Cellular mechanisms regulating sperm-zona pellucida interaction

For mammalian spermatozoa to exhibit the ability to bind the zona pellucida （ZP） they must undergo three distinct phases of maturation, namely, spermatogenesis （testis）, epididymal maturation （epididymis） and capacitation （female reproductive tract）. An impressive array of spermatozoa surface remodeling events accompany these phases of maturation and appear critical for recognition and adhesion of the outer vestments of the oocyte, a structure known as the ZP. It is becoming increasingly apparent that species-specific zona adhesion is not mediated by a single receptor. Instead, compelling evidence now points toward models implicating a multiplicity of receptor-ligand interactions. This notion is in keeping with emerging research that has shown that there is a dynamic aggregation of proteins believed to be important in sperm-ZP recognition to the regions of sperm that mediate this binding event. Such remodeling may in turn facilitate the assembly of a multimeric zona recognition complex （MZRC）. Though formation of MZRCs raises questions regarding the nature of the block to polyspermy, formation and assembly of such a structure would no doubt explain the strenuous maturation process that sperm endure on their sojourn to functional maturity.

Carbohydrates mediate sperm-ovum adhesion and triggering of the acrosome reaction

The fertilization process is the net result of a complex sequence of events that collectively result in the fusion of theopposite gametes. The male gamete undergoes continuous morphological and biochemical modifications during spermdevelopment in the testis (spermatogenesis), maturation in the epididymis, and capacitation in the female reproductivetract. Only the capacitated spermatozoa are able to recognize and bind to the bioactive glycan residue(s) on the ovum'sextracellular coat, the zona pellucida (ZP). Sperm-zona binding in the mouse and several other species is believed totake place in two stages. First, capacitated (acrosome-intact) spermatozoa loosely and reversibly adhere to the zona-in-tact ovum. In the second stage tight irreversible binding occurs. Both types of bindings are attributed to the presence ofglycan- binding proteins (receptors) on the sperm plasma membrane and their complementary bioactive glycan units(ligands) on the surface of the ZP. The carbohydrate-mediated adhesion event initiates a signal transduction cascade re-sulting in the exocytosis of acrosomal contents. This step is believed to be prerequisite which allows the hyperactivatedacrosome-reacted spermatozoa to penetrate the ZP and fertilize the ovum. This review focuses on the role of carbohy-drate residues in sperm-ovum interaction, and triggering of the acrosome reaction. I have attempted to discuss extensiveprogress that has been made to enhance our understanding of the well programmed multiple molecular events necessaryfor successful fertilization. This review will identify these events, and discuss the functional significance of carbohy-drates in these events.

Inhibition of mouse acrosome reaction and sperm-zona pellucida binding by anti-human sperm membrane protein 1 antibody

Aim： To investigate the possible functions of human sperm membrane protein （hSMP-1） in the process of fertilization. Methods： A 576-bp cDNA fragment of HSD-1 gene coding for the extracellular domain of hSMP-1 was cloned and expressed. The localization of this protein on human and mouse sperm was determined by indirect immunofluorescent staining by using anti-recombinant hSMP-1 （anti-rhSMP-1） antibodies. Sperm acrosome reaction and spermzona pellucida （ZP） binding assay were carried out in 10-week-old BALB/c mice. Results： Recombinant hSMP-1 was successfully cloned and expressed. The expression of the native protein was limited on the acrosome of human and mouse sperm. Treatment of anti-rhSMP-1 antibodies significantly decreased the average number of sperms bound to each egg. Meanwhile, the percentage of acrosome reaction was decreased in comparison to pre-immune control after treatment with anti-rhSMP-1 （P 〈 0.05）. Conclusion： The results suggest that anti-rhSMP-1 antibody inhibited mouse acrosome reaction and sperm-ZP binding.

