External factors affecting fertility, and how to correct their impact.

Fertility of both men and women has been negatively influenced by external factors and life style in recent decennia. Mechanisms of hormone disruption, oxidative damage, and epigenetic DNA changes play a pivotal role in this process. In Belgium, strict regulations have been imposed to reduce the exposure to xeno-estrogens, which has resulted in a partial recovery of sperm quality. At the other hand, more couples require in vitro fertilisation (IVF) whereby ovarian stimulation may be associated with epigenetic DNA hyper-methylation of follicular cells, and increased risk of carcinogenesis among offspring. In order to reduce the health risks for the offspring it is recommended to optimize the oxidative, epigenetic and metabolic situation of both parents by means of lifestyle adaptation, and the use of appropriate food supplementation before conception and during pregnancy.

Hormones, herbal preparations and nutriceuticals for a better life after the menopause: part I.

In developed countries, women spend more than one-third of their life in the menopause and at least half of them experience vasomotor symptoms that impair their normal function and well-being. Long-term estrogen replacement therapy (HRT) with estrogen can suppress typical menopausal symptoms and prevents osteoporosis. When estrogen-only HRT is started within 10 years after the menopause, the prevalence of cardiovascular disease is reduced, mortality is lower, and the risk of breast cancer is not significantly increased. Postmenopausal genital and urinary problems with recurrent infections, incontinence, and dyspareunia can effectively be treated by vaginal application of estriol, which seems to be safe for women treated for breast cancer. HRT after the age of 60 years is associated with a lower number needed to treat than number needed to harm, implying that there would be one unfavorable side-effect for up to ten women experiencing a positive effect. However, further studies are needed regarding the risk-benefit ratio of HRT in women over 70 years. It is concluded that transdermal substitution therapy with estradiol may increase the number of quality-adjusted life years of postmenopausal women. The combination with nutriceutical food supplementation may add to this benefit, but complementary prospective trials are still needed.

Hormones, herbal preparations and nutriceuticals for a better life after the menopause: part II.

Long-term estrogen replacement therapy with estrogen has benefits for many postmenopausal women. However, some women prefer non-steroidal substitution with herbal preparations. The effectivity against vasomotor symptoms has been evidenced for the extracts of pine bark, of linseed and of Lepidium meyenii (Maca), whereas there is controversy about the effectiveness of genistein-rich soy extract. The extracts of cruciferous vegetables such as Broccoli and of linseed induce changes in the metabolism of estrogens, and antioxidants may reverse altered epigenetic DNA methylation, possibly reducing the risk of breast cancer or its recurrence. Indirect evidence from the literature and from clinical trials supports that a nutriceutical composed of plant extracts, low-dose vitamins and minerals may improve the quality of life by delaying certain age-related diseases. On the basis of epidemiologic studies, physiopathological considerations and controlled prospectieve trials, it is suggested that transdermal substitution therapy with estradiol together with nutriceutical food supplementation may increase the number of quality-adjusted life years of postmenopausal women, but complementary, large-scale, prospective trials are still needed.

Canine hip dyslasia: the significance of the Norberg angle for healthy breeding.

OBJECTIVES: To assess the reproducibility of the Fédération Cynologique Internationale (FCI) classification over time, and between assessors and to evaluate the benefit of computer-assisted measurement of the Norberg angle and of its percentile ranking by breed for the diagnosis of canine hip dysplasia, and for the selection of couples for breeding. METHODS: During the time period of 2006 to 2010, 5094 hip radiographs were evaluated according to the FCI rules, and 4400 have been submitted for statistical analysis. A system of computer-assisted image analysis (Digimizer(®) , MedCalc Software Ltd, Mariakerke, Belgium) was used to measure the Norberg angle. The Norberg angle value of individual dogs was expressed as percentile rank by breed. RESULTS: The agreement between individual assessors was highly significant (P<0·001), but there were important variations over time of the ratio of classes A or B. The Norberg angle and the percentile rank accurately discriminated between dogs with or without canine hip dysplasia, with positive and negative likelihood ratios of 6·31 and 0·21, respectively, for the Norberg angle at criterion value of 102·2°, and 4·21 and 0·18 for the percentile rank at criterion value of the 25th percentile. CLINICAL SIGNIFICANCE: The percentile rank of the Norberg angle may be a valuable tool for breeding selection.

Combined conventional/antioxidant "Astaxanthin" treatment for male infertility: a double blind, randomized trial.

