Effect of pentoxifylline on motility and membrane integrity of cryopreserved human spermatozoa

The purpose of this study was to examine the effects of pentoxifylline used before and after semen cryopreservation-thawing on sperm motility and membrane integrity. Twenty-four semen samples were split into four equal aliquots. Aliquots were incubated at 37 degrees C for 30 min, followed by cryopreservation with TEST-yolk freezing medium using slow programmable freezing protocol. After 2 weeks the sperm samples were thawed, washed twice in Quinn's Sperm Washing Medium (modified HTF with 5.0 mg/mL Human Albumin) and incubated at 37 degrees C for 30 min. Aliquots were treated by adding 3 mmol/L pentoxifylline to: (1) fresh sperm samples during incubation period prior to cryopreservation, (2) sperm samples as a supplement to the cryoprotectant prior to cryopreservation, and (3) thawed sperm samples during incubation period. One aliquot received no treatment (control group). The addition of 3 mmol/L pentoxifylline to fresh semen during incubation period prior to cryopreservation significantly decreased progressive and total motility compared with controls. However, the addition of 3 mmol/L pentoxifylline to cryopreserved semen after thawing significantly increased progressive and total motility compared with controls. After post-thaw, no differences in motion characteristics between sperm samples treated by adding 3 mmol/L pentoxifylline as a supplement to the cryoprotectant and control groups were observed. Post-thaw hypoosmotic swelling (HOS) test scores did not improve with the addition of pentoxifylline compared with the control group. It is concluded that pentoxifylline enhanced post-thaw motility of cryopreserved human spermatozoa when added after thawing. No improvement was found by freezing sperm with pentoxifylline.     

The influence of sperm density on the motility characteristics of washed human spermatozoa

To study the effects of sperm density on the results of computer-assisted semen analysis (CASA), 10 washed semen samples were diluted and measured with the CellTrak/S CASA system in a concentration range of 10–180×10⁶ spermatozoa/ ml. All sperm motility parameters were influenced to some extent by sperm density. The motility percentage was influenced significantly in 5 samples ( P< 0.005), the straight line velocity in all samples (P<0.0005 in 7 samples), the curvilinear velocity in 3 samples ( P< 0.005), the linearity in 9 samples (P<0.0005 in 6 samples) and the lateral head displacement in 9 samples (P< 0.005 in 6 samples). In general, the CellTrak/S data are influenced significantly if sperm density exceeds 50 × 10⁶ spermatozoa/ml.
The influence of sperm density on the motility parameters can be explained both by the accuracy of the CASA system and by actual changes in the motility of the spermatozoa. In the light of other published studies, it is concluded that sperm motility measurements with CASA systems should be assessed using 25–50 × 10⁶ spermatozoa/ml, especially in studies concerning lateral head displacement and the linearity, as in sperm hyperactivation studies.     

Factors affecting sperm motility VIII. Velocity and survival of human spermatozoa as related to temperatures above zero

The effect of temperature on motility and survival of ejaculated human spermatozoa was investigated with the aid of the multiple exposure photography (MEP) method for objective sperm motility determination. Fresh specimens from healthy donors were analyzed while being heated or cooled gradually, or during their storage at various temperatures from 0 to 48°C. Sperm velocity increased steadily from zero to 50.4 nm/sec between freezing point and body temperature. Thereafter, their activity dropped dramatically and total immobilization occurred at 45°C. The induced immobilization was reversible providing exposure to those extreme temperatures was short enough to prevent permanent damage. Sperm survived up to 24–48 h when stored at 23°C, while at body temperature, their survival in vitro was much shorter and rarely extended beyond 12 h. Their longevity was still shorter at higher or lower temperatures, especially when approaching 48°C. With the aid of the combined supravital staining and MEP methods it was found that temperatures of extreme levels induced mainly immobilization rather than a spermicidic effect. The possible mechanism of thermal effect on sperm motility and some of its practical implications are discussed.     

