Influence of pentoxifylline in severe male factor infertility

Pregnancy and neonatal outcomes of ICSI using pentoxifylline to identify viable spermatozoa in patients with frozen-thawed testicular spermatozoa

Introduction

Although the effectiveness of pentoxifylline (PF) as a selective inhibitor of phosphodiesterase to enhance sperm motility through increasing cyclic nucleotide in cases of absolute asthenozoospermia has been demonstrated for ICSI, data related to babies born from the PF-ICSI are still severely lacking. Concerns have been raised regarding the potential embryotoxicity of PF due to the controversial results obtained from the analysis of this compound on animal embryo development. This study aimed to determine whether the application of PF to trigger frozen-thawed TESA (testicular sperm aspiration) spermatozoa increases the risk of adverse obstetric and neonatal outcomes compared with non-PF frozen-thawed TESA ICSI and conventional ICSI using fresh ejaculation.

Materials and methods

A total of 5438 patients were analyzed in this study, including 240 patients underwent PF-TESA ICSI (ICSI using PF triggered frozen-thawed testicular spermatozoa), 101 patients underwent non-PF TESA ICSI (ICSI using frozen-thawed testicular spermatozoa) and 5097 patients underwent conventional ICSI using fresh ejaculation. Propensity score matching was executed to control the various characteristics of patients.

Results

No significant differences in pregnancy outcomes were observed among the three groups (PF-TESA ICSI, non-PF TESA ICSI and conventional ICSI), including biochemical pregnancy, clinical pregnancy, implantation, miscarriage, ectopic pregnancy, multiple pregnancy, and live birth, following propensity score matching. Additionally, neonatal outcomes were found to be similar among the three groups, with no statistical differences observed in the birth defect, birth weight, gestational age, preterm birth, and early-neonatal death.

Discussion and conclusion

PF-ICSI may be an alternative treatment in patients using frozen-thawed testicular spermatozoa, resulting in comparable pregnancy and neonatal outcomes.

Comparison between combination of tamsulosin and Pentoxifylline versus tamsulosin alone in the treatment of lower urinary tract symptoms due to benign prostate hyperplasia: A preliminary study

BACKGROUND

In older adults, bladder outlet obstruction (BOO) is prevalent, primarily due to benign prostatic hyperplasia (BPH). These patients' lower urinary tract symptoms can be treated surgically and with medical therapy. Compared to standard treatment with tamsulosin, Pentoxifylline, a phosphodiesterase inhibitor, could benefit patients with BOO due to its properties on microcirculatory blood flow and oxygenation of ischemic tissues. Hence, this trial intended to study the efficacy of Pentoxifylline combined with tamsulosin in treating BOO patients.

MATERIALS AND METHODS

This randomized, double-blind clinical trial recruited 60 patients with BPH from a single center in 2022. Upon consent of patients meeting the eligibility criteria, they were randomly allocated to intervention (Pentoxifylline + tamsulosin) and control (placebo + tamsulosin) groups. The patients were evaluated for international prostate symptom score (IPSS), quality of life (QoL), maximum urinary flow rate (Qmax ) by uroflowmetry, and post-void residual volume (PVR) by abdominal sonography at the onset of the study and after the 12th week.

RESULTS

Patients who used the combination therapy had significantly better results of prostate symptoms and quality of life improvement (IPSS: -36.6%, QoL: -45.3%) compared to patients who received tamsulosin alone (IPSS: -21.2%, QoL: -27.7%) (p < .001). Also, this study shows that the improvement in maximum urinary flow rate and residual volume by combination therapy is significantly higher (Qmax : +42.5%, PVR: -42.6%) compared to monotherapy (Qmax : +25.1%, PVR: -26.1%) (p < .001).

CONCLUSION

When combined with tamsulosin, Pentoxifylline could significantly improve the lower urinary symptoms of BPH patients. It is well tolerated, and the treatment outcomes are better in patients who receive the combination of Pentoxifylline and tamsulosin than those who only receive tamsulosin.

PDE5 inhibitors and male reproduction: Is there a place for PDE5 inhibitors in infertility clinics or andrology laboratories?

The objective of this review study is to evaluate the therapeutic role of PDE5 inhibitors (PDE5is) in the amelioration of oligoasthenospermia in infertile males. PDE5is have a beneficial influence on the secretory function of the Leydig and Sertoli cells, the biochemical environment within the seminiferous tubule, the contractility of the testicular tunica albuginea, and the prostatic secretory function. In several studies, the overall effect of sildenafil and vardenafil increased quantitative and qualitative sperm motility. Furthermore, some studies indicate that PDE5is influence positively the sperm capacity to undergo capacitation under biochemical conditions that are known to induce the sperm capacitation process. Additional research efforts are necessary in order to recommend unequivocally the usage of sildenafil, vardenafil, or avanafil for the alleviation of male infertility.

Efficacy and safety of papaverine as an in vitro motility enhancer on human spermatozoa

PURPOSE

The aim of this study was to examine the ability and safety of papaverine supplementation for in vitro sperm motility enhancement. In addition, sperm motility enhancement of papaverine was compared to pentoxifylline and theophylline. The post-thaw spermatozoa were used as an asthenozoospermia model.

METHODS

Post thaw sperm suspensions were divided into two groups: papaverine (100 μmol/L) and control, and each was investigated in two subgroups of 30- and 60-min exposure times. Detailed motility parameters were detected using a computerized sperm motility analyzer. Acrosomal status, viability, apoptosis, and DNA fragmentation were evaluated by flow cytometry. Furthermore, the motility-enhancing capacity of papaverine, pentoxifylline, and theophylline was compared.

RESULTS

Cryopreservation impaired sperm parameters dramatically but no significant changes occurred in acrosomal status and apoptosis. Supplementation of papaverine enhanced motility parameters consistently at all exposure intervals, significantly. However, viability was lower at the 60th minute compared to the 30th minute (p=0.019). Papaverine did not alter any acrosomal or apoptotic markers at any time points. All of the compounds compared in this study increased the motility parameters, where theophylline supplementation provided significantly better improvement in total motility compared to papaverine and pentoxifylline.

CONCLUSION

Our results suggest that in vitro papaverine treatment for 30 min adequately improves motility of post-thaw sperm, without leading to acrosome reaction, DNA damage, and viability loss. Theophylline's potency on increasing the ratio of total motile spermatozoa was found significantly superior than the two tested compounds. Prospective clinical studies with embryo production, pregnancy, and live birth data should be undertaken.

