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Background: The identification of potential environmental hazards may have clinical relevance for diagnosis of male infertility. Knowledge about these factors will improve prevention of fertility disorders., Results: Apart from drugs or factors related to lifestyle such as alcohol and tobacco smoke, various environmental and occupational agents, both chemical and physical, may impair male reproductive functions. With regard to the complex regulation of the male reproductive system, the available information concerning single exogenous factors and their mechanisms of action in humans is limited. This is also due to the fact that extrapolation of results obtained from experimental animal studies remains difficult., Conclusion: Nevertheless, the assessment of relevant exposures to reproductive toxicants should be carefully evaluated during diagnostic procedures of andrological patients.

In recent years, there has been growing concern that environmental pollutants in general, and organochlorines in particular, adversely affect male fertility. Therefore, we investigated the effects of tris(4-chlorophenyl)methanol (TCPM), non-ortho PCB 77 and gamma-hexachlorocyclohexane (gamma-HCH, lindane) on human sperm functions in vitro. Human spermatozoa from healthy donors were washed in human tubular fluid medium containing 1% human serum albumin, filtered through glass wool and exposed to different concentrations of TCPM, PCB 77 or gamma-HCH. After incubation for 5 h at 37 degrees C and 5% CO(2), sperm vitality and the percentage of living acrosome-reacted spermatozoa were examined using triple stain technique. Total sperm motility was evaluated by computer-assisted sperm analysis (Stroemberg-Mika) after 5 h. For TCPM, total motility was additionally measured after 18 and 40 h. Different concentrations of PCB 77 and gamma-HCH did not alter the percentage of spontaneous living acrosome-reacted spermatozoa, vitality and total motility. TCPM dose-dependently altered sperm motility, vitality and acrosome reaction. The percentage of living acrosome-reacted spermatozoa was increased at overtly toxic concentrations. Therefore, it is suggested that unspecific acrosomal loss has been induced by degenerative processes. In conclusion, even high concentrations of PCB 77 and gamma-HCH did not affect human sperm functions in vitro. Only very high cytotoxic TCPM concentrations modulated spontaneous acrosome reaction and total motility. Therefore, in vivo effects on human sperm function seem to be unlikely. However, individual susceptibility has to be considered and little is known about additive and possible synergistic effects as other environmental pollutants with similar potencies have been found in the human male and female reproductive tract.

Polychlorinated biphenyls (PCBs) are ubiquitous pollutants in the environment. They are present in body fluids associated with reproduction such as follicular fluid, seminal fluid and cervical mucus. Most PCB effects are mediated through the aryl hydrocarbon receptor, which is present in human spermatozoa. Additionally, PCBs may alter various biochemical reactions, such as calcium homeostasis. Therefore we investigated the effects of single non-ortho PCB 126, mono-ortho PCB 118, and di-ortho PCB 153 on human sperm motility, vitality, and calcium-dependent acrosome reaction (AR) in vitro. Human spermatozoa were either treated with different single PCB congeners or their combinations for 5 h at 37 degrees C (spontaneous AR), or for 16 h at room temperature and 4 degrees C (induced AR). Motility was measured after 5 h of incubation. Compared with the controls, PCB exposure had no effects on the percentage of living acrosome reacted spermatozoa, vitality, and motility. There was no difference in the inducibility of the AR between treatment groups and the respective controls after long term incubation. The PCB concentrations used were far higher than those found in cervical mucus or seminal fluid. In vivo effects of PCB congeners on human ejaculated spermatozoa seem to be unlikely. However these results cannot be easily transferred to the in vivo situation, because individual susceptibility has to be considered, and there is no information about synergistic or additive effects with other chemicals present in the male and female reproductive tract.

A new indication for testicular tissue cryopreservation is demonstrated in a patient with metachronous bilateral testicular tumours and azoospermia. At the age of 18 (1982) the patient underwent left orchidectomy and radical retroperitoneal lymphadenectomy for a testicular teratoma (pT1N0M0). Semen samples were not cryopreserved because of absence of motile spermatozoa after thawing. Seventeen years after the primary testicular cancer, a seminoma of the contralateral right testis was diagnosed (pT1N0M0). Since the patient was azoospermic, no semen samples could be cryopreserved. However, spermatozoa were detected in testicular biopsy material of the right testis and were cryopreserved for ICSI. Since all spermatozoa were dead after thawing, testicular sperm extraction (TESE) was performed in the remaining tissue samples at the time of ICSI treatment. Only spermatids could be extracted from frozen-thawed samples due to the inhomogeneous distribution of spermatogenic activity in the testicular tissue. Although one oocyte was fertilized with these spermatids, a clinical pregnancy was not achieved. Despite the disappointing results of ICSI in the couple presented here, this case report demonstrates that cryopreservation of testicular tissue and TESE should be considered in patients with bilateral testicular tumours and azoospermia, if frozen semen samples are not available.

