Melatonin hormone profile in infertile males

Melatonin is a hormone produced by the pineal gland. There is much controversy about its relationship to the male reproductive process. In this study, seminal plasma as well as the serum melatonin levels were studied in different infertile male groups and were correlated with their semen parameters and hormonal levels. One hundred twenty male cases subdivided into six equal groups were consecutively included; fertile normozoospermic men, oligoasthenozoospermia (OA), OA with leucocytospermia, OA with varicocele, non-obstructive azoospermia (NOA) with high serum follicle stimulating hormone (FSH) and NOA with normal FSH. Semen analysis, estimation of melatonin, FSH, testosterone (T) and prolactin (PRL) hormone was carried out. Mean level of serum melatonin was higher than its corresponding seminal concentrations in all investigated groups with a positive correlation between their levels (r = 0.532, p = 0.01). Serum and seminal plasma melatonin levels in all infertile groups were reduced significantly compared with their levels in the fertile group. The lowest concentrations were in OA with leucocytospermia group. Melatonin in both serum and semen demonstrated significant correlation with sperm motility (r = 607, 0.623 respectively, p = 0.01). Serum melatonin correlated positively with serum PRL (r = 0.611, p = 0.01). It may be concluded that melatonin may be involved in the modulation of reproductive neuroendocrine axis in male infertility. Also, low levels of melatonin in semen were observed in infertile groups having reduced sperm motility, leucocytospermia, varicocele and NOA.     

Assessment of seminal plasma laminin in fertile and infertile men

Aim： To assess laminin levels in the seminal plasma of infertile and fertile men, and to analyze the correlation of laminin levels with sperm count, age, sperm motility and semen volume. Methods： One hundred and twenty-five recruited men were equally divided into five groups according to their sperm concentration and clinical examination： fertile normozoospermia, oligoasthenozoospermia, non-obstructive azoospermia （NOA）, obstructive azoospermia （OA） and congenital bilateral absent vas deferens （CBAVD）. The patients＇ medical history was investigated and patients underwent clinical examination, conventional semen analysis and estimation of seminal plasma laminin by radioimmunoassay. Results： Seminal plasma laminin levels of successive groups were： 2.82 ± 0.62, 2.49 ± 0.44, 1.77 ± 0.56, 1.72 ± 0.76, 1.35 ± 0.63 U/mL, respectively. The fertile normozoospermic group showed the highest concentration compared to all infertile groups with significant differences compared to azoospermic groups （P 〈 0.05）. Testicular contribution was estimated to be approximately one-third of the seminal laminin. Seminal plasma laminin demonstrated significant correlation with sperm concentration （r = 0.460, P 〈 0.001） and nonsignificant correlation with age （r = 0.021, P = 0.940）, sperm motility percentage （r = 0.142, P = 0.615） and semen volume （r = 0.035, P = 0.087）. Conelusion： Seminal plasma laminin is derived mostly from prostatic and testicular portions and minimally from the seminal vesicle and vas deferens. Estimating seminal laminin alone is not conclusive in diagnosing different cases of male infertility.     

不育病人精浆胆固醇酯转运蛋白的检测

目的 :检测不育病人精浆胆固醇酯转运蛋白 (cholesterolestertransferprotein ,CETP)的含量 ,并探讨其与不育的关系。　方法 :随机选择 163例不育病人及 15例生育男性 ,行精液常规分析及精浆CETP浓度测定 ,其中5 5例不育病人同时测定了血清CETP含量。　结果 :不育病人及生育男性精浆CETP含量分别为 ( 2 .2 1± 1.2 3 )μg/L和 ( 1.40± 0 .45 ) μg/L ,两组间差异无显著性 (P >0 .0 5 ) ;在不育病人中 ,无精子症组 (n =2 9)、少弱精子症组(n =5 8)、少精子症组 (n =15 )、弱精子症组 (n =44 )及正常精子症组 (n =17)间CETP含量差异也无显著性 (P >0 .0 5 )。精浆平均CETP含量仅占血清的 1/ 10 0 0 ,不育病人精浆及其血清CETP含量间并无相关性 (r =0 .0 0 9,P>0 .0 5 )。　结论 :精浆CETP含量极低 ,与精子密度、活率的改变无关 ,可能保证了精子在未进入女性生殖道前膜结构与功能的完整性     

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.     

