Influence of pentoxifylline in severe male factor infertility

Effects of pentoxifylline on sperm motility and hyperactivation in normozoospermic and normokinetic semen

OBJECTIVE

To determine the effects of in vitro incubation with pentoxifylline on sperm motion characteristics of spermatozoa from normozoospermic, normokinetic specimens.

DESIGN

Prospective, controlled experiment.

SETTING

Andrology laboratory, university-based fertility center.

PARTICIPANTS

Healthy, untreated male partners of couples attending the fertility center.

INTERVENTION

Each specimen was washed, pelleted by centrifugation, then resuspended in human tubal fluid medium (HTF). Two portions were incubated at 37 degrees C, one with pentoxifylline (final concentration = 1 mg/mL = 3.6 mM) and the other without pentoxifylline (control). After 1 hour, the pentoxifylline-treated portion was divided: one half was washed to remove pentoxifylline, then further incubated in HTF; the other half remained incubated in HTF with pentoxifylline.

MAIN OUTCOME MEASURES

Motility, hyperactivation, amplitude of lateral head displacement (ALH), curvilinear velocity (VCL), straight line velocity (VSL), linearity (LIN), beat-cross frequency.

RESULTS

Incubation with pentoxifylline did not increase motility, VSL, LIN, or beat-cross frequency but did significantly increase HA, VCL, and ALH at 1, 2, and 4 hours, compared with control. Incubation in control medium without pentoxifylline did not significantly increase any of the parameters measured. After 24 hours of incubation with or without pentoxifylline, all parameters measured were significantly decreased, with the exception of LIN.

CONCLUSIONS

Pentoxifylline does not increase percentage motility of washed spermatozoa in capacitation medium. Enhancement of sperm HA by pentoxifylline in capacitation medium occurs with normozoospermic, normokinetic semen specimens. This effect persists for up to 4 hours when pentoxifylline is removed from the medium after 1 hour of incubation.

Effect of pentoxifylline on sperm motion

The ability of pentoxifylline to stimulate sperm motility characteristics was assessed. The effect of pentoxifylline was immediate and lasted for 240 min. The percent motility was increased 1.5-fold when compared with the control at 120, 180, and 240 min after pentoxifylline treatment. Significant increases in velocity and amplitude of lateral head displacement by the agent were observed at 120 min after the start of incubation. Conversely, linearity was reduced by pentoxifylline. Beat-cross frequency did not show any significant change by the agent at any time point. Sperm swelling was not influenced by pentoxifylline throughout the experiment. It would appear that pentoxifylline stimulates sperm motion in vitro with no change of the sperm membrane.

Sperm treatment with pentoxifylline improves the fertilizing ability in patients with acrosome reaction insufficiency

OBJECTIVE

To test whether pentoxifylline, a drug previously shown to sensitize spermatozoa from normal samples to the action of acrosome reaction stimuli, can be used to improve the fertilizing ability of spermatozoa from patients with acrosome reaction insufficiency.

DESIGN

Prospective analysis of pentoxifylline effects on the acrosome reaction and zona-free egg penetration; retrospective comparison of IVF results with and without the use of pentoxifylline.

SETTING

Private hospital, public research center, and university-based laboratory.

PATIENTS

In vitro fertilization patients selected on the basis of a previous acrosome reaction test.

INTERVENTIONS

None in the experimental part; IVF-ET in the clinical part of this study.

MAIN OUTCOME MEASURES

Frequency of the acrosome reaction, rate of penetration of zona-free eggs, normal fertilization in IVF attempts.

RESULTS

Pentoxifylline improves the acrosome reaction scores and zona-free egg penetration rates in patients with acrosome reaction insufficiency. Preliminary clinical experience shows an improvement of IVF results in these patients.

CONCLUSIONS

In vitro pentoxifylline treatment of spermatozoa to be used in IVF improves the sperm fertilizing ability in patients with acrosome reaction insufficiency. However, the effect of pentoxifylline on the acrosome reaction should be tested individually in each patient before the application of the drug in this new indication.