Role of Urokinase-type Plasminogen Activator in the Precontact Sperm-egg Communication and Fertility of Mice in vitro

Objective To explore the role of urokinase-type plasminogen activator（uPA） in precontact sperm-egg communication and fertility of mice in vitro. Methods Firstly, sperm chemotaxis （SC） induced by uPA was assayed by measuring the sperm densities in capillaries with a descending gradient or no gradient of uPA respectively. Secondly, the role of uPAR that exists in sperm plasma membrane in SC was studied by examining the change of sperm density in capillary after incubating spermatozoa with anti-uPAR antibody. Thirdly, SC induced by eggs, which had been treated with uPA, PAl-1 and anti-uPAR beforehand respectively, was assayed to study the role of uPA in PSEC. Lastly, the fertilization capability of spermatozoa treated with uPA was examined by counting the number of fertilized eggs. Results 1）The density of spermatozoa that migrated down the gradient of uPA into the capillary was significantly lower than that into the capillary containing no-gradient uPA. 2） When uPAR of spermatozoa was inhibited by anti-uPAR antibody, the density of spermatozoa that migrated into the capillary with ascending gradient of uPA decreased correspondingly. 3） The density of spermatozoa attracted by eggs, which were treated with uPA beforehand, increased significantly than that of attracted by non-treated eggs. On the contrary, the sperm density decreased correspondingly when the egg was treated with PAI-1. 4） The number of fertilized eggs increased significantly after the spermatozoa used here was treated with uPA beforehand. Conclusion uPA could induce SC of mice sperm in vitro through the uPAR on its membrane, enhance the capability of egg inducing SC, and promote spermatozoa to fertilize eggs. Thus, uPA may act as an attractant in PSEC, increase the chance encounter of spermatozoa and eggs, therefore, enhance the fertility success correspondingly. This study, in some degree, provides an evidence that uPA may be used as a new medicine and diagnostic reagent for male infertility.

Protein tyrosine phosphorylation of the human sperm head during capacitation： immunolocalization and relationship with acquisition of sperm-fertilizing ability

The occurrence of tyrosine phosphorylation （TP） in the sperm head during capacitation has been poorly investigated, and no data exist on the relationship of its dynamics with the acquisition of sperm fertilizing ability. This study localized TP of head proteins in human spermatozoa during capacitation and explored its relationship with acquisition of the ability to display progesterone （P）-stimulated acrosome reactions （ARs） and to penetrate zona-free hamster oocytes. By immunofluorescence, TP immunoreactivity was revealed in the acrosomal region of formaldehyde-fixed/unpermeabilized samples, whereas it was abolished in fixed/permeabilized samples, in which TP immunoreactivity was high in the principal piece. No TP immunoreaetivity was detectable in unfixed spermatozoa. Head TP immunoreactivity was localized externally to the acrosome, close to the cytoplasmic membrane, as assessed by transmission electron microscopy. The increase in head TP was an early event during capacitation, occurring within 1 h in capacitating conditions. At this time, the P-stimulated ARs were also increased, whereas egg penetration was as poor as in uncapacitated spermatozoa. At 5 h of capacitation, the extent of neither head TP nor the P-induced ARs were greater than that at 1 h, whereas egg penetration had significantly increased. Seminal plasma inhibited head TP, P-induced ARs and egg penetration. None of these inhibitory effects, unlike those on tail TP, were prevented by the cAMP analogue dbcAMP （N,2-O-dibutyryladenosine 3＇,5＇-cyclic monophosphate）. In conclusion, head TP is a subsurface event occurring early during capacitation and is closely related to acquisition of the ability to display P-stimulated ARs, whereas the ability to fuse with oolemma and to decondense is a later capacitation-related event.

Fluorescence Tracking of Exogenous DNA in Genetic Transformation of the Chinese Oak Silkmoth Antheraea Pernyi via Sperm-Mediated Gene Transfer

Exogenous DNA expressing green fluorescent protein( GFP) and labeled with fluorescein isothiocyanate( FITC) was used to transform the Chinese oak silkmoth Antheraea pernyi( A. pernyi)via sperm-mediated gene transfer( SMGT). Sperms entry into the female reproductive system and eggs were observed using fluorescence microscopy. The ability of A. pernyi sperms to uptake exogenous DNA was confirmed,and transfer of the exogenous DNA was shown by GFP expression in the transgenic eggs. Our result suggested that SMGT could also be used to directly generate transgenic A. pernyi expressing functional genes of interest.