Designing the selenium and bladder cancer trial (SELEBLAT), a phase lll randomized chemoprevention study with selenium on recurrence of bladder cancer in Belgium

Background

Growing evidence indicates that oxidative stress can be a primary cause of male infertility. Non-enzymatic antioxidants play an important protective role against oxidative damages and lipid peroxidation. Human seminal plasma is a natural reservoir of antioxidants. The aim of this study was to determine glutathione (GSH) concentrations, trace element levels (zinc and selenium) and the lipid peroxidation end product, malondialdehyde (MDA), in the seminal plasma of men with different fertility potentials.

Methods

Semen samples from 60 fertile men (normozoospermics) and 190 infertile patients (74 asthenozoospermics, 56 oligozoospermics, and 60 teratozoospermics) were analyzed for physical and biochemical parameters. Zinc (Zn) and selenium (Se) levels were estimated by atomic absorption spectrophotometry. Total GSH (GSHt), oxidized GSH (GSSG), reduced GSH (GSHr) and MDA concentrations were measured spectrophotometrically.

Results

Zn and Se concentrations in seminal plasma of normozoospermics were more elevated than the three abnormal groups. Nevertheless, only the Zn showed significant differences. On the other hand, Zn showed positive and significant correlations with sperm motility (P = 0.03, r = 0.29) and count (P < 0.01, r = 0.49); however Se was significantly correlated only with sperm motility (P < 0.01, r = 0.36). GSHt, GSSG and GSHr were significantly higher in normozoospermics than in abnormal groups. We noted a significant association between seminal GSHt and sperm motility (P = 0.03). GSSG was highly correlated to sperm motility (P < 0.001) and negatively associated to abnormal morphology (P < 0.001). GSHr was significantly associated to total sperm motility (P < 0.001) and sperm count (P = 0.01). MDA levels were significantly higher in the three abnormal groups than in normozoospermics. Rates of seminal MDA were negatively associated to sperm motility (P < 0.01; r = -0.24) and sperm concentration (P = 0.003; r = -0.35) Meanwhile, there is a positive correlation between seminal lipid peroxidation and the percentage of abnormal morphology (P = 0.008).

Conclusions

This report revealed that decreased seminal GSH and trace element deficiencies are implicated in low sperm quality and may be an important indirect biomarker of idiopathic male infertility. Our results sustain that the evaluation of seminal antioxidant status in infertile men is necessary and can be helpful in fertility assessment from early stages.     

精浆催乳素浓度与精子计数、活动率的关系

对107例男性进行精液分析并测定其精浆催乳素(PRL)浓度,精子活动率和精子密度正常男性的精浆PRL为11.53±5.36ng/ml,与精子活动率正常而少精子的男性相比(13.06±4.62ng/ml),两组间无显著性差异(t=0.91,t>0.2);而精子密度正常、正常精子活率组和低活率组相比,低活率组的精浆PRL水平(17.24 ±5.86ng/ml)明显增高(t=4.15,P<0.001).相关分析表明精浆PRL与精子活动率呈负相关(r=-0.38,P<0.001);与精子密度亦呈负相关(r=-0.37,P<0.001).49例受试者取精液前抽血测定血清PRL水平,精浆PRL水平与血清PRL无关(r=0.204,P>0.1).     

