Cytochrome P450-2D6*4 polymorphism seminal relationship in infertile men

This study aimed to assess cytochrome (CY) P450-2D6*4 polymorphism relationship with semen variables in infertile men. In all, 308 men were included; fertile normozoospermia (N) (n = 77), asthenozoospermia (A) (n = 70), asthenoteratozoospermia (AT) (n = 75) and oligoasthenoteratozoospermia (OAT) (n = 86). They were subjected to history taking, clinical examination, semen analysis, sperm acrosin activity, seminal malondialdehyde (MDA) and CYP450-2D6*4 genotyping. CYP450-2D6*4 wild-type allele was represented in 76.5% of N, 70% of A, 66.7% of AT and 57.7% of OAT men where homozygous gene mutation was present in 5.9% of N, 20% of A, 26.6% of AT and 26.9% of OAT men, respectively. Sperm acrosin activity, sperm concentration, sperm motility, linear sperm velocity and sperm normal forms were significantly higher, and seminal MDA level was significantly lower in men with CYP450-2D6*4 wild-type allele compared with men with homozygous mutation. It is concluded that CYP450-2D6*4 wild-type allele has higher frequency where homozygous-type allele has lower frequency in N men compared with A, AT and OAT men. Sperm acrosin activity index, sperm concentration, sperm motility, linear sperm velocity and sperm normal forms were significantly higher, and seminal MDA level was significantly lower in men with CYP450-2D6*4 wild-type allele compared with men with homozygous mutation.

In vitro study of cypermethrin on human spermatozoa and the possible protective role of vitamins C and E

Cypermethrin, a type II synthetic pyrethroid pesticide, is widely used in pest control programmes in agriculture and public health. This study aimed to assess the potential effect of cypermethrin on human spermatozoa and the possible ameliorative effects of vitamins C and E. Semen samples of 20 healthy normozoospermic men were divided into six aliquots at room temperature. The first aliquot served as control not exposed to treatments, and the second was incubated with 20 mm vit. C and 2 mm vit. E where the third one was exposed to 10 μm cypermethrin for 6 h. The other three aliquots were incubated with vit. C, vit. E and both vitamins for 30 min before cypermethrin exposure. Semen aliquots were analysed for sperm motility, sperm viability, hypo-osmotic swelling test and modified alkaline comet assay. The results demonstrated a significant decrease in sperm motion, sperm function and increased sperm DNA damage in the cypermethrin group. Addition of vitamins C and E alone/combined led to significant improvement in sperm motion, sperm function and DNA damage, being maximal with both vitamins together. It is concluded that in vitro cypermethrin can alter sperm function and induce DNA damage in spermatozoa, which is improved after using vitamins C and E.

Seminal androgens, oestradiol and progesterone in oligoasthenoteratozoospermic men with varicocele

This study aimed to assess seminal androgens, oestradiol, progesterone levels in oligoasthenoteratozoospermic (OAT) men with varicocele (Vx). In all, 154 men with matched age and body mass index were investigated that were divided into healthy fertile controls (n = 35), OAT men with Vx (n = 55), OAT men without Vx (n = 64). They were subjected to assessment of semen parameters, seminal levels of testosterone (T), androstenedione (A), 5α-androstane-3 α,17 β-diol (3 α-diol), oestradiol (E2 ), 17-hydroxyprogesterone (17-OHP) and progesterone (P). Seminal levels of T and A were significantly decreased where seminal levels of 3 α-diol, E2 , 17-OHP, P were significantly higher in OAT men with/without Vx compared with fertile controls. Sperm count, sperm motility and sperm normal forms percentage demonstrated significant positive correlation with seminal T and A and significant negative correlation with seminal 3 α-diol, E2 , P. It is concluded that in fertile men, seminal T and A are significantly increased and seminal 3 α-diol, E2 , 17-OHP, P are significantly decreased compared with infertile OAT men with/without Vx. Association of Vx demonstrated a nonsignificant influence on these hormonal levels in OAT cases. Sperm count, sperm motility and sperm normal forms demonstrated significant positive correlation with seminal T, A and significant negative correlation with seminal 3 α-diol, E2 , P.