Cryodamage to plasma membrane integrity in head and tail regions of human sperm

Aim: To investigate the effect of cryopreservation on the plasma membrane integrity in the head and tail regions ofindividual sperm, and the relationship between intact cryopreserved sperm and its motility and zona-free hamster oocytepenetration rate. Methods: The eosin Y exclusion and the hypoosmotic swelling tests were combined to form a sin-gle test (HOS-EY test) to identify the spermatozoa with four types of membrane integrity. Results: After cryop-reservation, there was a marked decline in the percentage of spermatozoa with Type Ⅳ membrane integrity (head mem-brane intact/tail membrane intact), and a significant increase in those with Type Ⅰ (head membrane damaged/tail mem-brane damaged) and Type Ⅲ (head membrane damaged/tail membrane intact) membrane integrity (n = 50, P <0.01). The value of Type Ⅲ integrity had a wide range of variability, whereas Type Ⅱ (head membrane intact/tailmembrane damaged) was uncommon after thawing. A high correlation was observed between the percentage of Type Ⅳin     

Selection of physiological spermatozoa during intracytoplasmic sperm injection

Sperm genomic integrity has a significant effect on intracytoplasmic sperm injection (ICSI) outcomes, especially post‐implantation. Spermatozoa selected based on motility and morphology do not guarantee the genomic integrity of spermatozoa. Nearly fifty percentage of spermatozoa in infertile men with normal morphology present different degrees of DNA fragmentation. However, capacitated or hyperactivated spermatozoa show lower degrees of DNA fragmentation. Therefore, selection of hyperactivated spermatozoa may improve ICSI outcome. Routinely, for ICSI, fast‐moving spermatozoa with A or B motility pattern are mainly selected for injection. The result of this study shows that in processed semen samples, hyperactivated spermatozoa are mainly observed in B motility pattern while, in viscous medium like polyvinylpyrrolidone (PVP), hyperactivated spermatozoa are mainly present in spermatozoa with C pattern of motility (nonprogressive). Therefore, we propose spermatozoa with C motility pattern which contains the main population of physiological or hyperactivated spermatozoa should be selected for ICSI.     

A new CentriSwim procedure to increase the recovery of motile spermatozoa

A prospectively controlled in vitro study was performed to compare sperm concentration, sperm motility and progressive sperm motility recovered following the standard swim-up procedure and a new CentriSwim procedure. The CentriSwim procedure involves creating a centrifugal force to counteract the force of gravity during sperm swim-up procedure. Two aliquots of semen from 12 normozoospermic ejaculates and 12 laboratory-induced oligoasthenozoospermic specimens were diluted, centrifuged, and 1.0 ml of media layered over the sperm pellet. One aliquant was processed by standard swim-up technique. The other aliquant was processed by CentriSwim procedure involving centrifugation at 200 rpm on a 2-cm radius upward-directing arm, at an angle of 60 degrees for 10 min, creating roughly 0.8 g centrifugal force at room temperature (22-24 degrees C) to counteract the force of gravity. The numbers of spermatozoa recovered from the upper 0.5 ml of the medium following CentriSwim from the normozoospermic ejaculates and laboratory-induced oligoasthenozoospermic specimens were significantly higher than following standard swim-up procedure. No statistical differences in the recovery of percentage sperm motility and progressive sperm motility between the two techniques were observed. In conclusion, the CentriSwim procedure yields higher numbers of motile spermatozoa than the standard swim-up technique.     

Oxygen uptake by mitochondria in demembranated human spermatozoa: a reliable tool for the evaluation of sperm respiratory efficiency

In this work we report a relatively simple and fast method for analysing oxygen consumption and therefore mitochondrial functionality, in individual human ejaculates. This oxygraphic method requires a low number of cells, is highly reproducible and linearly correlates with sperm concentration. Our results have shown that oxygen uptake by mitochondria of demembranated sperm cells from normozoospermic subjects is significantly stimulated by a large set of respiratory substrates and ADP. The respiratory control ratio (RCR) values indicate a good coupling between respiration and phosphorylation by sperm mitochondria and thus a well preserved integrity of the mitochondria themselves. Interestingly, whereas the rates of oxygen uptake, as expected, changed with different sperm concentrations, the RCR values remained constant, thus demonstrating a linear response of the assay. In asthenozoospermic subjects, however, a significant decrease in the sperm respiratory efficiency was found. The results obtained suggest that this method, besides its potential clinical application, could be useful for a deeper understanding of the biochemical properties of sperm mitochondria and their role in ATP production in human spermatozoa.     

