人类精子受精潜能与内源性血小板激活因子含量有关

血小板激活因子(PAF)是一个有强效传导信号的磷酸酯类物质,它被发现存在于哺乳动物的精子中,而且与受精能力呈正相关。尽管PAF存在于人的精子中,但是,有关血小板激活因子含量与精子受精的潜能之间的关系未见报道,因此,本研究的目的是应用精子穿透试验决定是否诱导获能的精子PAF含量与精子的受精潜能有关。与去透明带仓     

40岁以上男性精子DNA损伤与其精液常规参数的关系分析

目的分析40岁以上男性精子DNA损伤与其精液常规参数的关系。方法收集本院148例40岁不育男性患者精液以及120例40岁已生育体检男性精液,采用计算机辅助精液分析系统和双尾彗星实验检测常规精液参数及精子DNA损伤情况,分析40岁男性精子DNA损伤与其精液常规参数的关系。结果 40岁组不育男性精液的总活力、前向运动率和顶体反应率显著低于40岁正常组,DNA碎片化指数(DFI)值显著高于40岁正常组,差异具有统计学意义(P0.05);40岁不育男性中,DFI值≤30%组(112例)精子浓度、总活力、正常形态率、前向运动率和顶体反应率均显著高于DFI30%组(36例)(P0.05),其DFI值与精子浓度、总活力、正常形态率、前向运动率和顶体反应率呈显著负相关;40岁不育男性中,精子单链损伤比例高组(108例)精子浓度、总活力、正常形态率、前向运动率和顶体反应率均显著高于双链损伤比例高组(40例)(P0.05),其双链损伤指数/DFI(DSB-DFI/DFI)值与精子浓度、总活力、正常形态率、前向运动率和顶体反应率呈显著负相关,而单链损伤指数/DFI(SSB-DFI/DFI)值与精液各参数无显著相关性。结论 40岁不育男性精液参数异常和DNA损伤情况较同龄已育男性严重,精液DNA碎片化指数和双链损伤类型对40岁以上不育男性生殖情况具有一定评估价值。     

5型磷酸二酯酶抑制剂对男性精子质量及功能的影响

由于5型磷酸二酯酶(PDE5)抑制剂在治疗男性勃起功能障碍方面取得了巨大成功,关于其药理作用也被广泛研究。近年来的研究表明,PDE5抑制剂还可用于治疗心血管疾病,下尿路症状和早泄等。现有的大多数研究表明,其应用对精液量、精子计数、精子浓度、精子活力、正常形态精子百分比、精子膜完整性和精子穿透试验均无不良影响。此外,该类药物还能在精子获能中起作用,但关于顶体反应尚有争议。     

富硒地区与非富硒地区男性精液质量的比较研究

目的探讨富硒与非富硒地区硒与精液质量之间的关系。方法选择富硒与非富硒地区健康成年男性336人,检测血清及精浆中的硒浓度,并进行精液常规、精浆生化、精子功能、性激素5项检测。结果富硒组血清及精浆中硒浓度略高于非富硒组,差异无统计学意义(P0.05)。富硒组精子密度及活力高于非富硒组,差异具有统计学意义(P0.05)。而两组精浆生化水平、血清激素水平及精子顶体酶活性均无统计学差异(P0.05),DNA碎片率富硒组明显降低,差异具有统计学意义(P0.05)。结论富硒组男性的血清及精浆中硒浓度较非富硒组略高,富硒组精子浓度及活力优于非富硒组,精子DNA碎片率明显低于非富硒组,因此富硒组精液质量较非富硒组好。     

精浆内脂质运载蛋白型前列腺素D合成酶与α-葡萄糖苷酶的相关性研究

目的分析脂质运载蛋白型前列腺素D合成酶(L-PGDS)与精浆其他参数之间的关系,探讨L-PGDS在男性生殖系统中的作用。方法分析92份精液中的精子密度、精子活力、L-PGDS浓度、酸性磷酸酶活力以及α-葡萄糖苷酶活力。依据精子密度,将标本分为3组:正常组(精子密度>20×106/ml)、寡精子组(精子密度<20×106/ml)及无精子组(精子密度为0)。彩色精子质量分析系统测定精子密度及活力,双抗体夹心酶联免疫吸附试验(ELISA)检测精浆内的L-PGDS浓度,分光光度计测定α-葡萄糖苷酶活力。结果正常组、寡精子组以及无精子组患者精浆L-PGDS浓度依次降低,差异显著(P<0.001)。L-PGDS的浓度与α-葡萄糖苷酶、精子密度及精子活力呈正相关,相关系数(r)分别为0.426、0.813和0.380。结论精浆L-PGDS浓度可作为少精子症的辅助诊断指标。     