The synthesis of a novel pentoxifylline derivative with superior human sperm motility enhancement properties

mPTF1 demonstrated lower genotoxicity, higher affinity for PDEs, & reasonable pharmacokinetic, druglikeness & ADMET properties compared to Pentoxifylline.

Quinoline Derivative Enhances Human Sperm Motility and Improves the Functional Competence

In this study, we aimed to explore the beneficial properties of novel quinoline derivatives on human sperm motility and its functional competence. Nine novel quinoline derivatives were screened for their effect on motility in human spermatozoa from normozoospermic ejaculates. Compounds with impressive sperm motility enhancement properties were further assessed for their effect on functional competence of human spermatozoa. To determine the effect on the fertilizing ability of spermatozoa processed with quinoline derivatives and to assess developmental competence of embryos derived, in vitro fertilization (IVF) was performed using mouse model. Among the nine quinoline derivatives, 2 compounds (6MQT and 2,6DQT) exhibited significant enhancement in sperm progressive motility and survival at 24 h. Further, non-significant increase in curvilinear velocity (VCL), straight line velocity (VSL), and amplitude of lateral head displacement (ALH) was observed. Capacitation, intracellular cAMP level and tyrosine phosphorylated sperm proteins were significantly higher in 6MQT (P < 0.05) and 2,6DQT (P < 0.001) compared to control. In vitro fertilization (IVF) experiments using Swiss albino mice revealed that spermatozoa processed with 6MQT had non-significantly higher blastocyst rate and a superior blastocyst quality, while, 2,6DQT resulted in significantly lower blastocyst rate (P < 0.05) compared to control. Quinoline derivative 6MQT has significant motility enhancement property under in vitro conditions.

Use of dimethylxanthine theophylline (SpermMobil®) does not affect clinical, obstetric or perinatal outcomes

PURPOSE

To evaluate whether the use of a commercially available dimethylxanthine theophylline compound (SpermMobil^®) for artificial sperm activation would negatively affect clinical, obstetric and perinatal outcomes.

METHODS

Artificial sperm activation (ASA) was used when sperm motility after preparation was low or absent in our clinical standard procedure practice. ICSI cycles using either testicular or ejaculated sperm with concentration smaller than 5 million/ml from August 2012 to January 2018 were retrospectively analyzed (n = 815) and divided into two groups, a control group where no ASA was needed and the SpermMobil^® group with ASA.

RESULTS

The fertilization rate was significantly higher in the control group, but pregnancy and implantation rates did not differ significantly. Number of embryos transferred, good quality embryos for ET and number of frozen blastocysts were similar in both groups. Clinical pregnancy loss was significantly reduced in the SpermMobil^® group, which was reflected in slightly better live birth rates than in the control group. Furthermore, there were no significant differences regarding gestational age, weight, height and z score for singletons or multiples in the SpermMobil^® (n = 27 and n = 10) or control (n = 144 and n = 67) groups. There were no reports of malformation, perinatal mortality or intensive therapy in the SpermMobil^® group, whereas in the control group, 12 babies needed intensive care, besides one intrauterine death.

CONCLUSION

The use of SpermMobil^® in samples with mostly immotile sperm not only facilitates the embryologists work but also optimizes the treatment outcomes for those patients with a bad prognosis. This is the first report of obstetric and perinatal outcomes after applying a theophylline derivative in human clinical use.

The Effect of Different Concentrations of Caffeine, Pentoxifylline and 2’-Deoxyadenosine on the Biological Properties of Frozen-Thawed Canine Semen

Artificial insemination (AI) and semen cryopreservation are the most accessible and commonly used techniques for breeding domestic animals. Among many parameters, such as plasma membrane integrity and acrosome structure, one of the key factors that determine the quality of frozen-thawed samples for artificial insemination is sperm motility. Sperm motility is one of the key parameters that determine the quality of frozen-thawed samples for AI. The total number of progressively motile spermatozoa in thawed canine semen is correlated with fertility. A variety of substances were used to compare sperm motility with the control. The aim of this study was to determine the effect of semen extender supplementation with motility stimulants, pentoxifylline (PTX), caffeine (CAF) and 2’-deoxyadenosine (DX), after different post-thaw incubation times (30, 60, 120 min) on the motility, selected kinematic parameters, plasma membrane integrity and mitochondrial membrane potential of cryopreserved canine spermatozoa. During attempts to improve the quality of cryopreserved semen, the applied substances exerted beneficial effects at a concentration of 10 mM. We demonstrated that both phosphodiesterase inhibitors, caffeine and pentoxifylline, as well as 2’-deoxyadenosine increased the motility and selected kinematic parameters of thawed canine spermatozoa.

Supplementation of biotin to sperm preparation medium enhances fertilizing ability of spermatozoa and improves preimplantation embryo development

PURPOSE

Motility of spermatozoa helps not only in planning the type of infertility treatment but also directly reflects the success rate in assisted reproductive technology (ART). Previously, biotin, a water-soluble vitamin, has been shown to increase the motility and longevity of cryopreserved human spermatozoa. The present study was designed to understand the molecular basis of the beneficial effects of presence of biotin in sperm wash medium on early embryo development.

METHODS

The effect biotin supplementation to sperm wash medium on the sperm parameters were assessed in swim-up fraction of normozoospermic and asthenozoospermic ejaculates collected from infertile men. Fertilization and early embryo development was studied using Swiss albino mice.

RESULTS

Even though both biotin and pentoxifylline (PTX) enhanced the motility of spermatozoa from normozoospermic and asthenozoospermic samples, biotin group exhibited higher in vitro survival. Using mouse model, we observed that presence of biotin or PTX in sperm wash medium improved the fertilization rate and blastocyst rate compared to control. Blastocysts from these groups had significantly higher total cell number (P < 0.01) and lower apoptotic index. In silico target prediction revealed that GTPase HRas (HRas), tyrosine-protein phosphatase nonreceptor type 1 (PTP1B), and glucokinase are the probable targets for biotin. Solution-state Nuclear Magnetic Resonance (NMR) studies confirmed that biotin interacts both with human HRas and PTP1B.

CONCLUSION

Our results indicate that presence of biotin in sperm wash medium can improve the fertilization potential and preimplantation embryo development and can be considered as a safe alternate to PTX.