AIM: To evaluate the treatment of male infertility with a strong natural antioxidant, in addition to conventional treatment. METHODS: Using a double blind, randomized trial design, 30 men with infertility of > or =2 months and female partners with no demonstrable cause of infertility received conventional treatment according to the guidelines of the World Health Organization (WHO), and either a strong antioxidant Astaxanthin 16 mg/day (AstaCarox, AstaReal AB, Gustavsberg, Sweden) or placebo for 3 months. The effects of treatment on semen parameters, reactive oxygen species (ROS), zona-free hamster oocyte test, serum hormones including testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH) and Inhibin B, and spontaneous or intrauterine insemination (IUI)-induced pregnancies were evaluated. RESULTS: ROS and Inhibin B decreased significantly and sperm linear velocity increased in the Astaxanthin group (n = 11), but not in the placebo group (n = 19). The results of the zona-free hamster oocyte test tended to improve in the Astaxanthin group in contrast with the placebo group, though not reaching statistical significance. The total and per cycle pregnancy rates among the placebo cases (10.5 % and 3.6 %) were lower compared with 54.5 % and 23.1 % respectively in the Astaxanthin group (P = 0.028; P = 0.036). CONCLUSION: Although the present study suggests a positive effect of Astaxanthin on sperm parameters and fertility, the results need to be confirmed in a larger trial before recommending Astaxanthin for the complementary treatment of infertile men.

Testicular volume in relation to hormonal indices of gonadal function in community-dwelling elderly men.

Aging is accompanied by involutional changes in testicular function; limited data suggest a decrease in bilateral testicular volume (BTV). We studied BTV by ultrasonography in relation to serum gonadal hormones in 115 healthy elderly men (median age, 78 yr) and 42 young men (median age, 26.5 yr). Elderly men had a clearly smaller BTV (mean, 20.6 vs. 29.7 ml; P < 0.001), whereas serum inhibin B was slightly but significantly decreased (mean, 176.8 vs. 212.8 ng/liter; P = 0.04); lower values in the elderly were observed for bioavailable (Bio) testosterone (T), Bio 17 beta-estradiol, inhibin B/FSH (mean, 18 vs. 58 ng/mU; P < 0.001), and T/LH ratios. In the elderly and the young, respectively, BTV was associated with inhibin B (r = 0.53, P < 0.001; r = 0.41, P < 0.01), FSH (r = -0.53, P < 0.001; r = -0.48, P < 0.01), and inhibin B/FSH ratio. Only in the old men was BTV significantly associated with LH (r = -0.32; P < 0.001), Bio T (r = 0.26; P < 0.01), and T/LH (r = 0.48; P < 0.001). In a multivariate analysis, FSH, inhibin B, and Bio T were independently associated with BTV in the elderly (R(2) = 0.34). Receiver operating characteristics curve analysis indicated that BTV at a criterion value of 14.3 ml had a sensitivity of 46% and a specificity of 79% to predict low serum Bio T levels in the elderly. In conclusion, the moderately decreased BTV observed in elderly men, strongly associated with a decrease of the inhibin B/FSH ratio, is consistent with a reduced Sertoli cell mass, compensated by increased FSH stimulation resulting in only limited decrease of Sertoli cell function. Finding of a low testicular volume in elderly men can contribute to the diagnosis of hypogonadism, but this criterion has low sensitivity to detect decreased T production.

The effects of combined conventional treatment, oral antioxidants and essential fatty acids on sperm biology in subfertile men.

We evaluated the effects of combined conventional treatment, oral antioxidants (N-acetyl-cysteine or vitamins A plus E) and essential fatty acids (FA) on sperm biology in an open prospective study including 27 infertile men. The evaluation included sperm characteristics, seminal reactive oxygen species (ROS), FA of sperm membrane phospholipids, sperm oxidized DNA (8-OH-dG), and induced acrosome reaction (AR). Treatment did not improve sperm motility and morphology, nor decrease the concentration of round cells and white blood cells in semen. Sperm concentration increased in oligozoospermic men (7.4+/-1.3 to 12.5+/-1.9 million/ml). Treatment significantly reduced ROS (mean+/-SEM) (775.3+/-372.2 to 150.3+/-105.2 x 10(3)counts/10 second) and 8-OH-dG (45.3+/-10.4 to 16. 8+/-3.3 fmol/microg DNA). Treatment increased the AR (55.1+/-2.2 to 71.6+/-2.2%), the proportion of polyunsaturated FA of the phospholipids, and sperm membrane fluidity. The overall pregnancy rate was 4.5% in 134 months. The per month pregnancy rate tended to be higher in partners of (ex)-smokers (7.15%, n=14,70 months) than in never-smokers (1.6%, n=13,64 months) (OR:4.57, 95% Cl:0.55-38.1).

