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.     

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.     

精浆左旋肉碱与精子密度、活力和活动率关系的研究

目的:研究精浆中左旋肉碱浓度与精子密度、活力和活动率的相关性,探讨肉碱在男性不育发病中的作用。方法:分别选取精液常规检查结果为正常、少精、弱精和少弱精的不育患者12、16、20、16例,以液相色谱-质谱/质谱联用技术检测精浆中左旋肉碱浓度,以化学发光免疫分析法检测精浆中睾酮浓度,结果以SPSS15.0行双变量相关分析分析精浆中肉碱浓度与精子密度、活力和活动率的相关性,并以精浆睾酮浓度为控制变量行肉碱与精子密度的偏相关分析。结果:共有64例患者纳入研究,精浆中总肉碱浓度、游离肉碱浓度及酰基肉碱浓度分别为(91.33±40.49)mg/L、(40.89±24.13)mg/L、(50.44±21.90)mg/L;双变量相关分析结果为精浆中总肉碱浓度与精子密度、活力和活动率的相关系数分别为0.637(P<0.001),0.161(P=0.235),0.114(P=0.370),去除少精组后游离肉碱与活力和活动率的相关系数分别为0.325(P=0.024)和0.316(P=0.029);偏相关分析结果显示在剔除睾酮影响后的精子密度与肉碱的相关性仍有显著统计学意义(r=0.641,P<0.001)。结论:精浆中肉碱浓度与精子密度和活力呈正相关,其中与密度的相关性更明显。     

Serum levels of dimeric and monomeric inhibins and the degree of seminal alteration in infertile men with varicocele

The aim of the present study was to establish the serum levels of inhibins and their relationship with the degree of seminal alteration in infertile men. Thirty-six patients with varicocele (Va) and seven non-obstructive azoospermic men (Az) were included. The Va group was divided into two subgroups: Va I (sperm concentration: >20 x 106; n = 21) and Va II (sperm concentration: < 20 x 106; n = 15). Twelve fertile men were included as a control group (Co). Semen analysis and serum follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), inhibin B and Pro-alphaC levels were determined. Serum inhibin B and T levels were significantly lower and FSH and LH significantly higher in group Az when compared with the Co. Inhibin B was unable to differentiate Va I from Va II groups. However, in Va II an increase in FSH levels was observed. An inverse correlation between inhibin B and FSH, a direct correlation between inhibin B and testosterone, sperm concentration, motility and morphology were found. No such correlations were seen when only the Va group was analysed. The lack of correlation between serum levels of inhibin B, gonadotrophins, sperm concentration and seminal parameters observed in Va, adds other factor to the complex pathophysiology of varicocele. Finally, further studies are needed to elucidate if oligozoospermic patients with varicocele have also an impaired negative feed-back mechanism that regulates FSH synthesis and secretion.     

Serum leptin correlates in infertile oligozoospermic males

Leptin is an adipocyte-secreted protein that participates in the regulation of energy homeostasis. Eighty men were investigated; fertile normozoospermia as a control (n = 30) and infertile oligozoospermia (n = 50). The patients underwent estimation of body weight (kg), height (cm), calculation of body mass index (BMI), semen analysis, serum leptin and testosterone hormones. Mean body weight was significantly higher in infertile oligozoospermia compared with controls. Mean height, BMI and serum testosterone levels showed nonsignificant differences between the two groups. Infertile oligozoospermia had significantly higher mean serum leptin level than controls (mean +/- SD; 6.88 +/- 8.65, 16.3 +/- 13.98 ng ml(-1), P < 0.01). Serum leptin demonstrated significant positive correlation with age, body weight, BMI and significant inverse correlation with serum testosterone. It had nonsignificant correlation with the height and sperm concentration. These results are suggestive of a link between the adipocyte derived hormone, leptin and male reproduction.     

