精囊在男性生殖和性功能中的作用

精囊在男性生殖活动中发挥重要作用,精囊分泌果糖,是精子体外运动的主要能量来源;精囊还分泌多种生命活性物质,参与精液凝固,与精液的粘稠度有关,而且对于精子活力,精子染色质的稳定,精液的抗氧化作用以及精子在女性生殖道的免疫豁免都具有重要意义;此外,最新的研究成果表明精囊的饱胀程度还与男性性功能关系密切。精囊功能的异常可能造成性功能障碍、男性不育症等严重影响男性生殖健康的疾病。     

精囊的神经生理学效应

精囊参与射精过程中精液的汇聚,其收缩后排出的精囊液约占精液量的50%~80%,其分泌物果糖是精子成熟必不可少的营养物质,故精囊是与精液量和精子质量有密切关系的雄性附属性腺。精液汇聚过程中,交感神经和副交感神经对精囊上皮分泌功能和平滑肌层收缩功能的调控,以及精囊上皮和平滑肌层中肾上腺能神经受体、胆碱能神经受体、多巴胺能神经受体及各种神经递质受体的分布,对于男性生育能力具有重要影响,现就射精过程中精囊的神经生理学效应的研究进展作一综述。     

精囊的分泌活性及其与精子活力的关系

在不育门诊就诊的146名男子,以校正精液果糖值(每毫升果糖毫克数×每毫升精子百万数)来评定精囊的分泌活性。将校正果糖值低视为精囊功能低下。对精液中每高倍视野白细胞>20个、精子凝集>10％视为生殖道的炎症证据。在精液培养阳性的受检     

精囊凝胶蛋白Semenogelin Ⅰ的研究进展

精液的凝固和液化过程亦是精子获能的过程,是精子取得前向运动所必需的。射精后的人类精液最初呈凝固状态,主要是由于精囊特异性分泌的精液凝胶蛋白SemenogelinⅠ(SgⅠ)的作用,在随后精液液化过程中被前列腺分泌的前列腺特异性抗原(PSA)水解,产生许多相对分子质量较小的具有各种生物学活性的肽段,这些肽段被发现存在于精子的表面或被精子利用,调控精子获能和向前运动的能力。文中对SgⅠ的生理功能研究进展进行了综述。     

精液离心沉淀分析在无精子症诊断中的应用

世界范围内不育症的发病率高达10％-15％，与男性相关的因素约占50％，其中又有10％的男性不育为无精子症。精液质量分析是诊断和治疗男性不育症的重要依据，而目前临床对无精子症与少精子症的治疗方法多采用辅助生殖技术。因此，无精子症患者精液中是否存在精子不仅决定无精子症诊断成立与否，也关系到患者在采用辅助生殖技术治疗时如何获取精子。在临床工作中常遇到很多医疗单位仅凭常规镜检时未发现精子即作出无精子症的诊断。为此，本研究对经外院检查为无精子而来我院男性不育科就诊的301例患者精液进行离心涂片复检，现将检测结果报告如下。     

精液微量元素锌、铜及铅对精子质量的影响

自1921年Betrand和Vladesco首次发现精液中的锌浓度明显高于其他体液的含量以后,许多学者对精液和精浆中微量元素进行了大量研究,迄今报道在精液或精浆中测出的元素有十几种[1].研究表明,微量元素与性功能、性激素分泌及生殖系统的病变密切相关,某些元素的代谢紊乱可导致男性不育.目前对男性不育研究较多的是锌、铜、铅、锰、铁等元素的代谢变化.研究微量元素对男性生殖系统的影响,不仅可作为男性生殖道疾病的诊断和治疗依据,也是生殖生理、男性计划生育研究的重要课题之一.一般认为,微量元素锌、铜、铅与性功能、性激素分泌及生殖系统病变的关系最密切.本文就精液锌、铜及铅对精液质量的影响进行综述.     