The presence of components of the renin angiotensin system (RAS) and specific receptors of angiotensin II in the female and male reproductive tract supports the hypothesis that reproductive functions may be controlled by RAS. Therefore, the present study investigated the influence of ACE and angiotensins on sperm functions and the sperm-egg interaction. The experiments did not indicate direct effects of ACE on the capacitation process or acrosome reaction. Release of ACE from human spermatozoa during capacitation was not related to their ability to undergo acrosome reaction after stimulation with ionophore. Therefore, ACE release does not seem to be a useful clinical marker for human sperm capacitation. However, decreased binding of human spermatozoa to the oolemma of zonafree hamster oocytes after inhibition of ACE by captopril indicates that kininase II is involved in sperm-egg interactions. In contrast to other studies, incubation with captopril had no influence on sperm binding to the zona pellucida. Because effects of ACE on sperm-egg interactions but not on capacitation or acrosome reaction were observed, several experiments were performed to study the influence of substrates and products on the acrosome reaction. Angiotensin II induced the acrosome reaction dose-dependently, whereas angiotensin I had no effect on the acrosome reaction. The effect of angiotensin II on acrosome reaction seems to be calcium-dependent and mediated by protein kinases. Since a specific type 2 angiotensin II receptor inhibits the acrosome reaction induced by angiotensin II, this subtype of receptors may be present at the surface of sperm heads. Another clue for the presence of type 2 receptors on human spermatozoa is the finding that pertussis toxin did not inhibit the angiotensin II induced acrosome reaction. In contrast to type 1 angiotensin II receptors, type 2 receptors are known to be G-protein independent.

Angiotensin-converting enzyme (ACE) is known to be released from human spermatozoa during capacitation. However, it has not yet been localized ultrastructurally in ejaculated sperm cells. Therefore, the purpose of the present study was to demonstrate the location of ACE by means of immunoelectron microscopy and direct immunofluorescence. In addition, ACE activity of spermatozoa was correlated with standard semen parameters. The activity of angiotensin-converting enzyme was measured in spermatozoa from 115 donors and patients attending the andrological outpatient department. Progressive motility was negatively correlated with sperm ACE activity (Spearman rank correlation r=-0.364, P < 0.0001), whereas no statistically significant correlations with sperm concentration, total motility and morphology were observed. Immunoelectron microscopy demonstrated that ACE is mainly located at the plasma membrane of the acrosomal region, equatorial segment, postacrosomal region and midpiece. In contrast, only weak ACE-like immunoreactivity was found at the flagellum. In cases of cells with missing plasma membranes ACE seems also to be located at the surface of the outer acrosomal membrane. By means of immunohistochemical methods, different patterns of ACE-like immunofluorescence were observed: (i) fluorescence of the acrosome or the entire sperm head, midpiece and flagellum; (ii) fluorescence of the postacrosomal region, midpiece and flagellum; (iii) bright fluorescence of the equatorial segment with less intensive labelling of the postacrosomal region and flagellum. Induction of the acrosome reaction by calcium ionophore A23187 resulted in an increase of spermatozoa with weak acrosomal fluorescence, indicating loss of the plasma membrane.

Many studies have examined the impact of genital tract infections on male fertility; however, the effect of bacteriospermia on sperm quality is still controversial. Bacterial infections are more frequently found in semen samples from asymptomatic infertile patients than in those from fertile men. Bacteriospermia is also a common problem of male partners from couples undergoing IVF. Therefore, the effects of microorganisms on human sperm acrosome reaction of oocytes have been studied in vitro and in vivo. Incubation of spermatozoa with Escherichia coli or Mycoplasma hominis in vitro resulted in reduced sperm motility and inducibility of acrosome reaction (delta AR) after exposure to calcium ionophore A23187. To show possible effects of E. coli and mycoplasma species on sperm functions in vivo, data from 488 patients were evaluated, in whose ejaculates microbiological examinations and determinations of acrosome reaction after exposure to low temperature had been performed. U. urealyticum and E. coli were found in semen samples from 52 and 31 men, respectively. M. hominis was only present in a minor number of samples and was not included in this study. Semen concentrations of E. coli and U. urealyticum ranged between 500-100,000 cfu x ml-1 and 100-80,000 cfu x ml-1. No correlation was found between delta AR and concentration of bacteria (Spearman rank correlation coefficient, E. coli: r-0.081, P = 0.6644; U. urealyticum: r = -0.081, P = 0.5698). In 69% of cases with U. urealyticum infection and reduced inducibility of acrosome reaction, this sperm function was normal after antibiotic therapy. However, improvement of acrosomal function may only be due to intra-individual variations of acrosome reaction. While E. coli and mycoplasma species affect sperm functions in vitro, the present data and a review of the literature fail to demonstrate similar effects in vivo.

