精囊生理功能的研究进展

精囊的生理功能影响到生育,现综述近年来精囊功能的常用指标、精囊对精液凝固功能及精液粘稠度的影响、以及精囊调节精子的运动和抗氧化功能及免疫效应方面的研究进展。     

Seminal fluid from men with agenesis of the Wolffian ducts: zinc-binding properties and effects on sperm chromatin stability

Zinc-binding properties were studied in 'prostatic fluid', i.e. in seminal plasma from patients with agenesis of the Wolffian ducts, and in split-ejaculate fractions dominated by seminal vesicular fluid. The effect of seminal fluid, with different zinc-binding properties, on the stability of zinc-dependent sperm chromatin was assessed by exposing sperm to 1% sodium dodecyl sulphate (SDS) for 60 min. Citrate was the only zinc ligand in 'prostatic fluid', as revealed by gel chromatography. Zinc in this fluid enhanced the stability of sperm chromatin. In contrast, the stability of sperm chromatin was decreased in seminal plasma dominated by vesicular fluid. These results are in accordance with the concept that prostatic fluid ensures the appropriate zinc content and stability of sperm chromatin, whereas abundance of vesicular fluid may jeopardize chromatin stability by reducing chromatin zinc content.     

Metenkephalin in Seminal Plasma of Infertile Men

Background: Enkephalin is one of the opioids, which is expressed widely in reproductive organs. However, the function of enkephalin in male reproduction is not completely understood. The effect of metenkephalin on sperm motility remains especially controversial. In this study we examined the level of metenkephalin in seminal plasma from men with normal sperm production and patients with asthenospermia, oligospermia, and azoospermia to investigate the role of metenkephalin in seminal plasma on sperm function. We also investigated the effect of metenkephalin on sperm motility in vitro.
Methods: Sixty nine infertile patients (31 oligospermic, 21 asthenospermic, and 17 azoospermic) were included in this study. The level of metenkephalin in seminal plasma of these men was measured and the effect of the peptide on the motility of human sperm was examined in vitro. Seventeen men with normal seminograms were a control group.
Results: The level of metenkephalin in the seminal plasma of semen from asthenospermic men was significantly lower than that from the controls ( P < 0.05). No significant correlations between the level of metenkephalin and the mean pathing or progressive velocity of sperm, or serum hormone levels were observed. In the in vitro study, which used semen from the controls, treatment of sperm with metenkephalin (50–200 pg/mL) maintained sperm motility for 4 hours. On the other hand, motility of sperm incubated without metenkephalin began to decrease at 3 hours. Metenkephalin levels of 50 pg/mL in seminal plasma is considered to be necessary for maintaining sperm motility.
Conclusion: These results suggest that metenkephalin in seminal plasma is an important clue in the investigation of decreased sperm motility.     

Quality of Semen Obtained from 627 Fertile Men

Six hundred and twenty seven men, whose wives conceived within 6 month of their semen analysis, were included in this study. Attention was focused on 516 men where conception occurred within 3 months of semen analysis. The quality of the seminal plasma (volume pH, fructose and calcium concentrations) and the spermatozoal characterization (concentration, motility, vitality and morphology) are given in details. It was concluded that spermatozoal motility and morphology are the most crucial factors in determining its fertilizing capacity. Measurement of vitality is important only in hypokinetic specimens. Sperm density is a limiting factor only below 10 million/ml.
A widely scattered range of sperm concentration was found among the fathered men which may indicate that the incidence of pregnancy is a multifactorial statistical probability which increases when the quality of the semen is high.     

Seminal fibronectin in fertile and infertile males

This study aimed to assess seminal plasma fibronectin in fertile and infertile males. Ninety infertile males were investigated; asthenozoospermia (n = 27), asthenoteratozoospermia (n = 30), oligoasthenoteratozoospermia (n = 33) compared with 20 healthy fertile controls. They were subjected to semen analysis, seminal plasma fibronectin estimation by radial immune diffusion, serum testosterone (T) and follicle stimulating hormone (FSH) estimation by ELISA. There was significant increase of seminal plasma fibronectin among different infertile groups compared with the controls. Significant negative correlation was elicited between seminal fibronectin and sperm count, sperm motility grades A, B, A + B, sperm velocity, linear velocity, linearity index, sperm normal forms and serum T. Seminal fibronectin showed significant positive correlation with grade D sperm motility and serum FSH. ROC curve analysis discriminating controls and other infertile groups demonstrated criteria value of < 674 mg l(-1) (sensitivity 100% and specificity 96.4%). It is concluded that increased seminal fibronectin is associated with decreased sperm count and sperm motility.     