Oestrogen receptor alpha gene polymorphisms relationship with semen variables in infertile men

This study aimed to assess the association of oestrogen receptor alpha (ER-α) gene polymorphisms and semen variables in infertile oligoasthenoteratozoospermic (OAT) men. In all, 141 men were grouped into fertile men (n = 60) and infertile OAT men (n = 81). They were subjected to assessment of semen analysis, acrosin activity, serum reproductive hormones and genotyping of ER-α gene. Frequencies of p and x alleles in ER-α gene PvuII and XbaI polymorphisms were more prevalent among fertile men compared with infertile OAT men. Presence of P and X alleles was associated with increased incidence of male infertility for genotypes PP, XX compared with genotypes pp and xx (OR = 2.8; 95% CI: 2.36-6.97; P = 0.001 and OR = 4.1, 95% CI: 1.49-11.39; P = 0.001, respectively). The mean of semen variables and sperm acrosin activity were significantly higher in cases associated with pp than PP and in xx than XX genotypes of ER-α gene. Mean levels of all serum reproductive hormones demonstrated nonsignificant differences in different ER-α genotypes except oestrogen that was elevated in PP and XX ER-α gene genotypes. It is concluded that as oestrogen is concerned in male gamete maturation, ER-α gene polymorphisms might play a role in the pathophysiology of male infertility.

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.

Cholesterol and desmosterol in two sperm populations separated on Sil-Select gradient

Sperm lipids are important for sperm viability, maturity and function. This study aimed to identify cholesterol and desmosterol composition of human spermatozoa of two sperm populations separated on Sil-Select gradient. Forty-eight males were divided into four groups namely healthy men (n = 13), asthenozoospermia (n = 11), asthenoteratozoospermia (n = 10) and oligoasthenoteratozoospermia (n = 14). Sperm cholesterol and desmosterol were estimated in two human sperm population separated by centrifugation in a discontinuous Sil-Select gradient. The results showed that cholesterol and desmosterol were the major sterols in human spermatozoa. Spermatozoa recovered from upper/lower layer interface (fraction I) had low fertilization potential, while those from the base (fraction II) had high fertilization potential. Median values of cholesterol and desmosterol in fraction I were 2.55 micromol and 0.77 micromol/10(9) spermatozoa and in fraction II were 1.16 micromol and 0.27 micromol/10(9) spermatozoa. Cholesterol/desmosterol ratio was significantly higher in fraction II than I (4.8 vs. 3.2, p < 0.01). Cholesterol, desmosterol, total phospholipids and sterols/phospholipids were negatively correlated with sperm concentrations, sperm motility, linear velocity, normal sperm morphology and acrosome reaction percentage whereas cholesterol/desmosterol ratio was positively correlated with these parameters. It is concluded that the difference in sterol composition of sperm subpopulations separated on Sil-Select gradient suggests that composition of sterols is related to sperm functions.

Mechanisms of sperm deficiency in male accessory gland infection

The presence of 2 million or more peroxidase-positive white blood cells per ml of semen, or the diagnosis of male accessory gland infection, is associated with important biochemical and biological changes in semen plasma and in the spermatozoa, reducing their fertilizing potential in vitro and in vivo (e.g., during intra-uterine insemination). In addition to the effects of reactive oxygen species, and its influence on the essential fatty acid composition of the sperm membrane, potentially unfavourable effects can occur through the intermediate of increased concentrations of certain cytokines, and decreased activity of enzymes such as alpha-glucosidase. In contrast, lower numbers of white blood cells may exert beneficial effects on spermatozoa thanks to the increased production of hepatocyte growth factor/scatter factor (a tissue repairing substance), and the stimulation of immuno-competent cells by particular cytokines (e.g., Interleukin-6).

