Biomedical subjects

Ralf Henkel

Publications and source records attributed to Ralf Henkel.

9 recordsLinked to original sources

PubMed2006

Chronic pelvic pain syndrome/chronic prostatitis affect the acrosome reaction in human spermatozoa.

Male genital tract inflammations constitute an important factor of male subfertility in which different mediators are discussed damaging sperm membranes. As acrosome reaction (AR) is ultimately a membrane function, this study aimed at investigating the effects of the chronic pelvic pain syndrome on AR. In a total of 56 patients with chronic pelvic pain syndrome NIH IIIA and NIH IIIB, AR, concentration of leucocytes in ejaculate and urine after prostate massage, sperm concentration, motility, vitality and morphology were determined. The control group (n = 95) consisted of patients with normozoospermia and proven absence of signs of inflammation. Compared to the control, both patients groups showed poorer sperm morphology (P < 0.0001) and sperm concentration (P < 0.002). In addition, while maximum AR was not affected, inducibility of AR was significantly lower (P < 0.004) and spontaneous AR increased (P < 0.02). Our data clearly demonstrate a significant influence of the inflammation on acrosomal functionality, which could be mediated by inflammatory mediators like ROS.

Acrosome Reaction↗

PubMed2005

Effect of reactive oxygen species produced by spermatozoa and leukocytes on sperm functions in non-leukocytospermic patients.

OBJECTIVE: To investigate whether there is an impact of different sources of reactive oxygen species (ROS) on sperm functions. DESIGN: Prospective study. SETTING: Patients at the Center for Dermatology and Andrology, Giessen, Germany. PATIENT(S): Semen collected from 63 randomly collected patients attending the IVF unit of the University of Giessen, Germany. INTERVENTION(S): Only patients with nonleukocytospermia were included in this study. MAIN OUTCOME MEASURE(S): Sperm count and motility before and after sperm separation by swim-up, morphology, DNA fragmentation, and extrinsic (by leukocytes) and intrinsic ROS production (by spermatozoa) were evaluated. RESULT(S): Leukocytes correlated significantly with extrinsic ROS production (r = 0.576), but markedly less with intrinsic ROS production (r = 0.296). Sperm count, morphology, and motility in the ejaculate were markedly more affected by extrinsic than by intrinsic ROS. The DNA fragmentation was strongly positively correlated with intrinsic ROS production, whereas this correlation was weaker for extrinsic ROS production. No correlation was found between DNA fragmentation and the number of leukocytes, whereas the correlations with motility in the ejaculate and the motile sperm count after swim-up were highly significant. Moreover, significant differences were observed for extrinsic and intrinsic ROS production between groups of patients having a high (> or = 1 x 10(6)/mL) and a low number (<1 x 10(6)/mL) of leukocytes in the ejaculate. CONCLUSION(S): The origin of ROS seems to have an influence on the site of the damage. Because leukocyte counts <1 x 10(6)/mL caused a significant decrease of motility and DNA integrity, the threshold given by the World Health Organization (WHO) should be re-evaluated.

Adult↗

PubMed2005

Molecular aspects of declining sperm motility in older men.

OBJECTIVE: To investigate the molecular mechanism for declining sperm motility in older men. DESIGN: Retrospective and prospective study. SETTING: University-based andrology unit. PATIENT(S): Semen was collected from 2,111 patients and sperm donors. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Age, sperm concentration, ejaculate volume, sperm motility (including velocity average path, velocity straight line, velocity curvilinear, linearity, and lateral head displacement), normal sperm morphology, percentage of abnormally blue-stained flagella, and total and free T, FSH, and LH concentrations were analyzed. In addition, the zinc concentration in the seminal fluid, flagella, and the whole spermatozoa was measured by means of atomic absorption spectrometry. RESULT(S): Patient age correlated negatively with T concentration and sperm motility, including velocity, but positively with the percentage of abnormally stained flagella and the flagellar zinc. Whereas the percentage of abnormally stained flagella correlated negatively with motility and sperm velocity, there was a positive relationship with the flagellar zinc content. Flagellar zinc content was negatively correlated with motility. Testosterone showed a positive relationship with motility and sperm concentration. CONCLUSION(S): Because the epididymis is functionally T-dependent, our data suggest that the removal of zinc from the outer dense fibers during epididymal sperm maturation is affected in aging men, which in turn will result in decreased sperm motility.

