Effect of phosphatidylcholine, lysophosphatidylcholine, arachidonic acid and docosahexaenoic acid on the motility of human sperm

Multiple transcriptome analyses reveal mouse testis developmental dynamics

The testes are the organs of gamete production and testosterone synthesis. Up to date, no model system is available for mammalian testicular development, and only few studies have characterized the mouse testis transcriptome from no more than three postnatal ages. To describe the transcriptome landscape of the developing mouse testis and identify the potential molecular mechanisms underlying testis maturation, we examined multiple RNA-seq data of mouse testes from 3-week-old (puberty) to 11-week-old (adult). Sperm cells appeared as expected in 5-week-old mouse testis, suggesting the proper sample collection. The principal components analysis revealed the genes from 3w to 4w clustered away from other timepoints, indicating they may be the important nodes for testicular development. The pairwise comparisons at two adjacent timepoints identified 7,612 differentially expressed genes (DEGs), resulting in 58 unique mRNA expression patterns. Enrichment analysis identified functions in tissue morphogenesis (3-4w), regulation of peptidase activity (4-5w), spermatogenesis (7-8w), and antigen processing (10-11w), suggesting distinct functions in different developmental periods. 50 hub genes and 10 gene cluster modules were identified in the testis maturation process by protein-protein interaction (PPI) network analysis, and the miRNA-lncRNA-mRNA, miRNA-circRNA-mRNA and miRNA-circRNA-lncRNA-mRNA competing endogenous RNA (ceRNA) networks were constructed. The results suggest that testis maturation is a complex developmental process modulated by various molecules, and that some potential RNA-RNA interactions may be involved in specific developmental stages. In summary, this study provides an update on the molecular basis of testis development, which may help to understand the molecular mechanisms of mouse testis development and provide guidance for mouse reproduction.

Lipidomics profiles of human spermatozoa: insights into capacitation and acrosome reaction using UPLC-MS-based approach

Introduction

Lipidomics elucidates the roles of lipids in both physiological and pathological processes, intersecting with many diseases and cellular functions. The maintenance of lipid homeostasis, essential for cell health, significantly influences the survival, maturation, and functionality of sperm during fertilization. While capacitation and the acrosome reaction, key processes before fertilization, involve substantial lipidomic alterations, a comprehensive understanding of the changes in human spermatozoa's lipidomic profiles during these processes remains unknown. This study aims to explicate global lipidomic changes during capacitation and the acrosome reaction in human sperm, employing an untargeted lipidomic strategy using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS).

Methods

Twelve semen specimens, exceeding the WHO reference values for semen parameters, were collected. After discontinuous density gradient separation, sperm concentration was adjusted to 2 x 106 cells/ml and divided into three groups: uncapacitated, capacitated, and acrosome-reacted. UPLC-MS analysis was performed after lipid extraction from these groups. Spectral peak alignment and statistical analysis, using unsupervised principal component analysis (PCA), bidirectional orthogonal partial least squares discriminant analysis (O2PLS-DA) analysis, and supervised partial least-squares-latent structure discriminate analysis (PLS-DA), were employed to identify the most discriminative lipids.

Results

The 1176 lipid peaks overlapped across the twelve individuals in the uncapacitated, capacitated, and acrosome-reacted groups: 1180 peaks between the uncapacitated and capacitated groups, 1184 peaks between the uncapacitated and acrosome-reacted groups, and 1178 peaks between the capacitated and acrosome-reacted groups. The count of overlapping peaks varied among individuals, ranging from 739 to 963 across sperm samples. Moreover, 137 lipids had VIP values > 1.0 and twenty-two lipids had VIP > 1.5, based on the O2PLS-DA model. Furthermore, the identified twelve lipids encompassed increases in PI 44:10, LPS 20:4, LPA 20:5, and LPE 20:4, and decreases in 16-phenyl-tetranor-PGE2, PC 40:6, PS 35:4, PA 29:1, 20-carboxy-LTB4, and 2-oxo-4-methylthio-butanoic acid.