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.

Levels of hepatocyte growth factor/scatter factor (HGF/SF) in seminal plasma of patients with andrological diseases

Hepatocyte growth factor/scatter factor (HGF/SF) has all the characteristics of a molecule suitable for functioning in regulatory networks of motility, such as the spermatogenic epithelium, where spermatogenic cells must migrate between the cells of Sertoli, and it exerts its effect through binding of its high-affinity receptor (c-met). Considering the findings that c-met receptor is expressed in the human testis and on spermatozoa, and that HGF/SF in seminal plasma consists of pro-HGF/SF, mature alphabeta-HGF/SF, and less active forms of HGF/SF, we investigated the concentration and biological activity of HGF/SF in seminal plasma and their correlation with parameters of spermatogenesis to obtain better insight into mechanisms that may be involved in the pathogenesis of male infertility. We also evaluated the potential value of assessment of hepatocyte growth factor concentration and its bioactivity for the diagnosis of certain pathological conditions of male reproduction. We studied the concentration and biological activity of HGF/SF in seminal plasma of normal men and of patients with a range of andrological diseases or conditions by measuring HGF/SF in seminal plasma by enzyme-linked immunosorbent assay and by scatter assay using Madin-Darby canine kidney epithelial cells. We identified three sources of HGF/SF in seminal plasma. In samples from vasectomized men (n = 30; 2.01 ng/ml) and in split ejaculate samples (n = 6; 1e fraction 2.75 ng/ml, 2e fraction 1.62 ng/ml), a prostatic origin can be certified. This HGF/SF has low biological activity (133.3 U/ml). In inflammation of the accessory sex glands (n = 40), a high amount of HGF/SF (3.04 ng/ml) can be generated by white blood cells and has moderate scatter activity (426.7 U/ml). In normozoospermic samples, there is a lower amount of HGF/SF (1.12 ng/ml), with strong scatter activity (1280.0 U/ml). Finally, the clear difference between the low amount of HGF/SF (1.06 ng/ml) with poor scatter activity (106.6 U/ml) in oligozoospermic samples (n = 28) and the high amount of HGF/SF (3.35 ng/ml) with strong scatter activity (853.3 U/ml) in samples from men with azoospermia of primary testicular failure (n = 18) suggests a mainly testicular origin, with different activity in different pathological conditions.

Purification and characterization of hepatocyte growth factor (HGF) from human seminal plasma

Naturally occurring forms of hepatocyte growth factor/scatter factor (HGF/SF) have been purified by heparin-Sepharose chromatography, followed by cation exchange chromatography from a pool of human seminal plasma. Using an enzyme-linked immunosorbant assay, MDCK scatter assay, and Western blot analysis, it was found that, after heparin-Sepharose chromatography, human HGF/SF present in seminal plasma eluted in two different fractions, between 0.72 and 0.85 M NaCl (fraction I) and between 0.95 and 1.10 M NaCl (fraction II). Further purification of fraction I by cation exchange chromatography resulted again in two fractions which eluted at 0.2-0.4 and at 0.6-0.8 M NaCl. The fraction which eluted at 0.2-0.4 M NaCl consisted of two biologically less active heavy chains of the heterodimeric form of HGF/SF (107.1 U/ng immunoreactive HGF), with approximate molecular weights of 65 and 62 kDa under reducing conditions. The second fraction, which eluted at 0.6-0.8 M NaCl, revealed three bands with molecular weights of 87, 65 and 62 kDa, respectively. The 87 kDa form is thought to be a single chain precursor of HGF/SF devoid of biological activity. After subjecting fraction II to cation exchange chromatography, only one major peak eluted between 0.9 and 1.0 M NaCl, and consisted of two biologically active heavy chains of the heterodimeric form of HGF/SF (708.3 U/ng immunoreactive HGF), with approximate molecular weights of 65 and 62 kDa under reducing conditions. Nonreducing conditions for both fraction I and fraction II revealed only one band with a molecular weight of 68 kDa. The ratio ofpro-HGF/SF and less biologically active HGF/ SF (fraction I) over mature heterodimeric HGF/SF (fraction II) was approximately 1:3, in seminal plasma from sperm donors. In seminal plasma, pro-HGF/SF represents an 87 kDa glycoprotein which, apparently, is converted by limited proteolysis into several bands with molecular weights of 65 and 62 kDa. This is the first report showing the presence of pro-HGF/SF and heterodimeric mature HGF/SF, as well as less biologically active forms of HGF/SF in human seminal plasma.