Zinc in Normal Human Seminal Plasma

Normal human seminal plasma (n = 9) was analysed for zinc by employing the method of instrumental neutron activation analysis. The range of concentration of zinc was from 2.5 to 25.7 mg%. The author is of the opinion that the zinc in seminal plasma functions in two ways.

• 1.

   1. The essential role it has inside the spermatozoa for its motility and
• 2.

   2. to provide a favourable medium for the activity of the spermatozoa.

a) die essentielle Rolle für die Motilität der Spermatozoen und b) die Ausstattung eines günstigen Mediums für die Aktivität der Spermatozoen (diese Funktion kann auch von anderen Ionen übernommen werden).
The second function can be replaced by other ions.
Zink im normalen menschlichen Spermaplasma

Zusammenfassung

Bei 9 gesunden, fertilen Männern wurde der Zinkgehalt im Spermaplasma mittels der instrumentellen Neuronen-Aktivations-Analyse bestimmt. Es ergab sich eine Konzentration von 2,5 – 25,7 mg%. Es wird die Auffassung vertreten, daß Zink zweierlei Funktionen im menschlichen Sperma besitzt     

冷冻保护剂与精液比例对冷冻复苏后精子活动力的影响

目的:比较冷冻保护剂与精浆的不同比例对人类精子冷冻复苏后活动力的影响。方法:将57例志愿者的精液标本分别采用冷冻保护剂∶精液=1∶1和冷冻保护剂∶精液=1∶3的体积比进行冷冻,比较精子复苏后的前向活动率和总活动率。结果:冷冻前的前向运动精子百分率和总活动率分别为(58.60±5.57)%和(66.17±5.24)%。采用冷冻保护剂∶精液=1∶1比例进行冷冻复苏后的前向运动精子百分率和总活动率分别为(40.53±8.97)%和(51.23±9.30)%;采用冷冻保护剂∶精液=1∶3比例进行冷冻复苏后的前向运动精子百分率和总活动率分别为(44.70±8.67)%和(51.50±7.40)%。冷冻前后精子的前向运动百分率和总活动率差异有显著性(P<0.05)。两种不同比例的保护剂相比冷冻后前向运动精子百分率差异有显著性(P<0.05),而总活动率差异没有统计学意义。结论:冷冻对精子活动力损伤明显,冷冻保护剂∶精液=1∶3比例较冷冻保护剂∶精液=1∶1比例可提高冷冻后前向运动精子百分率。     

Prostasomes as zinc ligands in human seminal plasma

Prostasomes are small vesicles, containing zinc, secreted by prostate in human seminal plasma and showing a physiological role on sperm properties. In this study, the possible correspondence between prostasomes and a prostatic high molecular weight protein complex, recently indicated as zinc ligand, has been investigated. Isolated prostasomes, examined by scanning electron microscopy, were dialysed to evaluate their zinc binding capacity. Furthermore, seminal plasma Sephadex G-75 elution was carried out before and after prostasome removal. Prostasome preparations, containing typical vesicles of 50-500 nm, showed a positive correlation between their zinc and protein levels. They were able to take up zinc against gradient. Furthermore, the seminal zinc amount, bound to the high molecular weight proteins, was strongly reduced in the free-prostasome sample with respect to the total seminal plasma. This study suggested the correspondence between the prostasomes and a high-sized zinc ligand complex of prostatic origin. Therefore, it demonstrated, for the first time, the zinc binding capacity of prostasomes, a new property which could be related to their biological functions.     

Seminal plasma proteins and their relationship with sperm motility and morphology in boars

The identification of biomarkers associated with seminal traits could aid in the selection of higher quality ejaculates and benefit the swine industry. The objective of this study was to identify boar seminal plasma proteins associated with sperm motility and morphology. Twenty ejaculates from fifteen adult boars from a commercial boar stud were used for this work. After routine semen collection and analysis, ejaculates were classified into two groups: high‐quality semen (HQS) and low‐quality semen (LQS), based on sperm motility and morphology. Semen samples were processed for seminal plasma separation and analysis by 2D SDS‐PAGE. Total and progressive sperm motility differed between groups (p < 0.001), as well sperm morphology (p < 0.05). The intensity of spots identified as Major seminal plasma PSP‐I (PSP‐I) and cathepsin B (CTSB) was higher in LQS as compared to HQS samples (p < 0.05). Also, PSP‐I was positively associated with major and sperm cauda defects. Sperm motility was negatively correlated with both PSP‐I and cathepsin B. We conclude that high concentrations of Major seminal plasma PSP‐I and cathepsin B in boar seminal plasma are associated with reduced total and progressive sperm motility and low sperm morphology and might be used as biomarkers for semen quality.     