Participation of epididymal cysteine-rich secretory proteins in sperm-egg fusion and their potential use for male fertility regulation

Rat protein DE is an androgen-dependent cysteine-rich secretory protein （CRISP） synthesized by proximal epididymal regions. DE, also known as CRISP-1, is localized on the equatorial segment of acrosome-reacted spermatozoa and participates in gamete fusion through binding to egg complementary sites. Immunization of rats with DE inhibits fertility and sperm fusion ability, suggesting that DE represents a good epididymal contraceptive target. Recombinant DE fragments and synthetic peptides revealed that DE binds to the egg via a 12-amino acid region of an evolutionarily conserved motif, Signature 2 （S2）. The ability of other CRISP to bind to the rat egg was correlated with their S2 amino acid sequences. Although testicular protein Tpx- 1 （CRISP-2） was capable of binding to rodent eggs, human epididymal AEG-related protein （ARP） and helothermine （from lizard saliva） were not. The S2 region presented only two substitutions in Tpx-1 and four in ARP and helothermine, compared with the DE S2, suggesting that this amino acid sequence was relevant for egg interaction. Studies with Tpx- 1 and anti-Tpx- 1 revealed the participation of this protein in gamete fusion through binding to complementary sites in the egg. In competition studies, DE reduced binding of Tpx- 1 dose-dependently, indicating that both CRISP share the egg complementary sites. That anti-DE and anti-Tpx-1 inhibit sperm-egg fusion while recognizing only the corresponding proteins, suggests functional cooperation between these homologous CRISP to ensure fertilization success. These results increase our understanding of the molecular mechanisms of gamete fusion and contribute to the development of new and safer fertility regulating methods. （Asian J Androl 2007 July; 9： 528-532）

The mechanism of sperm-egg interaction and the involvement of IZUMO1 in fusion

An average human ejaculate contains over 100 million sperm, but only a few succeed in accomplishing the journey to an egg by migration through the female reproductive tract. Among these few sperm, only one participates in fertilization. There might be an ingenious molecular mechanism to ensure that the very best sperm fertilize an egg. However, recent gene disruption experiments in mice have revealed that many factors previously described as important for fertilization are largely dispensable. One could argue that the fertilization mechanism is made robust against gene disruptions. However, this is not likely, as there are already six different gene-disrupted mouse lines （Calmegin, Adam Ia, Adam2, Adam3, Ace and Pgapl）, all of which result in male sterility. The sperm from these animals are known to have defective zona-binding ability and at the same time lose oviduct-migrating ability. Concerning spermzona binding, the widely accepted involvement of sugar moiety on zona pellucida 3 （ZP3） is indicated to be dispensable by gene disruption experiments. Thus, the landscape of the mechanism of fertilization is revolving considerably. In the sperm-egg fusion process, CD9 on egg and IZUMO1 on sperm have emerged as essential factors. This review focuses on the mechanism of fertilization elucidated by gene-manipulated animals.

Comparative study on efficacy of three sperm-separation techniques

Aim: To evaluate the comparative effectiveness of real-time sperm separation technique (Wang's tube method) andother two conventional methods in isolating high-quality sperm preparation, and to compare the spouse pregnancy ratein intrauterine insemination (IUI) with sperm preparations isolated by these methods. Methods: The effectivenessof the real-time sperm separation technique, the conventional swim-up and the Percoll discontinuous density gradientmethods in isolating sperm preparations from 60 infertile patients (20 with apparently normal semen and 40, abnormalsemen contaminated with microorganisms and other impurities) was evaluated and compared. The microorganisms to beremoved included bacteria, vires, Chlamydia trachomaticum, Ureaplsama urealyticum, etc. The spouse pregnancyrates in IUI with sperm preparations isolated by these three techniques from 80 oligoasthenoteratospermic patients werealso compared. Results: The quality (including the percentages of normal form, normal-chromatin and motilesperm, and the grade of motility) of sperm obtained by the real-time sperm separation technique was much higher ( P< 0.01) as compared with those by the other two methods. The Wang's tube method was also more effective in remov-ing microorganisms and other impurities. The method provided a higher IUI pregnancy rate than the other two spermseparation techniques ( P < 0.05). Conclusion: The real-time sperm separation technique is the most effectivemethod so far available in isolating high-quality sperm samples to be used in assisted reproduction.