The relation between reactive oxygen species and cytokines in andrological patients with or without male accessory gland infection

The presence of various cytokines, namely hepatocyte growth factor (HGF), interleukin-1 receptor antagonist (IL-1 RA), and interleukins (IL-1 alpha, IL-6, and IL-8), as well as the production of reactive oxygen species (ROS) was investigated in seminal plasma of fertile and infertile patients in order to evaluate the possible value of measuring these substances for the diagnosis of male accessory gland infection, and to assess the possible relationship between oxidative stress and cytokines during leucocytospermia and male accessory gland infection (MAGI). Our findings indicate that all of the measured cytokines seem to be produced locally as well as by white blood cells (WBC) and that, due to the presence of higher numbers of WBC, accessory gland infection may exert a deleterious effect on sperm quality through the production of ROS and/or of particular cytokines such as IL-1 alpha, IL-1 RA, and IL-8. The most specific marker for a sensitivity of 95% in discriminating between cases with or without MAGI is the measurement of IL-6 in seminal plasma. In the absence of WBC several cytokines are constitutively produced and correlate with sperm concentration (HGF, IL-8), alpha-glucosidase (IL-6), and gamma-glutamyltransferase activity (HGF). The measurement of these cytokines in semen may provide clinically useful information for the diagnosis of male accessory gland infection, as well as in the absence of WBC where it can provide information about certain mechanisms of male reproductive function and dysfunction.

The possible meaning of transferrin and its soluble receptors in seminal plasma as markers of the seminiferous epithelium

Transferrin (Tf) and soluble transferrin receptors (S-Tf-R) were measured by enzyme immunoassay in seminal plasma of 130 semen samples. The mean concentration of S-Tf-R in cases with normozoospermia was 10.4 IU/ml (95% confidence interval: 9.5-11.3) and it was significantly lower in patients with oligozoospermia (6.6, 95% CI: 5.8-7.5, P < 0.001), asthenozoospermia (8.5, 95% CI: 5.5-10.7, P < 0.05), azoospermia of primary testicular origin (7.9, 95% CI: 6.1-9.6, P<0.05) and post-vasectomy samples (5.9, 95% CI: 5.4-6.9, P < 0.001). The concentration of S-Tf-R in post-vasectomy samples was lower than that in patients with azoospermia of primary testicular origin (P < 0.05; positive likelihood ration = 7 at value of 8.3 IU/ ml). S-Tf-R was positively correlated with motile sperm concentration (r = 0.50, P < 0.0001), percentage motility (r = 0.38, P < 0.001), percentage of normal forms (r = 0.43, P < 0.001), sperm linear velocity (r = 0.42, P < 0.001), and ATP concentration (r = 0.67, P < 0.0001). Follicle stimulating hormone (FSH) was found to be negatively correlated with the concentrations of both Tf (r = -0.31, P < 0.05) and of S-Tf-R (r = -0.45, P < 0.01). The mean concentration of Tf in seminal plasma was 50.4 micrograms/ml (35.9-67.2) in samples with normozoospermia (n = 22), and the concentration was significantly lower in patients with oligozoospermia (P < 0.05), azoospermia of testicular origin (P < 0.001), and post-vasectomy samples (P < 0.001). Seminal Tf was correlated with motile sperm concentration (r = 0.36, P < 0.001), percentage of motile spermatozoa (r = 0.25, P < 0.05), linear velocity (r = 0.24, P < 0.05) and ATP concentration (r = p.44, P < 0.001). The concentration of Tf was positively correlated with that of S-Tf-R both in cases with spermatozoa present (r = 0.66, P < 0.001), and in cases with azoospermia of testicular origin (r = 0.51, P < 0.05) but not in vasectomy cases. It is concluded that S-Tf-R in seminal plasma is a marker of spermatogenesis and may give information on the presence or absence of spermatogenetic cells in cases with azoospermia. Further investigations are needed to assess its usefulness for clinical practice.