The pioneering of intracytoplasmic sperm injection: historical perspectives

Intracytoplasmic sperm injection (ICSI) has often been heralded as a ground-breaking technique that has transformed the treatment of couples with infertility. By injecting a single spermatozoon into the cytoplasm of the oocyte, ICSI bypasses the zona pellucida and increases the chances of fertilization and subsequent embryo development, independent of semen parameters. Ever since the first live births using ICSI were reported in 1992, ICSI has become the mainstay of treating male factor infertility as well as overcoming fertilization failure associated with conventional in vitro insemination. Today, ICSI is utilized in nearly 66% of all assisted reproductive treatments worldwide and has resulted in the birth of millions of babies. The primary goal of this review is to provide historical perspectives about the pioneering of ICSI. We begin by highlighting the scientific work of early investigators who elucidated the mechanisms central to mammalian fertilization. Furthermore, we briefly discuss how these findings contributed to the development of IVF for the treatment of infertility. We then emphasize the shortcomings of IVF in treating severe forms of male factor infertility and enumerate the micromanipulation techniques that were developed to circumvent these shortcomings. Finally, we indicate how the inadequacies of these micromanipulation techniques lead to the inception, application and popularity of ICSI.

Effect of various concentrations of caffeine, pentoxifylline, and kallikrein on hyperactivation of frozen bovine semen

Caffeine, pentoxifylline, and kallikrein are substances that affect the efficiency of sperms in the fertilization process; however, they have not been adequately studied. The present study aimed to examine the influence of caffeine, kallikrein, and pentoxifylline on sperm motility in bovine as well as investigate their optimum concentrations for increasing the movement of sperms in bovine. Frozen bovine sperms were thawed in universal IVF medium supplemented with 1, 5, and 10 mM caffeine or pentoxifylline or 1, 4, and 8 U/mL kallikrein and were then incubated for 30 min. Treated semen parameters were analyzed using a computer assisted semen analyzer (CASA). Data analysis showed that the mean values concerning progression and motility of sperm increased in caffeine and pentoxifylline treatments when compared with the kallikrein group. The obtained results revealed that kallikrein is not necessary for the improvement of bovine sperm motility. Additionally, our results revealed that 5 mM from caffeine was the best concentration added to the medium, followed by 1 or 5 mM from pentoxifylline. Therefore, it is concluded from the present study that caffeine has hyperactivation efficacy at 5 mM concentration compared to other treatments.

Clinically relevant enhancement of human sperm motility using compounds with reported phosphodiesterase inhibitor activity

STUDY QUESTION

Can we identify compound(s) with reported phosphodiesterase inhibitor (PDEI) activity that could be added to human spermatozoa in vitro to enhance their motility without compromising other sperm functions?

SUMMARY ANSWER

We have identified several compounds that produce robust and effective stimulation of sperm motility and, importantly, have a positive response on patient samples.

WHAT IS KNOWN ALREADY

For >20 years, the use of non-selective PDEIs, such as pentoxifylline, has been known to influence the motility of human spermatozoa; however, conflicting results have been obtained. It is now clear that human sperm express several different phosphodiesterases and these are compartmentalized at different regions of the cells. By using type-specific PDEIs, differential modulation of sperm motility may be achieved without adversely affecting other functions such as the acrosome reaction (AR).

STUDY DESIGN, SIZE, DURATION

This was a basic medical research study examining sperm samples from normozoospermic donors and subfertile patients attending the Assisted Conception Unit (ACU), Ninewells Hospital Dundee for diagnostic semen analysis, IVF and ICSI. Phase 1 screened 43 commercially available compounds with reported PDEI activity to identify lead compounds that stimulate sperm motility. Samples were exposed (20 min) to three concentrations (1, 10 and 100 µM) of compound, and selected candidates (n = 6) progressed to Phase 2, which provided a more comprehensive assessment using a battery of in vitro sperm function tests.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All healthy donors and subfertile patients were recruited at the Medical Research Institute, University of Dundee and ACU, Ninewells Hospital Dundee (ethical approval 08/S1402/6). In Phase 1, poor motility cells recovered from the 40% interface of the discontinuous density gradient were used as surrogates for patient samples. Pooled samples from three to four different donors were utilized in order to reduce variability and increase the number of cells available for simultaneous examination of multiple compounds. During Phase 2 testing, semen samples from 23 patients attending for either routine diagnostic andrology assessment or IVF/ICSI were prepared and exposed to selected compounds. Additionally, 48 aliquots of prepared samples, surplus to clinical use, were examined from IVF (n = 32) and ICSI (n = 16) patients to further determine the effects of selected compounds under clinical conditions of treatment. Effects of compounds on sperm motility were assessed by computer-assisted sperm analysis. A modified Kremer test using methyl cellulose was used to assess sperm functional ability to penetrate into viscous media. Sperm acrosome integrity and induction of apoptosis were assessed using the acrosomal content marker PSA-FITC and annexin V kit, respectively.

MAIN RESULTS AND THE ROLE OF CHANCE

In Phase 1, six compounds were found to have a strong effect on poor motility samples with a magnitude of response of ≥60% increase in percentage total motility. Under capacitating and non-capacitating conditions, these compounds significantly (P ≤ 0.05) increased the percentage of total and progressive motility. Furthermore, these compounds enhanced penetration into a cervical mucus substitute (P ≤ 0.05). Finally, the AR was not significantly induced and these compounds did not significantly increase the externalization of phosphatidylserine (P = 0.6, respectively). In general, the six compounds maintained the stimulation of motility over long periods of time (180 min) and their effects were still observed after their removal. In examinations of clinical samples, there was a general observation of a more significant stimulation of sperm motility in samples with lower baseline motility. In ICSI samples, compounds #26, #37 and #38 were the most effective at significantly increasing total motility (88, 81 and 79% of samples, respectively) and progressive motility (94, 93 and 81% of samples, respectively). In conclusion, using a two-phased drug discovery screening approach including the examination of clinical samples, 3/43 compounds were identified as promising candidates for further study.

LIMITATIONS, REASONS FOR CAUTION

This is an in vitro study and caution must be taken when extrapolating the results. Data for patients were from one assessment and thus the robustness of responses needs to be established. The n values for ICSI samples were relatively small.

WIDER IMPLICATIONS OF THE FINDINGS

We have systematically screened and identified several compounds that have robust and effective stimulation (i.e. functional significance with longevity and no toxicity) of total and progressive motility under clinical conditions of treatment. These compounds could be clinical candidates with possibilities in terms of assisted reproductive technology options for current or future patients affected by asthenozoospermia or oligoasthenozoospermia.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded primarily by the MRC (DPFS) but with additional funding from the Wellcome Trust, Tenovus (Scotland), University of Dundee, NHS Tayside and Scottish Enterprise. The authors have no competing interests. A patent (#WO2013054111A1) has been published containing some of the information presented in this manuscript.