Discussion

This study has been the first time to investigate the lipidomics profiles associated with acrosome reaction and capacitation in human sperm, utilizing UPLC-MS in conjunction with multivariate data analysis. These findings corroborate earlier discoveries on lipids during the acrosome reaction and unveil new metabolites. Furthermore, this research highlights the effective utility of UPLC-MS-based lipidomics for exploring diverse physiological states in sperm. This study offers novel insights into lipidomic changes associated with capacitation and the acrosome reaction in human sperm, which are closely related to male reproduction.

Glycerophospholipids protect stallion spermatozoa from oxidative damage in vitro

Stallion sperm membranes comprise a high proportion of polyunsaturated fatty acids, making stallion spermatozoa especially vulnerable to peroxidative damage from reactive oxygen species generated as a by-product of cell metabolism. Membrane lipid replacement therapy with glycerophospholipid (GPL) mixtures has been shown to reduce oxidative damage in vitro and in vivo. The aims of this study were to test the effects of a commercial preparation of GPL, NTFactor^® Lipids, on stallion spermatozoa under oxidative stress. When oxidative damage was induced by the addition of arachidonic acid to stallion spermatozoa, the subsequent addition of GPL reduced the percentage of 4-hydroxynonenal (4-HNE; a key end product of lipid peroxidation) positive cells (32.9 ± 2.7 vs 20.9 ± 2.3%; P ≤ 0.05) and increased the concentration of 4-HNE within the spent media (0.026 ± 0.003 vs 0.039 ± 0.004 µg/mL; P ≤ 0.001), suggesting that oxidized lipids had been replaced by exogenous GPL. Lipid replacement improved several motility parameters (total motility: 2.0 ± 1.0 vs 68.8 ± 2.9%; progressive motility: 0 ± 0 vs 19.3 ± 2.6%; straight line velocity: 9.5 ± 2.1 vs 50.9 ± 4.1 µm/s; curvilinear velocity: 40.8 ± 10 vs 160.7 ± 7.8 µm/s; average path velocity: 13.4 ± 2.9 vs 81.9 ± 5.9 µm/s; P ≤ 0.001), sperm viability (13.5 ± 2.9 vs 80.2 ± 1.6%; P ≤ 0.001) and reduced mitochondrial ROS generation (98.2 ± 0.6 vs 74.8 ± 6.1%; P ≤ 0.001). Supplementation with GPL during 17°C in vitro sperm storage over 72 h improved sperm viability (66.4 ± 2.6 vs 78.1 ± 2.9%; P ≤ 0.01) and total motility (53 ± 5.6 vs 66.3 ± 3.5%; P ≤ 0.05). It is concluded that incubation of stallion spermatozoa with sub-µm-sized GPL micelles results in the incorporation of exogenous GPL into sperm membranes, diminishing lipid peroxidation and improving sperm quality in vitro.

Effects of coadministration of DHA and vitamin E on spermatogram, seminal oxidative stress, and sperm phospholipids in asthenozoospermic men: a randomized controlled trial

BACKGROUND

It is unknown which compounds in spermatozoa or seminal plasma may be involved in the regulation of sperm motility.

OBJECTIVES

The aim of this study was to investigate the effects of DHA (22:6n-3), vitamin E, and their probable interactions in men with asthenozoospermia.

METHODS

A factorial, randomized, double-blind, placebo-controlled trial was conducted in infertility clinics in Tehran, Iran. The participants were idiopathic asthenozoospermic men aged 20-45 y, with normal endocrine function. Their concentration of spermatozoa and percentage of morphologically normal spermatozoa were equal to or above the lower reference limits, according to the fifth edition of the WHO guideline. Out of 717 men referred to the infertility clinics, 180 asthenozoospermic men were randomly assigned to 1 of 4 groups according to stratified blocked randomization by age and sperm concentration. Participants took daily 465 mg DHA plus 600 IU vitamin E (DE), 465 mg DHA plus placebo (DP), 600 IU vitamin E plus placebo (EP), or both placebo capsules (PP) for 12 wk. Sperm characteristics, oxidative stress of seminal plasma, serum and sperm membrane fatty acids, dietary intakes, anthropometric measurements, and physical activity were measured at baseline and after 12 wk.