Critical evaluation of the effectiveness of different modes of treatment of male infertility

Among cohorts of couples treated for infertility due to a male factor it is the effective cumulative rate of successful deliveries and the cost per delivery that must be considered in assessing the value of different modes of treatment. The 'wait and see', timed coitus, or counselling approach has a low success rate (about 15% in 12 months), and a relatively high cost per delivery because of the cost of control visits and of tests for the prediction of ovulation. The high success rate of varicocele treatment (35% in 12 months, between 60 and 80% after 24 months), and the moderate cost of retrograde venography and embolisation results in a low cost per delivery. This cost is the lowest in anti-oestrogen treatment of idiopathic oligozoospermia, with a 20-30% effective cumulative pregnancy rate in 6 months. Three months of intra-uterine insemination (IUI) of Percoll gradient selected spermatozoa has a higher effective cumulative success rate than conventional in vitro fertilization (IVF) applied in cases with similar sperm characteristics, and the cost per successful delivery of the former is eight times lower than that of the latter. Intracytoplasmic sperm injection can successfully be applied in cases with more severe sperm deficiency; it has a higher success rate than conventional IVF, and is slightly more cost-efficient. However, the effective cumulative pregnancy rate remains relatively low (about 45% in 12 months) because of the high drop-out rate and long time interval between treatment cycles among unsuccessful couples.

The receptor encoded by the human C-MET oncogene is expressed in testicular tissue and on human spermatozoa

Because of its distinctive ability to act as a mitogen, a mitogen and a morphogen, hepatocyte growth factor/scatter factor (HGF/SF) has all the characteristics of a molecule able to function in regulatory networks of motility, such as the spermatogenic epithelium, and this through binding of its receptor p190MET (C-MET). In this study we report the expression of C-MET in the human seminiferous epithelium and on spermatozoa from men being treated for infertility and sperm donors. The presence of C-MET was demonstrated by immunochemistry on the cell membrane of spermatogonia, spermatocytes, spermatids and on spermatozoa, whereas Sertoli cells and Leydig cells did not show expression. Comparison of C-MET expression on spermatozoa of the 90% Percoll layer of subfertile patients and donors revealed clearly two distinct groups (unpaired t-test, P < 0.001), whereas comparison of C-MET expression on spermatozoa in the 47% Percoll layer was not significantly different between patients and donors. In addition, there was a significant inverse correlation between sperm concentration and the C-MET expression of spermatozoa in the 90% Percoll layer (r = -0.80, 95% confidence interval, -0.92 to -0.55; P < 0.0001), but not with the C-MET expression of spermatozoa in the 47% Percoll layer. In conclusion, the presence of C-MET was demonstrated in the seminiferous epithelium and on mature and immature spermatozoa, indicating a role for this growth factor receptor in the differentiation and/or migration that occurs during human spermatogenesis.

