Ammonium (NH4+) plays a crucial role in the reproductive processes of key biotic groups in aquatic ecosystems-bivalves. This study aims to elucidate the effects of three different ammonium ion concentrations on sperm vitality, swimming kinematics, and morphology of Mimachlamys nobilis, Pinctada fucata martensii, and Saccostrea mordax. The results indicate that the sperm vitality and motility rates of M.nobilis and S. mordax are inversely proportional to the ammonium concentration, especially in the treatment group with an ammonium concentration of 3 mmol/L, where the decrease in sperm vitality and motility is most significant. In contrast, the sperm of P. fucata martensii reacted differently to increasing ammonium concentrations. After the addition of 2 mmol/L of ammonium, the sperm vitality and motility of P. fucata martensii reached a peak, showing a significant stimulatory effect. Additionally, as the ammonium concentration increased, the curling of the sperm flagella in M.nobilis and S. mordax increased. However, sperm flagella curling in P. fucata martensii showed no change compared to the control group. This study provides insights into the effects of ammonium concentrations on the sperm vitality and motility of three marine bivalve species and highlights the importance of sperm flagella curling as a factor affecting sperm.

Several studies have demonstrated interesting results considering the implication of three growth factors (GFs), namely nerve growth factor (NGF), erythropoietin (EPO), and the insulin-like growth factor-I (IGF-1) in the physiology of male reproductive functions. This review provides insights into the effects of NGF, EPO, and IGF-1 on the male reproductive system, emphasizing mainly their effects on sperm motility and vitality. In the male reproductive system, the expression pattern of the NGF system varies according to the species and testicular development, playing a crucial role in morphogenesis and spermatogenesis. In humans, it seems that NGF positively affects sperm motility parameters and NGF supplementation in cryopreservation media improves post-thaw sperm motility. In animals, EPO is found in various male reproductive tissues, and in humans, the protein is present in seminal plasma and testicular germ cells. EPO receptors have been discovered in the plasma membrane of human spermatozoa, suggesting potential roles in sperm motility and vitality. In humans, IGF-1 is expressed mainly in Sertoli cells and is present in seminal plasma, contributing to cell development and the maturation of spermatozoa. IGF-1 seems to modulate sperm motility, and treatment with IGF-1 has a positive effect on sperm motility and vitality. Furthermore, lower levels of NGF or IGF-1 in seminal plasma are associated with infertility. Understanding the mechanisms of actions of these GFs in the male reproductive system may improve the outcome of sperm processing techniques.

The aim of our study was to assess if the addition of PRGF to healthy human sperm affects its motility and vitality.
This was a prospective study, with 44 sperm donors on whom sperm analysis was performed. Nine mL of blood was collected and PRGF was obtained using PRGF-Endoret® technology. The influence of different dilutions of PRGF (5%, 10%, 20%, 40%) applied to 15 sperm donors was compared, and sperm motility was assessed after 30 minutes. In the second part of the study, 29 sperm donors were studied to analyze the influence of 20% dilution of PRGF at 15, 30 and 45 minutes in fresh and thawed sperm samples. Motility was assessed after the addition of PRGF and after analysis each aliquot was frozen. After thawing, concentration and motility were assessed at the same time periods.
There were no differences in sperm motility in fresh samples between dilutions of PRGF when assessed 30 minutes after administration, nor between them, nor when compared to the control group immediately prior to treatment. No trend was observed between motility and PRGF dilution in linear regression analysis. There were no significant differences in thawed samples.
The administration of 20% PRGF dilution had no effect on sperm motility compared to samples without PRGF. In addition, there was no change in sperm vitality when comparing samples with and without PRGF. More studies focusing on subnormal sperm samples, analyzing different PRGF concentrations and increasing the number of study variables are needed.