Serum inhibin B levels in community-dwelling elderly men.

BACKGROUND AND OBJECTIVE: Ageing in men is accompanied by a decline of Leydig cell function, with a 50% decrease of the population means for serum free testosterone between age 25 and 75 years. Information on Sertoli cell function and spermatogenesis in the elderly is scarce. Studies on seminal parameters in ageing men have suggested that spermatogenesis may be fairly well maintained in the elderly, but they included mostly selected subjects and only few men over 60 years. More systematic studies are lacking. The aim of the present study was to assess serum inhibin B levels in elderly men as an index of global Sertoli cell function and spermatogenic activity. SUBJECTS AND MEASUREMENTS: Specific immunoassays were used to determine serum levels of inhibin B, gonadotrophins, testosterone and oestradiol in blood obtained between 0800 and 1000 h. from 189 ambulatory, community-dwelling elderly men (age: 70-85 years) and, for comparison, from 51 middle-aged (35-54 years) and 50 young (< 35 years) controls. RESULTS: All age groups combined, serum inhibin B was only weakly negatively correlated to age (Spearman correlation coefficient: - 0.17; P < 0.01) and more strongly to serum FSH (- 0. 52; P < 0.001). In a multiple regression analysis serum FSH, but not age or serum free testosterone, emerged as an independent determinant of serum inhibin B levels. An age-related decline of median inhibin B levels in the study population was essentially limited to the younger age groups, with stable levels between age 35 and 79 years, and only a modest further decrease thereafter. There was a progressive age-related increase of serum FSH across age groups with, consequently, a marked decrease of the serum inhibin B : FSH ratio. The prevalence of men presenting with low serum inhibin B (below 10th percentile for inhibin B levels in men < 35 years), indicative of deficient Sertoli cell function and spermatogenesis, increased most strikingly between men < 35 years and those 35-54 years, which contrasts with the more progressive increase at an older age of the prevalence of low serum (free) testosterone. CONCLUSION: Global testicular Sertoli cell function and spermatogenic activity, as assessed indirectly through serum inhibin B levels, appear to be well maintained in ambulatory elderly men, albeit there are age-related alterations at the level of the Sertoli cells as indicated by a progressive increase of testicular drive by pituitary FSH.

Mechanisms and effects of male genital tract infection on sperm quality and fertilizing potential: the andrologist's viewpoint.

There are several mechanisms acting in synergism that can impair sperm characteristics of patients with accessory gland infection. In some cases, conventional sperm variables are disturbed with oligo and/or asthenozoospermia. In other patients, these sperm variables may appear normal, but the functional capacity of spermatozoa may be impaired. In particular, changes in the composition of the sperm membrane may result in reduced acrosome reactivity and capacity to fuse with the oolemma, and oxidative damage of the sperm DNA may induce mutagenesis. Changes in the biochemical make-up of seminal plasma can also reduce the in-vivo fertilizing capacity of spermatozoa, and infection-related disruption of the blood-testis barrier can induce the generation of anti-sperm antibodies and immunological infertility. Many of these functional abnormalities will not become evident upon 'basic semen analysis', which explains why some authors are unable to link infection of the accessory sex glands to subfertility. Also, functional and anatomical damage acquired as a result of infection is often permanent and not reversible by (antibiotic) treatment. Clearly, there are many more aspects of male accessory gland infection that require investigation. Available data should stimulate clinicians to place more emphasis on the prevention of infection-related infertility than on its treatment, as the latter is often unsuccessful.

[A strategy for the prevention of male infertility]. / Een strategie voor de preventie van mannelijke infertiliteit.