精浆锌检测在不育症病因诊断中的意义

精液中存在的一些微量元素，不仅参与维持精于生存环境的稳定，还参与精子的构成，同时对精子的成熟、获能均具有一定的作用。研究这些元素对诊断与治疗男性不育症至关重要。锌作为其中一种重要的微量元素，其在男性生殖中的作用已得到了证实[1-2]。锌可影响男性生殖功能，缺锌可导致不育。用锌治疗不育症获得了较好的效果[3]，可见锌与男性不育关系密切。本文对不同病因的不育症病人精浆锌进行检测，并分析其在不育症病因诊断中的意义，现报告如下。1对象和方法1.l检测对象对照组58例为妻子怀孕待产的止常男性，201例不育男子均来自于本院…     

射精管梗阻

射精管梗阻是导致男性不育的重要原因之一。根据病因可分为先天性梗阻和继发性梗阻两类。通过病史、体检、精液分析和经直肠B超检查可为本病诊断提供重要依据。精液检查见四低(精液量少、无精子或少精子、pH值低、精浆果糖水平低)是其特征性表现。锝(99Tcm)硫胶体精囊闪烁扫描对功能性梗阻、部分性和完全性梗阻的鉴别有重要价值,经皮穿刺输精管造影、穿刺精囊抽吸精囊液及造影可明确诊断。经尿道微创外科治疗可使部分患者获满意疗效,术后仍不能生育者可行辅助生殖治疗。     

人类精子扫描电子显微镜标本制备与观察

精子是男性成熟的生殖细胞，光镜下精液分析是一项用于评估男性生殖能力的最基本检测手段，单纯光镜精液分析误差相对较大，对于精子形态学评估有其局限性，且不同实验室对同一标本检测误差甚大。扫描电子显微镜（SEM）能够非常直观地观察了解精子头、体、尾的形态及细胞膜表面的完整性。SEM观察预期效果如何与电镜样本的制备技术密切相关，现将笔者的工作体会报告如下。     

精液参数与射精频率的关系

通过对２０例性功能正常的男子（１０例精液正常，１０例少弱精症）连续１周，每天采集精液标本进行观察，探讨了他们的精液参数与射精频率之间的关系，结果表明，正常组的精液容积，１次射精的精子总数逐日下降，于第５天降至原水平５０％左右；以后维持在该水平上下波动，而精子密度并不下降，少弱精组精液容积，精子密度及１次射精的精子总数均显著下降，精子活力和形态在两组中都相对变化不大。     

Function of seminal vesicles and their role on male fertility

The present review has been designed to update the recent developments on the function of seminal vesicles and their role on male fertility. It is indicated that the true corrected fructose level is a simple method for the assessment of the seminal vesicular function. Measttrement of seminal fructose used universally as a marker of the seminal vesicle function is not an appropriate approach due to its inverse relationship with the sperm count. The llue corrected fructose defined as [ log. motile sperm concentration ] multiplied by [ seminal fructose concentration ] has been shown to be a better marker of the seminal vesicle function. Seminal vesicular secretion is important for semen coagulation, sperm motility, and stability of sperm chromatin and suppression of the immune activity in the female reproductive tract. In conclusion, the function of seminal vesicle is important for fertility. Parameters as sperm motility, sperm chromatin stability, and immuno-protection may be changed in case of its hypofunction.     

Hypofertility in males due to a secretion anomaly of the seminal vesicles and its treatment

Between 1981 and 1986, 5,000 males with infertility were treated. Eight (0.16%) of them had hypospermia, a decrease in seminal fructose, asthenospermia without oligospermia considered as a secretion anomaly of the seminal vesicles. Artificial Insemination with the Husband's sperm (AIH) combined with vesiculo-prostatic plasma from a vasectomized donor was performed successfully in 3 couples. In this series, failures were associated with an important fertility factor in the female. AIH combined with vesiculo-prostatic plasma from a vasectomized donor is considered as an effective treatment of male hypofertility caused by vesicular dysfunction.     