Toxicity of ornidazole and its analogues to rat spermatozoa as reflected in motility parameters

Ornidazole, a 5-nitro-imidazole derivative, has contraceptive properties in rats. As some ornidazole passes through the body unmetabolized after administration, the aim of this study was to investigate if ornidazole itself has a direct effect on sperm motility and whether these effects are limited or potentiated by the epididymal epithelium or structural changes to the molecule. Cauda epididymal spermatozoa or cauda epididymal tubules were incubated with ornidazole or ornidazole analogues, and motility parameters were subsequently measured by means of a computer-assisted sperm analysis (CASA) system. Incubation of spermatozoa in 2.5 mmol/L ornidazole for 4 h reduced their motility significantly, whereas incubation of epididymal tubules for 8 h in 10 mmol/L ornidazole was required to alter the velocity parameters of the enclosed spermatozoa upon release, suggesting that extratubular non-metabolized ornidazole can participate in inhibiting the motility in vivo. The in vitro toxicity of ornidazole derivatives depends on the halogen present and on the position of the nitro-group. The putatively inactive (R)- and the active (S)-ornidazole exhibited equivalent depression of sperm motility by direct incubation. This observation, and the differences between the in vitro and the in vivo efficacies of various ornidazole analogues, indicates distinct mechanisms of motility inhibition in the two experimental systems.     

Functional motion changes during sperm transit to the site of fertilization and in-vitro applications: a review

Continued research to define the parameters of sperm function should aid the evaluation of various approaches in infertility management as well as the efficacy of contraceptives for men which do not necessarily achieve azoospermia.
Many treatment forms have been advocated for male factor infertility but have yielded little effect. These include, for example, gonadotrophins, clomiphene citrate, the weakly androgenic steroid, mesterolone. Often, improvements in oligoasthenozoospermia that are not related to genital infection, do not attain normozoospermic levels.
Owing to lack of success with the various treatment modalities, assisted reproductive technology encompassing artificial insemination by husband or donor following in vitro enhancement of sperm function have assumed an important role in male infertility. Agents that have been shown to induce and support sperm capacitation processes such as hyperactivation, could serve an important role. These include human follicular fluid (HFF), maternal serum, fetal cord serum and methyl xanthine derivatives.     

Fertilization of hamster ova by human spermatozoa in relation to other semen parameters

Different indices of the zona-free hamster ovum test system were interrelated. High correlations were found between the fertilization percentage and the average number of penetrated spermatozoa/ovum (r = 0.99) and between the fertilization percentage and the number of spermatozoa attached to the ova surfaces (r = 0.72). Fertilization percentages from 63 subfertile patients were correlated with different semen factors assessed by multiple exposure photography (MEP). Low correlations were found between sperm concentration and fertilization percentage (r = 0.29) and between fertilization percentage and motile sperm count (r = 0.33). Spermatozoa progressing with high average velocity had low fertilization rates compared to specimen with moderate average velocity. Effects of sperm washing on the in vitro fertilizing capacity were studied in a group of 40 subfertile men. The fertilization percentages of 8 specimens -with visual seminal plasma abnormalities- increased significantly when immediate dilution of semen was applied.     

Fluorescence Supravital Stain of Human Sperm: Correlation with Sperm Motility Measured by a Transmembrane Migration Method/Supravital-Fluoreszenz-Färbung von menschlichen Spermatozoen: Korrelation zur Spermatozoenmotilität (Messung mittels Transmembran-Migration-Methode)

We developed a supravital stain of human sperm with fluorescent dyes. Either Hoechst 33,258 or fluorescein isothiocyanate could be used, the former stained sperm head while the later stained the whole sperm. Sperm vitality assessed with any of these two fluorescent dyes correlated well with that determined by eosin-nigrosin counterstain. When sperm vitality was compared with sperm motility measured with a transmembrane migration method, we found that many vital sperm were immotile because sperm vitality was higher than sperm motility in tested samples.     

