In Assisted Reproductive Technologies (ART), efficient sperm preparation is vital for successful fertilization, with washing media enhancing the process. This pilot study examines the molecular-level impact of a new serotonin-containing sperm-washing medium (Prototype) on sperm motility and ROS metabolism, comparing it with commercially available media (Origio and Irvine). Semen samples from thirty-one individuals underwent preparation using the swim-up method post-semen analysis. Each sample was separately washed with the Prototype, Origio and Irvine mediums. ROS formation was determined through flow cytometric, and AT2R and PRDX2 protein levels, associated with sperm motility, were assessed via Western blot. Statistical evaluation compared the findings among the three outlined media. Significant differences were found among three washing media in terms of total and progressive motility. The Prototype medium showed the highest increase in both total (66%) and progressive motility (59%), while the control group exhibited the lowest increases (41% and 27.7%, respectively). Regarding ROS levels, the prototype (11.5%) and Origio (10.7%) groups demonstrated a notable decrease, contrasting with Irvine (25.8%). Molecular assessment revealed a significant elevation in AT2R protein levels in the prototype medium (59%), compared to other media. Additionally, an increase in PRDX2 protein levels was observed in the prototype medium, although this didn’t reach statistical significance. Serotonin-activated washing media for sperm preparation can be a suitable choice for selecting high-quality sperm in ART. A broader molecular analysis with a larger sample size is required to explore the mechanisms and effectiveness of using a serotonin-containing sperm-washing medium in routine ART.

Hydrogen sulfide (H2S) has been shown to play a significant role in oxidative stress across various tissues and cells; however, its role in sperm function remains poorly understood. This study aimed to investigate the protective effect of GYY4137, a slow-releasing H2S compound, on sperm damage induced by H2O2. We assessed the effects of GYY4137 on motility, viability, lipid peroxidation and caspase-3 activity in human spermatozoa in vitro following oxidative damage mediated by H2O2. Spermatozoa from 25 healthy men were selected using a density gradient centrifugation method and cultured in the presence or absence of 10 μM H2O2, followed by incubation with varying concentrations of GYY4137 (0.625–2.5 μM). After 24 h of incubation, sperm motility, viability, lipid peroxidation, and caspase-3 activity were evaluated. The results indicated that H2O2 adversely affected sperm parameters, reducing motility and viability, while increasing oxidative stress, as evidenced by elevated lipid peroxidation and caspase-3 activity. GYY4137 provided dose-dependent protection against H2O2-induced oxidative stress (OS). We concluded that supplementation with GYY4137 may offer antioxidant protection during in vitro sperm preparation for assisted reproductive technology.

Infertility affects 15% of all couples worldwide and 50% of cases of infertility are solely due to male factors. A decrease in motility in the semen is considered one of the main factors that is directly related to infertility. The use of supplementation to improve the overall sperm quality has become increasingly popular worldwide. The purpose of this study was to evaluate whether sperm motility was affected by the combination of serotonin (5-HT), selenium (Se), zinc (Zn), and vitamins D, and E supplementation. Semen samples were incubated for 75 min at 37°C in medium containing varying concentrations of 5-HT, Se, Zn, vitamin D, and E. 5-HT (200 μM), Se (2 μg/ml), Zn (10 μg/ml), vitamin D (100 nM), and vitamin E (2 mmol) have also been shown to increase progressive sperm motility. Three different mixtures of supplements were also tested for their combined effects on sperm motility and reactive oxygen species (ROS) production. While the total motility in the control group was 71.96%, this was found to increase to 82.85% in the first mixture. In contrast the average ROS level was 8.97% in the control group and decreased to 4.23% in the first mixture. Inclusion of a supplement cocktail (5-HT, Se, Zn, vitamins D and E) in sperm processing and culture medium could create an overall improvement in sperm motility while decreasing ROS levels during the incubation period. These molecules may enhance the success of assisted reproduction techniques when present in sperm preparation medium.

Congenital domestic absence of vas deferens (CBAVD) is a common factor in male infertility, and percutaneous epididymal sperm aspiration (PESA) combined with intracytoplasmic sperm injection (ICSI) is a primary clinical treatment, but the effect of the sperm obtained on pregnancy outcome remains to be explored. This study aimed to investigate the relationship between sperm motility with clinical outcome of PESA–ICSI in infertile males with CBAVD. A cohort of 110 couples was enrolled. In total, 76 infertile males were included in the high motility group, while the remaining 34 males were placed in the low motility group. Clinical pregnancy, embryo implantation rate and live birth rate were included as the primary outcome. After all follow-ups, we found that the high motility group achieved higher normal fertilization rates, cleavage rates, transplantable embryo rates and high-quality embryo rates than those in low motility group (normal fertilization rate, 78.2 ± 11.7% vs. 70.5 ± 10.2%, P = 0.003; cleavage rate, 97.1 ± 2.9% vs. 92.3 ± 3.0%, P = 0.000; transplantable embryo rate, 66.8 ± 14.9% vs. 58.6 ± 12.6%, P = 0.009 and high-quality embryo rate, 49.9 ± 10.5% vs. 40.5 ± 11.2%, P = 0.000). Additionally, compared with the low motility group, the clinical pregnancy rates, embryo implantation rates, and live birth rates in the high motility group were significantly increased (pregnancy rate, 61.8% vs. 26.5%, P = 0.009; embryo implantation rate, 36.5% vs. 18.0%, P = 0.044; live birth rate, 55.3% vs. 17.6%, P = 0.000). We concluded that the motility of sperm obtained by PESA affected the clinical outcome of ICSI in infertile males with CBAVD.