RESULTS

After the intervention, mean ± SD sperm progressive motility was greater in the DE group (27.9 ± 2.8) than in the DP (25.7 ± 3.4), EP (26.1 ± 2.8), and PP (25.8 ± 2.6) groups (P < 0.05). Sperm count (P = 0.001) and concentration (P = 0.044) increased significantly in the DE group compared with the other 3 groups, whereas other semen parameters were not significantly different between the groups after the intervention. Serum concentrations of n-3 PUFAs were significantly higher in the DE and DP groups than in the EP and PP groups.

CONCLUSIONS

Combined DHA and vitamin E supplements led to increased sperm motility; however, no significant changes occurred in sperm morphology and vitality in asthenozoospermic men.This trial was registered at clinicaltrials.gov as NCT01846325.

Abnormal arachidonic acid metabolic network may reduce sperm motility via P38 MAPK

Asthenozoospermia is a common cause of male infertility, the aetiology of which remains unclear in 50–60% of cases. The current study aimed to characterize metabolic alterations in asthenozoospermic seminal plasma and to explore the signalling pathways involved in sperm motility regulation. At first, high-performance liquid chromatography–electrospray ionization–tandem mass spectrometry was used to detect the targeted metabolic network of arachidonic acid (AA). Metabolomic multivariate data analysis showed significant distinction of AA metabolites between asthenozoospermic and healthy seminal plasma. AA as well as its lipoxygenase (LOX) and cytochrome P450 metabolites were found to be abnormally increased, while cyclooxygenase (COX) metabolites were complicatedly disturbed in asthenozoospermic volunteers compared with those in healthy ones. In vitro experiments and western blot analysis of sperm cells revealed a decrease in sperm motility and upregulation of sperm phosphor-P38 induced by AA. P38 inhibitor could increase AA-reduced sperm motility. Also, all the inhibitors of the three metabolic pathways of AA could block AA-induced P38 mitogen-activated protein kinase (MAPK) activation and further improve sperm motility. We report here for the first time that an abnormal AA metabolic network could reduce sperm motility via P38 MAPK activation through the LOX, cytochrome P450 and COX metabolic pathways, which might be an underlying pathomechanism of asthenozoospermia.

Effect of sunflower lecithin on Kalahari Red goat semen during cryopreservation

Soybean lecithin had been used as an alternative to egg yolk in domestic animal semen extender during cryopreservation due to its characteristic phospholipid content which played a major cryoprotective role. This composition of soybean lecithin informed the replacement of soybean with sunflower lecithin (SL) in the extender for the Kalahari Red (KR) buck semen cryopreservation in this study. Effect of different levels of SL on the quality of the KR buck semen during cryopreservation using slow freezing method was evaluated. Semen samples were collected from four KR bucks of between two and two and half of age using artificial vagina, evaluated for motility and then diluted in extenders containing different levels of SL (1.5%, 3.0% and 4.5%) as experimental group and 0% SL or 20% egg yolk as control. Semen parameters including motility, acrosome integrity (AcI), membrane integrity (MI), malondialdehyde (MDA) concentration, cholesterol level and seminal arginase activity were evaluated for. The results showed that motility, acrosome integrity (AI) and membrane integrity were comparable at 0%, (22.00 ± 4.58, 82.00 ± 3.51 and 96.00 ± 2.03); 1.5%, (23.00 ± 2.08, 87.00 ± 3.79 and 89.00 ± 2.08); 3.0%, (13.00 ± 2.52, 81.33 ± 0.41 and 76.67 ± 1.20) and 4.5% (11.00 ± 4.51, 85.33 ± 9.88 and 84.00 ± 8.50), respectively, after thawing. SL at 0% had the highest (P < 0.05) values for MDA, cholesterol and seminal arginase activity (1.10 ± 0.008 nmol/ml, 236.35 ± 4.08 mg/dl and 0.54 ± 3.3 E-3 units/mg protein, respectively). Our data suggest that 1.5% sunflower lecithin can be used in place of soy lecithin as a substitute for egg yolk during the cryopreservation of caprine semen.