一氧化氮（NO）对男性生育能力的影响

一氧化氮（ＮＯ）是一具有多种生物学功能且有双重作用的体内局部调节因子。最近研究表明，低浓度ＮＯ具有保护精子活力的作用；而高浓度ＮＯ则损害生精功能，抑制精子的活动度，抑制精子的高反应性能力及降低顶体反应率，从而使男性生育能力低下严重时导致男性不育症。     

亚临床型精索静脉曲张患者精浆NO浓度与精子活力关系

目的 探讨亚临床型精索静脉曲张(SVC)精浆一氧化氮(NO)浓度与精子活力的关系.方法 选择亚临床型精索静脉曲张患者35例为实验组,同时选择正常健康男性35例作对照组.采用计算机辅助精液分析技术测定各组精子活力,采用硝酸还原酶法测定精浆中NO浓度.结果 ①实验组精浆中NO浓度为52.19±17.12μmol/L,对照组精浆中NO浓度为38.06±6.43 μmol/L,实验组明显高于对照组,两者比较差异具有统计学意义(P＜0.05).②实验组精浆中NO水平与精子活力水平呈负相关性,具有统计学意义(P＜0.05).结论 亚临床型精索静脉曲张患者精浆中NO浓度增高,并在一定范围内与精子活力呈负相关.     

人类精子RNA生殖功能研究进展

人类成熟精子中RNA的存在已经被证实,主要包括mRNA和部分小RNA家族成员。随着研究深入,发现精子mRNA表达差异,与精子活力和男性生育功能相关。而部分精子中特异存在的mRNA和小RNA在精卵融合和早期胚胎发育调控中有重要作用。已经获得的结果提示精源性RNA的表达具有个体差异性,并且是胚胎发育所必需的。对精子RNA功能的深入研究将会对男性不育、人类辅助生育技术以及核移植技术等相关领域产生推动作用。     

重庆市孕前男性精液质量的现状及影响因素初步调查

目的了解本市孕前男性精液质量现状及其影响因素,为孕前夫妇优生指导提供参考。方法对401例孕前男性进行体格检查和病史询问,填写健康调查表,并进行精液质量检测。结果 (1)孕前男性的精液量、精子浓度的中位数分别为3.0m L、71.7×106/m L;前向运动精子(PR)、精子总活力、存活率中位数分别是36.3%、46.5%、49.1%;精子形态正常率、精子DNA碎片指数正常率的中位数分别为3.1%,90.92%。(2)与WHO第五版标准对比:90%的孕前男性精液量、精子浓度和精子总数、精浆锌含量、精浆果糖含量正常;但精子PR,总活力和存活力、形态的正常率较低,符合率分别是53.8%,63.7%;63.7%、54.9%。(3)多因素关联性分析发现:吸烟、饮酒、经常热水浴和生活压力显著影响精子质量,差异具统计学意义(P0.05)。结论重庆市孕前男性精液质量较差,主要表现在精子活力下降和形态畸形。改变吸烟、饮酒、热水浴等不良生活习惯和减轻生活压力对提高男性精子质量非常重要。     

白藜芦醇对环磷酰胺诱导的人精子氧化损伤的保护作用乜照燕1,张亚楠2,花蕊2,陈丽君1,李亮1,吴海峰

目的 探讨白藜芦醇(RES)对环磷酰胺诱导的人精子氧化损伤的保护作用。方法 收集2018年1月至4月在河北医科大学第四医院生殖医学中心就诊男性患者的正常精液标本。将用密度梯度离心法处理后的正常精液标本用不同浓度(0、1.0、2.5、5.0、7.5μmol/L)环磷酰胺活性代谢产物4-过氧化氢环磷酰胺(4-HC)对精子进行体外毒性试验,继续培养24h,通过精子活力和精子存活率筛选4-HC作用半抑制浓度(IC50)。将处理后的正常精液用不同浓度RES(5、10、25、50、75μmol/L)预处理2h,再加入IC50浓度4-HC,测定精子活力和精子存活率选择RES最佳保护浓度。选择4-HC和RES浓度后,该实验分为四组:对照组(CON)、环磷酰胺组(4-HC)、环磷酰胺+白藜芦醇组(4-HC+RES)、白藜芦醇组(RES),检测各组精子活力、活率、氧化应激指标以及精子凋亡指标。结果 随4-HC浓度增加,精子活力和存活率降低,呈剂量依赖关系,依据IC50,2.5μmol/L4-HC为后续实验药物浓度。RES预处理后,精子活力和精子活率均得到改善,50μmol/L RES效果最佳,确定为后续实验药物浓度。结果显示:4-HC组较CON组,精子活力和存活率下降,氧化应激水平上升,精子凋亡增加,4-HC+RES组与4-HC组相比精子活力和存活率升高,氧化应激水平降低,精子凋亡降低。结论 RES可以减少化疗药物导致的精子氧化应激水平增加,能预防和缓解化疗药物对人精子造成的损伤。     

