Inhibition of forward and reverse transport of Ca via Na/Ca exchangers (NCX) prevents sperm capacitation.

Background: While calcium is known to play a crucial role in mammalian sperm physiology, how it flows in and out of the male gamete is not completely understood. Herein, we investigated the involvement of Na/Ca exchangers (NCX) in mammalian sperm capacitation. Using the pig as an animal model, we first confirmed the presence of NCX1 and NCX2 isoforms in the sperm midpiece.

Systematic review: pain, cognition, and cardioprotection-unpacking oxytocin's contributions in a sport context.

Introduction: This systematic review investigates the interplay between oxytocin and exercise; in terms of analgesic, anti-inflammatory, pro-regenerative, and cardioprotective effects. Furthermore, by analyzing measurement methods, we aim to improve measurement validity and reliability.

Methods: Utilizing PRISMA, GRADE, and MECIR protocols, we examined five databases with a modified SPIDER search.

Clustering of spermatozoa examined through flow cytometry provides more information than the conventional assessment: a resilience to osmotic stress example.

Context Conventional sperm quality tests may not be sufficient to predict the fertilising ability of a given ejaculate; thus, rapid, reliable and sensitive tests are necessary to measure sperm function. Aims This study sought to address whether a cluster analysis approach based on flow cytometry variables could provide more information about sperm function. Methods Spermatozoa were exposed to either isotonic (300mOsm/kg) or hypotonic (180mOsm/kg) media for 5 and 20min, and were then stained with SYBR14 and propidium iodide (PI).

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Background: Ion channels are essential for differentiation and maturation of germ cells, and even for fertilization in mammals. Different types of potassium channels have been identified, which are grouped into voltage-gated channels (Kv), ligand-gated channels (K ), inwardly rectifying channels (K ), and tandem pore domain channels (K ).

Material-methods: The present review includes recent findings on the role of potassium channels in sperm physiology of mammals.

Sperm function, mitochondrial activity and in vivo fertility are associated to their mitochondrial DNA content in pigs.

Background: Despite their low abundance in sperm, mitochondria have diverse functions in this cell type, including energy production, signalling and calcium regulation. In humans, sperm mitochondrial DNA content (mtDNAc) has been reported to be negatively linked to sperm function and fertility. Yet, the association between mtDNAc and sperm function in livestock remains unexplored.

Chromatin condensation but not DNA integrity of pig sperm is greater in the sperm-rich fraction.

Background: Protamination and condensation of sperm chromatin as well as DNA integrity play an essential role during fertilization and embryo development. In some mammals, like pigs, ejaculates are emitted in three separate fractions: pre-sperm, sperm-rich (SRF) and post sperm-rich (PSRF). These fractions are known to vary in volume, sperm concentration and quality, as well as in the origin and composition of seminal plasma (SP), with differences being also observed within the SRF one.

An intracellular, non-oxidative factor activates in vitro chromatin fragmentation in pig sperm.

Background: In vitro incubation of epididymal and vas deferens sperm with Mn induces Sperm Chromatin Fragmentation (SCF), a mechanism that causes double-stranded breaks in toroid-linker regions (TLRs). Whether this mechanism, thought to require the participation of topoisomerases and/or DNAses and thus far only described in epididymal mouse sperm, can be triggered in ejaculated sperm is yet to be elucidated. The current study aimed to determine if exposure of pig ejaculated sperm to divalent ions (Mn and Mg) activates SCF, and whether this has any impact on sperm function and survival.

The effects of red LED light on pig sperm function rely upon mitochondrial electron chain activity rather than on a PKC-mediated mechanism.

While irradiation with red LED light has been reported to modulate sperm function in different mammalian species, the mechanisms underlying their response are poorly understood. This work sought to provide new insights into whether this effect relies on a direct action upon mitochondrial electron chain and/or on PKC-linked mechanisms such as those related to opsins. For this purpose, pig semen was light-stimulated for 1, 5 or 10 min in the presence/absence of antimycin A, an inhibitor of the mitochondrial electron chain, or PKC 20-28 (PKCi), a PKC inhibitor.

Telomere length in bovine sperm is related to the production of reactive oxygen species, but not to reproductive performance.