Since 1990 there has been a simultaneous reduction of natality in Flanders (by approximately 12%) with increased demand for assisted reproduction, while sperm quality, mostly motility and morphology, have clearly deteriorated over recent decades. This evolution has been ascribed to the deleterious effects of hormone disrupting substances in the environment, synergistically enhancing unfavorable influences from life style and possible genito urinary diseases that can impair the function of the testes and accessory sex glands. It is probable that this synergistic effect is exerted through the intermediate of free oxygen radicals (also called reactive oxygen species) that damage both the sperm membrane and sperm DNA, which could allow certain minimal inborn genetic defects (such as point lesions) to come to expression. Both pseudo- or xeno-estrogens (such as certain organo chlorides, alkyl phenols, phthalates, etc.) and anti-androgens are held responsible for prenatal testicular damage and increased prevalence of testicular carcinoma and oligozoospermia, for anatomical malformations, as well as postnatal depression of testicular function and spermatogenesis. However, methods presently available to detect hormone disrupters are tedious and not fully adequate. A first strategic goal is to develop a simple method for the detection of these substances so that environmental pollution can be mapped. Fazing out the production and application of hormone disrupters, and removing them from the environment are the second strategic step. Also, a health food is being developed that will inhibit the absorption of these chemicals from the intestinal tract. In addition it is projected to detect and treat common genital diseases that can cause infertility, such as varicocele and infection of the urinary tract and accessory sex glands. The first could be organized to take place during medical examinations at school, whereas the second requires correct medical treatment of any cysto urethritis in adolescents. Non surgical treatment of varicocele by means of transcatheter embolization offers a cost effective approach, with minimal risk and complications, and high level of efficacy. Improving food quality and educational efforts aimed at a healthier life style should score high priority. The suggested strategy uses several entries in order to address the multifactorial mechanisms involved in the pathogenesis of male infertility. Preliminary epidemiological and biological data suggest that the proposed strategy can, indeed, be successful within a relatively short lapse of time.

Hormonal regulation of inhibin B secretion by immature rat sertoli cells in vitro: possible use as a bioassay for estrogen detection.

The influences of follicle-stimulating hormone (FSH), gonadal steroids, and culture time were studied in relation to inhibin B production by Sertoli cells of immature rats cultured in vitro. Sertoli cell-enriched cultures were established from 18-day-old rats and were maintained in medium supplemented with insulin, transferrin, and epidermal growth factor at 34 degrees C. A recently developed ELISA for the measurement of inhibin B was used to assess the effects of recombinant human FSH (rh FSH), testosterone (T), and estradiol (E2) on inhibin B production and accumulation in the culture media of Sertoli cell-enriched cultures and to optimize the cell culture system to serve as a bioassay for the detection and quantification of estrogens and estrogenlike substances. Prolonging the incubation time (24, 48, or 72 hours) of Sertoli cells with control medium without rh FSH, T, or E2 resulted in a time-dependent increase of inhibin B production. Incubation with rh FSH (1, 2.5, 5, or 10 U/L) caused a dose- and time-dependent increase of inhibin B production by Sertoli cells (but not by cultured Leydig cells), reaching a plateau at 5 U/L rh FSH. Addition of T in concentrations of 2.88, 5, or 50 ng/ml to medium without rh FSH and E2 significantly lowered the daily production rate of inhibin B (P < 0.05). In contrast, addition of E2 (0.01 and 0.1 ng/ml) caused a dose-responsive increase in inhibin B production after 24 and 48 hours. The relative increment of inhibin B production induced by E2 was maximal after 24 hours in the presence of 2.5 U/L rh FSH (acting synergistically) and in the absence of T. When these conditions are implemented, the Sertoli cell culture system may serve as a bioassay for estrogenic substances, and it may reflect the possibly harmful effect they may have on spermatogenesis.

The correlates and alleged biochemical background of the resazurin reduction test in semen.

Reduction of the blue dye resazurin to pink resorufin is used to estimate the concentration of metabolically active spermatozoa in semen samples. In order to quantify the reduction of resazurin, a spectrophotometric method was developed measuring the change from blue to pink in the butanol extracted colour. The biochemical mechanisms involved in the reduction of resazurin by motile spermatozoa and seminal plasma were investigated. Addition of NADH + H+ to sperm suspension or seminal plasma increased the reduction of resazurin. The reduction reaction was inhibited by high concentrations of dicoumarol, a specific inhibitor of the diaphorase enzyme, in a dose-dependent manner. It is suggested that the sperm diaphorase enzyme transfers electrons from NADH + H+ to resazurin, reducing it to resorufin. The degree of resazurin reduction was strongly correlated with the concentration of motile spermatozoa recovered from the 90% Percoll fraction (r = 0.98, p < 0.001). A positive correlation was also found between the reducing capacity of seminal plasma (n = 62) on the one hand, and sperm concentration (r = 0.72, p < 0.0001), progressive motility (r = 0.45, p < 0.01), normal morphology (r = 0.50, p < 0.01), and gamma-glutamyltransferase (r = 0.36, p < 0.05) on the other hand. These findings, together with our previous observations that the reduction reaction is inhibited by reactive oxygen species and polymorphonuclear white blood cells, increase our understanding of the biochemical basis of the resazurin test and may provide better insight into the interpretation of this test.

