108 EFFECT OF DIMETHYLFORMAMIDE AND METHYLFORMAMIDE ON OXIDATIVE STATUS OF MANGALARGA STALLIONS CRYOPRESERVED SEMEN

2010 ◽  
Vol 22 (1) ◽  
pp. 213
Author(s):  
F. A. Oliveira Neto ◽  
M. Nichi ◽  
E. G. A. Perez ◽  
J. R. C. Gurgel ◽  
G. H. Ferreira ◽  
...  

Cryopreservation of equine semen has been widely studied by several research groups because of the large breed and individual variation in sperm freezability. A key factor in sperm cryopreservation is the high incidence of oxidative stress, an imbalance between reactive oxygen species (ROS) and antioxidant protection, which impairs sperm functionality by attacking plasma membrane, acrosome, mitochondria, and DNA. In order to study the resistance of equine spermatozoa to different reactive oxygen species (ROS), sperm samples from 4 Mangalarga stallions were collected using an artificial vagina. Samples were cryopreserved in extenders containing dimethylformamide (DMF) or methylformamide (MF). After thawing and washing, sperm samples were then incubated (1 h, 37°C) with 4 ROS inducer mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate/ferrous sulfate (4 mM; produced hidroxyl radical), and malondialdehyde (MDA, lipid peroxidation product). Samples were evaluated using the 3-3′ diamino benzidine (DAB) stain, as an indicator of mitochondrial activity; the eosin nigrosin staining, to evaluate plasma membrane integrity; the simple stain (fast green/Bengal rose), to assess acrosome integrity; and the measurement of thiobarbituric acid reactive substances (TBARS), a lipid peroxidation product. Statistical analysis was performed using the Student t-test and LSD test. Results showed that sperm mitochondrial potential of frozen-thawed samples in MF was highly susceptible to the attack of hydroxyl radical and hydrogen peroxide. No effect of ROS was observed on membrane and acrosome integrity. On the other hand, samples cryopreserved in DMF showed no differences in susceptibility to ROS. When evaluating the main effects of different extenders, results showed a higher protective effect of the MF extender on acrosome integrity and mitochondrial potential (MF: 12.1 ± 2.2 and 7.8 ± 2.3% v. DMF: 3.4 ± 0.7 and 1.1 ± 0.7%, respectively, P < 0.05). However, a negative effect of MF extender was observed regarding the percentage of sperm showing intact membrane and TBARS content (MF: 2.0 ± 0.8% and 517 ± 115 ng/106 sperm v. DMF: 20.6 ± 1.7% and 118 ± 44 ng/106 sperm, respectively, P < 0.05). A strong negative correlation was found between TBARS and plasma membrane integrity (r = -0.88; P = 0.004) for samples cryopreserved in DMF, whereas a positive correlation was found between TBARS and sperm with full mitochondrial potential (r = 0.73; P = 0.04). Results of the present study indicate that DMF may play a role in the protection of sperm against the attack of ROS. However, such action is apparently limited to the plasma membrane. On the other hand, the MF-supplemented extender exerts an intracellular protection. Therefore, the antioxidant therapy, especially hydrogen peroxide and hydroxyl radical scavengers, may be an alternative to improve the post-thaw quality of MF-supplemented cryopreserved semen in stallions, by increasing extracellular antioxidant capacity. The authors thank Nutricell for financial support and the media used in the present experiment.

2010 ◽  
Vol 22 (1) ◽  
pp. 316
Author(s):  
R. O. C. Silva ◽  
E. G. A. Perez ◽  
R. P. Cabral ◽  
D. G. Silva ◽  
C. H. C. Viana ◽  
...  