The secretory activity of the seminal vesicles and its relationship to sperm motility: effects of infection in the male reproductive tract

In 146 males aged between 20 years and 40 years attending an infertility service, the secretory activity of the seminal vesicles was assessed by measurement of corrected seminal fructose concentration. This value was related to the presence of a positive semen culture, other evidence of inflammatory processes in the reproductive tract and sperm motility. Only 48% of subjects with a positive semen culture showed evidence of inflammation in the reproductive tract, as assessed by the presence of more than 20 white blood cells per high power field, and greater than 10% spermagglutination in the ejaculate. There was a relationship between the inflammatory process, hypofunction of the seminal vesicles and poor sperm motility. When the semen culture was positive but there was no evidence of inflammation neither seminal vesicle function nor sperm motility was affected. When the semen culture was negative, i.e. no evidence of inflammation and the subjects were asthenozoospermic, the corrected fructose levels were normal. It is proposed that in these conditions the cause of asthenozoospermia may be factors other than accessory sex organ dysfunction. In conclusion, there was no close relationship between the bacteriological results and evidence of inflammation of the accessory glands. A positive semen culture was related to lower levels of corrected fructose (hypofunction of the seminal vesicles) when the positive sperm culture was associated with inflammation of the reproductive tract and asthenozoospermia.     

Seminal Vesicle Aspiration of Fertile Men

Purpose

Whether sperm normally reside in the seminal vesicles of fertile men without ejaculatory duct obstruction, and the effect of duration of sexual abstinence on results of seminal vesicle aspiration were determined.

Materials and Methods

Bilateral seminal vesicle aspiration was performed on 12 fertile volunteers under transrectal ultrasound guidance with randomization according to 0 and 5 days of abstinence. Seminal vesicle were examined microscopically for number and motility of sperm. A positive aspirate was defined as greater than 3 sperm per high power microscopic field.

Results

Duration of abstinence had a significant effect on outcome of seminal vesicle aspiration in fertile volunteers. No volunteer with 0 days of abstinence had a positive aspirate from either seminal vesicle, whereas a third of those with 5 days of abstinence had at least 1 positive seminal vesicle aspirate.

Conclusions

Significant numbers of sperm are not normally found in the seminal vesicles of fertile men immediately after ejaculation. Diagnostic seminal vesicle aspiration should be performed after 0 days of abstinence. Longer periods of sexual abstinence may be used in patients undergoing seminal vesicle harvesting of sperm for assisted reproduction.     

Functional structure and ultrastructure of seminal vesicles

The function of the seminal vesicles in animals and man is under androgen control. The use of a new marker of the seminal vesicle function, termed corrected fructose, demonstrates an association between serum testosterone levels and seminal corrected fructose levels. The human seminal vesicles secrete a variety of products, and there is good evidence of a close relationship between functions of the seminal vesicles and sperm motility. Some of their products of secretion, such as potassium, bicarbonate, prostaglandins, and prolactin, directly stimulate the motility of the sperm through actions at the level of the mechanisms of production of the energy necessary for the motion. Several constituents are secreted by the seminal vesicles, some of which have no specific functions.     

Rapid disappearance of spermatozoa after vasal occlusion in the dog

The reproductive system of the male dog is unusual in that the seminal vesicles and bulbourethral glands are absent. Therefore, we chose the dog as a model to evaluate the effect of seminal vesicles on clearance of spermatozoa from the male reproductive tract after vasal occlusion. Thirty adult male beagle dogs with ejaculates containing at least 500 x 10(6) sperm with greater than 90% motility were used for this study. The dogs' vasa were occluded percutaneously using a Vasocclude clip-applying device through a small scrotal puncture site. Dogs were ejaculated and semen analysis was performed before and after vas occlusion. The first 24 dogs were completely azoospermic 1 week following vas occlusion. In order to explain these unanticipated results, an additional 6 dogs were evaluated to determine the specific time course of sperm disappearance from the ejaculate at 1, 3, 5, and 7 days after vas occlusion. The results revealed that spermatozoa were almost completely absent within 1 day after vas occlusion (99.9% reduction, X = 1.0 + 1.1 x 10(6) sperm per milliliter at 1 day, P <.0005 vs prevas occlusion). The rapid elimination of spermatozoa after vas occlusion indicates that sperm transit rapidly through the vas deferens in dogs. Therefore, the delayed clearance of spermatozoa from the ejaculate in humans may be due to sperm storage in the seminal vesicles.     