Aminopeptidase in Human Seminal Plasma

Aminopeptidase of seminal plasma was studied in normozoospermic, oligozoospermic, obstructive and non-obstructive azoospermic men. Significantly higher activity was observed in non-obstructive azoospermic patients than that of other three groups. L-Alanine beta-naphthylamide hydrochloride was found to have highest hydrolysis rate in comparison to various other aminoacyl beta-naphthylamide hydrochlorides which were used for determining substrate specificity. 50% inhibitions of the enzyme activity by EDTA and 1,10-phenanthroline were obtained at 5.77 X 10(-3) M and 3.13 X 10(-6) M concentrations respectively. A single band for aminopeptidase in the activity - gel electrophoresis was obtained for all the categories of seminal plasma and the enzyme exhibited the characteristics of metalloprotein.     

Seminal level of clusterin in infertile men as a significant biomarker reflecting spermatogenesis

The objective of this study was to assess the impact of seminal clusterin level on spermatogenesis in infertile men. This study included 89 men who visited our clinic due to infertility, consisting of 28, 33, and 28 diagnosed with normospermia, oligozoospermia and nonobstructive azoospermia (NOA) respectively. The seminal clusterin concentrations measured by enzyme‐linked immunosorbent assay were 47.9, 28.2 and 18.4 ng ml^?1 in men with normospermia, oligozoospermia and NOA, respectively, with significant differences among these three groups (P < 0.01). Microdissection testicular sperm extraction (MD‐TESE) was performed in the 28 men with NOA, and spermatozoon was successfully retrieved from 9. There was a significant correlation between seminal clusterin level and testicular clusterin protein expression evaluated by immunohistochemical staining in these men with NOA (P = 0.026). Of several parameters available before MD‐TESE, the univariate analysis identified serum follicle‐stimulating hormone (FSH) level <10 IU ml^?1 and seminal clusterin level ≥18 ng ml^?1 as significant predictors of sperm retrieval, and of these, only serum FSH level <10 IU ml^?1 was shown to be independently associated with sperm retrieval in the multivariate analysis. Accordingly, it might be worthy to further evaluate the significance of seminal clusterin level as a biomarker for the assessment of spermatogenic status in infertile men.     

Determination of Total Protein in Human Seminal Plasma

Summary: Methodological problems are encountered in determinating human seminal protein content since results are influenced especially by techniques which are used, and by modifications due to liquefaction process. In order to test these two points, three methods (Folin, Biuret and Meulemans's reactions) were applied to the same seminal samples and results were compared. The differences seem principally due to the high level of glyco-proteins. To determine the modifications of total protein content with time after semen collection, each sample was separated in aliquot fractions and proteolysis was blocked at different times for each fraction. There is an increase of the protein concentration during the first fifteen minutes that follows semen collection. The cause of this phenomenon is discussed.
Zusammenfassung: Bestimmung des Gesamt-Eiweiß im menschlichen Spermaplasma
Bei der Bestimmung des Proteingehaltes des menschlichen Sperma-plasmas ergeben sich methodische Probleme. Die Resultate werden nämlich von der ver-wendeten Technik beeinflußt und von den Veränderungen, die mit der Verflüssigung in Zu-sammenhang stehen. Um hier eine Klärung herbeizuführen, wurden drei verschiedene Me-thoden angewendet (Folin-Reaktion, Biuret-Reaktion, Reaktion nach Meulemans) und die Ergebnisse identischer Spermaproben miteinander verglichen. Es wird festgestellt, daß Un-terschiede vor allein auf dem hohen Gehalt an Glykoproteinen beruhen. Um die Veränderungen des Gesamteiweißgehaltes in Abhängigkeit von der Zeit nach der Spermagewin-nung festzustellen, wurde jede Probe in mehrere Fraktionen aufgeteilt und die Verflüssigung für jede Fraktion zu verschiedenen Zeitpunkten blockiert. Es kann festgestellt werden, daß ein Anstieg der Protein-Konzentration innerhalb der ersten fünfzehn Minuten nach der Ejakulatgewinnung zu beobachten ist. Dieses Phänomen wird diskutiert.     