Epicatechin (EPC) is a flavonoid belonging to the family of catechins; it has been described as a powerful scavenger of a wide spectrum of reactive oxygen species (ROS) and a modulator of ex vivo sperm vitality. In this study, we assessed the potential protective abilities of EPC on cryopreserved bovine spermatozoa. We focused on conventional quality parameters, as well as the oxidative profile of spermatozoa alongside capacitation patterns, and expression profiles of proteins involved in the process of capacitation. Semen samples were cryopreserved in the presence of 25, 50 or 100 μmol/L EPC and compared to native semen (negative control) as well as ejaculates frozen in the absence of EPC (positive control). A dose-dependent improvement of conventional sperm quality parameters was observed following EPC administration, particularly in case of the sperm motility, membrane, acrosome and DNA integrity in comparison to the positive control. Experimental groups exposed to all EPC doses presented with a significantly lower proportion of capacitated spermatozoa as opposed to the positive control. While no significant effects of EPC were observed in cases of superoxide production, a significant decrease in the levels of hydrogen peroxide and hydroxyl radical were recorded particularly in the experimental groups supplemented with 50 and 100 μmol/L EPC. Western blot analysis revealed that supplementation of particularly 100 μmol/L EPC to the semen extender prevented the loss of the cation channel of sperm (CatSper) isoforms 1 and 2, sodium bicarbonate cotransporter (NBC) and protein kinase A (PKA), which play important roles in the process of sperm capacitation. In summary, we may hypothesize that EPC is particularly effective in the stabilization of the sperm membrane during the freeze-thaw process through its ability to quench ROS involved in damage to the membrane lipids and to prevent the loss of membrane channels crucial to initiate the process of sperm capacitation. These attributes of EPC provide an additional layer of protection to spermatozoa exposed to low temperatures, which may be translated into a higher post-thaw structural integrity and functional activity of male gametes.

Two isoforms of the gonadotropin-releasing hormone (GnRH), GnRH-I and GnRH-II, are expressed in mammals, and the presence of one or more GnRH-like peptides has been demonstrated in the male reproductive tract. GnRH and its receptors (GnRHR) are present in human and non-human primate testis, prostate, epididymis, seminal vesicle, spermatozoa and seminal human plasma. GnRH-II is site-specific and acts directly in an inhibitory or stimulatory fashion. Previous studies speculated that GnRH-II could disrupt specific sperm processes, such as sperm motility or capacitation and could be utilized as an effective contraceptive agent. Our study aimed to investigate the in-vitro effects of GnRH-I and GnRH-II on Vervet monkey sperm function. Electro-ejaculated semen samples from 10 Vervet monkeys (Chlorocebus aethiops) were used to select motile sperm populations. Sperm aliquots were incubated with GnRH-I and GnRH-II at different concentrations for 1 h, where after sperm motility and kinematic parameters were assessed using the automated Sperm Class Analyser. Additional sperm aliquots were incubated with two 10-amino acid control peptides, a non-related peptide and an inactive peptide to exclude the possible influence on sperm motility from other peptides with a structure similar to GnRH. Additionally, a GnRHR-I antagonist (GnRHR-A), Cetrorelix, was tested to establish its antagonistic capability on GnRH. The effect of selected concentrations of GnRH-I and GnRH-II on sperm vitality and acrosome intactness was also evaluated after 10- and 60 min exposure. Analysis of the percentage total sperm motility revealed that different concentrations for GnRH-I and GnRH-II inhibited sperm motility significantly. While sperm progressiveness was also notably affected and a trend of decreased sperm kinematics were evident, no effect was found on sperm vitality or acrosome intactness. The non-related and inactive peptides had no impact on sperm motility. The GnRHR-A demonstrated no effect on sperm motility and effectively blocked the inhibitory outcome on the motility of both GnRH isoforms. While GnRH-I or GnRH-II at low-dose concentrations resulted in in-vitro inhibition of sperm motility, it appears to have no adverse effects on other sperm functional parameters evaluated. These collective observations possibly indicate an essential role for GnRH in the in-vivo process of sperm selection in the female reproductive tract.

The first two editions of the World Health Organization laboratory manual described the determination of live spermatozoa by a dye exclusion method as a sperm \"viability\" test, whereas subsequent editions classified it as a \"vitality\" test, without providing an explanation for the reclassification. Additionally, the hypo-osmotic swelling (HOS) test, which assesses the functional integrity of the human sperm membrane, was placed in the same category as the dye exclusion test. Although the two terms might seem synonymous, the term \"vitality\" merely means \"alive,\" whereas \"viability\" assesses qualities or physiological functions of a living entity. After comparing the morphological, physiological, and clinical findings obtained from dye exclusion testing vs. the HOS test, we conclude that the HOS test should be classified as a viability test, not merely as a vitality test.