High seminal platelet-activating factor acetylhydrolase activity in men with spinal cord injury

Spinal cord injury (SCI) causes male infertility, with low sperm motility the major long-term cause. It has been suggested in previous studies that some seminal components may be responsible for the pathological asthenozoospermia. It is hypothesized that platelet-activating factor (PAF) acetylhydrolase (PAFah), which originates in the epididymis and other accessory sexual glands, may be a causative factor. This enzyme catalyzes PAF to acetate and biologically inactive lyso-PAF. PAF is well recognized to be an important phospholipid mediator that stimulates sperm motility and enhances sperm capacitation and fertilization. The present study was designed to analyze differences in PAFah activity in semen of men with SCI and age-matched healthy men. PAFah assay reagent kits were used to measure enzymatic activity by monitoring the production rates of 4-nitrophenol on a spectrophotometer during a given interval. The results showed that subjects with SCI had a higher concentration of PAFah than men in the control group (P < .001). A statistically significant negative correlation was found between enzymatic activity and sperm motility (r(2) = 0.8449; P < .001). Further studies will determine whether seminal vesicle dysfunction in men with SCI leads to abnormal PAFah activity, resulting in low sperm motility.     

Asthenozoospermia: Cellular and molecular contributing factors and treatment strategies

Semen sample with poor sperm motility, which called asthenozoospermia, is considered as one of the main factors contributing to male infertility. Recognition of the cellular and molecular pathways contributing to sperm motility reduction may lead to applying novel treatment strategies for overcoming low sperm motility in asthenozoospermia individuals. In this review, we intend to discuss the main causes of sperm motility reduction in asthenozoospermia and some treatment strategies used to overcome low sperm motility.     

New areas of research in male infertility

Recent research in male reproduction holds much promise for future clinical application. Research on the relationship between sperm, semen, and the immune system may provide novel approaches to treating immune-related infertility. Investigations of sperm motility have shed new light on these complex mechanisms and may lead to rational approaches to the improvement of sperm function. New assays for secretory products unique to the testis show potential as markers for specific testicular cellular functions. In-vitro fertilization promises to become a viable treatment option for couples with male-factor infertility. Research on male contraception may lead to the development of safe and reversible male contraceptives.     

Absence of direct effect of beta-endorphin and calcitonin on human sperm motility

Beta-endorphin and calcitonin are found in the male reproductive tract. To elucidate the role of these hormones in reproduction, we studied their effect on sperm motility in vitro. Eight semen specimens were obtained from healthy donors, washed, and incubated with different concentrations of human beta-endorphin and human calcitonin. After 30 min of incubation, percentage of motile sperm (% motility), mean progressive velocity (MPV), and lateral head displacement (LHD) were assessed by a computerized semen analyzer. There were no significant differences in any of the sperm motility parameters between control and treated sperm. There was also no correlation between the concentration of beta-endorphin or calcitonin and any sperm motility parameters. It would appear that beta-endorphin and calcitonin may not directly affect sperm motility parameters in vitro.     

Acidification of intracellular pH in bovine spermatozoa suppresses motility and extends viable life

Intracellular pH (pHi) was determined in ejaculated bovine spermatozoa using a ratiometric absorbance technique under various incubation conditions that drastically altered sperm motility. The pHi was directly correlated with sperm motility. In a medium of Sodium, Potassium, and Magnesium [NKM] that supported active sperm motility, pHi was 6.9. In medium containing weak acids (NKM equilibrated with 100% CO2 or containing 80 mM 5,5-dimethyl-2,4-oxazolidinedione; DMO), pHi was depressed at least 0.5 pH unit and sperm motility was suppressed. After complete immobilization of sperm was established, removal of the weak acids indicated that suppression of motility was fully reversible for up to 48 hours in CO2 and up to 24 hours in DMO. This study shows that expression and conservation of sperm motility are inversely related, and that depression of pHi by weak acids can reversibly inhibit sperm motility. These findings may help to explain the mechanisms by which sperm are immobilized within the male reproductive tract, and could be applicable to the design of improved ambient temperature semen extenders.     