生育与不育男性精浆总抗氧化能力分析

目的:分析生育与不育男性精浆中总抗氧化能力(TAC)及其在男性生育中意义。方法:225例男性不育患者分为6组,分别为:梗阻性无精子症组(n=10),非梗阻性无精子症组(n=42),少精子症组(n=20),弱精子症组(n=78),少弱精子症组(n=57),以及正常精子症组(n=18)。28例正常生育男性作为对照(生育组)。分别采用计算机辅助精液分析(CASA)系统进行精液参数分析,采用比色法检测精浆TAC水平。结果:生育组男性精浆TAC为(19.82±6.33)U,梗阻性无精子症组(1.71±1.33)U,非梗阻性无精子症组(12.73±9.44)U,少精子症组(10.85±6.64)U,弱精子症组(13.88±8.24)U,少弱精子症组(11.20±7.02)U,正常精子症组(18.07±8.73)U;与生育组精浆TAC[(19.82±6.33)U]相比,在各不育症组中,除正常精子症组精浆TAC与生育组差异无显著性外,其余各组均显著低于生育组(P<0.01)。精浆TAC与精子密度(r=0.182,P<0.05)和a级精子(r=0.150,P<0.05)呈显著正相关。结论:精浆中TAC水平与男性不育密切相关,精浆中过低的TAC水平可能是引起男性不育的病因之一。     

Seminal factor VII and factor VIIa: supporting evidence for the presence of an active tissue factor-dependent coagulation pathway in human semen

Human semen spontaneously coagulates into a semisolid mass and then wholly liquefies in a process that may have some similarity to that of normal blood. This well described phenomenon is referred to as coagulation and liquefaction of semen. Besides other active components of the haemostatic system, semen contains a significant amount of functional tissue factor (TF). However, TF needs factor (F)VII in order to exert it actions. In this study, we assessed human semen for the presence of FVII and FVIIa, and related their levels to conventional fertility parameters. Using a functional, one stage, clotting assay based upon the prolongation of the prothrombin clotting time, using the ACL 300R analyser and an Imubind FVIIa ELISA assay, FVII and FVIIa levels were measured in 97 semen specimens obtained from sub-fertile (sperm counts <20 x 10(6)/mL), normally fertile (sperm counts >or=20 x 10(6) but <60 x 10(6)/mL), fertile sperm donors (sperm counts >or=60 x 10(6)/mL), vasectomized subjects and in a pooled normal semen parameters group (categorization into groups was based on the World Health Organization guidelines on fertility criteria). In addition, conventional semen parameters were analysed on all semen samples. Both FVII and FVIIa were quantifiable in human semen. The mean levels of FVII and FVIIa were 4.4 IU/dL and 12 ng/mL respectively. Despite the observed variations of FVIIa levels in the studied groups they did not meet statistical significance when the groups were tested against each other. However, seminal FVIIa levels showed a significant positive association with semen liquefaction time, sperm motility and semen volume. The anti-sperm antibodies and sperm-agglutination groups were also associated with raised seminal FVIIa levels. We observed no significant relationship between FVIIa levels and total sperm concentration, sperm count per mL (sperm density), sperm progression and days of sexual abstinence. This study demonstrates that human semen contains appreciable amounts of FVII and FVIIa. It is possible to quantify these using commercially available assays. There also appears to be a direct correlation between the levels of these factors and certain seminal parameters. This finding reinforces the concept of an active clotting system in human semen, by establishing the missing link in the activation of a TF-dependent pathway.     

Influence of Seminal Plasma on the Chromatin Stability of Ejaculated Human Spermatozoa

Nuclear chromatin decondensation (NCD) of human ejaculated spermatozoa exposed to sodium dodecyl sulphate (SDS) has been studied. A high proportion of NCD reacting spermatozoa was only found in semen samples with a relatively low activity of some prostatic factor(s) (i.e. zinc/fructose ratio below 0.18) in the seminal plasma. Exposure to SDS for one h was found sufficient to reveal the main proportion of spermatozoa undergoing NCD in such a solution.
Addition of seminal plasma with an apparently normal composition to a sperm population with a high NCD reactivity restored the sperm SDS resistance to normal, i.e. blocked the NCD-response. Other results indicated that NCD reactivity was decreased or abolished upon prolonged storage of the spermatozoa in the seminal plasma.
The various results indicated that some factor(s) in the seminal plasma can preserve the nuclear chromatin stability of human spermatozoa and that this factor most likely is of prostatic origin.,     