Semen quality is one of the main limiting factors for the success of artificial insemination in goats. It is well known that reactive oxygen species (ROS) lead to structural and functional damages to sperm, impairing or avoiding fecundation. The understanding of sperm oxidative mechanisms in goats may provide information on possible treatments to improve semen quality and fertility rates. The aim of the present study was to verify the resistance of goat spermatozoa to different reactive oxygen species. Sperm samples from 4 goats were collected using an artificial vagina. Sperm samples were then incubated (1 h, 37°C) with 4 ROS inducer mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate/ferrous sulfate (4 mM; produces hydroxyl radical), and malondialdehyde (MDA, lipid peroxidation product). Samples were analyzed for mitochondrial activity using the 3,3′ diaminobenzidine stain, for membrane integrity using the eosin/nigrosin staining, for acrosome integrity using the simple stain (fast green/Bengal rose), and for lipid peroxidation by dosing thiobarbituric acid reactive substances (TBARS). Results showed that goat sperm is more sensitive to hydrogen peroxide, when compared to superoxide anion, hydroxyl radical, and MDA, when considering acrosome integrity, membrane integrity, and mitochondrial potential (Table 1). On the other hand, TBARS production was increased in samples submitted to hydroxyl radical incubation. Strong negative correlations were found between sperm samples showing impaired mitochondrial potential and both membrane and acrosome integrity (r = -0.97, P < 0.0001 and r = -0.91, P < 0.0001, respectively). The concentration of TBARS correlated negatively with the percentage of sperm showing intact membranes (r = -0.53, P = 0.06), and the later correlated negatively with sperm showing no mitochondrial activity (r = -0.78, P = 0.0006). Results of the present experiment suggest that goat sperm are extremely susceptible to the attack of hydrogen peroxide, being resistant to other ROS. Therefore, an alternative to improve the use of goat semen in reproductive biotechnologies would be the treatment with catalase or glutathione peroxidase, important hydrogen peroxide scavengers. Table 1.Effect of different ROS on goat sperm The authors thank Nutricell for the media used in this experiment.


2016 ◽  
Vol 68 (3) ◽  
pp. 620-628 ◽  
Author(s):  
L.S.L.S. Reis ◽  
A.A. Ramos ◽  
A.S. Camargos ◽  
E. Oba

ABSTRACT This study evaluated the plasma membrane integrity, acrosomal membrane integrity, and mitochondrial membrane potential of Nelore bull sperm from early puberty to early sexual maturity and their associations with sperm motility and vigor, the mass motility of the spermatozoa (wave motion), scrotal circumference, and testosterone. Sixty Nelore bulls aged 18 to 19 months were divided into four lots (n=15 bulls/lot) and evaluated over 280 days. Semen samples, collected every 56 days by electroejaculation, were evaluated soon after collection for motility, vigor and wave motion under an optical microscope. Sperm membrane integrity, acrosomal integrity, and mitochondrial activity were evaluated under a fluorescent microscope using probe association (FITC-PSA, PI, JC-1, H342). The sperm were classified into eight integrity categories depending on whether they exhibited intact or damaged membranes, an intact or damaged acrosomal membrane, and high or low mitochondrial potential. The results show that bulls have a low amount of sperm with intact membranes at puberty, and the sperm show low motility, vigor, and wave motion; however, in bulls at early sexual maturity, the integrity of the sperm membrane increased significantly. The rate of sperm membrane damage was negatively correlated with motility, vigor, wave motion, and testosterone in the bulls, and a positive correlation existed between sperm plasma membrane integrity and scrotal circumference. The integrity of the acrosomal membrane was not influenced by puberty. During puberty and into early sexual maturity, bulls show low sperm mitochondrial potential, but when bulls reached sexual maturity, high membrane integrity with high mitochondrial potential was evident.


2019 ◽  
Vol 31 (9) ◽  
pp. 1434
Author(s):  
Andressa Dalmazzo ◽  
João D. A. Losano ◽  
Daniel S. R. Angrimani ◽  
Isabel V. A. Pereira ◽  
Marcelo D. Goissis ◽  
...  