Adolescent↗

PubMed2004

Influence of macrophage migration inhibitory factor (MIF) on the zinc content and redox state of protein-bound sulphydryl groups in rat sperm: indications for a new role of MIF in sperm maturation.

The function of macrophage migration inhibitory factor (MIF) in sperm maturation was studied by investigating its role in the biochemical maturation of the outer dense fibres. Rat sperm obtained from the caput and cauda epididymis were stimulated overnight with either recombinant MIF or MIF-containing vesicles originating from epididymal fluid at various concentrations. The zinc content of both the sperm and the medium was determined by means of atomic absorption spectrometry. Incubation in both recombinant MIF and vesicular MIF resulted in a statistically significant decrease of the zinc content in stimulated caput sperm of approximately 50%. In parallel, the conditioned media showed a clear increase in the concentration of this trace metal. The effect of MIF was less marked in cauda sperm. In addition, we demonstrated a statistically significant increase of detectable free thiol groups in the sperm mid- and principle piece in isolated rat sperm after stimulation with MIF at concentrations of 25 and 50 ng/ml. Our data suggest that MIF plays an important role in the maturation process of rat sperm during epididymal transit by inducing the elimination of zinc and affecting the amount of free sulphydryl groups in the sperm flagella.

Animals↗

PubMed2004

Influence of deoxyribonucleic acid damage on fertilization and pregnancy.

OBJECTIVE: To investigate sperm DNA damage in relation to fertilization and pregnancy. DESIGN: Prospective study. SETTING: The Institute of Reproductive Medicine, Giessen, Germany. PATIENT(S): Semen collected from 249 patients attending the IVF program. MAIN OUTCOME MEASURE(S): The percentage of terminal deoxynucleotidyl transferase-mediated dUDP nick-end labeling- (TUNEL-), Fas-, and annexin-V-positive sperm and the proportion of green-fluorescing sperm in the acridine orange stain was determined and correlated with sperm concentration, motility, fertilization, and pregnancy. RESULT(S): Significant correlations with the concentration of motile sperm were only found for the acridine orange stain (before and after sperm separation) and for the TUNEL assay (after sperm separation). Moreover, patients whose sperm had a high percentage of DNA fragmentations showed significantly lower pregnancy rates (TUNEL assay: 19.05% vs. 34.65%; acridine orange stain: 24.58% vs. 37.93%). The apoptosis parameters (annexin V binding and Fas expression) showed no statistically significant differences. CONCLUSIONS: Our data clearly demonstrate that DNA fragmentation, as determined by the TUNEL assay, is predictive for pregnancy in IVF. This implies that spermatozoa with DNA fragmentation can still fertilize an oocyte but that when paternal genes are "switched on," further embryonic development stops, resulting in failed pregnancy. It seems that, at least in the patients we analyzed, apoptosis in the sperm does not play a role for fertilization. This would imply that DNA fragmentation in human spermatozoa is caused by external factors, such as reactive oxygen species, rather than by apoptosis.

Acridine Orange↗

PubMed2003

Metal chelators change the human sperm motility pattern.

OBJECTIVE: To investigate the influence of zinc on the generation of motility. DESIGN: Prospective study. SETTINGS: Outpatient clinic of the Center of Dermatology and Andrology. PATIENT(S): Seventy-three patients and 10 sperm donors. INTERVENTION(S): Motile spermatozoa were isolated by swim-up and incubated for 1, 2, 4 or 6 hours with DL-penicillamine, 2,3-dimercaptopropan-1-sulfonate, and meso-2,3-dimercapto-succinimic acid at concentrations of 1, 10, and 100 micro mol/L. MAIN OUTCOME MEASURE(S): Motility was analyzed by means of computer-assisted semen analysis (CASA). RESULT(S): Significant dose-dependent changes in nonlinear motility, progressive motility, and velocity straight line (VSL) were observed. After only 1 hour of incubation, nonlinear motility decreased, and progressive motility and VSL increased. The percentage of immotile spermatozoa was not affected. Time-dependent changes in motility were observed on a significantly higher or lower level as compared to the control. Comparing the chelators after 2 hours revealed that DL-penicillamine showed the strongest effect on the sperm. CONCLUSION(S): The results imply that chelators can eliminate at least some part of the zinc from the flagellum. This zinc elimination appears to lead to comparable changes of the outer dense fibers as seen in vivo during epididymal maturation, finally resulting in improved motility.