Seminal plasma androgen/oestrogen balance in infertile men

The hypothesis that the balance between oestrogen and androgen in seminal plasma is important for normal fertility was investigated. We determined the concentrations of oestradiol and testosterone in blood and seminal plasma from 62 infertile men and 32 normozoospermic men. Infertile men were classified according to semen analysis (concentration, motility and morphology): asthenozoospermia, oligozoospermia and oligoteratoasthenozoospermia. Serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were determined in all participants. For all subjects, mean testosterone levels were lower and mean oestradiol were higher in seminal plasma than in blood. Seminal plasma testosterone levels were lower in the infertile groups vs. control men ( p < 0.0002). Oligpzoospermic and oligoteratoasthenozoospermic men had significantly higher seminal plasma oestradiol levels compared with controls ( p < 0.03). The three infertile groups had significantly lower seminal plasma testosterone/oestradiol ratio than control men ( p < 0.001). Sperm analysis data (concentration, motility and morphology) significantly correlated with seminal plasma testosterone/oestradiol ratio. The findings of elevated seminal plasma oestradiol, decreased testosterone and testosterone/oestradiol ratio in infertile men, and the significant correlation between hormone levels and sperm analysis data suggest that the local balance between androgen and oestrogen is important for spermatogenesis.     

Phospholipid composition of human sperm and seminal plasma in relation to sperm fertility

The phospholipid and fatty acid composition of sperm was studied in 8 healthy and 16 infertile men. Infertile men randomly formed from the patients with normal semen parameters according to WHO criterion. Therefore, all semen parameters of infertile patients were similar to the same characteristics of the semen of healthy men, except the abnormal forms. The amount of abnormal forms in infertile men was significantly higher than in healthy men. Sperm from infertile men show a drastic loss of phosphatidyl ethanolamine. At the same time, the significant increase of phosphatidyl serine in the sperm and seminal plasma of sterile patients was found. Lysophosphatidyl serine in the sperm of the infertile men was detected. Fatty acid composition of the semen of infertile men was altered. The levels of stearic and n-3 polyunsaturated fatty acids (eicosopentaenoic and docosahexaenoic acids) was dramatically lowered, but the values of some n-6 polyunsaturated fatty acids (linolenic and docosatetraenoic) acids increased. There was significant positive correlation between docosahexaenoic acid and sperm motility (r = .82, p < .001) and negative correlation between linolenic acid and spermatozoa motility (r = -0.58. p < .05). Infertility of men with normal semen quality can originate from the disorder of sperm lipid metabolism. The drastic loss of phosphatidyl ethanolamine and n-3 polyunsaturated fatty acids with simultaneous enhancement of phosphatidyl serine and some n-6 polyunsaturated fatty acids in sperm could be an important cause of male infertility.     

Seminal plasma transferrin concentration: relationship with seminal parameters and plasma hormone levels.

Seminal plasma transferrin concentrations were determined in 155 infertile male patients and in 15 pregnancy-proven fertile males (control group); then the relationship between these concentrations and seminal parameters and plasma hormone levels was investigated. The concentrations of seminal plasma transferrin in patients with a sperm concentration below 20 x 10(6)/ml were significantly lower than those in the control group (p < 0.01). There was no significant difference in seminal plasma transferrin concentration between patients with a sperm concentration of 40 x 10(6)/ml or more and the control patients. A positive correlation was observed between sperm concentration and seminal transferrin content (r = 0.56; p < 0.05). However, correlations between seminal transferrin concentration and sperm motility and between seminal plasma transferrin content and sperm morphology did not show any significance, nor did the seminal transferrin content correlate with plasma LH, FSH, prolactin or testosterone levels. It, therefore, seems that while transferrin is indicative of certain physiopathological conditions in the germ cells, this protein is not a distinctive marker of the fertility potential of an individual.     