The possibilities of treating male subfertility are still limited. Approaches at medical therapy include stimulation of spermatogenesis at the testicular level, improvement of epididymal function (sperm maturation), influence on sperm transport and activation of sperm metabolism with improvement of sperm motility. Causal therapy has been most successful in patients with hormonal insufficiency and male adnexitis, while microsurgical reconstructive measures have yielded best results in cases of occlusion within the efferent seminal ducts. New therapeutic approaches include the use of mast cell blockers and alpha blockers as well as vitamin C/E as an antioxidative treatment to reduce reactive oxygen species. If medical or surgical therapy has failed, methods for improvement of sperm quality in vitro must be considered (swim-up technique, glass wool filtration, migration/sedimentation technique, density gradient centrifugation). In cases of severe male sterility factor, intracytoplasmic sperm injection (ICSI) has been a breakthrough in the therapy of childlessness. A further progress is the collection of spermatozoa from the epididymis (MESA = microsurgical epididymal sperm aspiration) or testis (TESE = testicular sperm extraction). Finally, pressure in terms of time and organization can now be avoided by the use of cryopreserved spermatozoa from the ejaculate, epididymis or testicular tissue so that microinjection may be planned independently of the partner. In any case, a close cooperation between gynecologist and andrologist is of utmost importance.

Escherichia coli are known to reduce human sperm motility. The purpose of the present study was to examine whether these bacteria may also affect the acrosome reaction, which is another important sperm function. The acrosome reaction was determined in spermatozoa from 29 fertile men by triple stain after 3-h incubation at 37 degrees C with 2 x 10(6) E. coli/mL or without bacteria (control). Each sample was treated with 0.1% DMSO (spontaneous acrosome reaction) or calcium ionophore A23187 (induced acrosome reaction) for 1 h at 37 degrees C. The inducibility of the acrosome reaction was significantly lower in semen samples pretreated with E. coli than in the control samples (9.8 +/- 4.2% vs. 12.7 +/- 5.3%; p < .05). The results demonstrate that E. coli affect the inducibility of the acrosome reaction in vitro and may impair the fertilizing capacity of human spermatozoa.

For the evaluation of sperm functions it is important to assess the acrosome reaction after induction with various stimuli. Acrosome reaction tests normally include the capacitation of spermatozoa, treatment with an inducer, and detection of acrosomal loss by dyes, lectins or antibodies. Since most of these methods are time-consuming or require expensive equipment, paramagnetic beads coated with Pisum sativum agglutinin (PSA) were investigated for their usefulness in facilitating the detection of human sperm acrosome reaction. Binding of PSA beads to the acrosomal region increased significantly after incubation of capacitated spermatozoa with 10 microM A23187 (20.3 +/- 6.7% [mean +/- SD, absolute binding], n = 21), 1 mM dibutyryladenosine cyclic monophosphate (17.1 +/- 8.5%, n = 25) and 10 mM phorbol myristate acetate (21.1 +/- 12.5%, n = 10). Bead binding was significantly reduced by pre-incubation with a protein kinase inhibitor. Beads bound to Concanavalin A (ConA) were also attached to the acrosomal region after induction of the acrosome reaction by A23187 or dbcAMP, but a lower number of spermatozoa were bound to ConA-beads than to PSA beads. Pre-treatment of spermatozoa with alpha-methyl-D-mannoside before addition of the PSA beads markedly decreased bead binding, which indicates its mannose-specificity. Electron microscopic examinations demonstrated that PSA beads mainly bound to membrane structures of spermatozoa that were undergoing, but had not completed the acrosome reaction.

Microsurgical epididymal sperm aspiration (MESA) and testicular sperm extraction (TESE) require close cooperation between andrologists, urologists and gynaecologists. Intracytoplasmic sperm injections were established in Giessen in March 1994 and embryo transfer (ET) was performed in 342 of 375 patients (91.2%). The percentage of pregnancies and ongoing pregnancies are 35.4% per ET (32.3% per cycle) and 25.1% per ET (22.9% per cycle), respectively. Microsurgical procedures such as epididymovasostomy or vasovasostomy and cryopreservation of human semen are also established methods. The purpose of the present study was to describe the andrological work-up for patients before MESA and TESE. Experiments demonstrate that incubation of testicular tissue samples in IVF medium and treatment with 1 mg ml-1 pentoxifylline increase the number of extracted motile spermatozoa. Centrifugation of the medium results in a further concentration of sperm cells. If no motile spermatozoa can be found in the supernatant medium, they may be extracted directly from the testicular tissue samples by means of a micromanipulator.

