但两种冷冻方法相比差异无统计学意义。结论使用不加入冷冻保护剂的玻璃化方法冷冻人的精子是可行的,可取得与常规冷冻相同的效果。     

The routine assessment of sperm motility at room temperature and 37°C

The World Health Organization (WHO) laboratory manual (1992) states that assessment of sperm motility can be performed at either 37^OC or room temperature (20–24^OC). The motility of spermatozoa in 44 semen samples (22 fresh samples and 22 frozen-thawed samples) was assessed at both of these temperatures and a significant difference in the motility profiles was noted, specifically an increase at 37^OC in the percentage (expressed here as median and ranges) of spermatozoa with excellent progressive motility and an overall increase in the percentage with total progressive motility. With fresh samples the excellent progressive motility increased from 41 (19–53) to 54 (30–66) and the overall motility from 58.5 (39–74) to 65.0 (40–79). With the frozen—thawed samples the excellent motility increased from 14 (1–33) to 25 (6–45) and the overall motility from 30.5 (14–51) to 33.0 (16–52). As the WHO laboratory manual was published. 'In response to a growing need for the standardisation of procedures for the examination of human spermatozoa' it is proposed that only one temperature for routine analysis should be used, namely 37^OC, which may have more physiological relevance and eliminate effects of fluctuations in ambient laboratory temperature.     

Validation of a single-step procedure for the objective assessment of sperm motility characteristics

A relatively cheap method is described for the objective assessment of sperm concentration and motility characteristics. The method uses a digitizing tablet with cursor, a micro-computer and a phase-contrast or dark-field microscope equipped with a drawing tube. With this technique the following are accurately assessed: sperm concentration, percentage motility, motility grading, concentration of grade a motile spermatozoa, sperm velocity, linear velocity, linearity and angularity. The data are acquired in less than 5 min. Validation studies reveal this method to be accurate, reproducible (coefficient of variation of motility characteristics = less than 7%) and clinically useful.     

Tadalafil as an in vitro sperm motility stimulant

Tadalafil (Cialis) is a known oral selective phosphodiesterase-5 inhibitor used widely in the management of erectile dysfunction. To assess its ability on human sperm motility in vitro, 70 asthenozoospermic semen specimens delivered by masturbation were investigated. Semen samples were divided equally into four tubes, one as a control and to the others tadalafil dissolved solution was added in vitro in three different concentrations (4.0, 1.0, 0.5 mg ml(-1) respectively). The tubes were incubated and were followed up for sperm motility per cent changes for 0.5, 1, 2, 3 h. It was found that the concentration used played an important role in the degree of sperm enhancement. Specimens treated with 4 mg ml(-1) tadalafil solution demonstrated a significant decrease in sperm motility compared with the controls. Specimens treated with 1.0 mg ml(-1) solution demonstrated significant increase in sperm progressive forward motility. Specimens treated with 0.5 mg ml(-1) solution demonstrated significant increases in sperm motility but lower than that of 1 mg ml(-1) concentration. It is concluded that in vitro use of tadalafil solution in special concentration has a significant stimulatory effect on asthenozoospermic sperm motility.     

Hypotonic challenge reduces human sperm motility through coiling and folding of the tail

Human ejaculates collected for in vitro procedures show variably rapid increases in osmolality, depending on enzymatic degradation of compounds. Changes in osmolality can affect cell functions due to the energy consuming processes needed to control cell volume. The aim was to examine the effects of a hypotonic challenge for spermatozoa exposed to increased osmolality. Spermatozoa were selected by density gradient centrifugation and washed in media with different osmolalities. Osmolality was measured by freezing-point depression and sperm velocities by CASA. Swimming pattern observations and assessments of tail morphology of fixed spermatozoa were done with phase contrast microscopy. Increased osmolality did not change the curvilinear velocity (VCL), while decreased osmolality reduced or abolished VCL nonreversibly. For spermatozoa first exposed to 400 mOsm/kg, reversal of osmolality to 290 mOsm/kg reduced the VCL and the average path velocity (VAP) permanently. Hypotonic challenges increased sperm tail coiling and folding in a dose-response pattern. Spermatozoa once adjusted to high osmolality in the liquefied ejaculate are likely to suffer if exposed to a medium with a lower osmolality. For improved success of Assisted Reproductive Technologies (ART), it appears to be important to minimise the duration of sperm exposure to the ejaculate, by early dilution or sperm preparation.     