Motility and fertility of rabbit sperm cryopreserved using soybean lecithin as an alternative to egg yolk

This study was conducted to investigate whether soy lecithin can be used as an alternative cryoprotectant to establish a procedure that does not require the use of egg yolk to cryopreserve rabbit strains. Semen from Japanese White rabbits was frozen with HEPES extender containing 20% egg yolk (EYH), 0.5% (Lec-0.5), 1.5% (Lec-1.5), 2.5% (Lec-2.5), or 3.5% (Lec-3.5; wt/vol) lecithin (type IV-S, ≥30%), and the motility of thawed sperm was analyzed. The sperm motility in the Lec-1.5 group was significantly higher than that in the Lec-2.5 and 3.5 groups and equivalent to the EYH group. From 17 rounds of artificial insemination with frozen-thawed sperm in the EYH and Lec-1.5 groups, 12 rabbits in both groups were pregnant (70.6%) and delivered offspring. The litter size was 3.3 in the EYH group and 5.1 in the Lec-1.5 group. These results indicate that soy lecithin can be used as a substitute for egg yolk as a cryoprotectant on the basis of motility and fertility of the frozen-thawed rabbit sperm and that 1.5% lecithin (type IV-S, ≥30%) in the semen extender was the optimum concentration for rabbit sperm cryopreservation.

Liposome encapsulated soy lecithin and cholesterol can efficiently replace chicken egg yolk in human semen cryopreservation medium

Cryopreservation of spermatozoa plays a significant role in reproductive medicine and fertility preservation. Chicken egg yolk is used as an extender in cryopreservation of human spermatozoa using glycerol egg yolk citrate (GEYC) buffered medium. Even though 50% survival of spermatozoa is generally achieved with this method, the risk of high levels of endotoxins and transmission pathogens from chicken egg yolk is a matter of concern. In the present study we attempted to establish a chemically defined cryopreservation medium which can replace the chicken egg yolk without affecting sperm survival. Ejaculates from 28 men were cryopreserved with GEYC based freezing medium or liposome encapsulated soy lecithin-cholesterol based freezing medium (LFM). The semen samples were subjected to rapid thawing after 14 days of storage in liquid nitrogen. Post-thaw analysis indicated significantly higher post-thaw motility and sperm survival in spermatozoa cryopreserved with LFM compared to conventional GEYC freezing medium. The soy lecithin and cholesterol at the ratio of 80:20 with sucrose showed the highest percentage of post-thaw motility and survival compared to the other compositions. In conclusion, chemically defined cryopreservation medium with liposome encapsulated soy lecithin and cholesterol can effectively replace the chicken egg yolk from human semen cryopreservation medium without compromising post-thaw outcome.

Soy lecithin interferes with mitochondrial function in frozen-thawed ram spermatozoa

Egg yolk and milk are the 2 major membrane cryoprotectants commonly used in freezing media for the long-term preservation of semen (alone or in combination with others). However, in recent years, there have been increasing arguments against the use of egg yolk or milk because of the risk of introducing diseases through the use of cryopreserved semen. In this study, we analyzed the protective effect of lecithin as an alternative to egg yolk for the cryopreservation of ram semen, using a range of functional markers for sperm viability, motility, apoptosis, and mitochondrial functionality analyses (mitochondrial inner membrane surface [MIMS], mitochondrial inner membrane potential [MIMP], and cell membrane potential) as methods of assessment in samples diluted in 3 different media: Tris-citrate-glucose as control and 2 media supplemented with soy lecithin or egg yolk. The results showed that lecithin was able to effectively protect certain sperm quality characteristics against freezing-induced damage. However, lecithin induced loss of mitochondrial membrane potential or mitochondrial loss that was not reflected by modifications in sperm motility in fresh semen. MIMS and MIMP values decreased in thawed lecithin-treated samples, concomitant with a lower (P < .05) percentage of total and progressively motile cells, compared with those in egg yolk-containing samples. Further incubation of thawed samples revealed changes in motility and mitochondrial functionality that otherwise would not have been detected. These results indicated that lecithin may have affected the inner mitochondrial membrane in frozenthawed spermatozoa and confirmed that sublethal damages that seriously affect sperm functionality, not detected by classic sperm quality analyses, can be evidenced by changes in the inner mitochondrial membrane surface. These findings strengthen the relationship between mitochondrial membrane potential and motility and show that the mitochondrial alterations induced by the cryopreservation process could be specific targets for the improvement of semen cryopreservation protocols.