The aim of this study was to confirm gene and protein expression of oxytocin receptor (OTR) and sex hormone-binding globulin (SHBG) in the testis and epididymis of dogs, correlating these data with sperm quality and production and testosterone concentrations. Positive correlations were found between OTR and SHBG expression in both the testis and epididymis. Testicular OTR expression was positively associated with plasma membrane and acrosome integrity in canine spermatozoa, whereas SHBG expression in the testis was positively correlated with various sperm characteristics, such as sperm concentration, total and progressive motility, plasma membrane integrity and acrosome integrity. Testicular expression of both OTR and SHBG was negatively correlated with low sperm mitochondrial activity. In the epididymis, SHBG expression was only positively correlated with plasma membrane integrity. Analysis of protein expression revealed that testicular OTR was positively correlated with testosterone concentrations and negatively correlated with the absence of sperm mitochondrial activity. In addition, SHBG expression in the testes was associated with epididymis SHBG expression and morphologically normal cells. Immunohistochemical (IHC) analysis revealed the presence of both OTR and SHBG in testicular smooth muscles and Leydig cells. However, in the epididymis, OTR was only located in smooth muscle cells, whereas neither IHC nor western blotting detected SHBG. Together, the results of this study suggest that OTR and SHBG play key roles in spermatogenesis and sperm maturation, being essential for male reproductive success.


2019 ◽  
Vol 31 (1) ◽  
pp. 175
Author(s):  
C. Young ◽  
N. Ravida ◽  
P. Pennington ◽  
B. Durrant

Once nearly extinct in the wild, the southern white rhinoceros is currently listed as near threatened by IUCN. This status is likely to change as poaching continues to escalate. To preserve the species’ current genetic diversity, cryopreserving and biobanking white rhinoceros sperm is imperative. The horse is the closest domestic relative of the rhinoceros and a useful model for the development of assisted reproductive technologies, including semen cryopreservation. Two equine semen cryopreservation protocols were compared to a common rhinoceros freezing method. Semen was collected from a single male on 3 occasions by electroejaculation. Initial semen parameters were 86% motility; speed 3.2 (scale 1-5); 89% plasma membrane integrity; and 95% intact acrosomes. Semen was extended 1:1 in INRA 96 (IMV Technologies, L’Aigle, France) before centrifugation at 400×g for 10min. Supernatant was removed and the sperm pellet was subjected to 1 of 2 treatments: resuspension in 500µL of either BotuCrio (Botupharma, Botucatu, Brazil) or Cryomax (ARS Inc., Chino, CA, USA), both containing a proprietary combination of glycerol and an amide as cryoprotectants. Following a 40-min cool at 4°C, extended semen was frozen in vials at a cooling rate of 30°C/min for 3min before LN submersion. Control semen was extended 1:1 in TEST-Y buffer without cryoprotectant and cooled for 2.5h before adding glycerol to a final concentration of 4%. Extended sperm (500µL) was frozen in vials at 12.5°C/min for 15min before LN submersion. Initial motility score (IMS;% motile×speed of progression2), plasma membrane integrity (IPL), and acrosome integrity (IAC) were recorded after extension. All vials were thawed at 37°C for 60s and the cryoprotectant was removed by centrifugation. Sperm pellets were resupended in M199+HEPES and sperm was evaluated for the characteristics described above at 37°C at 0, 30, and 60min (T0, T30, T60) post-thaw. All data are expressed as a percentage of initial (%IMS,%IPL, and%IAC) to account for the differences in sperm parameters between ejaculates. Cryopreservation protocol significantly affected%IMS at T0 (P=0.0131, Table 1). Although the differences were significant only at T0, sperm frozen in Botucrio or Cryomax tended to maintain a higher%IMS than the control freeze at all time points. However, sperm frozen in Cryomax lost a greater percentage of%IMS over time (67% from T0 to T60v. 44 and 46% for Botucrio and TEST-Y, respectively). Cryopreservation protocol did not affect%IAC or%IPL at any time point, but again Cryomax and Botucrio tended to be higher than TEST-Y. This study indicates that rhinoceros sperm may suffer less cryodamage in Botucrio or Cryomax frozen at 30°C/min than in the conventional TEST-Y frozen at 12.5°C/min. Table 1.Percent of initial motility score (IMS), plasma membrane integrity (IPL), and acrosome integrity (IAC) at 0, 30, and 60min post-thaw (T0, T30, and T60, respectively)


2010 ◽  
Vol 76 (24) ◽  
pp. 7918-7924 ◽  
Author(s):  
Ana Mendes-Ferreira ◽  
Belém Sampaio-Marques ◽  
Catarina Barbosa ◽  
Fernando Rodrigues ◽  
Vítor Costa ◽  
...  