Supplementation of biotin to sperm preparation medium increases the motility and longevity in cryopreserved human spermatozoa

PURPOSE

To study the effect of supplementing biotin to sperm preparation medium on the motility of frozen-thawed spermatozoa.

METHODS

Semen samples of men attending the University infertility clinic (n = 105) were cryopreserved using glycerol-egg yolk-citrate buffered cryoprotective medium in liquid nitrogen. After a period of two weeks, the semen samples were thawed and the motile spermatozoa were extracted by swim-up technique using Earle's balanced salt solution (EBSS) medium supplemented with either biotin (10 nM) or pentoxifylline (1 mM). The post-wash motility was observed up to 4 h after incubation.

RESULTS

Both biotin and pentoxifylline supplementation resulted in significant increase in total motility (p < 0.05), progressive motility (p < 0.001) and rapid progressive motility (p < 0.05 v/s biotin and p < 0.01 v/s pentoxifylline) compared to the control at 1 h post-incubation period. Significantly higher percentage of total (p < 0.01, p < 0.05 in biotin and pentoxifylline respectively), progressive (p < 0.001) and rapid progressive motilities (p < 0.01) were observed in these two groups even at 2 h compared to the control. In the control group at 4 h after incubation, ~11% decline in total motility and ~8% decline in progressive motility was observed. However, in both biotin and pentoxifylline group the motility was significantly higher than control (p < 0.001). No significant difference in the motility was observed between biotin and pentoxifylline groups at any of the time intervals studied.

CONCLUSIONS

Biotin can enhance the sperm motility and prolong the survival of frozen-thawed semen samples which may have potential benefit in assisted reproductive technology field.

Pentoxifylline for endometriosis

BACKGROUND

Endometriosis is a chronic, recurring condition that occurs during the reproductive years. It is characterized by endometrial tissue developing outside the uterine cavity. This endometrial tissue development is dependent on oestrogen produced primarily by the ovaries and, therefore, traditional management has focused on ovarian suppression. In this review we considered the role of modulation of the immune system as an alternative approach. This is an update of a Cochrane Review previously published in 2009 (Lu 2009).

OBJECTIVES

To assess the effects of pentoxifylline, which has anti-inflammatory effects, in subfertile, premenopausal women for the management of endometriosis.

SEARCH METHODS

For the first publication of this review we searched the following databases (from inception to December 2008) for trials: Cochrane Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, CINAHL, and PsycINFO. In addition, all reference lists of included trials were searched and experts in the field were contacted in an attempt to locate trials. This search was rerun to 23 November 2011, for this update.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing pentoxifylline with placebo or no treatment, medical treatment, or surgery in subfertile, premenopausal women were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed trial risk of bias, and extracted data using data extraction forms. We contacted study authors for additional information and data. The domains assessed for risk of bias were sequence generation, allocation concealment, blinding, incomplete outcome data, and selective outcome reporting. Peto odds ratios (OR) were used for reporting dichotomous data with 95% confidence intervals (CI), whilst mean differences (MD) were expressed for continuous data. Statistical heterogeneity was assessed using the I(2) statistic.

MAIN RESULTS

Four trials involving 334 participants were included. One RCT [n=34] showed pentoxifylline had no significant effect on reduction in pain (MD -1.60, 95% CI -3.32 to 0.12). There was no evidence of an increase in clinical pregnancy events in the pentoxifylline group compared with placebo (three RCTs [n=67] OR 1.54, 95% CI 0.89 to 266). One RCT studied recurrence of endometriosis [n=88] (OR 0.88,95% CI 0.27 to 2.84). No trials reported the effects of pentoxifylline on the odds of live birth rate per woman, improvement of endometriosis-related symptoms, or adverse events.

AUTHORS' CONCLUSIONS

This review has been updated in 2011. The results of the original review published in 2009 remain unchanged. There is still not enough evidence to support the use of pentoxifylline in the management of premenopausal women with endometriosis in terms of subfertility and relief of pain outcomes.

The role of antioxidant therapy in the treatment of male infertility

Oxidative stress contributes to defective spermatogenesis leading to male factor infertility. The aim of this study was to review the current literature on the effects of various antioxidants to improve fertilisation and pregnancy rates. The sources of literature were Pubmed and the Cochrane data base. Reviewing the current literature revealed that Carnitines and vitamin C and E have been clearly shown to be effective by many well-conducted studies and may be considered as a first line treatment. The efficacy of antioxidants, such as glutathione, selenium and coenzyme Q10 has been demonstrated by few, but well-performed studies, and may be considered second line treatment. There is, however, a need for further investigation with randomised controlled studies to confirm the efficacy and safety of antioxidant supplementation in the medical treatment of idiopathic male infertility as well as the need to determine the ideal dose of each compound to improve semen parameters, fertilisation rates and pregnancy outcomes.

Oxidative stress and antioxidants for idiopathic oligoasthenoteratospermia: Is it justified?

Oxidative stress contributes to defective spermatogenesis and the poor quality of sperm associated with idiopathic male factor infertility. The aim of this study was to review the current literature on the effects of various types of antioxidant supplements in patients to improve fertilization and pregnancy rates in subfertile males with idiopathic oligoasthenoteratozoospermia (iOAT). Review of recent publications through PubMed and the Cochrane database. Oxidative stress is implicated in impaired spermatogenesis leading to the poor semen parameters and increased DNA damage and apoptosis in iOAT. Strategies to modulate the level of oxidative stress within the male reproductive tract include the use of oral antioxidant compounds to reinforce the body's defence against oxidative damage. In our evaluation, carnitines were considered the most established pharmacotherapeutic agent to treat iOAT, as evidence and data concerning carnitine supplementation have been shown to be most consistent and relevant to the population of interest. Other therapies, such as combined vitamin E and C therapy, are still considered controversial as vitamin C can act as a pro-oxidant in certain instances and the results of randomized controlled trials have failed to show significant benefit to sperm parameters and pregnancy rates. There is a need for further investigation with randomized controlled studies to confirm the efficacy and safety of antioxidant supplementation in the medical treatment of idiopathic male infertility as well as the need to determine the dosage required to improve semen parameters, fertilization rates and pregnancy outcomes in iOAT.