White blood cells cause oxidative damage to the fatty acid composition of phospholipids of human spermatozoa.

The lipid composition of the sperm membrane has been shown to exert a significant effect upon the functional quality of spermatozoa. We have studied the effect of induced peroxidation and of the presence of polymorphonuclear white blood cells (WBCs) on the fatty acid composition of the phospholipids of human spermatozoa. The spermatozoa were fractionated by a discontinuous Percoll gradient in two fractions (47% and 90% Percoll). Induced peroxidation of spermatozoa was assessed by determining the production of thiobarbituric acid reactive substances (TBARS), mostly malondialdehyde, after incubation with ferrous sulphate and sodium ascorbate as a promoter of peroxidation. TBARS production after induction of peroxidation was correlated with the abundance of polyunsaturated fatty acids (PUFA)(r = 0.68, p < 0.0001), with the double bond index (r = 0.72, p < 0.0001), and with the oxidative potential index (r = 0.73, p < 0.0001) of fatty acids of phospholipids. In comparison with samples containing > 1 x 10(6) WBCs/mL, those with < 1 x 10(6) WBCs/mL contained higher proportions of PUFA (90% Percoll, p < 0.05; 47% Percoll, p < 0.05), total omega 3 fatty acids (90% Percoll, p < 0.05; 47% Percoll, p < 0.001), docosahexaenoic acid (90% Percoll p < 0.05; 47% Percoll, p < 0.05), and double bond index (90% Percoll, p < 0.05; 47% Percoll, p < 0.001). In addition, mean melting point was significantly lower (90% Percoll, p < 0.05; 47% Percoll, p < 0.001) in samples with < 1 x 10(6) WBCs, indicating higher membrane fluidity. The increase of TBARS production by spermatozoa after incubation with the xanthine-xanthine oxidase system and/or ferrous sulphate as promoter of peroxidation was associated with a significant decrease of PUFA. Incubation of spermatozoa with WBCs, with or without activation by phorbol ester, decreased the PUFA (p < 0.05). Also, TBARS production was increased (p < 0.01) after activation of WBCs with phorbol ester. Our data provide evidence that oxidative stress induced by WBCs has a damaging effect on the polyunsaturated fatty acids of sperm phospholipids which may result, amongst other effects, in decreased membrane fluidity.

Performance of the sperm quality analyser in predicting the outcome of assisted reproduction.

The present study was undertaken to assess the relationship between the results of conventional semen analysis and the sperm motility index (SMI) as measured by the sperm quality analyser (SQA), and to evaluate these in relation to the fertilization and/or pregnancy outcome of assisted reproduction. SMI determinations and conventional semen analyses were performed on 223 samples from subfertile men in two laboratories in Leuven (n = 136) and Antwerp (n = 87), and on spermatozoa prepared on a Percoll gradient (n = 136) used for treatment of male factor infertility in 57 cycles of intrauterine insemination (IUI), 44 attempts at in vitro fertilization (IVF) and 31 attempts at intracytoplasmic sperm injection (ICSI). SMI values for native semen correlated significantly with sperm concentration, motility and morphology. Multiple regression analysis revealed sperm concentration after preparation, and the concentration of motile spermatozoa with normal morphology and SMI (before preparation) to be the independent determinants for SMI after preparation. SMI values were significantly higher after, than before, preparation (p < 0.0001). In regular IVF (n = 44) the percentage of fertilized oocytes correlated significantly (p < 0.05) with sperm motility (A + B%, r = 0.33), with the percentage of spermatozoa with normal morphology (r = 0.46) before preparation, with the values of SMI both before and after preparation (r = 0.54, r = 0.48), with sperm concentration (r = 0.34) and with the motile sperm concentration (r = 0.29) after preparation. For the occurrence of pregnancy (all treatment methods), comparison of areas under ROC curves (AURC) indicated motile sperm concentration after preparation, as well as SMI both before and after preparation, to have the highest AURC, with no significant difference between these values as far as predictive power was concerned. These results indicate that the SQA allows for rapid evaluation of sperm characteristics and of the effectiveness of sperm preparation techniques. However, it is not superior to conventional semen analysis in predicting the outcome of assisted reproduction.