A basic semen investigation has established principles that are necessary for ascertaining reliable and internationally comparable results. Although these principles have been present in the WHO manual since its inception, the baseline issue across most published studies and practice in reproductive medicine (in which the male is considered) is repetitive failure to adhere to these principles, thereby leading to relevant comparable data and accuracy. To address this failure, the sixth edition of the WHO manual includes revised basic methods, and a complementary formal standard of the International Standards Organization (ISO23162:2021) for basic semen examination has been published. Perhaps the most significant change in the sixth edition is the reintroduction of the four-category distinction of sperm motility, which causes additional work for laboratories in changing reporting parameters but is clinically important. Another essential change is the widened focus from mainly a prognostic tool for medically assisted reproduction to additionally raising awareness of semen examination as a measure of male reproductive functions and general male health.

In order to address the large percentage of unexplained male infertility in humans, more detailed investigations using sperm functional tests are needed to identify possible causes for compromised fertility. Since many environmental and lifestyle factors might be contributing to infertility, future studies aiming to elucidate the effect of such factors on male fertility will need the use of appropriate research models. The current study aimed to assess the effects of two heavy metals, namely copper sulphate, and cadmium chloride, on non-human primate (NHP) sperm function in order to establish the possibility of using these primate species as models for reproductive studies. Our combined results indicated that the functionality of NHP spermatozoa is inhibited by the two heavy metals investigated. After in vitro exposure, detrimental effects, and significant lowered values (p < 0.05) were obtained for sperm motility, viability and vitality, acrosome intactness, and hyperactivation. These metals, at the tested higher concentrations, therefore, have the ability to impair sperm quality thereby affecting sperm fertilizing capability in both humans and NHPs.

C60 fullerene (C60) is a nano-pollutant that can damage the respiratory system. Eugenol exhibits significant anti-inflammatory and antioxidant properties. We aimed to investigate the time course of C60 emulsion-induced pulmonary and spermatic harms, as well as the effect of eugenol on C60 emulsion toxicity. The first group of mice (protocol 1) received intratracheally C60 emulsion (1.0 mg/kg BW) or vehicle and were tested at 12, 24, 72 and 96 h (F groups) thereafter. The second group of mice (protocol 2) received intratracheally C60 emulsion or vehicle, 1 h later were gavaged with eugenol (150 mg/kg) or vehicle, and experiments were done 24 h after instillation. Lung mechanics, morphology, redox markers, cytokines and epididymal spermatozoa were analyzed. Protocol 1: Tissue damping (G) and elastance (H) were significantly higher in F24 than in others groups, except for H in F72. Morphological and inflammatory parameters were worst at 24 h and subsequently declined until 96 h, whereas redox and spermatic parameters worsened over the whole period. Eugenol eliminated the increase in G, H, cellularity, and cytokines, attenuated oxidative stress induced by C60 exposure, but had no effect on sperm. Hence, exposure to C60 emulsion deteriorated lung morphofunctional, redox and inflammatory characteristics and increased the risk of infertility. Furthermore, eugenol avoided those changes, but did not prevent sperm damage.

Lately, there is a systematic research consensus that reveals adverse effects of aspirin on semen quality characteristics; however, such consensus is lacking further confirmation by human studies. Therefore, here, we asked whether sperm motility and vitality are affected in the presence of aspirin at 0.1 and 1 mM in the ejaculated semen, and whether such effect may be due to an alteration in seminal calcium ions or seminal nitric oxide production. Forty-three semen samples from different normozoospermic men were recruited in this study. Sperm motility was measured by Makler counting chamber, and sperm vitality was measured by Eosin test. Calcium chelating effect of aspirin and seminal nitric oxide production was measured spectrophotometrically. Aspirin at both tested concentrations significantly (p < .05) reduced progressive grade-a motility and vitality of spermatozoa. Additionally, aspirin was found to have significant ability (p < .05) to bind seminal calcium ions, but insignificantly reduced the amount of seminal nitric oxide. In conclusion, sperm motility and vitality were reduced in the presence of aspirin at 0.1 and 1 mM in semen. Such reduction may be attributable to the ability of aspirin to chelate seminal calcium ions, but not to an alteration in the amount of nitric oxide produced.