Lipid peroxidation in human spermatozoa and maintenance of progressive sperm motility

Washed and deep frozen spermatozoa of 46 patients from an infertility clinic were separated into 3 different groups depending on their progressive motility (expressed as the sperm motile efficiency index according to Ishii et al ., 1977), determined 0 and 3  h after liquefaction, and were examined for their lipid peroxidation (LPO) potential by means of the thiobarbituric acid assay. Spontaneous and iron-catalysed generation (after 15, 30 and 60  min incubation) of thiobarbituric acid-reactive substances (TBARS) was measured spectrophotometrically. Spontaneous LPO revealed the highest generation of TBARS in the group of spermatozoa with initially normal progressive motility and decreased maintenance of progressive motility after 3  h of aerobic incubation. Iron-catalysed LPO generally revealed the highest amounts of TBARS after 60  min, especially in the aforementioned group with decreased motility maintenance. The differences between this group and the two other groups were highly significant. Consequently, spermatozoa with initially normal progressive motility but decreased maintenance of motility, generated higher amounts of stable LPO products than others, which suggests that loss of motility under aerobic incubation seems to be the consequence of enhanced LPO processes.     

Estimate of oxygen consumption and intracellular zinc concentration of human spermatozoa in relation to motility

Aim: To investigate the human sperm oxygen/energy consumption and zinc content in relation to motility. Methods: In washed spermatozoa from 67 ejaculates, the oxygen consumption was determined. Following calculation of the total oxygen consumed by the Ideal Gas Law, the energy consumption of spermatozoa was calculated. In addition, the zinc content of the sperm was determined using an atomic absorption spectrometer. The resulting data were correlated to the vitality and motility. Results: The oxygen consumption averaged 0.24μmol/106 sperm×24 h, 0.28μmol/106 live sperm×24 h and 0.85μmol/106 live & motile sperm×24 h. Further calculations revealed that sperm motility was the most energy consuming process (164.31 mJ/106 motile spermatozoa×24 h), while the oxygen consumption of the total spermatozoa was 46.06 mJ/106 spermatozoa×24 h. The correlation of the oxygen/ energy consumption and zinc content with motility showed significant negative correlations (r= -0.759; P<0.0001 and r=-0.441; P<0.0001, res     

Evaluation of the effect of a cervical cap device on sperm functional characteristics in vitro

Intracervical insemination continues to be employed for homologous and donor insemination in natural and stimulated cycles. Efficacy studies for potential fertility involve in vivo assessment; however, in vitro testing of particular sperm function(s) critically involved in fertilization is an important component of such evaluation. We report here on the in vitro evaluation of the effects of the silicone Veos cervical cap (Veos, London, UK) on sperm function. Donor semen was exposed to the Veos cervical cap or a sterile 15-cc centrifuge tube (control), or treated with the spermicide nonoxynol-9 (5 mg x ml(-1) in saline) for 4 h at 37 degrees C and 5% CO2 in water-saturated air. After exposure, motility characteristics, both in semen and in spermatozoa processed by standard swim-up procedure, cervical mucus penetration and sperm-zona pellucida interaction using the hemizona assay were assessed. Results indicated that exposure to the Veos cervical cap had no effect on either sperm motility characteristics or sperm-zona pellucida interaction. A small but significant difference was observed for cervical mucus penetration (P = 0.05); however, for both the control and treated groups, vanguard spermatozoa exceeded manufacturer's guidelines for a normal test, a penetration distance of > or = 30 mm. As expected, nonoxynol-9 was a potent inhibitor of sperm function. Lack of adverse effects on in vitro spermatozoa functional characteristics after exposure to the silicone Veos cervical cap supports its addition to the repertoire of fertility treatment modalities when cervical insemination is indicated.     