Microsurgical aspiration of sperm from the epididymis: a mobile program

We report data from 25 microsurgical aspirations of the epididymis on 22 men. There were 14 men with congenital absence of the vas, 6 with failed vasoepididymostomy, 1 with adult cystic fibrosis and 1 with a childhood hernia repair. The specimens were used for assisted reproductive technologies, including in vitro fertilization and tubal embryo transfer. The protocol for aspiration, ovulation induction and sperm processing evolved during the course of these studies, and the patients were classified into 2 groups on the basis of methodology. Seventeen procedures were performed for the in-house in vitro fertilization team but 8 other procedures were done for nearby in vitro fertilization centers, and the final prepared sperm samples were transported as part of our mobile program. Group 1 patients underwent standard aspiration techniques, standard ovulation induction and sperm processing by wash and swim up. Among this group there were no fertilizations or pregnancies with 8 in-house and 2 transported specimens. Group 2 patients had leuprolide suppression before ovulation induction, direct intratubular aspiration and a complex sperm preparation, including pentoxifylline stimulation, mini-Percoll filtration and incubation with human follicular fluid. Among this group there were 2 fertilizations and 1 pregnancy with 9 in-house cases, and 3 fertilizations and 2 pregnancies with 6 transported specimens. These results suggest that a mobile program for microsurgical aspirations of sperm from the epididymis and in vitro fertilization or tubal embryo transfer is feasible within the framework of a strict protocol.

Effects of pentoxifylline on human sperm motility in normospermic individuals using computer-assisted analysis

OBJECTIVE

To determine if pentoxifylline has an in vitro effect on human sperm motility in subjects with normal semen analysis.

DESIGN

Prospective, longitudinal study of the effect of pentoxifylline on normospermic semen samples using computerized analysis.

SETTING

The Assisted Conception Unit, Royal Maternity Hospital, Belfast.

SUBJECTS

Eight healthy male volunteers of proven fertility within 2 years of study and whose general health was unchanged in the intervening period.

RESULTS

Pentoxifylline did not consistently increase the number of progressively motile sperm or their straight line velocity (VSL). In marked contrast, the curvilinear velocity (VCL) was increased significantly at all times, up to and including 240 minutes of exposure to the drug. This resulted in a substantial reduction in the linearity (VSL/VCL) of sperm progression. The most dramatic effect that pentoxifylline had on sperm movement was to increase the amplitude of lateral head displacement (ALH) over the same time interval. This change was accompanied by an increase in the beat cross frequency.

CONCLUSIONS

The addition of pentoxifylline to prepared sperm samples from normospermic men does not increase the number of progressively motile sperm nor the progressive velocity. However, it does significantly alter the quality of certain characteristics of already motile sperm.

Pentoxifylline is not useful in enhancing sperm function in cases with previous in vitro fertilization failure

OBJECTIVE

To assess the efficiency of the addition of pentoxifylline to spermatozoa for in vitro fertilization (IVF) in cases with previous fertilization failure.

DESIGN

After retrieval, oocytes were divided at random and inseminated with spermatozoa prepared with or without pentoxifylline.

SETTING

In vitro fertilization program of the Centre for Reproductive Medicine of the Dutch-speaking Brussels Free University, Belgium, a tertiary referral institution.

PATIENTS

Couples in this study were undergoing a second or third IVF attempt for the treatment of male factor infertility.

INTERVENTIONS

Sperm samples were divided into two equal parts. The first part was prepared with 3.6 mM pentoxifylline (treatment group) and the other part without pentoxifylline (control group). After swim-up, oocytes were randomly inseminated with spermatozoa from either treatment.

MAIN OUTCOME MEASURES

Fertilization and cleavage rates after IVF.

RESULTS

Overall a fertilization rate of 8.8% was achieved with no significant differences between treatment and control groups. Cleavage rate was 81.5% and was not different between groups.

CONCLUSIONS

This study demonstrates no therapeutic advantage of using pentoxifylline in IVF for male factor infertility in cases with previous fertilization failure.

Effects of phosphodiesterase inhibitors caffeine and pentoxifylline on spontaneous and stimulus-induced acrosome reactions in human sperm

OBJECTIVE

To determine whether the phosphodiesterase inhibitors caffeine and pentoxifylline influence the acrosome reaction in the conditions in which they are currently used as sperm movement enhancers.

DESIGN

The frequency of acrosome reaction occurring spontaneously in capacitating media or induced by physiological (follicular fluid [FF]) and artificial (ionophore A23187) stimuli was compared in the presence and absence of the phosphodiesterase inhibitors.

SETTING

Private hospital and research laboratory.