Correlation between the motility of frozen–thawed epididymal spermatozoa and the outcome of intracytoplasmic sperm injection

The purpose of this study was to investigate if the outcome of ICSI was influenced by epididymal sperm motility in frozen-thawed specimens. A total of 18 ICSI treatment cycles using spermatozoa retrieved by microsurgical epididymal sperm aspiration (MESA) were analysed retrospectively. Cryopreservation of epididymal spermatozoa was performed when enough epididymal aspirates were collected. Sixty-nine out of 126 oocytes injected with spermatozoa retrieved by MESA were fertilized, giving a fertilization rate of 54.8%. Out of 18 embryo transfer cycles, 6 (33.3%) achieved pregnancies. Fresh epididymal spermatozoa were used in 5 cycles while frozen-thawed epididymal spermatozoa were used in 13 cycles for ICSI. The fertilization rates were 68.6% (35/51) in the former group and 45.3% (34/75) in the latter group, respectively. There was a significant difference between the two groups (p < 0.05). In ICSI treatments using fresh epididymal spermatozoa, the cells used for injection were all motile. However, motile epididymal spermatozoa could be used in only five ICSI treatment cycles after freeze-thawing. In 6 cycles, only immotile sperm were used for injection of frozen-thawed spermatozoa. The fertilization rate in each group was 68.4% (13/19) and 31.6% (12/38), respectively. There was a significant difference between these groups (p < 0.01). These results indicate that the outcome of ICSI was influenced by sperm motility in frozen-thawed epididymal specimens. When no sperm motility could be recovered after freeze-thawing even with chemical treatments, consideration should be given to retrieving fresh epididymal spermatozoa again to achieve a better fertilization rate in such patients.     

Visco-elasticity of seminal fluid in relation to the epididymal and accessory sex gland function and its impact on sperm motility

Seminal viscopathy was shown to be associated with male infertility. However, our knowledge about the regulatory mechanism of this process is still limited. In semen samples from 411 men attending for fertility assessment, traditional semen parameters including visco-elasticity were assessed according to the World Health Organization guidelines. Sperm motility was evaluated by use of computer aided sperm analysis (CASA). Seminal activity of neutral alpha-glucosidase (NAG) and concentrations of prostate-specific antigen (PSA), zinc, and fructose were measured. The activity of NAG, and the concentrations of PSA and zinc were significantly lower in hyper-visco-elastic semen samples (medians: 5 vs. 8 mU/mL; 741 vs. 924 mg/L; 1 vs. 2 mM/L), than in those with normal visco-elasticity (p = 0.004, 0.005 and 0.011, respectively). When comparing the total amounts, only for seminal fructose there was a difference between samples with high visco-elasticity as compared with those of normal visco-elasticity (median: 74 vs. 53 microM/ejaculate, p = 0.007) This seminal marker was the only significant independent parameter in predicting seminal visco-elasticity in a multiple logistic regression analysis (odds ratio for the highest quartile = 4.67). Hyper-visco-elasticity was associated with a lower percentage of motile spermatozoa (43 vs. 50%, p = 0.045). Similar trend was found for the CASA motility characteristics curvilinear velocity (VCL), average path length (VAP), amplitude of lateral head displacement (ALH) (p = 0.008, 0.038 and 0.020, respectively). Our study demonstrated the interplay between the regulatory effect of post-testicular organs on semen visco-elasticity. Hyper-visco-elasticity was associated with asthenozoospermia and lower levels of VCL, VAP and ALH.     