The fatty acid composition of phospholipids of spermatozoa from infertile patients.

The lipid composition of the sperm membrane has a significant effect upon the functional characteristics of spermatozoa. In the present study we investigated the fatty acid (FA) composition of subpopulations of spermatozoa separated on a discontinuous Percoll gradient (47:90%) and the FA composition of phospholipids (PL) of sperm heads and tails in both normal and abnormal semen samples. In normozoospermic samples, polyunsaturated fatty acids (PUFA) represented 34.0 +/- 1.3 (mean +/- SE, mole %) and 25.6 +/- 1.2% of total FA of PL of the 47 and 90% Percoll fractions respectively. Docosahexaenoic acid (22:6omega3, DHA) contributed to more than 60% of total PUFA. DHA was significantly lower in both the 47% (P < 0.05) and the 90% (P < 0.01) Percoll fractions of oligozoospermic samples and in the 90% Percoll layer of asthenozoospermic samples (P < 0.01), compared with normozoospermic samples. The omega6/omega3 ratio was significantly increased in both Percoll fractions of samples with oligozoospermia (47%, P < 0.001 and 90%, P < 0.001) or with asthenozoospermia (47%, P < 0.05 and 90%, P < 0.001) compared with normozoospermic samples. The oxidative potential index (OPI) of spermatozoa recovered from the 47% Percoll layer was significantly higher (P < 0.0001) than of those recovered from the 90% Percoll. Mean melting point (MMP), an index of membrane fluidity, was significantly lower in head than in tails (P < 0.01) of spermatozoa, and also in both the 47% (P < 0.01) and 90% (P < 0.001) Percoll fractions of normozoospermic samples in comparison with oligozoospermic samples. The MMP was significantly higher (P < 0.05) in samples of patients with idiopathic oligo/asthenozoospermia, varicocele, and male accessory gland infection (MAGI). These differences in FA composition of PL in subpopulations of human spermatozoa, and in their heads and tails may be related to sperm maturity and to differences in physiological function.

Seminal plasma alpha-glucosidase activity and male infertility.

Measurement of alpha-glucosidase (alpha-GLUC) activity by means of a simple colorimetric test using a commercial kit (EpiScreen; FertiPro, Lotenhulle, Belgium) yielded results that were strongly correlated with the values obtained for the neutral iso-enzyme measured by a fluorimetric reference method (r=0.85, P=0.003, n=13). The former method was characterized by a low intra- and inter-coefficient of variation (6.6 and 4.3% respectively). Vasectomized men with azoospermia (n=27) had a significantly lower alpha-GLUC activity in semen than vasectomized men with residual spermatozoa present (n=11, P < 0.01) and men with azoospermia of primary testicular origin (n=33, P < 0.01). Receiver operating curve (ROC) analysis showed alpha-GLUC measurement to be reasonably accurate in differentiation between cases with obstructive versus testicular azoospermia at criterion value 13.5 U/l (sensitivity=82%, specificity= 70%). In cases with spermatozoa present, alpha-GLUC activity and output per ejaculate were positively correlated with sperm concentration (r=0.53 and 0.38, n=472), linear velocity (r=0.35 and 0.30, n=224), curvilinear velocity (r=0.32 and r=0.29, n=224), semen adenosine triphosphate (r=0.35 and 0.26, n=64), the concentration of 5alpha-dihydrotestosterone (r=0.31 and 0.29, n=74), and gamma-glutamyltransferase activity (r=0.62 and 0.32, n=275) in seminal plasma. The activity of alpha-GLUC was inversely correlated with ROS generation after 12-myristate, 13-acetate phorbol ester stimulation (r=-0.27, n=104), and both alpha-GLUC activity and total output were inversely correlated with the concentration of peroxidase-positive white blood cells among samples with > or =1x10(6)/ml of these cells (r=-0.30 and -0.19, n=165). It is concluded that simple photometric measurement of alpha-GLUC activity in seminal plasma reflects the functional state of the epididymis and may be helpful for the differential diagnosis of certain cases with azoospermia.