Leucocyte populations in semen and male accessory gland function: relationship with antisperm antibodies and seminal quality

Semen samples from 279 infertility patients attending an Immunological Centre were analysed to evaluate the relationship between the populations of leucocytes, seminal quality, antisperm antibodies, and seminal vesicle function. The most frequent finding between leucocytospermic samples was asthenozoospermia (57%), whereas in non-leucocytospermic samples normozoospermia was the most frequent finding (47%). In the samples with asthenozoospermia, granulocytes predominated, whereas in those with oligozoospermia and azoospermia a reduction in the number of macrophages and lymphocytes was observed, suggesting an obstructive process at the level of epididymis and/or vas deferens where these leucocytes are mostly produced. In the case of hypofunction of the seminal vesicles there was a predominance in granulocytes. The increased levels of each type of leucocytes affected seminal quality only when seminal vesicles were affected. Only the elevated granulocytes count was related to a decrease in sperm motility. In those samples with leucocytospermia, positive antisperm antibodies (ASA) were associated with low sperm motility, low sperm normal morphology, and low value of seminal corrected fructose, whereas, in the absence of leucocytospermia, ASA, were more related to low sperm counts. These data suggest that granulocytes were more related to seminal vesicles dysfunction and sperm motility changes, and that ASA may be observed in the presence or absence of leucocytospermia.     

Relationship between Zinc Concentrations in Seminal Plasma and Various Sperm Parameters

The zinc concentration in seminal plasma from 98 infertile male patients and 8 fertile males was measured. The zinc concentration of the seminal plasma in azoospermic and oligoasthenozoospermic patients was significantly lower than that in the other groups (each, p<0.05). The seminal plasma zinc concentration in asthenozoospermic males was significantly higher than that in any other group (p<0.05). There was a positive correlation of zinc concentration with sperm concentration (r=0.33, p<0.05) and with sperm motility (r=0.22, p<0.05), while there was no correlation with sperm morphology. A correlation between zinc concentration and plasma testosterone concentration was observed (r=0.24, p<0.05). It is concluded that excessively high zinc concentration is apparently related to defective motility in asthenozoospermic patients, even though adequate seminal plasma content of the element is required for normal sperm function.     

True corrected seminal fructose level: a better marker of the function of seminal vesicles in infertile men

This study was designed to determine if the value obtained after multiplying motile sperm concentration by seminal fructose concentration, named "true corrected fructose", correlates with sperm motility in asthenozoospermic men. Forty-two male partners in infertile couples were studied. Men were treated with 100 mg daily of clomiphene citrate for 5 days. Blood and semen samples were collected before treatment and 24 h after the end of treatment. Serum testosterone, seminal fructose and sperm motility were measured in each subject. Corrected fructose (log. sperm concentration multiplied by seminal fructose), and true corrected fructose (log. motile sperm concentration multiplied by seminal fructose) values were calculated. Prevalence of asthenozoospermia was 42.85% (18 of 42). Prevalence of hypofunction of the seminal vesicles was 9.5% using seminal fructose as a marker; 40.5% using seminal corrected fructose as a marker and 47.6% using true corrected fructose as a marker of seminal vesicle function. Regression analysis showed a better coefficient of determination between true corrected fructose and motile sperm concentration (R2=0.20, p < 0.001) than with corrected fructose (R(2)=0.05, p < 0.1) or fructose concentration (R(2)=0.006, p < 0.5). Asthenozoospermia was observed in 22.7% of subjects with normal function of the seminal vesicles, and in 65% of men with low values of true corrected fructose (z=6.02, p < 0.0001). Multivariate analysis showed that sperm motility grade 3 improved after treatment with clomiphene if true corrected fructose increased (p < 0.002). In those men whose seminal vesicle function improved after clomiphene treatment, a reduction in the prevalence of asthenozoospermia from 50 to 28.6% (z=3.10, p < 0.002) was observed whereas in those whose seminal vesicles did not respond to clomiphene the prevalence of asthenozoospermia was not reduced (z=1.05; p: NS). In conclusion, true corrected fructose measurement relates with sperm motility in cases of asthenozoospermia. Asthenozoospermia improves with clomiphene treatment if seminal vesicle function improves after treatment.