Impact of using a fast‐freezing technique and different thawing protocols on viability and fertility of frozen equine spermatozoa

The effects of freezing technique and thawing protocol on thawed semen viability and fertility were studied. Ejaculates from 5 stallions (n = 25) were frozen by conventional or a fast‐freezing technique. Frozen semen was thawed by two thawing protocols (37 °C 30 s^?1 or 75 °C 7 s^?1). Thawed semen was evaluated by progressive motility, vigour, morphology and plasma membrane integrity. Mares (n = 25) were inseminated with 300 (n = 11) or 150 (n = 14) million spermatozoa. A greater (P < 0.05) vigour and progressively motile spermatozoa were detected, respectively, at thawing and after 20 min post‐thawing in the fast‐freezing technique than in the conventional one. Plasma membrane integrity was also greater (P < 0.05) in semen frozen with the fast‐freezing technique. Semen viability was not affected by thawing protocol. Pregnancy rate using the fast‐freezing technique was 76% (19/25), and did not differ (P > 0.05) between insemination doses. We concluded that the 150 million progressively motile spermatozoa per dose using a deep‐horn insemination maximises the use of equine semen. The fast‐freezing technique, as compared to the conventional one, efficiently preserves the viability and fertilising capacity of spermatozoa, indicating a new method to improve the fertility of frozen equine semen.     

Semen analysis with regard to and functional aspects sperm number,sperm morphology

The new World Health Organization （WHO） Manual for Semen Analysis contains several improvements. One is that the 20 million spermatozoa per mL paradigm has been ousted in favour of proper calculations of lower reference limits for semen from men, whose partners had a time-to-pregnancy of 12 months or less. The recommendation to grade the progressive motility as described in the third and fourth editions of the WHO manual was not evidence-based, and WHO was therefore motivated to abandon it. However, the new recommendation is not evidence-based either, and it is difficult to understand the rational for the new assessment. It may have been a compromise to avoid returning to the rather robust system recommended in the first edition （1980）. The unconditional recommendation of the ＇Tygerberg strict criteria＇ is not evidence-based, and seems to be the result of an unfortunate bias in the composition of the Committee in favour of individuals known to support the ＇strict criteria＇ method. This recommendation will have negative effects on the develop- ment ofandrology as a scientific field. Given the importance of the WHO manual, it is unfortunate that the recommenda- tions for such important variables, as motility and morphology, lack evidence-based support.     

全自动精子分析中各运动性参数间相关性研究

目的　考察全自动精子分析中各运动性参数间的相关性。方法　进行了 190份健康受试者精液全自动分析 ,并对其各运动性参数 :直线速度 (vsl)、曲线速度 (vcl)、平均路径速度 (vap)、直线性 (lin)、前向性 (str)、摆动性 (wob)、侧摆幅度 (alh)、平均移动角度 (mad)、鞭打频率 (bcf)、精子密度、精子活动率间进行相关性分析。结果　从相关性分析中可确定运动性参数具有代表意义的是vsl、str、mad。结论　全自动精子分析的众多参数中 ,可通过vsl、str、mad三参数了解精子活动性 ,从而达到简便、快速、准确诊断的目的     

Quality control workshops in standardization of sperm concentration and motility assessment in multicentre studies

Semen quality has been reported to vary markedly between different regions. To properly assess the differences among countries a minimization of the variation among centres in the assessments of sperm quality is essential. We here report on the training and two subsequent follow-up workshops on assessments of sperm concentration and motility. A total of 26 fresh ejaculates were analysed by four persons who were collecting these data in a multicentre study on sperm quality. In addition, two trained technicians from one of the laboratories analysed the samples. At the first training workshop, the median coefficient of variation among centres in sperm concentration was 27.7%, but decreased markedly to 17.0% at the second workshop and 8.1% (p = 0.048) at the third workshop. The CV for evaluation of the proportion of progressive motile sperm decreased less and not statistically significant from 16.5 to 14.1% and 11.0% (p = 0.94). At the third workshop there were no statistical significant differences among centres in assessments of sperm concentration or motility (p > 0.57). Furthermore the coefficient of variation in assessments of sperm concentration and motility among centres were at the same level as between two trained technicians (p > 0.72). This study indicates that training and subsequent follow-up workshops can assure minimum variability among centres in assessments of sperm concentration and motility.     