PATIENTS, PARTICIPANTS

Patients undergoing routine semen examination before in vitro fertilization (no pathology detected) and healthy sperm donors.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE

Percentage of acrosome-reacted sperm determined with the use of fluorescein-labeled Pisum sativum agglutinin as acrosomal stain.

RESULTS

Caffeine alone augmented the frequency of acrosome reaction, but this effect was not observed with pentoxifylline alone. However, pentoxifylline increased sperm responsiveness to the acrosome reaction-inducing stimuli, FF and ionophore A23187.

CONCLUSIONS

The promotion of spontaneous acrosome reaction may counteract the benefits from application of caffeine as motility stimulant. On the other hand, the sensitization to physiological acrosome reaction stimuli is expected to contribute to the improvement of sperm fertilizing ability by pentoxifylline and make this drug a potential candidate for the treatment of acrosome reaction anomalies.

Enhanced gamete interaction in the sperm penetration assay after coincubation with pentoxifylline and human follicular fluid

OBJECTIVE

To evaluate the effect of pentoxifylline and heat-inactivated human follicular fluid (FF) on performance in the sperm penetration assay (SPA) as a paradigm for the effect of these agents on human sperm-egg interaction in vivo and in vitro fertilization.

DESIGN

Semen specimens from men undergoing SPA testing for evaluation of suspected male factor infertility were coincubated with neat medium or media supplemented with pentoxifylline or human FF in a nonblinded manner.

PARTICIPANTS

Twenty male factor infertility patients.

INTERVENTIONS

Semen specimens were preincubated with: [1] pentoxifylline 0.25 mg/mL; [2] 10% human FF; [3] pentoxifylline+human FF; and [4] neat Biggers, Whitten, and Whittingham medium.

MAIN OUTCOME MEASURES

Differences in the rate of penetration of zona-free hamster oocytes.

RESULTS

Preincubation with either human FF or pentoxifylline produced a significant improvement in hamster egg penetration rates. Coincubation with a combination of human FF and pentoxifylline resulted in a significant enhancement of penetration as compared with single agent treatment.

CONCLUSIONS

Coincubation of sperm with human FF and pentoxifylline may provide a means of enhancing sperm activity for insemination and assisted reproduction.

Penetration of zona-free hamster oocytes using human sperm aspirated from the epididymis of men with congenital absence of the vas deferens: comparison with human in vitro fertilization

OBJECTIVES

To assess the ability of sperm aspirated from the epididymis of men with congenital absence of the vas deferens to penetrate zona-free hamster oocytes. To directly compare the performance of human epididymal sperm in the zona-free hamster oocyte sperm penetration assay (SPA) with the results of human in vitro fertilization (IVF).

DESIGN

Sperm penetration assay was carried out with epididymal sperm retrieved microsurgically, and with ejaculated sperm obtained from fertile donors (internal controls). For direct comparison, SPA was performed with the same epididymal sperm sample used for IVF.

PATIENTS, PARTICIPANTS

Men with congenital absence of the vas deferens undergoing sperm aspiration as part of their infertility treatment and control donors who provided ejaculated sperm.

RESULTS

Epididymal sperm penetrated SPA with a score of 0% to 30%. The SPA scores for internal controls using ejaculated sperm was 30% to 71%. Linear regression analysis of the association between penetration scores in SPA and fertilization rate in IVF indicated a positive correlation that was highly significative.

CONCLUSIONS

These findings using SPA confirm previous reports on the fertilizing potential of human epididymal sperm and its ability to produce normal pregnancies. The good correlation between SPA and human IVF using epididymal sperm suggest that SPA is an excellent bioassay to test laboratory experimental conditions for improving fertilizing capacity of human epididymal sperm.

Failure to fertilize in vitro in couples with male factor infertility: what next?

OBJECTIVE

To assess the predictive value of a failure to fertilize in vitro in couples with sperm abnormalities on future fertility.

DESIGN

Retrospective file review.

SETTING

In vitro fertilization and embryo transfer (IVF-ET) program in the Sheba Medical Center during the years 1983 to 1990.

PATIENTS

Seventy-six couples with sperm abnormalities who had at least one IVF cycle during which fertilization did not occur.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Occurrence of fertilization, percentage of fertilization, and pregnancies in additional IVF-ET cycles.