Evaluation of different doses of mashua (Tropaeolum tuberosum) on the reduction of sperm production, motility and morphology in adult male rats

Mashua is an edible-tuber crop that grows in the Andean region. Folk medicine describes the use of mashua to reduce reproductive function in men. The present study aimed: (i) to determine whether different doses of mashua (0.01, 0.1, 1 and 2 g kg(-1)) produced a dose-response reduction on sperm production and quality; and, (ii) to determine whether these anti-reproductive effects of mashua can be reversible after cessation of treatment (12 and 24 days of recovery time). Mashua-treated rats showed lower values of daily sperm production, epididymal and vas deferens sperm count and sperm motility; meanwhile, mashua increased the percentage of abnormal sperm morphology and epididymal sperm transit rate. The following variables follow a dose-response effect: sperm number in vas deferens, sperm motility and sperm transit rate. In addition, it was demonstrated that the reduction in reproduction function in male rats treated with mashua was reversible after 24 days of recovery time. Finally, lower doses mashua reduces sperm number and quality (motility and morphology), and these adverse effects on male reproductive system may be reversible after 24 days after cessation of the treatment.     

The effect of ketoconazole on endocrine and reproductive parameters in male mice and rats.

Ketoconazole has been shown to reduce steroidogenesis by inhibiting the cytochrome P-450 enzymes in these pathways. This finding, along with the observation that the compound reduces sperm motility, led us to study the effectiveness of ketoconazole as a male contraceptive agent administered in acute and chronic studies of both rats and mice. Four hours after a single administration, male rats showed significant reductions in both serum testosterone and corticosterone levels that completely recovered (testosterone) or nearly recovered (corticosterone) 24 hours after administration. Chronic administration of ketoconazole to male rats and mice resulted in steroid levels comparable with those of control animals. Epididymal sperm motility was only slightly reduced in male mice 4 hours after administration of the drug. No effect on sperm motility was noted after chronic administration in either species studied. In vitro exposure of epididymal sperm to ketoconazole resulted in a significant reduction of sperm motility. Breeding trials after ketoconazole administration resulted in normal fertility and fecundity even at the highest dosage studied. The lack of correlation between steroid levels and sperm immobilization, along with rapid in vivo and in vitro effects on sperm motility, suggests that the reduction in sperm motility is not related to a decrease in steroid levels. From these data, the authors conclude that ketoconazole is probably not a viable approach to the development of a male contraceptive.     

Relationship of seminal plasma testosterone and dihydrotestosterone to sperm count and motility in man.

A radioimmunoassay previously described for serum T and DHT was adapted for use in the measurement of these hormones in seminal plasma. The seminal plasmas of 273 semen specimens were assayed for T and DHT concentration. Mean levels of these hormones for various sperm count and sperm motility categories were determined. We found that: (1) the DHT level of the azoospermic group was significantly lower than all other groups; (2) the T level of the group whose mean sperm count exceeded 40 x 10(6)/ml was higher than that of all other groups; (3) the DHT level of the group with absent sperm motility was lower than the level of all other groups; and (4) changes in sperm motility were not accompanied by changes in T levels. We concluded that idiopathic male subfertility as evidenced by oligospermia, azoospermia, and decreased sperm motility may be related to insufficient androgen production due to a primary intratesticular defect.     

Biochemical parameters of initiation and regulation of sperm motility

Studies of in vitro models demonstrate that a forward motility protein (FMP) is required for the initiation of forward motility in the immature epididymal spermatozoa. FMP is a heat-stable glycoprotein derived from epididymal plasma. During the epididymal maturation of spermatozoa in vivo, there is a marked increase of intrasperm pH and level of cyclic adenosine monophosphate (cAMP). Several studies suggest that exogenous FMP in concert with elevated intrasperm pH and level of cAMP initiates flagellar motility during the epididymal transit of sperm. cAMP activates sperm cytosolic cAMP-dependent protein kinases, which in turn phosphorylate multiple intrasperm phosphoproteins that may regulate flagellar motility. Exogenous calcium ion activates intact sperm motility, although it inhibits motility of demembranated cells on reactivation. Occurrence of cAMP-dependent type I and II protein kinases, a novel cAMP-independent protein kinase, and a phosphoprotein phosphatase has been demonstrated on the external surface of spermatozoa. The sperm surface has a coupled-enzyme system: ecto-cAMP-independent protein kinase and phosphoprotein phosphatase that regulate the phosphorylation and dephosphorylation of endogenous sperm ectophosphoproteins. The specific activities of these ecto-enzymes increase markedly during forward progression, suggesting that they may have a role in regulating flagellar motility.