Tolerance of spermatozoa to hypotonic stress: role of membrane fluidity and correlation with cryosurvival

2015 ◽  
Vol 27 (2) ◽  
pp. 285 ◽  
Author(s):  
Harriëtte Oldenhof ◽  
Anna Heutelbeck ◽  
Anne-Kathrin Blässe ◽  
Heinrich Bollwein ◽  
Gunilla Martinsson ◽  
...  

The aim of this study was to evaluate inter-individual variability in osmotic properties of stallion spermatozoa and its correlation with cryosurvival. In addition, temperature dependency of hypo-osmotic tolerance and membrane fluidity were studied. Stallion sperm membranes exhibited good resistance towards hypotonic stress in the 15–30°C temperature range, whereas membrane stability was found to be decreased at 4 and 37°C. Bull spermatozoa showed greater hypo-osmotic tolerance compared with stallion spermatozoa, especially at temperatures above 30°C, which coincided with decreased membrane fluidity of bovine spermatozoa in this temperature range. The critical osmolality at 22°C, at which half of the sperm population survived exposure to hypotonic saline solution, was found to vary between 55 and 170 mOsm kg–1 among different stallions. Clear correlations were found for pre- versus post-freeze sperm motility and membrane integrity. Pre-freeze percentages of membrane-intact spermatozoa after exposure to hypotonic stress showed a weak correlation with sperm motility after cryopreservation. This correlation, however, was not found when data were corrected for initial numbers of membrane-intact spermatozoa in the sample. We thus conclude that studies on pre-freeze tolerance towards hypotonic stress cannot be used to predict sperm cryosurvival rates for individual stallions.

2009 ◽  
Vol 21 (1) ◽  
pp. 140
Author(s):  
E. M. Walters ◽  
J. D. Benson ◽  
A. Rieke ◽  
J. K. Graham ◽  
J. K. Critser

Difficulties associated with the cryopreservation of boar sperm include their sensitivities to osmotic stresses and chilling sensitivity. We investigated the effects of cholesterol-loaded cyclodextrin (CLC) on boar sperm motility and membrane integrity following exposure to various osmolalities. Samples were collected using the gloved hand method from crossbred boars, and ejaculates having greater than 75% motility were extended 1:3 with Androhep (Minitube Inc., Verona, WI) for this study. Samples were centrifuged at 700g for 5 min, and the resulting pellets were resuspended to 1.2 × 108 cells mL–1 in Androhep. Samples were then treated with 0, 1.5, or 3.0 mg of CLC/1.2 × 108 cells mL–1 for 10 min at room temperature. In experiment 1, samples were aliquoted into 1.5-mL centrifuge tubes, centrifuged at 700g for 5 min and the sperm exposed to Dulbecco’s PBS at different osmolalities for 5 min before being returned to 300 mOsm by adding Dulbecco’s PBS solutions at differing osmolalities. After returning the sperm to isosmotic conditions, sperm motility was analyzed. In experiment 2, samples were treated as in experiment 1 and following exposure to the various osmolalities, sperm were stained with Alexa 488-PNA and propidium iodide to determine sperm membrane integrity. Ten thousand sperm per treatment were analyzed by flow cytometry. Data were analyzed by standard ANOVA. The CLC-treated sperm (normalized means ± SEM; 33 ± 16, 80 ± 8, 86 ± 5, 100, 64 ± 4, 7 ± 3, 0 ± 0, respectively) exhibited greater percentages of motile cells following hypo-isosmotic exposure than control sperm (4 ± 1.6, 33 ± 9.6, 84 ± 7.1, 100, 37 ± 5.5, 3 ± 1.6, 0 ± 0, respectively), and there was a tendency for CLC-treated sperm (P = 0.0225) to maintain motility following hyper-isosmotic exposure. In addition, CLC-treated sperm (87 ± 4, 93 ± 1, 95 ± 1, 93 ± 2, 88 ± 4, 83 ± 3, 41 ± 9, respectively; P < 0.05) maintained greater percentages of membrane integrity following treatment with anisosmotic solutions compared with controls (29 ± 8, 63 ± 10, 81 ± 7, 92 ± 3, 73 ± 8, 44 ± 5, 21 ± 9, respectively). Using a combination of these osmotic tolerance data with previously published boar sperm membrane permeability characteristics, we mathematically modeled the number of steps needed for the addition or removal of cryoprotectants. Computer simulations indicate that an abrupt addition of 1 m glycerol will cause boar sperm to exceed their osmotic tolerance limits unless they are treated with 3 mg of CLC. Moreover, the addition of 1 m EG causes boar sperm to exceed all osmotic tolerance limits and therefore, the addition and removal of EG requires multiple-step protocols. However, the addition and removal of 1 m DMSO maintains volume excursions well within the osmotic tolerance limits with the addition of cholesterol (1.5 and 3 mg). Empirical data for addition of CPA have shown similar results as seen with the computer simulation. These data support the hypothesis that adding cholesterol to porcine sperm broadens their osmotic tolerance limits and potentially provide a mechanism to increase post-thaw survival of porcine sperm.


