首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 46 毫秒
1.
The study was conducted to investigate the effect of relaxin on motility, acrosome reaction (AR), viability and utilization of glucose in fresh and frozen‐thawed bovine spermatozoa. Both semen samples were washed twice through centrifugation (5 min at 600 g), and preincubated for 1 h at 39°C for swim up. The swim‐up separated spermatozoa were resuspended in a sperm Tyrode's albumin lactate pyruvate (Sp‐TALP) medium containing 0 (control) and 40 ng/mL porcine relaxin and incubated for 0–6 h. Sperm motility was determined on the basis of movement quality examined by a phase contrast microscope. Sperm viability and AR were evaluated by using the triple staining technique. The incorporation and oxidation of 14C‐glucose was assessed by a liquid scintillation counter. Motility was improved (P < 0.05) in both fresh and frozen‐thawed spermatozoa by the addition of relaxin to the Sp‐TALP medium, whereas relaxin showed no significant effect on viability in either fresh or frozen‐thawed spermatozoa. The percentage of AR increased (P < 0.05) when fresh or frozen‐thawed spermatozoa were incubated with relaxin. In contrast, the incorporation and oxidation of 14C‐glucose increased (P < 0.05) in both kinds of spermatozoa incubated with relaxin. Thus the results demonstrated that the addition of relaxin to the Sp‐TALP medium increased the motility, AR and utilization of glucose in fresh and frozen‐thawed bovine spermatozoa.  相似文献   

2.
Effects of sperm‐TALP (TALP) on the quality of fresh‐extended and frozen‐thawed epididymal cat sperm were evaluated. The epididymides suspended in Tris–glucose–citrate solution (Tris), a conventional medium, and TALP were cut into small pieces to recover epididymal sperm. In experiment 1, the sperm pellets remained after centrifugation were re‐suspended (1 : 2, v/v) in Tris and TALP. The sperm quality in all four groups, that is, sperm retrieved with Tris (I and II) or TALP (III and IV) and diluted with Tris (I and III) or TALP (II and IV) was assessed. The sperm motility at the 0‐h incubation in TALP–TALP was superior to that of the rest (p < 0.001 to p = 0.04). At the 2‐h incubation, the motility in Tris/TALP–TALP was greater than that in Tris/TALP–Tris (p ≤ 0.001). In experiment 2, after centrifugation, the sperm pellets were added with freezing extenders and frozen. The thawed sperm previously retrieved from the epididymides with Tris and TALP were allotted so as not to further diluted (Tris/TALP–O) and to further diluted (1 : 1, v/v) with Tris (Tris/TALP–Tris) and TALP (Tris/TALP–TALP) and were evaluated the quality. At both incubation times, the motility of frozen‐thawed sperm recovered with TALP (TALP–O/Tris/TALP) was comparable with or significantly higher than that in the Tris groups (Tris–O/Tris/TALP; p = 0.003 to p > 0.05). The motility and viability of thawed sperm in Tris–Tris were significantly decreased during the 2‐h incubation (p = 0.007 for the motility and p = 0.01 for the viability). In both experiments, neither type of diluent (Tris vs TALP) nor incubation time (0 vs 2 h) significantly affected the sperm membrane integrity under hypo‐osmotic condition (p > 0.05). According to beneficial effects on the quality of fresh‐extended and frozen‐thawed sperm demonstrated, sperm‐TALP could be used as an alternative medium for recovering sperm from the epididymides and for diluting epididymal sperm in the domestic cat.  相似文献   