Choline dehydrogenase polymorphism rs12676 is a functional variation and is associated with changes in human sperm cell function

Approximately 15% of couples are affected by infertility and up to half of these cases arise from male factor infertility. Unidentified genetic aberrations such as chromosomal deletions, translocations and single nucleotide polymorphisms (SNPs) may be the underlying cause of many cases of idiopathic male infertility. Deletion of the choline dehydrogenase (Chdh) gene in mice results in decreased male fertility due to diminished sperm motility; sperm from Chdh^−/− males have decreased ATP concentrations likely stemming from abnormal sperm mitochondrial morphology and function in these cells. Several SNPs have been identified in the human CHDH gene that may result in altered CHDH enzymatic activity. rs12676 (G233T), a non-synonymous SNP located in the CHDH coding region, is associated with increased susceptibility to dietary choline deficiency and risk of breast cancer. We now report evidence that this SNP is also associated with altered sperm motility patterns and dysmorphic mitochondrial structure in sperm. Sperm produced by men who are GT or TT for rs12676 have 40% and 73% lower ATP concentrations, respectively, in their sperm. rs12676 is associated with decreased CHDH protein in sperm and hepatocytes. A second SNP located in the coding region of IL17BR, rs1025689, is linked to altered sperm motility characteristics and changes in choline metabolite concentrations in sperm.

Group X secreted phospholipase A₂ specifically decreases sperm motility in mice

Different mammalian secreted phospholipases A(2) (sPLA(2) s) are expressed in male reproductive organs and/or in sperm cells but their cellular functions are still not fully characterized. Because several reports indicate a link between cellular lipids and sperm motility, we have investigated the effect of mouse group IIA, IID, IIE, V, and X sPLA(2) s on sperm motility. Among these enzymes, only mouse group X sPLA(2) (mGX sPLA(2) ) acts as a potent inhibitor of sperm motility that decreases track speed (VCL) and lateral displacement of the head (ALH) of both noncapacitated and capacitated sperm. The inhibitory effect of mGX sPLA(2) is dependent on its enzymatic activity because (i) both the proenzyme form of mGX sPLA(2) (pro-mGX) and the H48Q mutant of mGX sPLA(2) have very weak enzymatic activity and are unable to modulate sperm motility and (ii) LY329722, a specific inhibitor of sPLA(2) s, blocks the inhibitory effect of mGX sPLA(2) . Moreover, mGX sPLA(2) exerts a gradual potency on sperm subpopulations with different velocities, an effect which may be linked to the heterogeneity of lipid composition in these sperm subpopulations. Finally, we found that endogenous mGX sPLA(2) released during spontaneous acrosome reaction modulates sperm motility of capacitated sperm. Together, our results suggest a new role of sPLA(2) in sperm physiology where the sPLA2 selects a sperm subpopulation for fertilization based on its effect on sperm motility.