RESULTS

Of 44 couples who underwent an additional IVF attempt with husband's sperm, 36 (81.2%) fertilized, with a mean fertilization rate of 47.7% +/- 26.6%. Of 17 couples who failed twice, 11 attempted IVF again with husband's sperm and 7 fertilized, with a median rate of 33%. A higher sperm concentration was found on the cycles during which fertilization occurred. Men with single parameter abnormalities did not fertilize better than those with two or three defective parameters.

CONCLUSIONS

Failure to fertilize in vitro in couples with male factor infertility does not seem to predict future fertilization in IVF. At least two cycles of IVF should be tried before reverting to other options such as insemination by donor sperm or gamete micromanipulation.

The role of the laboratory in the handling of epididymal sperm for assisted reproductive technologies

This report describes the historical experience of our laboratory in the handling and processing of epididymal sperm from men with congenital absence of the vas deferens. Three different methods of sperm preparation were used: swim-up or resuspension in the first group of patients treated, mini-Percoll in the second group, and mini-Percoll used in conjunction with pentoxifylline and 2' deoxyadenosine in the third group. Twenty-four percent of cases achieved fertilization in group I, whereas in groups II and III the rate was 59% and 57%, respectively. Fertilization rates in each group were 6.5% in group I, 16% in group II, and 35% in group III. Three pregnancies were obtained in group I, 13 in group II, and 2 in group III. Groups II (21%) and III (63%) were able to have excess embryos to cryopreserve.

Methylxanthines in surgery: a bright future?

Methylxanthines have been used in clinical practice for over 100 years, and although understanding of their mechanisms of action is growing their effects are not fully understood. Nevertheless the knowledge to date has brought about a general upsurge of interest in methylxanthines and the development of novel derivatives. Methylxanthines are poised to escape the confines of their traditional role as these agents are applied in novel ways to surgical illnesses such as septic shock, the adult respiratory distress syndrome, cancer cachexia and functional neutrophil disorders. Methylxanthines, alone or in combination with other compounds, may well become part of the surgeon's future stock-in-trade.

Preliminary communication: possible role of reactive nitrogen intermediates in leucocyte-mediated sperm dysfunction

This preliminary study was designed to examine whether nitric oxide, a reactive nitrogen intermediate produced by leukocyte metabolism of L-arginine, could reduce sperm motility. Increasing doses (10(-6)-10(-4) M) of the nitric oxide-generating drug, sodium nitroprusside (SNP) were added to motile sperm preparations and incubated over 20 hr. Quantitative sperm motility measurements were made using a computer-assisted motility analyzer in each treated sample and controls over this time period. The percentage of motile sperm, progressive motility, and concentration of motile cells were all significantly reduced with all doses of SNP. This effect was not observed in preparations treated with oxyhaemoglobin (HbO2). Mean path velocity was unaltered. Sperm viability in SNP treated sperm did not differ significantly from that of control sperm over the same time period. We conclude that further experiments are required to determine whether the production of nitric oxide/reactive nitrogen intermediates in vivo by activated leukocytes could be a contributory factor in the development of immunologic infertility.

Pentoxifylline-mediated reduction of superoxide anion production by human spermatozoa

The release of superoxide anions from sperm suspensions prepared for in vitro fertilization was measured by superoxide dismutase-inhibitable reduction of ferricytochrome C in response to phorbol myristate acetate. The superoxide anion production was found to be within the range of 0.21-3.76 nmoles O2- per 10(6) spermatozoa. Spermatozoa pre-incubated in the presence of 3.7 or 10 mM of pentoxifylline for 30 min at 37 degrees C released less (P less than 0.001) superoxide anions than did the untreated-control spermatozoa. It has been concluded that the inhibitory effect of pentoxifylline on superoxide anion production may be a factor contributing to the improvement of sperm preparation before insemination, and may, thereby, increase the fertility potential.

Effect of pentoxifylline on superoxide anion production by human sperm

The in-vitro effect of pentoxifylline, a methylxanthine derivative, on superoxide anion generation by sperm was studied in 27 men with superoxide anion production ranging from 0.57 to 13.8 nmoles 02-. per 10(6) sperm. Superoxide anion release stimulated by phorbol myristate acetate, a potent activator of oxygen radical generation, was reduced by 29-72% following the addition of 10 mM pentoxifylline. The inhibitory effect of this millimolar concentration of the drug did not depend on the initial superoxide production in the presence of phorbol myristate acetate. These results point to a potential use for pentoxifylline in the treatment of male infertility in men with an increased superoxide anion generation capacity.