3.
The present study was undertaken to elucidate the effect of non‐luteal oviductal proteins on sperm characteristics in Murrah buffaloes. Oviducts from healthy buffaloes were collected immediately after slaughter and the oestrous cycle phase was determined as either luteal or non‐luteal based on ovarian morphology. Non‐luteal oviducts (n = 80) were flushed from the isthmic end of the oviduct with PBS, fluid was centrifuged at 10 000 g at 4°C for 20 min and then dialysed and clarified. The supernatant obtained was lyophilized to concentrate the protein and stored at ?20°C till use. Sixteen good quality ejaculates from four Murrah buffalo bulls were collected using an artificial vagina. After fresh semen analysis, each ejaculate was split into two parts and extended in Tris–citrate–egg yolk glycerol dilutor. Part I of the split ejaculate was treated with non‐luteal oviductal proteins at the dose rate of 1 mg/ml of diluted semen, while part II remained as control. The extended semen was equilibrated for 4 h at 5°C, filled in 0.5 ml French straws, exposed to LN2 vapour, plunged into LN2 and then stored at ?196°C. The equilibrated and frozen–thawed semen was evaluated for sperm motility, viability, acrosomal integrity, cervical mucus penetration test and hypo‐osmotic sperm swelling test (HOST). In frozen–thawed semen, the percentage of sperm motility, viability and acrosomal integrity was significantly (p < 0.05) higher in the treatment group compared to the control group. The incorporation of non‐luteal oviductal proteins in the extender increased the ability of sperm to penetrate cervical mucus both after equilibration and the freeze‐thaw process. Similarly, the proportion of sperm with intact plasma membrane, as revealed by HOST values, was also significantly (p < 0.05) higher in the treatment group (32.6%) than the control group (27%) in frozen–thawed semen. It was inferred that incorporation of non‐luteal whole oviductal fluid proteins improved the sperm quality in frozen–thawed semen in Murrah buffaloes.  相似文献   

4.
The present study evaluated the effectiveness of ascorbic acid, catalase, chlorpromazine and their combinations in reducing the cryodamages to crossbred bull (Bos taurus × Bos indicus) spermatozoa. A total of 32 ejaculates (eight each from four bulls) were diluted in Tris–citric acid–fructose–egg yolk–glycerol extender. Each ejaculate was split into six parts (five treatment and one control). Treatment groups included 10 mm ascorbic acid, 0.1 mm chlorpromazine, 200 IU/ml catalase, 10 mm ascorbic acid + 0.1 mm chlorpromazine or 200 IU/ml catalase + 0.1 mm chlorpromazine in the extender. Fluorescent probes (Fluorescein isothiocyanate–Pisum sativum agglutinin + Propidium iodide) were used for the assessment of spermatozoa viability and acrosomal status. The proportion of acrosome intact live (AIL), acrosome intact dead, acrosome reacted live and acrosome reacted dead sperm was assessed in fresh, equilibrated and frozen‐thawed semen. The functional status of the sperm was assessed using hypo‐osmotic sperm swelling test (HOSST). Activities of acrosin and hyaluronidase enzyme were also determined. Lipid peroxidation level was assayed based on the melonaldehyde (MDA) production. In cryopreserved semen, the values of AIL spermatozoa, HOSST response, hyaluronidase and acrosin activity were reduced by 53%, 47%, 34% and 54%, respectively from their initial values in fresh semen. However, MDA level was threefold higher in the frozen‐thawed sperm compared with fresh sperm. Significant (p < 0.05) improvement in motility, viability, HOSST response, retention of hyaluonidase and acrosin and reduction in MDA was recorded in ascorbic acid, catalase, ascorbic acid + chlorpromazine and catalase + chlorpromazine incorporated groups. The percentage of AIL sperm was significantly (p < 0.05) higher in ascorbic acid, catalase and ascorbic acid + chlorpromazine incorporated groups compared with the control. Chlorpromazine alone did not improve the post‐thaw semen quality but when combined with either ascorbic acid or catalse, improvement in semen quality was noticed. It was inferred that incorporation of ascorbic acid, catalase and ascorbic acid + chlorpromazine in semen extender improved the post‐thaw semen quality in crossbred bulls.  相似文献   

5.
Dairy bull sperm may be sex‐sorted, frozen and used to artificially inseminate heifers with acceptable fertility if the herd is well‐managed. One drawback to the technology is that donor bulls must be located within a short distance of the sorting facility in order to collect semen, which limits the number of bulls from which sorted sperm are available. A successful method used to overcome this limitation in sheep is sex‐sorting from frozen–thawed semen and refreezing for artificial insemination. This technique is attractive to the dairy industry, and therefore a series of three experiments was designed to investigate the optimal methods to prepare, sex‐sort and re‐freeze frozen–thawed bovine sperm. Sperm were prepared for sorting by density gradient separation in either PureSperm® or BoviPure?, followed by staining in one of three diluents (Androhep®, Bovine Sheath Fluid + 0.3% BSA or TALP buffer). Sperm were sorted and collected into Test yolk buffer, and frozen in an extender containing 0, 0.25, 0.375 or 0.5% Equex STM Paste. Frozen–thawed sperm were better orientated (p = 0.006) and had fewer damaged membranes (8.7 ± 0.6% vs 19.5 ± 2.4%; p = 0.003) after centrifugation in PureSperm® rather than BoviPure? gradients. Sperm orientation (p < 0.05) and motility (69.9 ± 3.0 vs 55.6 ± 4.0; p < 0.001) were highest after staining in Androhep® rather than in TALP buffer. Sperm were more motile (58.2 ± 4.7 vs 38.7 ± 3.5; p < 0.001) and had better acrosome integrity (74.3 ± 2.9 vs 66.8 ± 2.0; p < 0.001) after freezing in an extender containing 0.375% Equex STM Paste than in extender without Equex. Hence, a protocol has been developed to allow frozen–thawed bull sperm to be sex‐sorted with high resolution between the sexes, then re‐frozen and thawed with retention of motility and acrosome integrity.  相似文献   