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     

不育男性抗苗勒管激素与生殖激素及精液质量参数关系的研究

目的探讨男性不育患者精浆和血清抗苗勒管激素(AMH)与血清生殖激素及精液参数之间关系。方法选取2018年9～12月于我院生殖中心就诊的男性不育患者107例,按照《世界卫生组织人类精液检查与处理实验室手册(第五版)》操作规范检测精液体积、精子浓度、前向运动精子(PR)百分比、精子顶体酶、精子DNA完整性、正常形态精子率,根据精液参数分为4组:少精子症组(n=15)、弱精子症组(n=26)、少弱精子组(n=31)、正常精子组(n=35),比较各组患者精浆和血清AMH及血清FSH、LH、催乳素(PRL)、T、E2之间的差异,并对精浆和血清AMH与生殖激素及精液参数的相关性进行统计分析。结果弱精子症组血清AMH水平高于其他3组,但各组间差异无统计学意义(P>0.05);正常精子组精浆AMH水平[中位数(四分位距)]为1.28(7.71)ng/ml,显著高于少精子症组[0.11(1.26)ng/ml]和少弱精子组[0.16(2.15)ng/ml](P<0.05)。相关性分析显示,血清AMH与生殖激素及精液参数不存在相关(P>0.05);精浆AMH与血清FSH、LH呈负相关(P&...     

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)     

Seminal reactive oxygen species‐antioxidant relationship in fertile males with and without varicocele

The aim of this study was to assess seminal reactive oxygen species (ROS)‐antioxidants relationship in fertile and infertile men with and without varicocele. One hundred and seventy six males were studied; fertile healthy volunteers (n = 45), fertile men with varicocele (n = 45), infertile oligoasthenozoospermia (OA, n = 44) without varicocele and infertile OA with varicocele (n = 42). In their seminal plasma, two ROS parameters (malondialdehyde, hydrogen peroxide) and five antioxidants (superoxide dismutase, catalase, glutathione peroxidase, vitaminE, vitaminC) were estimated. Compared with fertile healthy men, in all other studied groups, estimated seminal ROS were significantly higher and estimated antioxidants were significantly lower. Infertile men with varicocele showed the same relationship as infertile men without varicocele. Sperm concentration, total sperm motility as well as sperm normal forms were negatively correlated with seminal malondialdehyde and were positively correlated with vitaminC. It is concluded that varicocele has an oxidative stress (OS) in fertile normozoospermic bearing conditions. This may allow understanding that, within men with varicocele, there is a threshold value of OS over which male fertility may be impaired.     

生精片对男性少弱精子症患者精液参数的影响及作用机制研究

目的:观察生精片治疗男性少弱精子症患者的临床有效性,并对其作用机制进行探讨。方法:选取少弱精子症患者120例,采取随机对照研究的方法,治疗组口服生精片,对照组服用维生素E,服用12周后,观察治疗前后两组精子浓度、精子活力及正常形态精子百分率,血清FSH、T、LH水平,DNA碎片指数,低渗肿胀精子百分率,精浆弹性蛋白酶、α-葡糖苷酶、精子顶体酶、果糖及精浆锌等指标变化。结果:生精片能显著改善精子浓度、活力和形态(P<0.01),血清FSH水平明显降低,T明显升高(P<0.01),DNA碎片指数明显降低,低渗肿胀精子百分率显著升高,弹性蛋白酶明显降低,α-葡糖苷酶、精子顶体酶、果糖、精浆锌等水平明显升高。结论:生精片通过多层次、多环节、多途径改善少弱精子症患者的精液参数,具有良好的临床疗效。     

Varicocele ligation on free testosterone levels in infertile men with varicocele

We have analyzed the effects of varicocele ligation on free testosterone levels, and investigated the interrelationships between free testosterone and fertility. The records were retrospectively evaluated for 42 infertile patients who underwent varicocele ligation, with serum free testosterone levels, follicle stimulating hormone (FSH), lutenizing hormone (LH), testosterone, estradiol, prolactin, ejaculated volume, sperm concentration and motility before and after surgery. Serum free testosterone levels increased from 12.97+/-4.16 to 13.59+/-3.93 pg/mL, but the difference was insignificant. The differences before and after surgery of patients in sperm concentration and motility were also insignificant. However, in free testosterone increasing group, the sperm concentration and motility increased significantly, from 4.05+/-4.35 to 7.90+/-8.19 million/mL (P=0.01) and from 30.64+/-21.87% to 41.00+/-22.00%, respectively (P=0.03). The increase in serum free testosterone level by varicocele ligation results in a significant improvement in sperm concentration and motility.     