Varicocele: indications for treatment

Varicocele is detected in about one-third of men with subfertile semen quality. Treatment by means of transcatheter embolization using the tissue adhesive Histoacryl improves Sertoli cell function with increased concentrations of transferrin in semen, and a significant increase in sperm concentration, normal morphology and linear velocity. Failure to attain pregnancy after varicocele treatment occurs if pre-treatment sperm quality is normal, or in the case of azoospermia with elevated blood FSH levels or obstruction, or when there is severe coincidental pathology impairing fertility of the male or female partner. In all other cases, the poor results of varicocele treatment reported in some studies can only be explained by inadequate techniques. Varicocele detection and embolization treatment at puberty or during adolescence should be advocated to prevent deterioration of testicular function.

Evaluation of beta-endorphin and interleukin-6 in seminal plasma of patients with certain andrological diseases

Human semen contains large amounts of opioid peptides and cytokines. We have measured the concentrations of interleukin (IL)-6 in 140 semen samples and of beta-endorphin in 77 semen samples. The median concentration of beta-endorphin in seminal plasma from normozoospermic men (n = 23) was 154.7 pg/ml (10th-90th percentiles, 42.0-774.6), and there was no significant difference in the beta-endorphin concentration among normozoospermic, oligozoospermic (n = 28), asthenozoospermic (n = 15), azoospermic (n = 4) and post-vasectomy (n = 7) samples. There was no correlation between beta-endorphin concentration and sperm characteristics, nor with blood hormones. beta-Endorphin concentration was lower in cases with immunological infertility, as revealed by a positive direct mixed antiglobulin reaction test (n = 12) (P < 0.01), than in matched controls. The median concentration of IL-6 in samples with normal sperm concentration, motility and morphology with or without white blood cells (n = 39) was 26.1 pg/ml (10th-90th percentiles, 7.3-172.3), and there was no significant difference in the IL-6 concentration among normozoospermic, oligozoospermic (n = 46), asthenozoospermic (n = 32), azoospermic (n = 13) and post-vasectomy (n = 10) samples. The IL-6 concentration was significantly higher in cases of varicocele (n = 22) without white blood cells in semen (P < 0.001) than in matched controls without varicocele (n = 23). In addition, the IL-6 concentration was elevated (P < 0.0001) in cases with accessory sex gland inflammation (n = 40). IL-6 concentration was positively correlated with white blood cells in semen (n = 60, r = 0.59, P < 0.0001), but there was no correlation with beta-endorphin concentration. The IL-6 concentration chosen to differentiate between cases with and without accessory gland inflammation was 45.3 pg/ml, with a specificity of 80.6% and a sensitivity of 92.5%. It is concluded that beta-endorphin in seminal plasma plays an immune suppressive role, and that increased IL-6 concentration may be related to testicular dysfunction in cases with varicocele. Furthermore, IL-6 is an accurate marker of accessory sex gland inflammation.

MedCalc: a new computer program for medical statistics

In recent years, the use and abuse of statistics in the medical literature has extensively been reviewed. Amongst others, the importance of the P-value has been challenged and the use of misleading graphics, including 3-dimensional displays, has been criticized. The ease of access to more complex statistical procedures, since the introduction of several statistical software packages for personal computers, has been identified as one of the factors involved in the misuse of statistics. Therefore, we have developed a new computer program that includes those statistical procedures commonly encountered in the medical literature and in statistical textbooks for medical researchers. More complex statistical analyses are not implemented in the software. If researchers with limited statistical training require more sophisticated statistical analyses, they should refer to a statistician, not to a more complete statistical software package.

Androgens in seminal plasma: markers of the surface epithelium of the male reproductive tract