Concentration of Calcitonin in Seminal Plasma of Infertile Men/Calcitonin-Konzentration im Spermaplasma von unfruchtbaren Männern

Calcitonin levels in peripheral plasma (8 cases) and seminal fluid (30 cases) were measured by direct Radioimmunoassay (RIA). Their relationship with seminal characteristics, calcium and swelling test were evaluated. Seminal plasma calcitonin averaged 7530 pg/ml which amounts to 142 times higher than that of serum averaging 53 pg/ml. There was no significant difference in the mean seminal plasma concentration of immunoreactive calcitonin (iCT) among normozoospermic, oligozoospermic and azoo-spermic groups. However, there was a significant difference (p less than 0.05) in the seminal plasma mean concentration between high and low motility groups. A significant correlation was found between iCT seminal plasma concentration and percent of motility (p less than 0.05), yet, no correlation was detected between iCT and other seminal characteristics including swelling test (p greater than 0.05). Seminal plasma calcium averaged 175.3 +/- 29.9 mg/L which was 1.75 times higher than that of the serum averaging 100.32 +/- 5 mg/L. No significant difference (p less than 0.05) was obtained between high and low motility groups as regard their calcium seminal plasma levels. A significant correlation was found between seminal plasma concentration of calcium and calcitonin (p less than 0.05), but not with the percent of motility (p less than 0.05). Calcitonin (CT) was present in seminal plasma in higher concentrations than those of serum, indicating its active secretion within the male accessory sex glands. The role of CT in human reproduction needs further elucidation, especially regarding sperm motility.     

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.     

Evaluation of tissue factor antigen level in human seminal plasma

We measured the seminal plasma levels of tissue factor (TF) and interleukin-6 (IL-6) in men and examined their relationship with sperm concentration and motility. The study comprised 71 patients in three groups: an infertile group with ( n=11) and without ( n=50) leukocytospermia and a fertile group ( n=10). The seminal plasma levels of TF were significantly higher in the infertile patients than in the fertile ones. The seminal plasma levels of both TF and IL-6 were significantly higher in the infertile patients with leukocytospermia than in those without leukocytospermia. In 54 nonazoopermic cases the seminal plasma levels of TF were significantly correlated with the sperm concentration and sperm motility. Further studies are necessary to clarify the role of TF in human fertilization.     

精浆游离L-肉毒碱水平及其与精子密度、活动率及活力的相关性研究

目的:研究正常生育及不育男性精浆中游离L-肉毒碱水平差异及其与精子密度、活动率(a+b+c级精子百分率)及活力(a+b级精子百分率)之间的相关性,探讨精浆中游离L-肉毒碱水平对男性生育力的影响及其在不育症检查和治疗中的作用。方法:分别采用高效液相色谱法和计算机辅助精液分析系统,测定了230例不育症患者(精子密度正常117例,少精子症81例,无精子症32例)和30例正常生育男性精浆中游离L-肉毒碱水平及精子密度、活动率、活力等参数。根据检查结果对不育症患者分组后,以SPSS12.0软件包进行统计学分析,比较各组间游离L-肉毒碱水平的差异以及游离L-肉毒碱水平与精子密度、活动率、活力之间的相关性。结果:正常生育组精浆游离L-肉毒碱水平明显高于不育组(P<0.01)。精液中精子密度越低、活力越弱,这种差异性越显著。相关性分析结果显示,精浆游离L-肉毒碱水平与精子密度呈显著正相关关系(r=0.521,P<0.01),与精子活动率和活力之间也具有正相关关系(r=0.319,P<0.01;r=0.251,P<0.01)。结论:精浆L-肉毒碱水平与精子密度、活动率和活力之间密切相关,其含量测定作为一项有用的生化指标,可为男性不育症检查及临床诊治和进行有关男性生殖功能机制研究提供参考。     

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。     

不育病人精浆前列腺特异性抗原的检测及意义

目的 :探讨不育病人精浆前列腺特异抗原 (PSA)检测的意义。　方法 :随机选择 85例不育病人 ,采用ELISA法检测不育病人精浆PSA水平 ,并分析其与精浆酸性磷酸酶 (ACP)、精子密度、活率之间的关系。　结果 :35例不液化病人、30例液化不全病人精浆PSA水平、ACP浓度、精子活率 (a +b +c级精子百分率 )均显著低于 2 0例液化正常病人 (P <0 .0 1) ;而精子密度则无差异 (P >0 .0 5 )。精浆PSA水平与精浆ACP浓度、精子活率显著正相关 (P<0 .0 1)。　结论 :精浆PSA水平与精液液化密切相关 ,其质和量的异常会使精子活率降低 ,从而导致男性生育力下降     