A Novel Contraceptive Vaccine: Design and Synthesis of the Chimeric Peptide Containing Multivalent Sperm-Specific Epitopes

ve To develop a novel multivalent chimeric peptide vaccine for bisexual fertility regulation

中年男性精子DNA碎片率对体外受精-胚胎移植妊娠结局的影响

目的探讨中年男性精子DNA碎片率(DFI)与精液质量和体外受精-胚胎移植妊娠结局的关系。方法共收集180例接受常规体外受精-胚胎移植治疗且男性年龄>38岁的精液标本。根据DFI的阈值分成(<30%和≥30%)两组。主要测量指标包括:常规精液参数、激素水平、DFI、受精率、优质胚胎率、临床妊娠率等。结果通过比较分析发现,DFI与男性卵泡刺激素(FSH)、精子活力、精子形态密切相关,且精子活力随着DFI水平的升高而下降(P<0.05);当DFI≥30%时,优质胚胎率下降(P<0.05),但两组的临床妊娠率差异无显著性(P>0.05)。结论DFI可以作为中年男性精液常规分析的重要参考指标,虽然DFI影响优质胚胎率,但与辅助生殖治疗的临床妊娠结局无关。

精子线粒体膜电位作为综合评估男性生育能力指标的初探

目的本研究旨在探讨精子线粒体膜电位(MMP)与精液常规、精子形态学以及精子DNA碎片指数(DFI)之间的关联,以及MMP对于临床评估和预测男性生育能力的价值。方法选择2023年4—7月于江苏省中医院男科进行孕前优生检查、生育咨询以及不育症治疗的患者的精液标本为研究对象,按照世界卫生组织(WHO)第5版标准进行精液常规和精子形态学分析,并通过流式细胞术检测精子DFI和MMP。根据不同精液质量分为两组:精液质量各项指标均正常,即精液量>2 ml、pH值7.2~7.8、精子浓度≥15×106/ml,精子前向运动(PR)≥32%、精子形态正常率≥4%、DFI<30%为精液质量正常组(n=57);PR<32%、精子形态正常率<4%、DFI≥30%为精液质量异常组(n=67),比较两组精液质量各项参数;采用Spearman相关性分析,分析MMP与精子浓度、PR、精子形态正常率以及DFI之间的关系;绘制受试者工作特征曲线(ROC),分析MMP对于临床评估男性生育能力的价值。结果两组间平均年龄、精液量比较均无显著差异(P>0.05),精液质量正常组精子浓度、PR、精子形态正常率、MMP显著高于精液质量异常组(P<0.05),DFI显著低于精液质量异常组(P<0.05);Spearman相关性分析结果显示,MMP与精液量无明显相关性(r=-0.065,P=0.475),与精子浓度(r=0.396,P<0.001)、PR(r=0.471,P<0.001)、精子形态正常率(r=0.468,P<0.001)呈显著正相关,与DFI(r=-0.701,P<0.001)呈显著负相关;ROC分析结果显示,MMP对精液质量整体水平预测的ROC曲线下面积(AUC)为0.891,敏感度87.5%,特异性83.3%,截断值53.69%;MMP对精子浓度预测的AUC为0.787,敏感度82.0%,特异性69.2%,截断值43.97%;MMP对PR预测的AUC为0.741,敏感度65.7%,特异性84.2%,截断值56.33%;MMP对精子形态正常率预测的AUC为0.733,敏感度71.1%,特异性69.1%,截断值56.63%;MMP对DFI预测的AUC为0.809,敏感度89.5%,特异性72.1%,截断值54.78%。结论精子MMP与精子浓度、PR、精子形态正常率呈显著正相关,与DFI呈显著负相关。与各单项精液指标相比,MMP能更全面地反映精子能量代谢和凋亡,推荐将MMP 54%作为全面评估和预测男性生育能力的参考值下限。

冷冻保存技术在蜜蜂精液保存中的研究与应用

蜜蜂精液冷冻保存对蜜蜂种质资源保护和品种改良具有重要意义,有利于蜜蜂育种中的后裔测定和基因组选择,加快育种进程。蜜蜂精子结构特殊,冷冻保存对其活力和受精率有较大影响,目前该技术尚未广泛应用。该文综述了蜜蜂精液冷冻保存的研究简况、蜜蜂精子的结构、冷冻损伤机理和精液冷冻技术的研究进展,以期为今后进一步优化改进蜜蜂精液冷冻保存技术提供参考。