Final report on the safety assessment of Lecithin and Hydrogenated Lecithin

Lecithin is a naturally occurring mixture of the diglycerides of stearic, palmitic, and oleic acids, linked to the choline ester of phosphoric acid, commonly called phosphatidylcholine. Hydrogenated Lecithin is the product of controlled hydrogenation of Lecithin. Bilayers of these phospholipids in water may form liposomes, a spherical structure in which the acyl chains are inside and not exposed to the aqueous phase. Lecithin and Hydrogenated Lecithin are used in a large number of cosmetic formulations as skin conditioning agents-miscellaneous and as surfactant-emulsifying agents. Hydrogenated Lecithin is also used as a suspending agent-nonsurfactant. Historical data on concentration of use of Lecithin reveals that 0.1% to 1.0% is the concentration range most frequently seen, with concentrations up to 50% reported for two moisturizing products. A solution of 65% Lecithin is currently reported to be used at concentrations up to 3% in cosmetics. Nonocclusive application of Lecithin-containing liposomes to murine skin resulted in 30% penetration to the subdermis. In piglet skin, the same application resulted in 99% accumulating in the stratum corneum. In general, liposomes are considered effective in capturing other compounds inside their spherical structure and delivering any such captured compound through the skin barrier. As a result, caution should be exhibited in formulating cosmetic products that contain these ingredients in combination with other ingredients whose safety is based on their lack of absorption or where dermal absorption is a concern. Lecithin is virtually nontoxic in acute oral studies, short-term oral studies, and subchronic dermal studies in animals. Lecithin is not a reproductive toxicant, nor is it mutagenic in several assays. In an oral carcinogenicity study, brain neoplasms were found in mice exposed to Lecithin. In a subcutaneous carcinogenicity study, no neoplasms were found in mice and rats exposed to Lecithin. Adverse reactions to Lecithin in a metered-dose inhaler have been reported. Lecithin and Hydrogenated Lecithin were generally nonirritating and nonsensitizing in animal and human skin. Based on the available data, Lecithin and Hydrogenated Lecithin are safe as used in rinse-off cosmetic products; they may be safely used in leave-on products at concentrations up to 15%, the highest concentration tested in clinical irritation and sensitization studies; but the safety of use could not be substantiated in cosmetic products likely to be inhaled. Because of the possibility of formation of nitrosamines, these ingredients should not be used in cosmetic products in which N-nitroso compounds may be formed.

Effect of DHA supplementation on DHA status and sperm motility in asthenozoospermic males

The effects of supplementation with docosahexaenoic acid (DHA) on DHA levels in serum, seminal plasma, and sperm of asthenozoospermic men as well as on sperm motility were examined in a randomized, double-blind, placebo-controlled manner. Asthenozoospermic men (n = 28; < or =50% motility) were supplemented with 0, 400, or 800 mg DHA/d for 3 mon. Sperm motility and the fatty acid composition of serum, seminal plasma, and sperm phospholipid were determined before and after supplementation. In serum, DHA supplementation resulted in decreases in 22:4n-6 (-30% in the 800-mg DHA group only) and total n-6 (-6 and -12% in the 400- and 800-mg DHA groups, respectively) fatty acids. Increases were noted in DHA (71 and 131% in the 400- and 800-mg DHA groups, respectively), total n-3 fatty acids (42 and 67% in the 400- and 800-mg DHA groups, respectively), and the n-3/n-6 ratio (50 and 93% in the 400- and 800-mg DHA groups, respectively). In seminal plasma, DHA supplementation resulted in a decrease in 22:4n-6 (-31% in the 800-mg DHA group only) and an increase in the ratio of n-3 to n-6 (35 and 33% in the 400- and 800-mg DHA groups, respectively). There were insignificant increases in DHA and total n-3 fatty acids. In sperm, decreases were noted in 22:4n-6 (-37 and -31% in the 400- and 800-mg DHA groups, respectively). There were no other changes. There was no effect of DHA supplementation on sperm motility. The results show that dietary DHA supplementation results in increased serum--and possibly seminal plasma--phospholipid DHA levels, without affecting the incorporation of DHA into the spermatozoa phospholipid in asthenozoospermic men. This inability of DHA to be incorporated into sperm phospholipid is most likely responsible for the observed lack of effect of DHA supplementation on sperm motility.

Lysophosphatidylcholine disrupts the acrosome of tammar wallaby (Macropus eugenii) spermatozoa

The acrosomal status of wallaby spermatozoa was evaluated by light and electron microscopy after incubation in 1-100 microM lysophosphatidylcholine (LPC) for up to 120 min. Treatment with 1 and 10 microM LPC for 120 min did not lead to acrosomal loss, or detectable alteration to the acrosome, as detected by Bryan's staining and light microscopy. Incubation with 25 microM LPC had little effect on acrosomal loss, however statistically significant changes (P < 0.05) in the acrosomal matrix (altered) were detected after 10-min incubation by light microscopy. Around 50% of acrosomes were altered after 20-min incubation in 50 microM LPC (P < 0.001), and 40% of spermatozoa had lost their acrosome after 60-min incubation (P < 0.001). Treatment with 75 and 100 microM LPC led to rapid acrosomal loss from around 50% of spermatozoa within 10 min (P < 0.001), and by 60 min acrosomal loss was 70-80%. LPC, like the diacylglycerol DiC8 (1,2-dioctanoyl-sn-glycerol), is thus an effective agent to induce loss of the relatively stable wallaby sperm acrosome, and it also induces changes within the acrosomal matrix. Ultrastructure of the LPC-treated spermatozoa revealed that the plasma membrane and the acrosomal membranes were disrupted in a manner similar to that seen after detergent treatment (Triton X-100). There was no evidence of point fusion between the plasma membrane overlying the acrosome and the outer acrosomal membrane. The plasma membrane was the first structure to disappear from the spermatozoa. The acrosomal membranes and matrix showed increasing disruption with time and LPC concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of antiepileptic drugs on sperm motility of normal controls and epileptic patients with long-term therapy