[Initial results of a novel technique for sperm retrieval in male infertility due to refractory retrograde ejaculation]

AIMS

To describe and evaluate a novel technique of spermatozoa retrieval from patients suffering from infertility secondary to refractory retrograde ejaculation.

METHOD

Prospective study to compare mobility and vitality of spermatozoa obtained from urine (U) after oral modification of chemical parameter (PH, Osmolarity) versus from endovesical instillation of sterile spermatozoa culture medium before ejaculation (F). Patients were their own controls. Twelve month prospective follow-up was achieved to document the results of assisted procreation.

RESULTS

Eight patients were included and mobility and vitality were improved in all patients after F technique was compared to U technique. With U technique, eight patients on eight had negative defrost test; after F technique, seven patients on eight had a positive defrost test and could therefore have access to assisted reproduction techniques. Four couples had five ICSI and obtained three pregnancies leading to five births.

CONCLUSION

Endovesical instillation of sterile spermatozoa culture medium before ejaculation was a safe and effective technique to improve spermatozoa quality in male infertility related to refractory retrograde ejaculation.

Pentoxifylline added to freezing or post-thaw extenders does not improve the survival or in vitro fertilising capacity of boar spermatozoa

This study evaluated whether pentoxifylline added to freezing and thawing extenders influenced the function of boar spermatozoa. In Experiment 1, pooled ejaculated sperm-rich fractions were frozen in 0.5 ml straws after dilution in extender supplemented with pentoxifylline to a final concentration of 0, 2, 4, 8, 16 or 32 mM. The addition of 4, 8, 16 and 32 mM pentoxifylline to the freezing extender significantly decreased the progressive and total motility of spermatozoa. The percentage of viable spermatozoa with intact acrosomes as well as the penetration rate and the efficiency of fertilisation were significantly lower in pentoxifylline-treated groups compared with the untreated control. In Experiment 2, a pool of three straws with ‘good’ post-thaw sperm quality parameters and another three straws with ‘poor’ sperm quality were diluted in extender with 0, 1, 2, 4, 8, 16 or 32 mM pentoxifylline. Post-thaw samples with both ‘good’ and ‘poor’ sperm quality with 0, 2, 4, 8 and 16 mM were used to assess IVF parameters. The addition of pentoxifylline to post-thaw extender did not improve the post-thaw motility or viability of spermatozoa compared with the control. The in vitro penetration was higher (P<0.05) than the control for oocytes fertilised with spermatozoa that were thawed and incubated in extender with 4, 8 and 16 mM pentoxifylline. However, no differences were observed in the efficiency of fertilisation. We conclude that pentoxifylline, as a supplement added to the freezing extender, has a deleterious effect and that it does not improve the survival or in vitro fertilising efficiency of frozen–thawed boar spermatozoa when added after thawing.

Pentoxifylline versus medical therapies for subfertile women with endometriosis

BACKGROUND

Endometriosis is a chronic, recurring condition that occurs during the reproductive years. It is characterized by endometrial tissue developing outside the uterine cavity. This endometrial tissue development is dependent on estrogen produced primarily by the ovaries and, therefore, traditional management has focused on ovarian suppression. In this review we considered the role of modulation of the immune system as an alternative approach.

OBJECTIVES

To determine the effectiveness and safety of pentoxifylline, which has anti-inflammatory effects, in the management of endometriosis in subfertile, premenopausal women.

SEARCH STRATEGY

We searched the following databases (from inception to December 2008) for trials: Cochrane Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, CINAHL, and PsycINFO. In addition, all reference lists of included trials were searched and experts in the field were contacted in an attempt to locate trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing pentoxifylline with placebo or no treatment, medical treatment, or surgery in subfertile, premenopausal women were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed trial quality, and extracted data using data extraction forms. We contacted study authors for additional information and data. The domains assessed for risk of bias were sequence generation, allocation concealment, blinding, incomplete outcome data, and selective outcome reporting. Odds ratios (OR) were used for reporting dichotomous data with 95% confidence intervals (CI), whilst mean differences (MD) were expressed for continuous data. Statistical heterogeneity was assessed using the I(2) statistic.

MAIN RESULTS

Four trials involving 334 participants were included. Results showed pentoxifylline had no significant effect on reduction in pain (one RCT, MD -1.60, 95% CI -3.32 to 0.12). There was no evidence of an increase in clinical pregnancy events in the pentoxifylline group compared with placebo (three RCTs, OR 1.54, 95% CI 0.89 to 266). For recurrence of endometriosis, one RCT reported an OR of 0.88 (95% CI 0.27 to 2.84). No trials reported the effects of pentoxifylline on the odds of live birth rate per woman, improvement of endometriosis-related symptoms, or adverse events.

AUTHORS' CONCLUSIONS

There is not enough evidence to support the use of pentoxifylline in the management of premenopausal women with endometriosis in terms of subfertility and relief of pain outcomes.

Molecular biology of sperm maturation in the human epididymis

Male infertility is a frequent cause of childlessness, and, indeed, a comparison of the contributions to conception failure made by male and female factors shows them to be equally frequent. In practice, male infertility appears to be resistant to most treatments. However, the major reason for this may be that often attempts are carried out without knowing the cause of the problem. Unlike in women, obstructions and hormonal disorders are rare in male infertility. Rather, it would appear that sperm disorders are the most common cause, reflecting a variety of pathogenetic mechanisms. Defects in sperm morphology, defective sperm movement, deficient development or functional failure of the acrosome, and the excessive generation of reactive oxygen species are changes that are often seen in infertile semen, but little is known about their aetiology. In 5–10% of men being treated for infertilty, an autoimmune reaction against spermatozoa is observed. Although the correlation between the presence of systemic antisperm antibodies and fertility potential is poor, the appearance of sperm-bound antibodies of immunoglobulin class IgA in semen seems to be closely associated with infertility. Studies in laboratory animals and humans have shown that complementary adhesion molecules are located on the surface of oocytes and spermatozoa. These molecules interact and lead to gamete fusion. Abnormalities in these molecules on the sperm surface might be expected to contribute to male infertility. However, their clinical significance has not yet been documented, and the molecular basis of human gamete interaction is far from being understood. Therefore, the key to understanding male infertility may lie in basic research which directly targets the fundamental cellular and molecular biology of the human spermatozoon.