Author(s):  
V. Madhavi ◽  
U. Kanchana Ganga ◽  
S. B. Sainath ◽  
B. Kishori

Aims: The present study was aimed to investigate the protective role of ginger against acephate-induced testicular toxicity in adult rats. Methodology: Rats were allocated into four groups where animals in group I served as controls, while animals in group II, III and group IV were treated as experimental rats. Rats in groups II, III and IV were treated with acephate (50mg/kg body weight), ginger (100mg/kg body weight) and combination of both acephate and ginger, respectively over a period of 60 days. After completion of experimental period sperm count, sperm viability, sperm motility, sperm membrane integrity, testicular steroidogenic marker enzymes (3β-HSD and 17β-HSD, serum testosterone and testicular architecture was performed in both control and experimental rats. Results: Relative weights of reproductive organs, sperm count, sperm viability, sperm motility and sperm membrane integrity were significantly decreased in acephate treated rats over controls. Acephate administration also reduced the circulatory levels of testosterone associated with a significant reduction in the testicular steroidogenic marker enzymes (3β-HSD and 17β-HSD) in rats. The testicular architecture was disrupted in acephate intoxicated rats. In contrast, ginger administration significantly recovered the acephate-induced suppressed selected reproductive parameters with increased circulatory levels of testosterone and restoration of sperm endpoints in as compared to acephate alone treated rats. No significant changes were observed in any of the selected reproductive endpoints in ginger treated rats as compared to controls. Conclusion: The results can be concluded that supplementation of ginger mitigates the negative effects of acephate on male reproductive health via amelioration of testicular setroidogenesis and spermatogenesis and epididymal sperm maturation events in rats.


2008 ◽  
Vol 20 (1) ◽  
pp. 217
Author(s):  
G. Wirtu ◽  
C. E. Pope ◽  
M. C. Gomez ◽  
R. A. MacLean ◽  
D. L. Paccamonti ◽  
...  

Compared to success rates in human, intracytoplasmic sperm injection (ICSI) is inefficient in ungulate species. Although factors such as injection of membrane-intact sperm and toxic effects of acrosome contents are suspected causes, the reasons for the inefficiency are unclear. A recent report in mice demonstrated that ICSI using spermatozoa treated with a physiological detergent, lysolecithin, improved oocyte activation, cleavage, and offspring production after embryo transfer (Morozumi K et al. 2006 PNAS 109, 17 661–17 666). The objectives of the present study were to evaluate the effects of detergent treatment on motility and membrane integrity of frozen thawed eland, bongo and bovine spermatozoa and to examine sperm decondensation/embryonic cleavage following ICSI of in vitro-matured bovine oocytes. In experiment 1, sperm motility was observed on a warm microscope stage during exposure to 3 lecithin concentrations, 0.04, 0.02, and 0.01%, and the time at which 100% of the spermatozoa lost motility was recorded. In experiment 2, spermatozoa were exposed to 0.02% lecithin for 22 s, and the membrane integrity and acrosome status of spermatozoa were determined using a combined trypan blue-Giemsa staining (Nagy et al. 1999 Theriogenology 52, 1153–1159). In experiment 3, bovine oocytes were injected, using the piezo drill, with lecithin-treated (0.02%, immobilized) or untreated (piezo pulse immobilized) eland, bongo, or bovine spermatozoa and subsequently cultured for 2 days in CR1aa containing 3 mg mL–1 BSA. Each experiment was replicated at least 3 times. Lecithin induced time- and concentration-dependent loss of sperm motility. The average time to loss of motility in 100% of the spermatozoa at 0.04, 0.02, and 0.01% lecithin was 107, 222, and 344 s in bovine; 82, 135, and 179 s in eland; and 65, 115, and 158 in bongo, respectively. Data on membrane integrity (intact or nonintact) and acrosome status (reacted or nonreacted) of detergent-treated or control spermatozoa are shown in Table 1. Sperm head decondensation and embryonic cleavage were observed following homologous and interspecies (antelope into bovine) ICSI of lecithin-treated or control spermatozoa. In conclusion, lecithin treatment induced concentration and time-dependent loss of motility and was effective in damaging the sperm membrane and acrosome in eland, bongo, and domestic bulls. Eland and bongo spermatozoa underwent decondensation and activated bovine oocytes after interspecies ICSI. Table 1.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nicolás Chiarante ◽  
Carlos A. I. Alonso ◽  
Jessica Plaza ◽  
Raquel Lottero-Leconte ◽  
Camila Arroyo-Salvo ◽  
...  