Over the last decades, selection in cattle has mainly been based on milk production rather than on reproductive efficiency. While, when applied, focus on reproduction has involved females, attention has barely been paid to males and, if so, it has only looked at classical sperm quality parameters. In effect, variables such as telomere length have been missed, despite the fact that longer telomeres have been suggested to be linked to male fertility in humans.

A Review on the Role of Bicarbonate and Proton Transporters during Sperm Capacitation in Mammals.

Alkalinization of sperm cytosol is essential for plasma membrane hyperpolarization, hyperactivation of motility, and acrosomal exocytosis during sperm capacitation in mammals. The plasma membrane of sperm cells contains different ion channels implicated in the increase of internal pH (pH) by favoring either bicarbonate entrance or proton efflux. Bicarbonate transporters belong to the solute carrier families 4 (SLC4) and 26 (SLC26) and are currently grouped into Na/HCO transporters and Cl/HCO exchangers.

Blocking NHE Channels Reduces the Ability of In Vitro Capacitated Mammalian Sperm to Respond to Progesterone Stimulus.

Few data exist about the presence and physiological role of Na+/H+ exchangers (NHEs) in the plasma membrane of mammalian sperm. In addition, the involvement of these channels in the ability of sperm to undergo capacitation and acrosomal reaction has not been investigated in any mammalian species. In the present study, we addressed whether these channels are implicated in these two sperm events using the pig as a model.

Exogenous Albumin Is Crucial for Pig Sperm to Elicit In Vitro Capacitation Whereas Bicarbonate Only Modulates Its Efficiency.

This work sought to address whether the presence of exogenous bicarbonate is required for pig sperm to elicit in vitro capacitation and further progesterone-induced acrosome exocytosis. For this purpose, sperm were either incubated in a standard in vitro capacitation medium or a similar medium with different concentrations of bicarbonate (either 0 mM, 5 mM, 15 mM or 38 mM) and BSA (either 0 mg/mL or 5 mg/mL). The achievement of in vitro capacitation and progesterone-induced acrosomal exocytosis was tested through the analysis of sperm motility, plasma membrane integrity and lipid disorder, acrosome exocytosis, intracellular calcium levels, mitochondria membrane potential, O consumption rate and the activities of both glycogen synthase kinase 3 alpha (GSK3α) and protein kinase A (PKA).

Sperm chromatin condensation as an in vivo fertility biomarker in bulls: a flow cytometry approach.

Background: Genetic selection in cattle has been directed to increase milk production. This, coupled to the fact that the vast majority of bovine artificial inseminations (AI) are performed using cryopreserved sperm, have led to a reduction of fertility rates over the years. Thus, seeking sensitive and specific sperm biomarkers able to predict fertility rates is of vital importance to improve cattle reproductive efficiency.

The TUNEL assay underestimates the incidence of DNA damage in pig sperm due to chromatin condensation.

Inconsistencies in the relationship between sperm DNA fragmentation and reproductive outcomes as well as the low incidence in farm animals raise concerns on its actual value as a sperm quality parameter. Previous studies suggested that the different sensitivity of techniques evaluating DNA fragmentation could explain variations in the correlation with reproductive outcomes. While the TUNEL assay is one of the most standardized methods to detect DNA damage and cell death, the steric impediment for the terminal nucleotidyl transferase enzyme to access the highly condensed sperm nucleus may decrease the ability of this test to detect internal DNA breaks.

Complete Chromatin Decondensation of Pig Sperm Is Required to Analyze Sperm DNA Breaks With the Comet Assay.

Sperm quality is usually evaluated prior to artificial insemination in farm animals. In addition to conventional semen analysis, other biomarkers, such as mitochondrial activity, integrity and lipid disorder of plasma membrane, generation of reactive oxygen species (ROS) and sperm DNA integrity, have been found to be related to fertility rates in different species. While mounting evidence indicates that the Comet assay is a sensitive method for the detection of DNA breaks, complete sperm chromatin decondensation is required in order to properly analyze the presence of single- and double-strand DNA breaks.

Inhibition of Potassium Channels Affects the Ability of Pig Spermatozoa to Elicit Capacitation and Trigger the Acrosome Exocytosis Induced by Progesterone.