This study examined the effect of a cryoprotectant with and without pentoxifylline supplementation on the motility and viability of human testicular sperm, both before and after freezing. Testicular samples were obtained from 68 patients with azoospermia who came to the Andrology Service of West China Second University Hospital, Sichuan University, for testicular biopsies from December 2019 to April 2020. All patients were assigned randomly to two groups: experimental, whose testicular sperm were added to the cryoprotectant with pentoxifylline, and the control, whose testicular sperm were added to the cryoprotectant without pentoxifylline. Both groups used the same freezing and thawing methods. Testicular sperm motility in the experimental group was significantly higher than that of the control group, both before and after cryopreservation. The recovery rate of sperm motility in the experimental group was significantly higher than that of the control group. The percentage of samples with motile testicular sperm in the experimental group was significantly higher than that of the control group after thawing. Sperm viability was unchanged between the experimental and control groups, both before and after freezing. Overall, a pentoxifylline-supplemented cryoprotectant can significantly improve the motility of testicular sperm before and after cryopreservation.

The aim of this study was to evaluate the effect of incubating semen for different periods (90, 270 or 450 min) with or without Trolox® (100 or 150 µM) on the quality of sperm from Saimiri collinsi. Sperm motility, vigour, and plasma membrane integrity (PMI) were evaluated in both fresh semen and semen incubated for different time periods, i.e. 90, 270 or 450 min of incubation. Supplementation of semen extender with Trolox® 100 µM improved sperm motility, vigour and PMI for up to 270 min of incubation.

The adaptive significance of variation in sperm phenotype is still largely unknown, in part due to the difficulties of observing and measuring sperm movement in its natural, selective environment (i.e., within the female reproductive tract). Computer-assisted sperm analysis systems allow objective and accurate measurement of sperm velocity, but rely on being able to track individual sperm, and are therefore unable to measure sperm movement in species where sperm move in trains or bundles. Here we describe a newly developed computational method for measuring sperm movement using Fourier analysis to estimate sperm tail beat frequency. High-speed time-lapse videos of sperm movement within the female tract of the neriid fly Telostylinus angusticollis were recorded, and a map of beat frequencies generated by converting the periodic signal of an intensity versus time trace at each pixel to the frequency domain using the Fourier transform. We were able to detect small decreases in sperm tail beat frequency over time, indicating the method is sensitive enough to identify consistent differences in sperm movement. Fourier analysis can be applied to a wide range of species and contexts, and should therefore facilitate novel exploration of the causes and consequences of variation in sperm movement.

Initiation of sperm motility in urodeles, which is induced by a sperm motility-initiating substance (SMIS) in the sequestered granules on the surface of egg jelly, is mediated by the acrosome reaction (AR), which is triggered by an AR-inducing substance (ARIS) on a sheet-like structure. Details of the unique process of the interaction between egg jelly and sperm in these species is still unclear. The current study showed the fine structure of egg jelly in the newt Cynops pyrrhogaster, a urodele species, revealing that its outer surface was covered by a sheet-like structure of approximately 0.29 μm in thickness. Granules of approximately 2 μm in diameter with small particles of approximately 54 nm were attached to its surface and distributed inhomogeneously just beneath the sheet-like structure. Emission spectrometry revealed that the Ca2+ concentration was maintained at a high level compared with that of the blood plasma and the vas deferens fluid, suggesting that egg jelly is a reliable source of Ca2+ for the sperm–egg interaction. Blockers of the T-type voltage-dependent Ca2+ channel (VDCC), but not the L-type VDCC, inhibited both AR and initiation of sperm motility. Conversely, Ni+, which affects the α1 H subunit of T-type VDCC, only inhibited the initiation of sperm motility. These data suggest that, in response to ARIS and SMIS, sequential gating of distinct Ca2+ channels occurs in the AR, followed by the initiation of sperm motility on the surface of the egg jelly in C. pyrrhogaster at fertilization.