Influence of autogenous leucocytes and Escherichia coli on sperm motility parameters in vitro

Urogenital infections are considered important factors in male infertility. In this in vitro study we have evaluated the impact of leucocytes in association with an artificial infection with Escherichia coli on the motility of human spermatozoa. Ejaculates and blood samples were obtained from healthy donors with normal semen parameters. Ejaculates were prepared by swim-up technique and five fractions were isolated for incubation. Leucocyte subtypes were separated from blood samples by gradient centrifugation. Purified sperm suspensions were adjusted to a concentration of 20 x 106 ml-1 and incubated with lymphocytes/ monocytes, polymorphonuclear granulocytes (PMN), and E. coli. Samples were incubated for up to 6 h at 37 degrees C. Motility analysis was performed using a computer-assisted sperm analyzer (CASA). Spermatozoa incubated with 3 x 106 PMN ml-1 revealed a significant (P=0.003) decrease in progressive motility after 2 h. This decrease remained weakly significant (P=0.024) after 4 and 6 h. Lymphocytes and monocytes had no effect on sperm motility. Spermatozoa incubated with granulocytes and E. coli demonstrated highly significant alterations in motility after 4 and 6 h of incubation (P < 0.001). The PMN indicate an effect on motility of spermatozoa under experimental conditions. However, the results suggest that bacteria are the primary agents that interfere with sperm motility.     

Influence of complement on sperm motility

Isolated sperm from normo-, oligo- and astheno-spermic men were incubated for 20 h in medium supplemented with 8% heat-inactivated or untreated human serum, and in medium with heated or untreated serum deficient in complement factor C3. Before and after incubation, sperm motility was assessed by means of a computer-assisted semen analyser. The results did not show significant differences between the motility of sperm incubated in heated or untreated serum. It is concluded that heating of homologous serum is not necessary for preserving sperm motility and in some cases may even be disadvantageous.     

速冻和缓慢冷冻法对精子运动特征的影响

目的了解冷冻方法对人精子运动特征的影响。方法精液标本进行速冻和缓慢冷冻保存,应用计算机精液分析仪进行精子运动特征分析。结果冷冻复温后精子运动能力与冷冻前精子运动能力比较明显下降(P<0.001,P<0.05);速冻与缓慢冷冻方法保存的精子运动参数相比较差异均无显著性(P>0.05)。结论冷冻保存易导致精子运动能力下降,速冻与缓慢冷冻方法对精子运动参数影响无明显差异。     

计算机辅助精液分析男性不育患者精子运动参数与精子活力的相关性

目的探讨计算机辅助精液分析精子运动参数在评价男性不育患者精子活力中的价值。方法按《WHO人类精液及精子-宫颈黏液相互作用实验检验手册》标准,采用国产WLJY-9000伟力彩色精子质量检测系统对276例男性不育患者的精液进行平均直线运动速度、平均曲线运动速度、运动的前向性、运动的直线性、运动的摆动性、平均路径速度、精子活力及分级等进行检测并分析其相关性。结果276名男性不育患者的平均精子活力为（48.93±19.10）%,分级为A级（32.11±17.25）%、B级（17.03±8.91）%、C级（10.14±5.99）%。平均直线运动速度、平均曲线运动速度、运动的前向性、运动的直线性、运动的摆动性、平均路径速度与精子活力的相关系数分别为0.60（P〈0.01）、0.59（P〈0.01）、0.51（P〈0.01）、0.55（P〈0.01）、0.52（P〈0.01）、0.67（P〈0.01）。结论计算机辅助精液分析精子运动参数平均直线运动速度、平均曲线运动速度、平均路径速度是反映精子活力的有效指标,精子运动参数对男性不育的诊断和生育能力的评估具有实用意义。     

Kruger strict morphology and post-thaw progressive motility in cryopreserved human spermatozoa