The functional significance of leucocytes in human reproduction

There is now considerable evidence that leucocytes and their products have significant effects on the functional capacity of spermatozoa both in the male and female reproductive tract. Recent advances in the accurate detection of these leucocytes and their products using monoclonal antibodies and a parallel increase in the application of sophisticated sperm function tests has now made it possible to further determine the influence of the leucocytes on sperm function. It is therefore likely that this field of reproductive biology will be an area of considerable activity in the near future.

Effects of phosphodiesterase-5 inhibitors on sperm parameters and fertilizing capacity

The aim of this review study is to elucidate the effects that phosphodiesterase 5 (PDE5) inhibitors exert on spermatozoa motility, capacitation process and on their ability to fertilize the oocyte. Second messenger systems such as the cAMP/adenylate cyclase (AC) system and the cGMP/guanylate cyclase (GC) system appear to regulate sperm functions. Increased levels of intracytosolic cAMP result in an enhancement of sperm motility and viability. The stimulation of GC by low doses of nitric oxide (NO) leads to an improvement or maintenance of sperm motility, whereas higher concentrations have an adverse effect on sperm parameters. Several in vivo and in vitro studies have been carried out in order to examine whether PDE5 inhibitors affect positively or negatively sperm parameters and sperm fertilizing capacity. The results of these studies are controversial. Some of these studies demonstrate no significant effects of PDE5 inhibitors on the motility, viability, and morphology of spermatozoa collected from men that have been treated with PDE5 inhibitors. On the other hand, several studies demonstrate a positive effect of PDE5 inhibitors on sperm motility both in vivo and in vitro. In vitro studies of sildenafil citrate demonstrate a stimulatory effect on sperm motility with an increase in intracellular cAMP suggesting an inhibitory action of sildenafil citrate on a PDE isoform other than the PDE5. On the other hand, tadalafil's actions appear to be associated with the inhibitory effect of this compound on PDE11. In vivo studies in men treated with vardenafil in a daily basis demonstrated a significantly larger total number of spermatozoa per ejaculate, quantitative sperm motility, and qualitative sperm motility; it has been suggested that vardenafil administration enhances the secretory function of the prostate and subsequently increases the qualitative and quantitative motility of spermatozoa. The effect that PDE5 inhibitors exert on sperm parameters may lead to the improvement of the outcome of assisted reproductive technology (ART) programs. In the future PDE5 inhibitors might serve as adjunct therapeutical agents for the alleviation of male infertility.

FSCB, a Novel Protein Kinase A-phosphorylated Calcium-binding Protein, Is a CABYR-binding Partner Involved in Late Steps of Fibrous Sheath Biogenesis

We report characterization of a novel testis- and sperm-specific protein, FSCB (fibrous sheath CABYR binding), that is expressed post-meiotically and localized in mouse sperm flagella. FSCB was identified as a binding partner of CABYR, a calcium-binding protein that is tyrosine-phosphorylated during capacitation. Orthologous genes of FSCB are present in other mammals, including rat and human, and conserved motifs in FSCB include PXXP, proline-rich and extensin-like regions. FSCB is phosphorylated by protein kinase A as shown by in vitro phosphorylation assay and also by determining phosphorylation sites in native FSCB from mouse sperm. Calcium overlay assay showed that FSCB is a calcium-binding protein from sperm. FSCB is a post meiotic protein first expressed at step 11 of mouse spermatogenesis in the elongating spermatids, and it subsequently incorporates into the flagellar principal piece of the sperm. Ultrastructurally, FSCB localized to a cortical layer of intermediate electron density at the surface of the ribs and longitudinal columns of the fibrous sheath. Due to its temporal appearance during spermiogenesis and location at the cortex of the fibrous sheath, FSCB is postulated to be involved in the later stages of fibrous sheath assembly.

Pentoxifylline improves sperm capacitation and in vitro fertilization of oocytes in the golden hamster

Pentoxifylline (PF) is used to improve motility of spermatozoa from subfertile or nonfertile males to accomplish in vitro fertilization in humans. The possible adverse effect of PF on pre- and peri-implantation stage embryo development in a suitable rodent model, such as the golden hamster, is yet to be determined. In this study, hamster cauda epididymal spermatozoa were exposed to different concentrations (0.23 to 3.6 mM) of PF, and their quantitative [percentage of motility] and qualitative [Score 0 to 5] motility were assessed and values expressed as the sperm motility index. Upon addition of spermatozoa to dishes containing PF, an immediate increase in sperm motility and sperm motility index was evident, which increased up to 4 to 6 h and then declined. The sperm motility index increase by PF was dose-dependant, and >or= 1.8 mM PF was detrimental after 4 h. The optimum dose of PF was found to be 0.45 mM. To assess the fertilizing ability of PF-treated spermatozoa, in vitro fertilization was carried out. Fertilization rates for spermatozoa treated with 3.6 mM PF were lower (53.8 +/- 7.8) than for the controls (69.5 +/- 10.2), whereas treatment with 0.45 mM PF increased the rates (91.6 +/- 4.3) compared with that of the controls (80.2 +/- 5.9). In conclusion, low concentrations (0.23 to 0.45 mM) of PF improve sperm capacitation and fertilization of oocytes in vitro in the golden hamster.

Pentoxifylline therapy after laparoscopic surgery for different stages of endometriosis: a prospective, double-blind, randomized, placebo-controlled study

STUDY OBJECTIVE

To evaluate the effects of pentoxifylline administration on patients with different stages of endometriosis on whom laparoscopy was performed.

DESIGN

Prospective, double-blind, randomized, placebo-controlled clinical (Canadian Task Force classification I).

SETTING

University and private hospitals.

PATIENTS

Eighty-eight women, all with infertility, some with dysmenorrhea, dyspareunia, or pelvic pain, on whom a laparoscopic diagnosis of endometriosis was made.

INTERVENTIONS

The treatment group received 800 mg pentoxifylline daily for 6 months immediately after surgery. The control group received placebo capsules. All patients were followed-up for 1 year thereafter.

MEASUREMENTS AND MAIN RESULTS

A comparison of pregnancy rate and recurrence of signs and symptoms in the 2 groups was performed. Forty-three patients were studied in the pentoxifylline group and 45 in the placebo group. The cumulative pregnancy rate was 39.5% and 35.6% in the treatment and control groups, respectively. The overall recurrence of signs and symptoms was 14% in the former group and 15.6% in the latter. There were no statistically significant differences between the 2 groups in rates of pregnancy and recurrence (p = .700 and .832, respectively). Nor was there any significant statistical difference between the same stages in the 2 groups regarding immunomodulation.