6.
Sex‐sorted, frozen–thawed stallion spermatozoa remain out of reach of commercial horse breeders because of the low efficiency of the sex‐sorting process and unacceptable fertility rates after insemination. Two experiments were designed to test the effects of alternative staining and freezing media to improve the viability of sex‐sorted frozen–thawed stallion spermatozoa. Experiment 1 compared two freezing media, INRA 82® and a modified lactose‐ethylenediaminetetraacetic acid (EDTA), for the cryopreservation of sex‐sorted stallion spermatozoa. No significant differences between the two freezing media could be identified, suggesting that both cryodiluents would be suitable for incorporation into a sex‐preselection protocol for stallion spermatozoa. Experiment 2 compared Kenney’s modified Tyrode’s (KMT) and Sperm TALP (Sp‐TALP) as the staining and incubation medium for stallion spermatozoa prior to sex‐sorting. A significant increase in the percentage of acrosome‐reacted spermatozoa occurred after staining and incubation in the clarified Sp‐TALP compared with KMT. As no improvements in sorting rates were achieved using Sp‐TALP, it was concluded that stallion sorting protocols could include KMT as the staining and incubation medium while either INRA 82® or lactose‐EDTA could be employed as a cryodiluents.  相似文献   

7.
The present study aimed to compare cat sperm quality after thawing using two different temperatures (37 and 70°C) and to investigate the effects of post‐thaw dilution on the sperm quality and longevity of ejaculated cat spermatozoa. Six ejaculates of each of six male cats were collected using an electroejaculator (total 36 ejaculates). The semen was frozen in 0.25‐ml straws using a Tris egg yolk extender containing Equex STM paste. Four straws prepared from each ejaculate were thawed at four different occasions; (i) at 37°C for 15 s, (ii) at 37°C for 15 s and diluted 1 : 2 with Tris buffer (v/v), (iii) at 70°C for 6 s, (iv) at 70°C for 6 s and diluted 1 : 2 with Tris buffer (v/v). The percentages of motile spermatozoa, the scores of progressive motility, the percentages of spermatozoa with intact plasma membrane (using SYBR‐14/EthD‐1 stains) and intact acrosome (using fluorescein isothiocyanate conjugated peanut agglutinin/propidium iodide stains) were evaluated in fresh semen at 0, 2, 4 and 6 h after thawing. The thawing temperature had no effect on any sperm parameters throughout the incubation period (p > 0.05). The dilution after thawing improved sperm motility, progressive motility and acrosome integrity (p < 0.05). The thawing of cat spermatozoa and subsequently diluting with Tris buffer resulted in an immediate (at 0 h) overall (combined over temperature) percentage of motile sperm of 64.8 ± 10.7 (mean ± SD), a score of progressive motility of 4.0 ± 0.5, a percentage of spermatozoa with intact plasma membrane of 64.4 ± 12.1 and intact acrosome of 44.8 ± 20.2. In conclusion, frozen cat semen can be thawed either at 37 or 70°C and post‐thaw dilution is recommended to reduce the toxic effect of some ingredients in the extender during post‐thaw incubation.  相似文献   