Abstract Previously we demonstrated that multidrug resistance-associated protein 4 transporter (MRP4) mediates cAMP efflux in bovine spermatozoa and that extracellular cAMP (ecAMP) triggers events associated to capacitation. Here, we deepen the study of the role of MRP4 in bovine sperm function by using MK571, an MRP4 inhibitor. The incubation of spermatozoa with MK571 during 45 min inhibited capacitation-associated events. MRP4 was localized in post-acrosomal region and mid-piece at 15 min capacitation, while at 45 min it was mainly located in the acrosome. After 15 min, MK571 decreased total sperm motility (TM), progressive motility (PM) and several kinematic parameters. The addition of ecAMP rescued MK571 effect and ecAMP alone increased the percentage of motile sperm and kinematics parameters. Since actin cytoskeleton plays essential roles in the regulation of sperm motility, we investigated if MRP4 activity might affect actin polymerization. After 15 min capacitation, an increase in F-actin was observed, which was inhibited by MK571. This effect was reverted by the addition of ecAMP. Furthermore, ecAMP alone increased F-actin levels while no F-actin was detected with ecAMP in the presence of PKA inhibitors. Our results support the importance of cAMP efflux through MRP4 in sperm capacitation and suggest its involvement in the regulation of actin polymerization and motility.


2019 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Muhammad Riyadhi ◽  
Anis Wahdi ◽  
Muhammad Rizal

ABSTRAK                                                                        Penelitian bertujuan untuk mengetahui efektivitas nira aren sebagai pengencer alternatif dalam proses pembekuan (kriopreservasi) semen kambing boer.Kriopreservasi semen kambing boer menggunakan pengencer tris-gliserol-kuning telur (P1 73-7-20%), nira aren-gliseol-kuning telur(masing-masing P2 74-6-20%, P3 73-7-20%, dan P4 72-8-20%) dan andromed (P5 tanpa mengandung kuning telur dan gliserol). Parameter evaluasi meliputi motilitas, viabilitas, dan membrane plasma utuh setelah pengenceran, ekuilibrasi dan thawing.  Evaluasi motilitas pasca thawing menunjukkan P5 52% berbeda nyata (P<0.05) dengan P1 42%, selanjutnya P5 dan P1 berbeda sangat nyata (P<0.05) dengan P2 8%, P3 6% dan P4 12%.  Viabilitas pasca thawing menunjukkan P5 65,4% tidak berbeda nyata (P>0,05) dengan P1 61,8%, akan tetapi P5 dan P1 berbeda sangat nyata (P<0.05) dengan P2 26,2%, P3 29,8%, dan P4 34%.  Membran plasma utuh (MPU) pasca thawing menunjukkan P5 66,2% tidak berbeda nyata (P>0,05) dengan P1 65,4%, akan tetapi keduanya berbeda sangat nyata (P<0.05) dengan P2 39%, P3 38%, dan P4 36,2%.  Disimpulkan kriopreservasi semen kambing boer dengan pengencer nira aren dan gliserol pada konsentrasi berbeda belum dapat dipergunakan sebagai sumber bibit berdasarkan standar nasional Indonesia.Kata Kunci : Kambing boer, semen, nira arenABSTRACTThe experiment was conducted to determine the effect of sugar palm juice as alternative extender for cryopreservation process of boer semen.Tris-glycerol-egg yolk (P1 73-7-20%), Sugar palm juice-glyserol-egg yolk (P2 74-6-20%, P373-7-20%, dan P4 72-8-20%), and andromed (P5) used as a extender  in the cryopreservation process of boer semen.  Sperm motility (%), live sperm (%) and sperm membrane integrity (%) were recorded after diluted, equilibration and freeze-thawing.  Result of post thawing motility showed that P5 52% was significantly different (P <0.05) with P1 42%, then P5 and P1 were significantly different (P <0.05) with P2 8%, P3 6% and P4 12%. Viability after thawing showed P5 65.4% was not significantly different (P> 0.05) with P1 61.8%, but P5 and P1 significantly different (P <0.05) with P2 26.2%, P3 29.8 %, and P4 34%. Spermmembrane integrity post-thawing showed P5 66.2% was not significantly different (P> 0.05) with P1 65.4%, but both were very significantly different (P <0.05) with P2 39%, P3 38% and P4 36.2%. Conclusions, sugar palm juice-glycerol-egg yolk with differentconcentrationsineffectively as an alternative extenderin cryopreservation of boer semen.Keywords: boer goat, semen, sugar palm juice