Medium containing different concentrations of catalase as a strategy for optimising sperm parameters and chromatin in normospermic persons

The aim of this study was to comprise the effect of catalase on sperm parameters and chromatin in normospermic persons. Semen samples were obtained from fertile men. A certain amount of different concentrations of catalase (0.1, 1, 10, 50, 100, 150 and 200 IU.ml) was added to each vial containing semen. Control group had similar condition to treated groups without treatment. Treatment was done for one hour in incubator and 4 and 24 hr in room temperature. Sperm parameters (motility, viability and morphology ) and chromatin were evaluated after incubation. The results show that percentage of motility was insignificantly increased at concentration of 100 IU.ml catalase. This increase was higher than other examined concentration in all incubation time. The increase in sperm motility had significant difference in concentrations of 100 IU.ml with other concentrations. Other parameters showed no significant difference in all concentrations. Regarding the health of sperm chromatin, low concentrations of catalase had significant effect on this variable. This effect was more in low concentrations than high concentrations. This study showed the use of lower concentrations of antioxidant can improve the sperm parameters and chromatin quality. The low concentrations of catalase led to protection of chromatin and optimisation of sperm parameters.     

The progesterone‐induced sperm acrosome reaction is a good option for the prediction of fertilization in vitro compared with other sperm parameters

Progesterone (P₄) is crucial for the physiological function of spermatozoa. In the study, we investigated the correlation between P₄‐induced sperm acrosome reaction (AR) and parameters including sperm progressive motility, normal morphology and sperm DNA fragmentation (SDF), and compared the in vitro fertilization (IVF) predictive values of these indicators based on the multivariate regressions analysis and receiver operator characteristics (ROC) curve analyses. The results demonstrated a negative correlation between P₄‐induced sperm AR and the SDF, with the correlation ?9.05 (?17.25 to ?0.84), p<0.05, n = 47). No relationship was found between the sperm progressive motility, normal morphology and the induced AR. The P₄‐induced AR and SDF were both significantly correlated to the fertilization rate. ROC curve analyses indicated that P₄‐induced AR was a better prognostic predictor for the fertilization rate compared with the SDF, with the areas under the curve 0.729 (0.580–0.849), p<0.01 and 0.637 (0.484–0.772), p=0.16 respectively. The cut‐off value for P₄‐induced AR to predict “50% fertilization rate” was 23.4% with sensitivity and specificity of 63.3% and 88.2% respectively. The overall results indicated that the assessment of P₄‐induced AR seemed to be a more sensitive indicator for fertilization rate in vitro compared with other sperm parameters.     

Comparison between a conventional index of progressive sperm motility and movement variables analysed by CellSoft®

Two different techniques of human sperm motion analysis were compared. In 25 ejaculates, diluted to an appropriate concentration, the sperm motion index called "specific progressive motility" (SPM) was assessed by a modified conventional method. The same sperm preparations were also analysed by the CellSoft system for computer assisted sperm analysis (CASA). The SPM-value was found to correspond mainly to the variables motility and curvilinear velocity presented by CASA (multiple r = 0.92, P less than 0.001). Linearity of sperm progression, lateral head displacement, and beat cross frequency did not significantly contribute to the relationship between SPM and CASA. For comparative studies between SPM and CASA the logarithmic values of SPM are recommended.     

Human sperm pattern of movement during chemotactic ＇e-orientation towards a progesterone source

Human spermatozoa may chemotactically find out the egg by following an increasing gradient of attractant molecules. Although human spermatozoa have been observed to show several of the physiological characteristics of chemotaxis, the chemotactic pattern of movement has not been easy to describe. However, it is apparent that chemotactic cells may be identified while returning to the attractant source. This study characterizes the pattern of movement of human spermatozoa during chemotactic re-orientation towards a progesterone source, which is a physiological attractant candidate. By means of videomicroscopy and image analysis, a chemotactic pattern of movement was identified as the spermatozoon returned towards the source of a chemotactic concentration of progesterone (10 pmol l⁻¹). First, as a continuation of its original path, the spermatozoon swims away from the progesterone source with linear movement and then turns back with a transitional movement that can be characterized by an increased velocity and decreased linearity. This sperm behaviour may help the spermatozoon to re-orient itself towards a progesterone source and may be used to identify the few cells that are undergoing chemotaxis at a given time.