CONCLUSIONS

According to the results of this study, and while keeping in mind that appropriate surgery is the main aspect of endometriosis treatment, there is no evidence that immunomodulation with pentoxifylline aids fertility or lessens recurrence of signs and symptoms in women with different stages of endometriosis (i.e., minimal, mild, moderate, or severe).

Mammalian sperm phosphodiesterases and their involvement in receptor-mediated cell signaling important for capacitation

This study investigated the presence and function of intracellular cyclic nucleotide phosphodiesterases (PDEs) in mature mouse spermatozoa. PCR analysis detected gene transcripts for most of the 11 known PDE families in whole testis, but mainly for PDEs 1, 3, 6, and 8 in spermatozoa. Using specific antibodies, the strongest evidence was obtained for PDE proteins 1, 4, 6, 8, 10, and 11 in both sperm lysates and intact cells. These showed a range of subcellular localizations, with PDE 1A being primarily in the flagellum but PDEs 4D and 10A being in both the acrosomal region and the flagellum, similar to specific G proteins and adenylyl cyclases implicated in cAMP regulation during capacitation. In live spermatozoa, inhibitors selective for PDE 1 (MMPX) and 4 (rolipram) significantly increased cAMP over control levels but only rolipram significantly stimulated capacitation and in-vitro fertilizing ability; this suggests that compartmentalization has functional implications since only PDE 4 was abundant in both head and flagellum. Treatment of spermatozoa with CGS 21680, a stimulatory adenosine receptor agonist, significantly reduced cAMP-PDE activity at the same time-point when it causes increased cAMP. Thus, certain receptor-regulated cAMP processes in spermatozoa may be controlled by changes in both PDE and cyclase activities. In addition to demonstrating for the first time that some of the more recently discovered PDE isoforms, including PDE 6 (usually associated with the retina), are present in mature spermatozoa, this study provides clear evidence that the intracellular location of specific PDEs has important functional significance during capacitation and fertilization.

Sperm preparation for ART

The onset of clinical assisted reproduction, a quarter of a century ago, required the isolation of motile spermatozoa. As the indication of assisted reproduction shifted from mere gynaecological indications to andrological indications during the years, this urged andrological research to understand the physiology of male germ cell better and develop more sophisticated techniques to separate functional spermatozoa from those that are immotile, have poor morphology or are not capable to fertilize oocytes. Initially, starting from simple washing of spermatozoa, separation techniques, based on different principles like migration, filtration or density gradient centrifugation evolved. The most simple and cheapest is the conventional swim-up procedure. A more sophisticated and most gentle migration method is migration-sedimentation. However, its yield is relatively small and the technique is therefore normally only limited to ejaculates with a high number of motile spermatozoa. Recently, however, the method was also successfully used to isolate spermatozoa for intracytoplasmic sperm injection (ICSI). Sperm separation methods that yield a higher number of motile spermatozoa are glass wool filtration or density gradient centrifugation with different media. Since Percoll as a density medium was removed from the market in 1996 for clinical use in the human because of its risk of contamination with endotoxins, other media like IxaPrep, Nycodenz, SilSelect, PureSperm or Isolate were developed in order to replace Percoll. Today, an array of different methods is available and the selection depends on the quality of the ejaculates, which also includes production of reactive oxygen species (ROS) by spermatozoa and leukocytes. Ejaculates with ROS production should not be separated by means of conventional swim-up, as this can severely damage the spermatozoa. In order to protect the male germ cells from the influence of ROS and to stimulate their motility to increase the yield, a number of substances can be added to the ejaculate or the separation medium. Caffeine, pentoxifylline and 2-deoxyadenosine are substances that were used to stimulate motility. Recent approaches to stimulate spermatozoa include bicarbonate, metal chelators or platelet-activating factor (PAF). While the use of PAF already resulted in pregnancies in intrauterine insemination, the suitability of the other substances for the clinical use still needs to be tested. Finally, the isolation of functional spermatozoa from highly viscous ejaculates is a special challenge and can be performed enzymatically to liquefy the ejaculate. The older method, by which the ejaculate is forcefully aspirated through a narrow-gauge needle, should be abandoned as it can severely damage spermatozoa, thus resulting in immotile sperm.

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.

CABYR, a novel calcium-binding tyrosine phosphorylation-regulated fibrous sheath protein involved in capacitation

To reach fertilization competence, sperm undergo an incompletely understood series of morphological and molecular maturational processes, termed capacitation, involving, among other processes, protein tyrosine phosphorylation and increased intracellular calcium. Hyperactivated motility and an ability to undergo the acrosome reaction serve as physiological end points to assess successful capacitation. We report here that acidic (pI 4.0) 86-kDa isoforms of a novel, polymorphic, testis-specific protein, designated calcium-binding tyrosine phosphorylation-regulated protein (CABYR), were tyrosine phosphorylated during in vitro capacitation and bound (45)Ca on 2D gels. Acidic 86-kDa calcium-binding forms of CABYR increased during in vitro capacitation, and calcium binding to these acidic forms was abolished by dephosphorylation with alkaline phosphatase. Six variants of CABYR containing two coding regions (CR-A and CR-B) were cloned from human testis cDNA libraries, including five variants with alternative splice deletions. A motif homologous to the RII dimerization domain of PK-A was present in the N-terminus of CR-A in four CABYR variants. A single putative EF handlike motif was noted in CR-A at aas 197-209, while seven potential tyrosine phosphorylation-like sites were noted in CR-A and four in CR-B. Pro-X-X-Pro (PXXP) modules were identified in the N- and C-termini of CR-A and CR-B. CABYR localizes to the principal piece of the human sperm flagellum in association with the fibrous sheath and is the first demonstration of a sperm protein that gains calcium-binding capacity when phosphorylated during capacitation.

Male infertility: tales of progress and frustration

This article describes andrology research, inspired by Professor Michael Hull, to develop sperm function tests and to understand the basic causes of male infertility. No generally acceptable sperm function test has yet been devised. Computer-assisted semen analysis (CASA) proved of limited value in predicting the outcome of in vitro fertilization (IVF) although it was more useful in donor insemination. High intracellular Ca2+ activity, [Ca2+]i, is involved in decreasing motility in cryopreserved sperm. Capacitative calcium entry after depletion of intracellular stores may generate the sustained increase in [Ca2+]i that initiates the acrosome reaction. Our data support the presence of Ca2+ stores as thapsigargin increased [Ca2+]i in sperm in Ca2+ -free medium. Recent observations indicate that cAMP enhances capacitative calcium entry, acting upstream of emptying of the store. Excess reactive oxygen species (ROS) is an important cause of sperm pathology but at low concentrations ROS regulate capacitation. Our evidence shows that ROS are produced by leucocytes present in sperm suspensions. We have been unable to demonstrate that human sperm produce ROS. The relationship between ROS production and lipid peroxidation indicates that sperm from some men are resistant to lipid peroxidation, possibly because of better antioxidant defences. We conclude that the future of andrology lies in the identification of the basic causes of infertility and not in more detailed descriptions of the properties of semen.