The in vitro effects of four antiepileptic drugs (AEDs) on human sperm motility were studied with a transmembrane migration method. Sperm motility of epileptic patients receiving chronic AED therapy was also investigated. Sperm motility was measured immediately after semen had been mixed with AED and after a 2-h preincubation at 37 degrees C. Both in vitro and in vivo studies demonstrated that AEDs inhibited sperm motility. When the drug effect was evaluated after the semen-AED mixture had been preincubated for 2 h, sperm motility was inhibited to 50% of control at concentrations of 1.59, 4.23, and 5.00 mM for phenytoin, carbamazepine, and valproate, respectively. Both with and without preincubation, phenobarbital, even up to 12.92 mM, did not inhibit the motility to less than 50% of the control. In the in vivo study, poor sperm motility was noted in epileptic patients with long-term AED therapy despite serum levels within the therapeutic range. Shorter duration of activity of spermatozoa was also observed in these patients. Interference with sperm membrane function by AEDs may be the underlying mechanism.

Etiology of severe asthenozoospermia and fertility prognosis. A screening of 5216 semen analyses

A review of n = 5216 semen analyses performed in our two Clinics from January 1986 to December 1989 allowed to identify n = 35 patients whose sperm had constantly very low motility (less than 5% progressive motile gametes in three subsequent analyses; necrozoospermia cases were excluded from this study). This apparently rare but severe anomaly was found to be associated not only with ultrastructural anomalies (n = 18), but also with positive seminal bacteriology (n = 8) or the presence of antisperm antibodies (n = 2). In eight cases the cause(s) for this constant asthenozoospermia remained obscure. The fertility potential of the men affected was followed-up and is discussed in relation to their anamnesis, physical exam and seminal characteristics.

Capacitation of bovine spermatozoa by lysophospholipids and trypsin

Bovine spermatozoa were incubated in vitro with lysophosphatidylserine (LPS), lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), lysophosphatidylinositol (LPI), or trypsin. Capacitation of sperm was evaluated by penetration of the zonae pellucidae of dead bovine oocytes. Capacitation times could be shortened to 3 h or less by treatment of spermatozoa with each of these lysophospholipids (LPLs) (P less than .05). The maximum oocyte penetration percentages for individual LPLs were 40% for 10 microM LPS. 24% for 160 microM LPC, 31% for 320 microM LPE, and 19% for 320 microM LPI. Capacitation also was facilitated (P less than .01) by trypsin treatment of spermatozoa. Spermatozoa treated with 250 or 2,500 units/ml of trypsin penetrated more oocytes (17 and 18%) than spermatozoa treated with 0 or 25 units/ml of trypsin (0 and 3%). Spermatozoa treated with increasing concentrations of LPL showed a decrease in both the percentage of intact acrosomes and of progressively motile spermatozoa. Increasing levels of trypsin in the incubation medium also led to a decrease (P less than .05) in the percentages of intact acrosomes and a decrease (P less than .01) in the percentages of progressively motile spermatozoa. Percentages of live, ovulated oocytes fertilized by spermatozoa incubated for 1 h in LPS (86%, 6/7) were not different from those incubated for 24 h in control medium (71%, 5/7). Percentages of oocytes fertilized with both of these capacitation treatments were higher (P less than .05) than for oocytes exposed or killed or uncapacitated sperm. Rapid induction of capacitation and the acrosome reaction can be accomplished by exogenous treatment of bovine sperm with lysophospholipids or trypsin.