The influence of oxidative damage on viscosity of seminal fluid in infertile men

Increased oxidative damage has been suggested to play an important role in the viscosity changes of blood. However, changes in levels of oxidative damage products in semen and their relationship to seminal fluid viscosity are unknown. The aim of our study was to investigate whether oxidative damage was associated with seminal plasma viscosity in infertile subjects. The levels of malondialdehyde, and protein carbonyls were measured in sperm and seminal plasma from 102 individuals, including 60 infertile patients. Seminal fluid viscosity and semen viscosity were studied by use of capillary viscometer and glass pipettes, respectively. Significantly higher levels of oxidative stress and damage markers were found in subfertile subjects compared with the control subjects. The seminal fluid viscosities of patients were found to be significantly higher, although all of the control and patient subjects had normal viscoelasticity when semen samples were assessed according to World Health Organization guidelines. From Pearson correlation analysis, there were significant positive correlations between seminal fluid viscosity and seminal malondialdehyde and carbonyl levels in infertile males (r = .676, P < .01; r = .276, P < .05, respectively). Our results suggest that increased oxidative damage might be a factor for hyperviscosity of seminal plasma in infertile males.     

精浆和血清生殖激素与精液质量的关系

目的为了评估精液质量不同的男性精浆和血清生殖激素的浓度与精子浓度及活动力的关系,探索精浆与血清生殖激素的关系。方法对301名男性进行精液检查,按照精液的质量参数将受试对象分成4组:精液正常组(n=176),弱精子症组(n=66),少精子症组(n=40)和非梗阻性无精子症组(n=19)。采用电化学发光免疫法测定各组受试对象血清卵泡刺激素(FSH)、黄体生成素(LH)、泌乳素(PRL)、孕酮(P)、睾酮(T)和雌二醇(E2)六项生殖激素和精浆PRL、T、P和E2四项生殖激素的浓度,比较组间差异并进行相关性分析。结果精液正常组和弱精子症组血清FSH和E2的浓度显著低于少精子症组和非梗阻性无精子症组(P0.05),精液正常组血清LH和P的浓度显著低于弱精子症、少精子症和非梗阻性无精子症的人群(P0.05);而精液正常、弱精子症和少精子症三组精浆PRL的浓度则高于非梗阻性无精子症组(P0.05)。除了非梗阻性无精子症组,受试者血清FSH的浓度与其精子浓度呈负相关(r分别为-0.350、-0.273和-0.448,P0.05)。精液正常组精浆PRL的浓度和精子的浓度之间呈正相关(r=0.269,P0.05);在少精子症组中,亦有相同趋势的相关性(r=0.432,P0.05)。结论精浆PRL及血清FSH的浓度能够反映精子浓度或活动力,在男性不育的病因分析中具有一定的指导价值。     

Antioxidant activity of seminal plasma in fertile and infertile men

This study was conducted to evaluate and compare the total antioxidant capacity among fertile and infertile men. Thirty infertile patients and 20 fertility-proven healthy donors with normal sperm analysis were included in the study. Total antioxidant capacity, zinc and fructose levels of seminal plasma, and various sperm parameters were compared among fertile controls and idiopathic infertility patients prospectively. The mean antioxidant capacity of fertile controls (2.02 +/- 0.16 mmol/L) was significantly higher than that of the infertile patients group (1.78 +/- 0.23 mmol/L) (p < .01). Furthermore, asthenozoospermic and asthenoteratozoospermic groups had significantly lower mean antioxidant values (1.73 +/- 0.11 and 1.64 +/- 0.13, respectively) when compared to fertile control group (p < .01). The mean fructose level was significantly lower in the fertile control group and mean zinc level was significantly lower in the entire infertile group. On the other hand, antioxidant capacity is positively correlated to sperm motility (p = .001). Decreased antioxidant capacity was associated with impaired sperm function as a result of either increased ROS production or insufficient antioxidant capacity.     