During capacitation, sperm undergo a myriad of changes, including remodeling of plasma membrane, modification of sperm motility and kinematic parameters, membrane hyperpolarization, increase in intracellular calcium levels, and tyrosine phosphorylation of certain sperm proteins. While potassium channels have been reported to be crucial for capacitation of mouse and human sperm, their role in pigs has not been investigated. With this purpose, sperm samples from 15 boars were incubated in capacitation medium for 300 min with quinine, a general blocker of potassium channels (including voltage-gated potassium channels, calcium-activated potassium channels, and tandem pore domain potassium channels), and paxilline (PAX), a specific inhibitor of calcium-activated potassium channels.

HVCN1 but Not Potassium Channels Are Related to Mammalian Sperm Cryotolerance.

Little data exist about the physiological role of ion channels during the freeze-thaw process in mammalian sperm. Herein, we determined the relevance of potassium channels, including SLO1, and of voltage-gated proton channels (HVCN1) during mammalian sperm cryopreservation, using the pig as a model and through the addition of specific blockers (TEA: tetraethyl ammonium chloride, PAX: paxilline or 2-GBI: 2-guanidino benzimidazole) to the cryoprotective media at either 15 °C or 5 °C. Sperm quality of the control and blocked samples was performed at 30- and 240-min post-thaw, by assessing sperm motility and kinematics, plasma and acrosome membrane integrity, membrane lipid disorder, intracellular calcium levels, mitochondrial membrane potential, and intracellular O⁻ and HO levels.

The Effects of Red Light on Mammalian Sperm Rely upon the Color of the Straw and the Medium Used.

Previous research has determined that irradiation of mammalian sperm with red light increases motility, mitochondrial activity, and fertilization capacity. In spite of this, no study has considered the potential influence of the color of the straw and the extender used. Therefore, this study tests the hypothesis that the response of mammalian sperm to red light is influenced by the color of the straw and the turbidity/composition of the extender.

Red LED Light Acts on the Mitochondrial Electron Chain of Mammalian Sperm via Light-Time Exposure-Dependent Mechanisms.

This work analyzes the effects of red LED light on mammalian sperm mitochondrial function, using the pig as an animal model. Liquid-stored pig semen was stimulated with red-light for 1, 5 and 10 min in the presence or absence of oligomycin A, a specific inhibitor of mitochondrial ATP synthase, or carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone (FCCP), a specific disruptor of mitochondrial electron chain. Whereas exposure for 1 and 5 min significantly ( < 0.

Medium-term effects of the diluted pig semen irradiation with red LED light on the integrity of nucleoprotein structure and resilience to withstand thermal stress.

This study sought to evaluate the effects of irradiating pig seminal doses with red LED light irradiation on their quality and longevity over liquid-storage at 17 °C. For this purpose, boar ejaculates were diluted in a commercial extender at a final concentration of 3 × 10 sperm/mL and stored at 17 °C for 96 h. Upon arrival to our laboratory (5-6 h within collection), 1.

The Presence of Seminal Plasma during Liquid Storage of Pig Spermatozoa at 17 °C Modulates Their Ability to Elicit In Vitro Capacitation and Trigger Acrosomal Exocytosis.

Although seminal plasma is essential to maintain sperm integrity and function, it is diluted/removed prior to liquid storage and cryopreservation in most mammalian species. This study sought to evaluate, using the pig as a model, whether storing semen in the presence of seminal plasma affects the sperm ability to elicit in vitro capacitation and acrosomal exocytosis. Upon collection, seminal plasma was separated from sperm samples, which were diluted in a commercial extender, added with seminal plasma (15% or 30%), and stored at 17 °C for 48 or 72 h.

Long-term storage of boar seminal doses contaminated with Proteus vulgaris: A dose-dependent effect on sperm motility and sperm-bacteria interaction.

This study evaluated how Proteus vulgaris affects sperm quality and sperm-bacteria interaction in stored semen samples. A strain of P. vulgaris resistant to streptomycin, penicillin, lincomycin and spectinomycin was added to boar semen in doses of 10, 10, 10, 10 and 10 CFU/mL.