浮游板优化精液与密度梯度离心结合上游法的比较

目的应用浮游板和密度梯度离心结合上游法优化人类精液,明确优化效果并比较两种方法优化后精子参数的差异。方法收集正常精液样本85例和轻中度少弱精子症精液样本59例,每例样本分为原液组、密梯组和浮游组各1 ml进行后续处理。原液组在精液液化后未做任何处理;密梯组精液液化后用密度梯度离心法结合上游法进行处理,浮游组则在精液液化后应用精子浮游板进行处理。比较原液组、密梯组、浮游组3个亚组间的精子浓度、前向运动精子百分率、正常形态精子百分率;应用流式细胞仪检测精子线粒体膜电位和精子DNA碎片指数,使用单精子活性氧分析仪检测单精子活性氧水平,使用电子显微镜观察精子超微结构并进行组间比较。结果无论是正常精液还是轻中度少弱精子症精液,与原液组比较,密梯组与浮游组的前向运动精子百分率、正常形态精子百分率及精子线粒体膜电位均显著升高(P<0.05),精子DNA碎片指数显著降低(P<0.05);密梯组和浮游组各指标无显著性差异(P>0.05)。正常精液中,浮游组的精子浓度显著高于密梯组(P=0.029),单精子活性氧水平显著低于原液组(P=0.038)。轻中度少弱精子症精液中3亚组间的单精子活性氧水平均无显著性差异(P>0.05)。电子显微镜观察发现正常精液中3个亚组的精子均未见明显异常;轻中度少弱精子症精液中密梯组部分精子可观察到精子细胞膜断裂和线粒体肿胀等异常,而浮游组精子超微结构未见明显异常。结论密度梯度离心结合上游法和浮游板法用于精液的处理和优化,均可有效回收活力、形态和功能更好的精子。精子浮游板法的体外干预小,操作简便,可以获得活性氧更少、损伤更小的精子。

基于下一代测序的精液菌群研究进展

精液菌群在男性生殖健康中发挥着重要作用,其构成可能与精子质量、少弱精子症的发生、辅助生殖技术妊娠结局相关。同时,由于精液菌群可能向伴侣及后代传递,因此对女性生殖健康及后代的健康都可能产生影响。常规细菌培养方法因耗时、条件限制等难以发现完整的精液菌群结构。下一代测序技术(NGS)可以揭示完整的精液菌群组成,有助于阐明人类生理学和病理生理学基础上复杂的微生物-宿主相互作用。本文就基于NGS研究的精液菌群构成、与男性不育症的关系、损伤精子质量的作用机制等内容进行综述,总结使用NGS来描述不同男性生殖道解剖部位的细菌定植模式的研究结果。目前的研究结果揭示了男性精液呈现独特的多样性菌群结构,精液菌群结构异常与精子质量和生育状态密切相关,精液可能具有支持健康功能的原生菌群。但迄今为止,精液菌群的来源、构成、及其对生育力和妊娠结局的影响尚不明确,精液菌群多样性影响精子的具体机制还需要具有大样本量和适当的对照标本进一步研究。

胞裂蛋白12在男性不育中的研究进展

胞裂蛋白12(SEPT12)基因是胞裂蛋白基因(SEPTIN)家族的成员之一,在成年男性的睾丸组织中优势表达,在精子发生与成熟过程中发挥重要作用,对维持精子尾部结构的完整性至关重要。同时,SEPT12与精子形态异常密切相关,该基因突变导致男性生育力下降或男性不育。该文就SEPT12结构、生物学作用以及SEPT12突变导致男性不育症等方面进行研究进展的总结和展望。

稀释液添加不同抗氧化剂对冷冻姜曲海猪精子质量的影响

旨在探究稀释液中添加不同抗氧化剂对冷冻姜曲海猪精子的保护作用。采用精子直线运动检测精子活力,异硫氰荧光素标记的花生凝集素(FITC-PNA)染色检测精子顶体完整性,碘化丙啶(PI)染色检测精子质膜完整性,体外受精和培养检测受精卵的卵裂情况,透射电镜观察精子超微结构,评价冷冻保存对精子质量的影响;对姜曲海猪精液分别冷冻保存1周、1个月、3个月、6个月、9个月和12个月,观察冷冻保存时间对精子质量的影响;在稀释液中分别添加抗氧化剂甲磺酸米托醌(MitoQ),2,4-二硝基酚(DNP)和4-羟基-2,2,6,6-四甲基哌啶-1-烃氧基(Tempol),每种抗氧化剂均添加25、50和100μmol/L 3种浓度,以筛选出冷冻保存效果最优的抗氧化剂;对添加50μmol/L MitoQ的解冻精子进行透射电镜观察。结果显示:精子冷冻保存不同时间后,各指标均无显著差异(P>0.05);添加不同浓度的MitoQ、DNP和Tempol均对冷冻保存1周精子的活力、顶体完整率、质膜完整率和体外受精卵裂率有一定的改善作用,但以添加50μmol/L MitoQ效果最好;添加50μmol/L MitoQ对精子质膜、线粒体和微管等结构均具有一定的冷冻保护作用。综上,稀释液中添加50μmol/L MitoQ对于超低温保存姜曲海猪精液具有潜在的保护优势,具有一定的开发价值。