Effects of Ginsenoside Rb2 and Rc on inferior human sperm motility in vitro

The purpose of the study was to investigate the effects of two constituents of Panax notoginseng flower extract, Ginsenoside Rb2 and Rc, on human sperm motility and progression in vitro. Semen samples were collected from 20 patients with sperm motility between 20% and 40% of normal. All samples had sperm counts of over 20 million per milliliter, in accordance with the World Health Organization standard. Sperm were separated by a Percoll discontinuous gradient technique, and divided into a Percoll sperm control group, and three Ginsenoside Rb2 experimental groups (0.1, 0.01 and 0.001 mg/ml) and three Ginsenoside Rc experimental groups (0.1, 0.01 and 0.001 mg/ml). The results showed that at concentrations of 0.01 mg/ml and 0.001 mg/ml, Ginsenoside Rc enhanced both sperm motility and sperm progression significantly at the end of the 1st and 2nd hour. However, the three concentrations of Ginsenoside Rb2 did not increase sperm motility at the 1st or 2nd hour, but promoted sperm progression at the 2nd hour, when compared to the Percoll group.

Pentoxifylline improves in vitro fertilization and subsequent development of bovine oocytes

The purpose of this study was to examine whether pentoxifylline improves in vitro fertilization and developmental rates of bovine oocytes. In the first experiment, we examined the effects on the fertilization rate of various concentrations of pentoxifylline (0-7.5 mM) combined with heparin (10 IU/mL). In the second experiment, we examined fertilization cleavage and blastocyst rates after frozen-thawed spermatozoa, obtained from four different bulls, were incubated with heparin (10 IU/mL) with or without caffeine (5 mM) or pentoxifylline (5 mM). In the first experiment, a significantly higher fertilization rate was obtained in heparin containing 5 mM pentoxifylline compared to that in heparin alone or in heparin containing 7.5 mM pentoxifylline (86% vs 60% vs 64%, respectively). The percentage of monospermy in 5 mM pentoxifylline (81%) was significantly higher than in heparin alone (57%). In the second experiment, the interactions among Bulls A, B, C, and D; between treatments (pentoxifylline-with-heparin, caffeine-with-heparin and heparin alone), and between bulls and treatments were analyzed for the number of oocytes penetrated, monospermic oocytes, cleaved oocytes and blastocysts. Among bulls, there was a significant difference in the number of oocytes penetrated (P < 0.01), monospermic oocytes (P < 0.05), cleaved oocytes (P < 0.001), and blastocysts (P < 0.001). Between treatments, there was a significant difference in the number of oocytes penetrated (P < 0.001), monospermic oocytes (P < 0.01) and cleaved oocytes (P < 0.001). Interaction between bulls and treatments was observed for the number of oocytes penetrated (P < 0.05). Individually, for Bulls A, C and D, the numbers of oocytes penetrated and monospermic oocytes in pentoxifylline-with-heparin were significantly higher than in heparin alone. For Bull D, significantly higher results were obtained for the number of oocytes penetrated, monospermic oocytes, cleaved oocytes and blastocysts in pentoxifylline-with-heparin compared to caffeine-with-heparin and heparin alone (P < 0.05). These results suggest that treating sperm with 5 mM pentoxifylline in combination with heparin is effective for bovine in vitro fertilization and it that this treatment is effective even for bulls that produce low fertilization and blastocysts after sperm treatment with caffeine-with-heparin or heparin alone.

The use of pentoxifylline to improve motility of cryopreserved equine spermatozoa

Pentoxifylline was evaluated as a method to increase motility of cryopreserved equine spermatozoa. In a preliminary experiment, pentoxifylline (3.5 mM or 7.0 mM) was added to extended semen that was chilled to 4 degrees C. Motility was evaluated at 8-h intervals for 48 h. The addition of 3.5 or 7.0 mM pentoxifylline appeared to increase the motility of chilled spermatozoa compared to controls. Based on these results, similar concentrations of pentoxifylline were added to semen either before or after cryopreservation. The addition of pentoxifylline (3.5 or 7.0 mM) to semen before cryopreservation significantly (P < 0.001) decreased total and progressive motility compared to controls. However, the addition of pentoxifylline (3.5 or 7.0 mM) to cryopreserved semen immediately after thawing significantly (P < 0.01) increased total and progressive motility compared to controls. These results indicate that pentoxifylline enhanced the postthaw motility of cryopreserved equine semen when added after thawing. Further research is required to evaluate the effect of pentoxifylline on the fertility of cryopreserved equine semen.

Pentoxifylline initiates motility in spontaneously immotile epididymal and testicular spermatozoa and allows normal fertilization, pregnancy, and birth after intracytoplasmic sperm injection

PURPOSE

Pentoxifylline (PF) has been used to enhance sperm motility in many in vitro fertilization programs. The twofold purpose of this study was to determine whether PF stimulates fresh or frozen epididymal and testicular totally immotile spermatozoa and whether it can be used to select viable spermatozoa for intracytoplasmic sperm injection (ICSI).

METHODS

To test the effect of PF on motility, 10 samples of totally immotile spermatozoa were incubated for 10 min with 3.6 mM PF. Motility was initiated in all cases (14.8% mean motility after PF treatment of five samples of fresh or frozen epididymal spermatozoa and 13.6% mean motility of five samples of fresh or frozen testicular spermatozoa). To assess PF for selection of viable spermatozoa before ICSI, we compared the outcome of ICSI in 20 cycles using fresh or frozen epididymal or testicular PF-treated immotile spermatozoa and 139 control ICSI using fresh or frozen epididymal or testicular spontaneously motile spermatozoa.

RESULTS

Fertilization rates were similar in the PF and control groups (45.2% vs. 51.0%). Embryo quality and division stages at the time of transfer were comparable. Six pregnancies occurred in PF-ICSI group (30.0% per cycle vs. 26.6% in control group) including two deliveries of healthy children and four ongoing pregnancies.