Androgens in seminal plasma have been investigated in relation to other markers of the male reproductive system. Testosterone and dihydrotestosterone (DHT) were measured by radioimmunoassay after paper chromatography in 104 semen samples. Concentrations of testosterone and DHT were significantly lower in samples from patients with abnormal sperm characteristics than in men with normozoospermia. Both testosterone and DHT were correlated significantly with sperm concentration (r = 0.40, p < 0.001; r = 0.41, p < 0.001, respectively), motile sperm concentration (r = 0.35, p < 0.01; r = 0.35, p < 0.01) and ATP concentration (r = 0.59, p < 0.001; r = 0.45, p < 0.001). In addition, the total amounts of testosterone and DHT were correlated with total activity of alpha-glucosidase (r = 0.49, p < 0.001; r = 0.58, p < 0.01), and gamma-glutamyltransferase (r = 0.49, p < 0.001; r = 0.48, p < 0.001) in seminal plasma. Transferrin (Tf) concentration in seminal plasma was significantly lower in samples without spermatozoa, and total Tf content was lower in oligozoospermic samples (p < 0.05). Testosterone and DHT were correlated positively with Tf levels in seminal plasma (r = 0.48, p < 0.0001; r = 0.78, p < 0.0001 respectively). Testosterone, DHT and Tf in seminal plasma were higher in the first than in the second fraction of split ejaculates, and DHT, but not testosterone, increased significantly in each of six patients treated with tamoxifen. Testosterone, DHT, and Tf in seminal plasma were not correlated with serum concentrations of LH, FSH, testosterone or prolactin, but the DHT : T ratio in seminal plasma was correlated with serum LH (r = 0.36, p < 0.05). It is concluded that the concentration of androgens in seminal plasma is related predominantly to the activity of the seminiferous epithelium and, to a lesser extent, to the function of the accessory sex glands.

Evaluation of the role of reactive oxygen species in male infertility

Reactive oxygen species (ROS) production from spermatozoa has been measured by chemiluminescence in the two fractions of a Percoll gradient column (47 and 90%). Chemiluminescent signals were recorded in each fraction after the addition of luminol and horse-radish peroxidase (basal state), and after stimulation with formyl-methionyl-leucyl-phenylalanine and phorbol ester (PMA). Oligozoospermic samples show a higher rate of ROS production than the normozoospermic samples in both fractions of Percoll. Also, ROS were generated at a higher rate by asthenozoospermic samples in the 90% Percoll fraction than by normal samples after stimulation with PMA. Our data confirm that fact that white blood cells play a major role in the production of ROS, even after purification on a Percoll gradient. Immunological cases were also found to be associated with an increased production of ROS, which may be caused by the same underlying pathological condition responsible for the production of the antibodies. Repeated centrifugation of the samples triggers a burst of ROS in excess of that produced after Percoll preparation. In addition, superoxide dismutase activity was found to be significantly increased in cases with an elevated production of ROS. It is concluded that measuring the ROS generation by semen may yield useful information on the functional capacity of spermatozoa, which may be used to improve the success of male infertility management.

Relationship between resazurin reduction test, reactive oxygen species generation, and gamma-glutamyltransferase

The production of reactive oxygen species (ROS) from spermatozoa has been measured by chemiluminescence in the two fractions of a Percoll gradient column (47 and 90%). Chemiluminescent signals were recorded in each fraction after addition of luminol and horse-radish peroxidase (basal state), and after stimulation with formyl-methionyl-leucyl-phenyl-alanine (FMLP) and phorbol ester (PMA). We found an inverse correlation between the reducing capacity of the semen as estimated by the resazurin test, and the production of ROS by the spermatozoa, especially after stimulation with PMA (r = 0.51, P < 0.001). gamma-glutamyltransferase activity of seminal plasma was inversely correlated with ROS (r = -0.47, P < 0.01) and the resazurin test result (r = -0.43, P < 0.001) suggesting a possible role of prostatic secretions in the protection of spermatozoa against oxygen radicals. The resazurin test has a positive predictive value of 92.5% at a criterion value of colour scale 4 to discriminate between normal and excessive ROS production by spermatozoa, with sensitivity 79% and specificity 74%. In addition, at criterion value of colour scale 3, the resazurin test could distinguish between samples with normal or low activity of gamma-glutamyltransferase, with sensitivity 57% and specificity 93%. It is concluded that the result of the resazurin test can be influenced by the oxidative stress of spermatozoa and by prostatic function.