鸡精液甘油简易冷冻保存技术改进与优化效果评价

[目的]改进与优化鸡精液甘油细管简易冷冻保存技术。[方法]采用单因素设计试验,使用6%的冻存(3、6、9个月)与现配甘油保护液制作细管冷冻精液,比较冷冻精液冻后精子活力、活率及畸形率。采用液氮面上熏蒸法优化一步冷冻法冷冻速率,并用优化后一步冷冻法与前期研发的两步冷冻法制作细管冷冻精液,检测两种冷冻方案冻后与离心去甘油后的精子活力、活率、畸形率及种蛋受精率、孵化率。采用一步冷冻法冷冻不同品种公鸡精液,并采用不同输精轮次应用于不同年龄母鸡,通过输精试验评价输精效果。[结果]①添加冻存3、6、9个月的甘油保护液与现配甘油保护液冻后精子活力、活率、畸形率均无显著差异(P>0.05)。②经优化和重复率比较后一步冷冻法最佳冷冻速率为细管精液距离液氮面3 cm冷冻3 min,样品精子活力≥60%的重复率为100%,精子活力≥65%的重复率为65%。③一步冷冻法精子活力、精子活率分别为62.84%和76.00%,均极显著高于两步冷冻法(58.17%和68.62%)(P<0.01),两种冷冻方案的精子畸形率无显著差异(P>0.05)。一步法、两步法冷冻精液离心去甘油前、后平均精子活力、种蛋平均受精率和平均孵化率均无显著差异(P>0.05),单日最高受精率分别为68.34%和80.00%。④采用一步冷冻法制备的黑凤鸡与湘东鸡冻精输精后的种蛋受精率和孵化率均无显著差异(P>0.05)。给30周龄母鸡输精后种蛋受精率极显著高于68周龄母鸡(P<0.01)。3轮4次输精模式种蛋受精率极显著高于1轮2次输精模式(P<0.01)。[结论]将甘油保护液制备成储备液在―20℃冻存,采用一步冷冻法并预先进行冷冻速率优化,输精时注意精液冷藏时长、母鸡年龄、输精轮次,能得到稳定较好的输精效果。

车叶草苷对少弱精症大鼠抗氧化应激及抗细胞凋亡的作用机制研究

目的:探讨车叶草苷(ASP)对少弱精症大鼠抗氧化应激及抗细胞凋亡的作用机制。方法:通过灌胃奥硝唑建立少弱精症大鼠模型,将SD大鼠按照随机数字表法分为对照组、模型组、车叶草苷组(60 mg/kg)和通路抑制剂(第3周腹腔注射2 mg/kg)+车叶草苷组,每组10只。检测大鼠精子参数;酶联免疫吸附试验法检测血清丙二醛(MDA)、谷胱甘肽(GSH)、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)水平;实时萤光定量聚合酶链式反应法检测睾丸组织B细胞淋巴瘤2(Bcl-2)、B细胞淋巴瘤2相关X蛋白(Bax)和核因子E2相关因子2(Nrf2)基因水平;蛋白质免疫印迹法检测睾丸组织Kelch样ECH关联蛋白1(Keap1)、Nrf2和血红素加氧酶1(HO-1)水平。结果:与对照组比较,模型组精子活力、精子浓度、GSH-Px、GSH、SOD、Bcl-2、Keap1、Nrf2、HO-1水平下降(P<0.05),MDA和Bax水平上升(P<0.05);与模型组比较,车叶草苷组精子活力、精子浓度、GSH-Px、GSH、SOD、Bcl-2、Keap1、Nrf2、HO-1水平上升(P<0.05),MDA和Bax水平下降(P<0.05)。结论:ASP能有效改善少弱精症大鼠精子活力、精子浓度,减少睾丸组织细胞的凋亡,改善氧化应激损伤,Keap1/Nrf2信号通路的激活可能是其作用机制。