The reasons for the discrepancy between 'patency' and 'pregnancy' in the outcome of microsurgical refertilization are partially unknown. The quality of the intra-operative aspirate and of the spermatozoa at the level of the anastomosis are discussed worldwide as important factors influencing the success of fertilization in the case of post-operative patency. In 152 men undergoing microsurgical refertilization (vasovasostomy, tubulovasostomy, microsurgical epididymal sperm aspiration, transurethral resection of the ejaculatory duct), 281 aspirates were classified intra-operatively according to Silber, and post-operatively using the Shorr staining technique. In 62 aspirates a computer-aided sperm analysis (CASA) was performed. The percentage of intact spermatozoa decreased from 94.9% at the caput to 9.4% at the cauda epididymidis. The post-operative classification demonstrated an acceptable correlation (0.71) to all grades of intraoperative classification. There was a good correspondence in Silber 4 and 5 but worse in Silber 1 and 2. In CASA, the percentage of motile spermatozoa was not different between epididymal and post-epididymal aspirates. Furthermore, velocity parameters did not differ significantly, but there was a significantly higher straightness of post-epididymal spermatozoa in comparison to epididymal spermatozoa.

Smoking and varicocele are frequent findings in the medical history and physical examination of patients attending andrological outpatient departments. However, data about their influence on human semen parameters, such as sperm concentration and motility, are contradictory. Therefore, the purpose of this study was to examine sperm function (acrosin activity and induction of the acrosome reaction) in smokers (n = 30) and varicocele patients (n = 30) compared with normal fertile donors (n = 20). The acrosome reaction was detected by triple staining after 3 h of incubation at 37 degrees C, followed by treatment with 0.1% dimethylsulphoxide (spontaneous acrosome reaction) and 10 microM calcium ionophore A23187 (induced acrosome reaction) for 1 h at 37 degrees C. Acrosin activity was measured by gelatinolysis. The diameters around the sperm heads after gelatinolysis and the percentages of spermatozoa showing halo formations were evaluated. The inducibility of the acrosome reaction was significantly lower in semen samples from smokers than in those from the fertile group (7.1 +/- 3.2 versus 11.2 +/- 4.0%, P < 0.01), whereas no statistically significant difference was demonstrated in spermatozoa from patients with varicocele (9.3 +/- 4.3%). Both the percentages of spermatozoa with halo formation (53.3 +/- 20.0 versus 76.6 +/- 13.6%, P < 0.05) and the halo diameters (16.1 +/- 6.6 versus 31.0 +/- 14.5 microns, P < 0.001) were significantly lower in the varicocele group than in the samples from fertile men. These data suggest that smoking and varicocele affect sperm function, and that the standard semen parameters alone are insufficient to evaluate the influence of both factors on human male fertility.

Human spermatozoa from healthy donors (n = 7) were washed in Tyrode's medium containing 0.6 mg/ml freeze-dried egg yolk, filtered through glass wool and exposed to 0.5, 5, 50, 500 or 1000 microM hydrogen hexachloroplatinate. Viability, membrane integrity and the acrosome reaction were examined using trypan blue exclusion, hypo-osmotic swelling test and fluoresceinated Pisum sativum agglutinin, respectively, after incubation for 3 or 6 h at 37 degrees C. While sperm motility, viability and membrane integrity were not affected by the platinum compound after incubation for 3 h, the number of acrosome-reacted spermatozoa increased from 16.0 +/- 6.4% (control, mean +/- SEM) to 21.0 +/- 3.3 (0.5 microM), 22.3 +/- 4.3% (5 microM), 28.0 +/- 4.3% (50 microM, p < 0.01), 29.3 +/- 3.9% (500 microM, p < 0.01) and 43.9 +/- 7.4% (1 mM, p < 0.001); a further increase was detected after incubation for 6 h. However, the percentages of dead and immotile spermatozoa and those with defective membranes were also higher, suggesting that the acrosome reaction was caused by degenerative processes after long-term incubation. In conclusion, hydrogen hexachloroplatinate does not affect sperm motility, membrane integrity or viability, but it does induce the acrosome reaction after incubation for 3 h before cytotoxic effects are measurable. Similar effects of halide salts of platinum on receptor-mediated exocytosis have been described in other cells such as mast cells and basophils in vivo and in vitro.

Tail stump syndrome, which may be associated with primary ciliary dyskinesia, is also associated with morphological defects of the flagellum resulting in severe asthenozoospermia. Until recently, these morphological anomalies caused definite male infertility. Today, however, new methods such as micromanipulation techniques provide a rational therapy for this patient group. A pregnancy followed by living offspring was achieved following the intracytoplasmic injection of immotile spermatozoa from a patient with tail stump syndrome.