ABSTRACT Throughout alcoholic fermentation, nitrogen depletion is one of the most important environmental stresses that can negatively affect the yeast metabolic activity and ultimately leads to fermentation arrest. Thus, the identification of the underlying effects and biomarkers of nitrogen limitation is valuable for controlling, and therefore optimizing, alcoholic fermentation. In this study, reactive oxygen species (ROS), plasma membrane integrity, and cell cycle were evaluated in a wine strain of Saccharomyces cerevisiae during alcoholic fermentation in nitrogen-limiting medium under anaerobic conditions. The results indicated that nitrogen limitation leads to an increase in ROS and that the superoxide anion is a minor component of the ROS, but there is increased activity of both Sod2p and Cta1p. Associated with these effects was a decrease in plasma membrane integrity and a persistent cell cycle arrest at G0/G1 phases. Moreover, under these conditions it appears that autophagy, evaluated by ATG8 expression, is induced, suggesting that this mechanism is essential for cell survival but does not prevent the cell cycle arrest observed in slow fermentation. Conversely, nitrogen refeeding allowed cells to reenter cell cycle by decreasing ROS generation and autophagy. Altogether, the results provide new insights on the understanding of wine fermentations under nitrogen-limiting conditions and further indicate that ROS accumulation, evaluated by the MitoTracker Red dye CM-H2XRos, and plasma membrane integrity could be useful as predictive markers of fermentation problems.


2020 ◽  
Vol 3 (2) ◽  
pp. 58-66
Author(s):  
Fikri Ardhani ◽  
Hayatul Mufidah ◽  
Rahmah Samsuriati ◽  
Hilman Pratama Putra

The purpose of this study was to determine the effect of frozen storage time for Bali Bull in artificial insemination station in Samarinda City, East Kalimantan on the quality of motility, viability, velocity, abnormality, plasma membrane integrity (MIn), acrosome integrity (AIn), and DNA damage of spermatozoa. The study design used a completely randomized design (CRD) with 5 treatments (storage time) and 5 replications. Frozen semen of Bali Bull used in 2009 (10 years of storage), 2011 (7 years of storage), 2013 (5 years of storage), 2015 (3 years of storage), and 2017 (1 year of storage). The storage time of frozen semen stored for one to ten years in liquid nitrogen at the artificial insemination station in Kota Samarinda, East Kalimantan was still suitable for use in artificial insemination based on motility quality (44.99±2.40%), viability (55.33±2,60%), velocity (0.050±0.002 mm/sec), abnormality (12.87±1.09%), plasma membrane integrity (58.83 ± 1.86%), acrosome integrity (75.48 ± 1 , 61%), and DNA damage of spermatozoa (1.60 ± 0.21%).


2015 ◽  
Vol 27 (1) ◽  
pp. 222
Author(s):  
M. Bianchi Rodrigues Alves ◽  
A. Furugen Cesar de Andrade ◽  
R. Paes de Arruda ◽  
L. Batissaco ◽  
R. Lançoni ◽  
...  