Author(s):  
Michael N. Forster

Aesthetics, or the philosophy of literature and art, was one of Herder’s main focuses. By valorizing these areas of culture (in comparison with others such as science and religion) and in several other ways he prepared the ground for German Romanticism. He also established many principles of great intrinsic importance: rejecting apriorism and systematization in aesthetics in favor of an empirical, non-systematic approach; insisting that arts such as sculpture and painting express meanings and therefore require interpretation; recognizing the central role of genre not only in literature but also in such arts; perceiving the deep historical, cultural, and even individual variability of literature and art in respect of semantic content, genre, moral values, and aesthetic values, plus the major implications this variability has for both interpretation and evaluation; developing a set of radical views concerning beauty; and emphasizing the importance of literature and art as means of moral pedagogy.


Author(s):  
Takashi Yamamoto ◽  
Akihito Kurimoto ◽  
Riona Sato ◽  
Shoki Katada ◽  
Hirotaka Mine ◽  
...  

Ethanol conversion by Ga2O3-ZrO2 solid solution was examined in the temperature range 573–773 K, and acetone/isobutene formation was confirmed under cofeeding of H2O vapor. The reaction pathway was empirically investigated...


GeroScience ◽  
2021 ◽  
Author(s):  
Monica Baciu ◽  
Sonja Banjac ◽  
Elise Roger ◽  
Célise Haldin ◽  
Marcela Perrone-Bertolotti ◽  
...  

AbstractIn the absence of any neuropsychiatric condition, older adults may show declining performance in several cognitive processes and among them, in retrieving and producing words, reflected in slower responses and even reduced accuracy compared to younger adults. To overcome this difficulty, healthy older adults implement compensatory strategies, which are the focus of this paper. We provide a review of mainstream findings on deficient mechanisms and possible neurocognitive strategies used by older adults to overcome the deleterious effects of age on lexical production. Moreover, we present findings on genetic and lifestyle factors that might either be protective or risk factors of cognitive impairment in advanced age. We propose that “aging-modulating factors” (AMF) can be modified, offering prevention opportunities against aging effects. Based on our review and this proposition, we introduce an integrative neurocognitive model of mechanisms and compensatory strategies for lexical production in older adults (entitled Lexical Access and Retrieval in Aging, LARA). The main hypothesis defended in LARA is that cognitive aging evolves heterogeneously and involves complementary domain-general and domain-specific mechanisms, with substantial inter-individual variability, reflected at behavioral, cognitive, and brain levels. Furthermore, we argue that the ability to compensate for the effect of cognitive aging depends on the amount of reserve specific to each individual which is, in turn, modulated by the AMF. Our conclusion is that a variety of mechanisms and compensatory strategies coexist in the same individual to oppose the effect of age. The role of reserve is pivotal for a successful coping with age-related changes and future research should continue to explore the modulating role of AMF.


Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1956
Author(s):  
Francesco Manfrevola ◽  
Bruno Ferraro ◽  
Carolina Sellitto ◽  
Domenico Rocco ◽  
Silvia Fasano ◽  
...  

The etiology of human asthenozoospermia is multifactorial. The need to unveil molecular mechanisms underlying this state of infertility is, thus, impelling. Circular RNAs (circRNAs) are involved in microRNA (miRNA) inhibition by a sponge activity to protect mRNA targets. All together they form the competitive endogenous RNA network (ceRNET). Recently, we have identified differentially expressed circRNAs (DE-circRNAs) in normozoospermic and asthenozoospermic patients, associated with high-quality (A-spermatozoa) and low-quality (B-spermatozoa) sperm. Here, we carried out a differential analysis of CRISP2, CATSPER1 and PATE1 mRNA expression in good quality (A-spermatozoa) and low quality (B-spermatozoa) sperm fractions collected from both normozoospermic volunteers and asthenozoospermic patients. These sperm fractions are usually separated on the basis of morphology and motility parameters by a density gradient centrifugation. B-spermatozoa showed low levels of mRNAs. Thus, we identified the possible ceRNET responsible for regulating their expression by focusing on circTRIM2, circEPS15 and circRERE. With the idea that motility perturbations could be rooted in quantitative changes of transcripts in sperm, we evaluated circRNA and mRNA modulation in A-spermatozoa and B-spermatozoa after an oral amino acid supplementation known to improve sperm motility. The profiles of CRISP2, CATSPER1 and PATE1 proteins in the same fractions of sperm well matched with the transcript levels. Our data may strengthen the role of circRNAs in asthenozoospermia and shed light on the molecular pathways linked to sperm motility regulation.


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