Effect of smoking on seminal plasma ascorbic acid in infertile and fertile males

This work aimed to assess the relationship of seminal ascorbic acid levels with smoking in infertile males. One hundred and seventy men were divided into four groups: nonobstructive azoospermia [NOA: smokers (n = 20), nonsmokers (n = 20)]; oligoasthenozoospermia [smokers (n = 30), nonsmokers (n = 20)]; asthenozoospermia [smokers (n = 20), nonsmokers (n = 20)] and normozoospermic fertile men [smokers (n = 20), nonsmokers (n = 20)]. The patients underwent medical history, clinical examination, conventional semen analysis and estimation of ascorbic acid in the seminal plasma calorimetrically. There was a significant decrease in the mean seminal plasma ascorbic acid levels in smokers versus nonsmokers in all groups (mean +/- SD; 6.03 +/- 2.18 versus 6.62 +/- 1.29, 7.81 +/- 1.98 versus 9.44 +/- 2.15, 8.09 +/- 1.98 versus 9.95 +/- 2.03, 11.32 +/- 2.15 versus 12.98 +/- 12.19 mg dl(-1) respectively). Fertile subjects, smokers or not, demonstrated significant higher seminal ascorbic acid levels than any infertile group. Seminal plasma ascorbic acid in smokers and nonsmokers was correlated significantly with sperm concentration (r = 0.59, 0.60, P < 0.001), sperm motility (r = 0.65, 0.55, P < 0.001) and negatively with sperm abnormal forms per cent (r = -0.53, -0.50, P < 0.001). Nonsignificant correlations were elicited with semen volume (r = 0.2, 0.09) or liquefaction time (r = 0.03, 0.06). It is concluded that seminal plasma ascorbic acid decreased significantly in smokers and infertile men versus nonsmokers and fertile men, and is significantly correlated with the main sperm parameters: count, motility and normal morphology. Also, cigarette smoking is associated with reduced semen main parameters that could worsen the male fertilizing potential, especially in borderline cases.     

Beta-endorphin in serum and seminal plasma in infertile men

Aim:To access beta-endorphin levels in serum as well as seminal plasma in different infertile male groups.Methods:Beta-endorphin was estimated in the serum and seminal plasma by enzyme-linked immunosorbent assay(ELISA)method in 80 infertile men equally divided into four groups:non-obstructive azoospermia(NOA),obstructive azoosper-mia(OA),congenital bilateral absent vas deferens(CBVAD)and asthenozoospermia.The results were compared tothose of 20 normozoospermic proven fertile men.Results:There was a decrease in the mean levels of beta-endorphin in the seminal plasma of all successive infertile groups(mean±SD:NOA 51.30±27.37,OA 51.88±9.47,CBAVD 20.36±13.39,asthenozoospermia 49.26±12.49 pg/mL,respectively)compared to the normozoospermicfertile control(87.23±29.55 pg/mL).This relation was not present in mean serum level of beta-endorphin betweenfour infertile groups(51.09±14.71,49.76±12.4,33.96±7.2,69.1±16.57 pg/mL,respectively)and the fertilecontrol group(49.26±31.32 pg/mL).The CBVAD group showed the lowest seminal plasma mean level of beta-endorphin.Testicular contribution of seminal beta-endorphin was estimated to be approximately 40%.Seminal beta-endorphin showed significant correlation with the sperm concentration(r=0.699,P=0.0188)and nonsignificantcorrelation with its serum level(r=0.375,P=0.185)or with the sperm motility percentage(r=0.470,P=0.899).Conclusion:The estimation of beta-endorphin alone is not conclusive to evaluate male reproduction as there aremany other opiates acting at the hypothalamic pituitary gonadal axis.(Asian J Androl 2006 Nov;8:709-712)