The effects of Percoll density gradient centrifugation on sperm quality, in vitro fertilizability and developmental capacity of frozen–thawed boar sperm were evaluated. Two-step density gradient centrifugation by Percoll enhanced significantly the motility parameters of sperm compared with a simple centrifugation procedure. Percentages of motile sperm and sperm with intact plasma and acrosome membranes after Percoll separation were significantly greater than those after simple centrifugation. The rates of penetration, cleavage and blastocyst formation after in vitro fertilization were significantly improved by Percoll separation compared with simple centrifugation and were influenced positively by the intactness of sperm head membranes, but not any sperm motility parameters. However, insemination with increased concentrations of sperm prepared by Percoll gradient centrifugation did not improve the success of fertilization and embryo development in vitro. Our results indicate that the integrity of sperm head membranes after Percoll separation is important for successful embryo development in vitro, more so than sperm motility.

Sperm characteristics of scallops have not been well described in the scientificliterature. The effects of sperm release technique (thermal shock versus serotonininjection), of sperm collection technique (testis sampling versus serotonin injection), ofsperm sampling location along the genital tract, of in vitro sperm maturation, and of timepost activation on scallop sperm characteristics were assessed in the present work.Whatever sperm release technique used, no significant differences were observed regardingthe percentage of motile spermatozoa and the velocity of the average path (VAP). Comparedto testicular sperm, a higher percentage of motile spermatozoa, VAP and intracellularadenosine triphosphate (ATP) content were observed for sperm shed after serotonininjection. From the distal part of testes up to the gonopore, an increase of thepercentage of motile spermatozoa and VAP was assessed, suggesting a sperm ‘maturationprocess’ along the genital ducts. A higher increase in the percentage of motile sperm wasrecorded during a 5 min incubation of testicular sperm in seawater containing 2 mMserotonin and seawater containing 10 mM caffein compared to seawater (control). Inaddition, a higher VAP was assessed, incubating testicular sperm in caffein, compared tocontrol or serotonin. Then, the percentage of motile spermatozoa, VAP and intracellularATP content exhibited a progressive reduction during the 10 h swimming period. Mean valuesof the percentage of motile spermatozoa, VAP, sperm track linearity (LIN) andintracellular ATP content recorded at the beginning of the movement period for spermsamples collected after intragonadal serotonin injection, were 82 ± 7%,162 ± 15μm s-1, 0.33 ± 0.12 and 212 ± 133 nmol × 10-9 spermatozoa (n = 9 males), respectively. The presentstudy confirms the existence of a sperm “maturation process” along scallop genital ducts.In addition, the cessation of scallop sperm movement can be explained by the exhaustion ofATP content at the end of the movement phase.

The egg jelly of Discoglossus pictus contains sperm motility-activating activity, the molecular basis of which has not been studied. Discoglossus pictus sperm initiated motility immediately after immersion in egg-jelly extract, as well as after immersion in hyposmotic solution, which initiates sperm motility in the external fertilization of anuran amphibians. Sequential treatment of the D. pictus sperm with these two solutions revealed the predominant effect of hyposmolality in initiation of motility. The motility initiation induced by jelly extract was suppressed by a monoclonal antibody (mAb) that is specific for the 34 kDa sperm motility-initiating substance (SMIS) in the egg jelly of the newt, Cynops pyrrhogaster. Immunoblotting using the anti-SMIS mAb revealed several antigenic proteins that included major ones with sizes of 18- and 34-kDa in D. pictus jelly extract. Scanning electron microscopic observation revealed that granules of jelly matrix, in which SMIS localizes and which have a critical role in the internal fertilization of C. pyrrhogaster, were not observed near the surface of the D. pictus egg jelly. These results suggest that sperm motility-activating activity in egg jelly of D. pictus may be mediated by SMIS homologous proteins that act through a mechanism that is partially different from that of C. pyrrhogaster.

Fetal exposure to caffeine is associated with adverse pregnancy outcomes. Animal and human studies suggest that caffeine may have effects on the developing reproductive system. Here we report on mothers’ smoking, coffee and alcohol use, recorded during pregnancy, and semen quality in sons in the age group of 38–47 years. Subjects were a subset of the Child Health and Development Studies, a pregnancy cohort enrolled between 1959 and 1967 in the Kaiser Foundation Health Plan near Oakland, California. In 2005, adult sons participated in a follow-up study (n = 338) and semen samples were donated by 196 participants. Samples were analyzed for sperm concentration, motility and morphology according to the National Cooperative Reproductive Medicine Network (Fertile Male Study) Protocol. Mean sperm concentration was reduced by approximately 16 million sperms for sons with high prenatal exposure (5 cups of maternal coffee use per day) compared with unexposed sons (P-value for decreasing trend = 0.09), which translates to a proportionate reduction of 25%. Mean percent motile sperm decreased by approximately 7 points (P-value = 0.04), a proportionate decline of 13%, and mean percent sperm with normal morphology decreased by approximately 2 points (P-value = 0.01), a proportionate decline of 25%. Maternal cigarette and alcohol use were not associated with son's semen quality. Adjusting for son's contemporary coffee, alcohol and cigarette use did not explain the maternal associations. Findings for son's coffee intake and father's prenatal coffee, cigarette and alcohol use were non-significant and inconclusive. These results contribute to the evidence that maternal coffee use during pregnancy may impair the reproductive development of the male fetus.