Testicular degeneration, an important cause of male infertility, adversely affects sperm motility and morphology. However, few studies describe effects on integrity of plasma and acrosomal membranes, mitochondrial membrane potential, and DNA fragmentation; therefore, they were evaluated in the present study. Testicular degeneration was induced in 17 White Dorper rams (scrotal insulation for 72 h). Semen was collected (artificial vagina) twice before insulation and twice thereafter (15-day intervals between post-insulation collections). Sperm motility and morphology were analysed by SCA software (Sperm Class Analyser®, MICROPTIC®, Barcelona, Spain) and differential interference contrast microscopy (DIC, model 80i, Nikon, Tokyo, Japan), respectively. Membrane integrity and potential were assessed with fluorescent probes: Hoescht 33342, propidium iodide, FITC-PSA, and JC-1 (Celeghini et al. 2010 Arq. Bras. Med. Vet. Zootec. 62, 536–543) and imaged with fluorescence microscopy (Nikon Model 80i, Nikon, Tokyo, Japan). Fragmentation of DNA was evaluated with a Halomax® kit (Halotech® DNA, Madrid, Spain). Data were analysed with Statview software (Stat View 1998, SAS Institute Inc., Cary, NC, USA). Data obtained from the periods (before × after insulation) were evaluated by analysis of variance (ANOVA) and means were compared using Tukey's test. Total motility (before: 87.53 ± 1.21%; after: 46.53 ± 4.46%) and progressive motility (before: 58.64 ± 2.00%; after: 31.33 ± 3.82%) were reduced (P < 0.01) by scrotal insulation, as were sperm major defects (before: 10.64 ± 1.65%; after: 54.30 ± 3.67%) and total defects (before: 20.50 ± 2.40%; after: 63.85 ± 3.41%; P < 0.0001). Sperm with intact plasma and acrosomal membranes and high mitochondrial potential (PIAIH) decreased (P < 0.0001) after insulation. In that regard, 53.19 ± 2.20 and 28.48 ± 3.48% of sperm were classified as PIAIH before v. after insulation, respectively. Furthermore, plasma membrane integrity, acrosome membrane integrity, and high mitochondrial potential were assessed independently. The quantity of plasma membrane integrity cells (before: 62.01 ± 2.07%; after: 33.92 ± 3.94%), acrosome membrane integrity cells (before: 57.17 ± 2.30%; after: 31.47 ± 3.77%), and high mitochondrial potential cells (before: 85.72 ± 1.42%; after: 57.28 ± 3.12%) were also reduced (P < 0.0001) after insulation. Likewise, DNA integrity decreased (P = 0.002) from 98.87 ± 0.26% before insulation to 91.88 ± 2.6% afterward. In conclusion, sperm plasma and acrosomal membrane integrity, mitochondrial membrane potential, and DNA fragmentation were adversely affected by testicular degeneration in rams induced by scrotal insulation.Research was supported by FAPESP process 2012/00040-0 and 2011/16744-3.


2010 ◽  
Vol 22 (1) ◽  
pp. 175
Author(s):  
E. G. A. Perez ◽  
M. Nichi ◽  
F. A. Oliveira Neto ◽  
R. O. C. Silva ◽  
A. Dalmazzo ◽  
...  

Ram sperm membrane displays a particular lipid composition, especially regarding the high quantity of polyunsaturated cholesterol. This trait improves membrane fluidity; however, the spermatozoa become more susceptible to the attack of reactive oxygen species (ROS), which may lead to structural and functional damage, impairment or even impeded fecundity. The aim of the present experiment was to study the resistance of ovine spermatozoa to different ROS. Sperm samples from 4 rams were collected using an artificial vagina. Sperm samples were then incubated (1 h, 37°C) with four ROS inducer mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate/ferrous sulfate (4 mM; produces hydroxyl radical), and malondialdehyde (MDA, lipid peroxidation product). Samples were analysed using the 3-3′ diamino benzidine (DAB) stain as an index of mitochondrial activity, the eosin nigrosin stain as an index of membrane integrity; the simple stain (fast green/Bengal rose) as an index of acrosome integrity; and the measurement of thiobarbituric acid reactive substances (TBARS) as an index of lipid peroxidation. Results showed that acrosome and membrane integrity as well as mitochondrial potential were highly impaired by hydrogen peroxide, which was not the case for the other ROS (Table 1). Surprisingly, TBARS production was higher in samples incubated with ascorbate and ferrous sulfate (hydroxyl radical). Furthermore, sperm showing impaired mitochondrial potential were negatively correlated with membrane and acrosome integrities (r = -0.83, P < 0.0001 and r = -0.62, P = 0.01, respectively). Results of the present experiment suggest that semen of rams is extremely susceptible to attack by hydrogen peroxide. However, the mechanism by which this substance impairs sperm quality apparently does not involve oxidative stress, because no increase in TBARS was observed. Despite the necessity of further studies to investigate how hydrogen peroxide negatively influences sperm function, the use of catalase and glutathione peroxidase, important hydrogen peroxide scavengers, appears to be an alternative to improve the quality of ram sperm. Table 1.Effect of different reactive oxygen species in semen of rams The authors thank Nutricell for the media used in the experiment and CAPES for financial support.


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