吸烟者精浆对非吸烟者精子功能的毒性效应

目的:吸烟已被公认具有普遍的健康危害,并且有证据表明吸烟对男、女生殖健康均有影响。本研究的目的就是提供证据说明吸烟通过改变精液和精子质量来影响男性的生育能力。方法:我们评价了吸烟者(SM)的精浆(SP)(用PBS进行不同浓度的稀释,1/0;1/1;1/2;1/6;1/10)对非吸烟者(NSM)精子的直接影响。结果:非吸烟者的精子暴露于吸烟者的精浆一定时间,可导致因丙二醛水平升高所致的精子膜完整性受到破坏、精子活力下降和环(在明胶载玻片上因顶体反应导致环绕精子头部的清晰区带)的数量减少。结论:吸烟者的精子暴露于非吸烟者的精浆导致精子功能障碍改善,提示,去除吸烟者的精浆,然后重新加入含足量抗氧化体系的精浆,可能对各种辅助生育技术应用于吸烟者有临床意义。     

生育与不育男性血清和精浆褪黑素检测及其意义

目的 :检测生育与不育男性精浆褪黑素 (MLT)浓度并探讨在男性生育中的意义。　方法 :年龄为 2 6～ 36岁的生育男性 (18例 )和年龄为 2 3～ 36岁的不育男性 (99例 ) ,其中 ,后者又分为正常精子症组 (13例 )、少精子症组(2 7例 )、弱精子症组 (31例 )、少弱精子症组 (17例 )和少弱畸精子症组 (11例 )。分别采集静脉血和精液 ,采用酶联免疫吸附实验 (ELISA)检测血清和精浆中MLT浓度。　结果 :血清MLT浓度在生育与不育男性之间无显著性差异 ,各组精浆MLT浓度均低于相应的血清值。生育组精浆MLT浓度与各不育组相比无显著性差异 ,而少弱精子症组和少弱畸精子症组MLT浓度下降较为明显 ,但尚未达到统计学意义 (P >0 .0 5 )。　结论 :本研究结果表明 ,精浆MLT可能对精子功能具有一定作用 ,其具体作用机制尚需进一步深入的研究。     

不育男性精浆总抗氧化能力与精子运动功能的关系

目的:研究不育男性精浆总抗氧化能力(TAC)与精子运动能力和方式之间的关系,探讨精浆TAC水平在男性生育中的临床意义。方法:113例精子密度正常的不育男性,28例正常生育男性作为对照组。精液于37℃液化后采用计算机辅助精液分析(CASA)系统进行精液常规分析,采用比色法进行精浆TAC分析。结果:正常生育组精浆TAC为(19.82±6.33)U,不育男性精子密度正常组精浆TAC为(14.37±8.45)U,不育男性精子密度正常组与正常生育组比较存在显著性差异(P<0.01)。精浆TAC与a级精子百分率(r=0.208,P<0.05)和(a+b)级精子百分率(r=0.231,P<0.05)呈显著正相关,精浆TAC与精子运动参数中的前向性(r=0.200,P<0.05)、直线性(r=0.208,P<0.05)、曲线速度(r=0.189,P<0.05)、直线速度(r=0.210,P<0.05)、平均移动速度(r=0.215,P<0.05)及鞭打频率(r=-0.248,P<0.01)之间有显著的相关性,其中前向性、直线性、直线速度、曲线速度、平均移动速度与TAC呈正相关(P<0.05),而鞭打频率与TAC呈负相关(P<0.01)。精浆TAC与摆动性、侧摆幅度、平均移动角度之间无显著相关。结论:精浆中TAC水平与精子运动能力和运动方式密切相关,适宜的精浆TAC为精子运动提供了良好的外部环境,精浆中过低的TAC水平与精子运动能力下降和运动方式改变有关,可能是引起男性不育的病因之一。精浆中TAC分析可为探讨男性不育的发病机制以及临床用药提供依据。     

Seminal plasma lead, cadmium and zinc in relation to tobacco consumption

The total quantity of zinc in the ejaculates of smokers was sipficantly lower than in non-smokers. This was not related to a significant increase in the quantities of seminal cadmium or lead, or to a decrease in sperm quality in the smoking group. It appears that tobacco consumption may have to exceed 20 cigarettedday before a noticeable increase in seminal cadmium can be recorded. It is suggested that this reduction in zinc secretion may jeopardize the content of chromatin zinc, and thereby the stability of the sperm chromatin. This may then contribute to reproductive failure or have consequences for fetal development.