少弱精子症和正常生育男性精液中尿激酶及其受体含量的研究

目的:通过研究精子正常和异常男性精浆和精子中尿激酶及受体含量差异,以了解尿激酶及受体与男性生育力的关系。方法:采用双抗体夹心ELISA法测定22例正常生育男性和44例少弱精子症男性精浆和精子中尿激酶及受体的含量。结果:①正常男性精浆尿激酶平均含量为(4 803.69±602.78)mU/L,与少弱精子症组[(4 061.35±736.23)mU/L]相比,差异有显著性(P<0.01)。正常生育男性精子尿激酶平均含量为(30.29±3.16)mU/106个精子,与少弱精子症组[(20.51±4.2)mU/106个精子],差异有显著性(P<0.01)。②正常生育男性精子尿激酶受体平均含量为(12.97±3.11)mU/106个精子相比,与少弱精子症组[(6.09±1.45)mU/106个精子]相比,差异有显著性(P<0.01)。③精子和精浆中尿激酶含量和精子活率和活力呈显著正相关。结论:尿激酶和男性生育力相关,少弱精子症和正常生育男性精液中尿激酶及其受体含量存在差异。     

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.     

Oxidative stress in normospermic men undergoing infertility evaluation

The purpose of this study was to determine whether normospermic infertile men have high seminal oxidative stress, using 3 measures of oxidative stress: reactive oxygen species (ROS), total antioxidant capacity (TAC), and a composite ROS-TAC score. Forty-three normospermic men without leukocytospermia and 19 healthy donors who came to our infertility clinic were included. Patients were categorized into 3 groups: group I, varicocele and no female factor (n = 16); group II, positive female factor (n = 16); and group III, idiopathic infertility (n = 11). In addition, 52 treated male factor patients and 19 donors were included as reference groups. We measured seminal ROS, TAC, and the ROS-TAC score in the patient groups and the controls. Normospermic infertile patients as a group had higher ROS levels (mean log [ROS + 1] 1.76 +/- 0.13) compared with controls (1.39 +/- 0.16; P = .03). Patients in the idiopathic subgroup had significantly higher ROS levels (2.29 +/- 0.25; P = .004) than controls. Normospermic infertile patients as a group not only had reduced TAC levels (970.18 +/- 73.95 Trolox equivalents), but each subgroup also had significantly lower TAC than controls (1650.93 +/- 95.87; P < .003). The ROS-TAC scores in all normospermic infertile patients as a group (35.7 +/- 1.8) as well as in each subgroup was significantly reduced compared with the ROS-TAC levels in the controls (50.0 +/- 2.1; P < .005). We conclude that oxidative stress is associated with male factor infertility. The presence of oxidative stress in infertile normospermic men may explain previously unexplained cases of infertility otherwise attributed to female factors.     

Relationship between seminal plasma interleukin-6 and tumor necrosis factor alpha levels with semen parameters in fertile and infertile men

The levels of two proinflammatory cytokines, namely tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6), were investigated in seminal plasma (SP) of proven fertile (n=24) and infertile (n=55) men to evaluate the relationship between diagnosis and semen parameters in a prospective study. Infertile men were divided into four groups as follows: (1) varicocele (n=23), (2) 3 months after varicocelectomy (post-varicocele, n=14), (3) male accessory gland infection (MAGI, n=10) and (4) bilateral testicular atrophy (n=8). IL-6 and TNF-alpha levels were similar in the SP of fertile and infertile men. There was a strong correlation between the levels of TNF-alpha and IL-6 in all groups (P<0.001). IL-6 levels were not correlated with seminal parameters (P>0.05). TNF-alpha levels were negatively correlated with the sperm motility and morphology (P<0.05), but there was no correlation with total sperm counts (P>0.05). The mean levels of IL-6 in the SP of the MAGI group was higher than in the other groups but did not reach statistical significance. No variation was found in the SP levels of the proinflammatory cytokines studied between the varicocele and the post-varicocele groups. Our results suggest that IL-6 and TNF-alpha are involved in male fertility. However, their measurement in SP seem to be unsuitable for routine infertility work, perhaps with the exception of men with inflammatory genital diseases.     