The purpose of this prospective study was to evaluate Kruger strict morphology and conventional semen analysis in predicting cryosurvival and the progressive motility recovery rate of frozen spermatozoa. Our study included 56 semen samples with >10 million spermatozoa per ejaculate. The main outcome measures were conventional semen analysis, strict morphology analysis by the Kruger method, cryosurvival rate and post-thaw sperm motility. A significant reduction in sperm motility after cryopreservation was demonstrated. The freeze-thawing process caused a 66% reduction in rapid progressive motile spermatozoa, a 45% reduction in slow progressive motile spermatozoa and a 2% reduction in nonprogressive motile spermatozoa. The cryosurvival and progressive motility recovery rates were not correlated with parameters of conventional semen analysis, such as sperm concentration, motility, WHO morphology and total motile count, but the progressive motility recovery rate was significantly correlated with the percentage of spermatozoa exhibiting Kruger normal morphology (P = 0.028). The recovery rate of rapidly progressive motility was profoundly decreased compared with slow progressive motility following the frozen-thaw procedure of semen. Kruger strict morphology assessment was a better predictor of the progressive motility recovery rate following the freezing-thaw procedure than parameters of conventional semen analysis.     

胞浆小滴可能是精子运动和正常精子形成的标志

哺乳动物生精过程后期精细胞胞浆脱落后,有一个微小部分经常会残留于精子鞭毛上,被称为胞浆小滴。胞浆小滴被认为在精子体积的调整中起到重要作用。然而,我们观察到含有胞浆小滴的精子大多显示出运动活力,而不含有胞浆小滴的精子则鲜有运动活力,说明在附睾成熟过程中胞浆小滴的存在对精子运动起重要作用。在本研究中,我们分析了小鼠及猴的精子在附睾成熟期间含有及不含有胞浆小滴的精子运动能力获得的关系,以及胞浆小滴在精子尾部位置的改变的关系。我们也检测了3种晚期精子生成缺陷基因敲除小鼠的精子胞浆小滴。我们的数据显示胞浆小滴是暂时存在于附睾精子上的正常附属器官,正常的胞浆小滴形态及位置与精子附睾成熟过程中正常的运动能力形成相关。胞浆小滴的异常形成,胞浆小滴的缺失或者异常的胞浆小滴预示着精子形成缺陷。如果胞浆小滴是精子运动形成的基础,那么胞浆小滴可以成为非激素类男性避孕药的理想的药物靶点。     

精子DNA冷冻损伤易感性与精子活动力相关性

目的研究不同活动力精子其核DNA对冷冻损伤的易感性。方法选取来本中心行精液常规分析,精子浓度5×106/ml、精子正常形态率4%者63例为研究对象。精子冷冻前后均采用染色质扩散(SCD)实验分析核DNA完整性,分别比较高活力组(d级30%,n=28)及低活力组(d级≥30%,n=35)精子在冷冻前后DNA完整性的差异。结果精液标本(n=63)经冷冻后,精子DNA碎片指数(SDF)较冷冻前显著升高[(23.1±12.5)%vs.(19.9±11.6)%,P0.05],其中代表精子DNA完整性较好的大晕轮精子比例显著降低[(71.9±13.3)%vs.(75.8±12.2)%,P0.05],而小晕轮精子比例则显著升高[(10.2±5.7)%vs.(8.2±3.9)%,P0.05]。在低活力组,精子SDF及大晕轮、小晕轮精子比例在冷冻前后亦差异显著(P0.05);而在高活力组,冷冻后仅小晕轮精子比例较冷冻前显著升高[(8.3±3.4)%vs.(6.8±3.0)%,P0.05],SDF及大晕轮、中晕轮、无晕轮的精子比例在冷冻前后均无显著差异(P0.05)。结论相比高活力组精子,低活力组精子核DNA冷冻耐受力较差,更易受损。     

弗司扣林对人精子运动功能的影响

目的 通过研究弗司扣林(forskolin)对体外人精子的运动功能有无影响，了解环磷酸腺苷／蛋白激酶A(cAMP／PKA)信号传导途径是否参与人精子运动功能的调节。方法 10例健康成年男性手淫获得新鲜精液，经上游优化处理后与不同浓度的forskolin一起孵育20、30、60min后，采用计算机辅助的精子分析系统(CASA)检测精子的各项运动参数，并进行对比分析。结果 forskolin在体外能显著提高人精于的活率及前向性运动百分率，而对精子的形态及直线速度(VSL)和曲线速度(VCL)无明显影响。结论 forskolin在体外能提高人精子的运动功能，此结果为证实cAMP/PKA信号传导通道参与调节人精子运动功能提供了一定的实验依据。