Chelating Agents↗

PubMed2003

Relationship between human sperm morphology and acrosomal function.

PURPOSE: In this study, we investigated the relationship between functionality of the acrosome and sperm morphology. METHODS: Acrosome reaction (AR) was separately determined in live and dead sperm and in those with normal, small, and large sized acrosomes by means of the triple stain. Morphology was analyzed according to strict criteria after Papanicolaou stain. RESULTS: AR and morphology correlated regarding detection of large and small sized acrosomes, but not for normal sized acrosomes. Spontaneous AR was significantly influenced by acrosomal size. Sperm with large (11.4%) and normal (9.2%) acrosomes exhibited a significantly higher percentage of life spontaneously acrosome-reacted sperm than those with small acrosomes (4.5%). Sperm with small acrosomes were associated with a higher percentage of cell death. CONCLUSION: The results indicate that sperm with small acrosomes are more susceptible to cell death and nonphysiological acrosomal loss. Acrosome size reflects the physiological capability of sperm function and therefore male fertility potential.

Acrosome↗

PubMedDate not supplied

DNA fragmentation of spermatozoa and assisted reproduction technology.

Despite the ever-increasing knowledge of the fertilization process, there is still a need for better understanding of the causes of sperm DNA fragmentation and its impact on fertilization and pregnancy. For this reason, human sperm DNA fragmentation was investigated by means of the terminal deoxynucleotidyl transferase-mediated dUDP nick-end labelling (TUNEL) assay and the production of reactive oxygen species (ROS) in the ejaculate and in the spermatozoa themselves. These data were correlated with fertilization and pregnancy data from IVF and intracytoplasmic sperm injection (ICSI) patients. Sperm DNA fragmentation did not correlate with fertilization rate, but there was a significantly reduced pregnancy rate in IVF patients inseminated with TUNEL-positive spermatozoa. ICSI patients exhibited the same tendency. This implies that spermatozoa with damaged DNA are able to fertilize an oocyte, but at the time the paternal genome is switched on, further development stops. The determination of ROS in the ejaculate and the percentage of ROS-producing spermatozoa revealed markedly stronger correlations between sperm functions (i.e. motility) and the percentage of ROS-producing spermatozoa. The influence of seminal leukocytes, known to produce large amounts of oxidants, on sperm DNA fragmentation should not be neglected.

DNA Damage↗

PubMedDate not supplied

Seasonal changes of neutral alpha-glucosidase activity in human semen.

Although there are contradictory reports, the biochemical evaluation of the seminal activity of neutral alpha-glucosidase (NAG) has repeatedly been described as an important parameter to test epididymal patency and is recommended by the WHO. Because, for a number of diagnostic parameters, seasonal variations have been described even in the human, it was the aim of this study to investigate possible circannual changes of NAG. This is an important aspect of andrological diagnosis, as seasonal changes of specific diagnostic parameters might have an impact on the accuracy and predictive power of these parameters, which in turn might have an effect on the therapeutic concept for the patients. In a total of 473 patients, sperm concentration, volume of the ejaculate, total motility, progressive motility, pH value, number of peroxidase-positive cells, concentration of fructose, and NAG as functional markers of the seminal vesicles and the epididymis, respectively, were analyzed according to standard procedures. Seminal activity of NAG was significantly correlated with the sperm concentration (P < .0001), ejaculate volume (P < .0001), and the pH (P = .0025). Moreover, significant (P = .0008) seasonal changes in the activity of seminal NAG with the maximum in spring (76.87 mU/ejaculate) and the minimum in autumn (58.55 mU/ejaculate) were found. The incidence of low-ranged activity of the enzyme was 9.2% in spring, while it was 20.3% in autumn. Thus, our data clearly demonstrate circannual changes of the seminal activity of neutral alpha-glucosidase. This in turn has clinical impact as the predictive power of the test system changes throughout the year.

Adolescent↗