Serum levels of inhibin B in men with different causes of spermatogenic failure

Inhibin B appears to be the physiological feedback signal for FSH. Herein the determination of serum levels of inhibin B, FSH, LH and testosterone in 148 infertile patients and their association with clinical findings and seminal parameters are reported. A significant negative correlation of FSH and inhibin B (r = -0.60) was found. LH levels showed a significant inverse correlation (r = 0.37), but a weak regression (c0 = 0.01). No correlation with testosterone levels occurred. A significantly positive correlation was observed between testis volume and inhibin levels (r = 0.39) as well as between sperm count and inhibin levels (r = 0.39). To evaluate whether the secretion of inhibin B depends on the nature of damage to the Sertoli cells, inhibin levels in 23 patients with varicocele; eight after cryptorchidism, and 16 after hemiorchiectomy were compared to those of other patients without these diseases, but identical sperm count. No significant differences were found. In 20 men undergoing testicular biopsy, inhibin levels were compared to histology. Although the men with Sertoli-cell-only syndrome had significantly lower levels ((15.83 +/- 12.2) pg ml-1) than those with normal spermatogenesis ((183.8 +/- 112.3) pg ml-1), a distinction between patients with hypospermatogenesis from those with normal spermatogenesis was not possible on the basis of inhibin levels. Between these groups, the distinction was better achieved by the FSH levels (sensitivity of 85%). We conclude that inhibin B levels are a serum marker of Sertoli cell function, but the prediction of the quality of spermatogenesis is not superior to that of FSH levels.     

精索静脉曲张不育患者精浆颗粒溶素与精液质量的相关性分析

目的探讨颗粒溶素在精索静脉曲张(VC)患者精液的表达水平及临床意义。方法选择2016年9月至2017年7月在本院就诊的80例男性不育患者作为观察组,其中45例为原发性VC(VC不育组),35例患者不合并VC(非VC不育组)。同时,本研究选取30例健康男性为可育对照组。检测所有入组精液精子密度、精子活动率、精子正常形态比例以及颗粒溶素的表达水平。结果VC不育患者精浆颗粒溶素的表达水平均显著高于可育对照组;此外,与非VC不育患者相比较,VC不育患者精浆颗粒溶素水平更高;精浆颗粒溶素的表达与精子浓度(r=-0.364,P<0.001)、精子活力(r=-0.397,P<0.001)和精子正常形态(r=-0.441,P<0.001)均呈负相关。结论不育合并VC患者精浆颗粒溶素表达水平显著高于正常健康人群,且其表达水平与VC等级密切相关。     

精索静脉曲张不育症的内分泌变化

受试者有正常对照(12人),以及精索静脉曲张不育症精子减少(20人)和精子无力(12人)三组,分别用放免法测定血清积精液中的睾酮、双氢睾酮、促黄体生成素及促滤泡成熟激素。结果雄激素稍有降低,促黄体生成素和促滤泡成熟激素均有增高,尤以后者变化显著。本文对精索静脉曲张不育症的内分泌变化,精索静脉曲张引起的睾丸病变和功能损害,以及精索内静脉高位结扎治疗精子减少有较明显效果等问题进行讨论。     

Hormonal and Seminal Parameters in Infertile Men

500 infertile patients (250 with and 250 without left side varicocele) and 33 fertile men were evaluated as far as seminal parameters and the hormonal status were concerned. Sperm motility was constantly lower in infertile patients also when infertile group was compared to fertile one with the same sperm density. Serum testosterone levels were lower in infertile groups when compared to fertile men, and this confirms the existence of an androgenic deficit as a common finding in infertility associated or not to varicocele. FSH and LH increased (p less than 0.001) when sperm density dropped to less than 5 X 10(6) spermatozoa/ml. A negative correlation was found between both gonadotropins and sperm count (p less than 0.001), also after exclusion of azoo- and oligozoospermic (less than 5 X 10(6) spermatozoa/ml) patients (p less than 0.01). Gonadotropins were moreover tightly correlated between each other (p less than 0.001). Our data suggest that both gonadotropins are tightly tuned with sperm output and thus with the spermatogenic potential.