8.
Sperm DNA fragmentation is one of the major causes of infertility; the sperm chromatin dispersion test (SCDt) evaluates this parameter and offers the advantage of species‐specific validated protocol and ease of use under field conditions. The main purpose of this study was to evaluate sperm DNA fragmentation dynamics in both fresh and post‐thaw bottlenose dolphin sperm using the SCDt following different cryopreservation protocols to gain new information about the post‐thaw differential sperm DNA longevity in this species. Fresh and cryopreserved semen samples from five bottlenose dolphins were examined for sperm DNA fragmentation dynamics using the SCDt (Halomax®). Sperm DNA fragmentation was assessed immediately at collection and following cryopreservation (T0) and then after 0.5, 1, 4, 8, 24, 48 and 72 h incubation at 37°C. Serially collected ejaculates from four dolphins were frozen using different cryopreservation protocols in a TES‐TRIS‐fructose buffer (TTF), an egg‐yolk‐free vegetable lipid LP1 buffer (LP1) and human sperm preservation medium (HSPM). Fresh ejaculated spermatozoa initially showed low levels of DNA fragmentation for up to 48 h. Lower Sperm DNA fragmentation (SDF) was found in the second fresh ejaculate compared to the first when more than one sample was collected on the same day (p < 0.05); this difference was not apparent in any other seminal characteristic. While there was no difference observed in SDF between fresh and frozen–thawed sperm using the different cryopreservation protocols immediately after thawing (T0), frozen–thawed spermatozoa incubated at 37°C showed an increase in the rate of SDF after 24 h. Sperm frozen in the LP1? buffer had higher levels (p < 0.05) of DNA fragmentation after 24‐ and 48‐h incubation than those frozen in TTF or HSPM. No correlation was found between any seminal characteristic and DNA fragmentation in either fresh and/or frozen–thawed samples.  相似文献   

9.
The present work studied different spermatozoa parameters and the ability of frozen rabbit spermatozoa to fertilize, in vitro, in vivo‐matured oocytes, as a test to predict their in vivo fertility and prolificacy. Semen from rabbit bucks was frozen using two freezing protocols [in a freezer at ?30°C or in liquid nitrogen vapour (LNV)]. For the in vivo trial, females were inseminated with frozen‐thawed spermatozoa. Oocytes used for in vitro testing were recovered 14 h after ovulation induction from donors and co‐incubated with 2 × 106 frozen‐thawed spermatozoa during 4 h at 37°C in Tyrode's medium under an atmosphere of 5% CO2 in air with maximal humidity. After co‐incubation period, presumptive zygotes were cultured in TCM199 supplemented with 20% foetal bovine serum (FBS), under the same conditions described above. Although no statistical differences were observed between freezing protocols in seminal parameters [motility rate: 40 and 35%, VCL: 35 and 46 μm/s, amplitude of lateral head displacement (ALH): 1.7 and 2.4 μm, for semen frozen at ?30°C and in LNV, respectively], significant differences were noted in the fertilizing ability in vivo and in vitro. Semen frozen at ?30°C showed the highest fertilizing ability in vitro (26.7% vs 6.2 and 8.7% for semen frozen at ?30°C, in LNV and fresh semen, respectively) and the lowest fertility rate in vivo (21.7% vs 64.2% and 70.6% for semen frozen at ?30°C, in LNV and fresh semen, respectively). Sperm frozen at ?30°C seemed to be more capacitated.  相似文献   

10.
This study assessed the effect of different semen storage temperatures and the influence of semen pooling in semen viability. In experiment 1, semen samples (n = 30) of five Majorera bucks were individually processed [Individual semen (IS)] and after the first dilution (Tris‐yolk extender), semen‐diluted aliquots from each male were pooled semen (PS). Thereafter, semen samples (IS and PS) were preserved as fresh semen (37 and 20°C), chilled semen (4°C) and frozen semen. Sperm motility and the percentage of abnormal sperm cells and intact membrane acrosomes were defined. Semen preservation at 20 and 4°C did not modify the quality of spermatozoa for the first 24 h, but the conservation at 37°C caused a dramatic fall in the semen motility from 12 h onwards. Furthermore, the longevity of frozen‐thawed semen was limited to 4–6 h. No differences were observed in semen parameters when PS was compared with semen from individual males in any of the preservation protocols assessed. In experiment 2, 120 goats were distributed in four experimental groups: in group fresh individual semen (FIS, n = 30) and group frozen‐thawed individual semen (FTIS, n = 30), does were transcervically inseminated with fresh semen and frozen‐thawed semen from each individual male, respectively, and in group fresh pooled semen (FPS, n = 30) and group frozen‐thawed pooled semen (FTPS, n = 30), goats were transcervically inseminated with FPS and FTPS, respectively. The kidding rate was very close in the FIS and FPS groups (70.0% and 73.7%, respectively), and no significant differences were observed in the fertility rate between FTIS and FTPS. The results of this study confirmed that semen samples may be preserved satisfactorily for 24 h both at 20 and 4°C. In addition, the mixture of semen of different bucks did not significantly modify the semen parameters when compared with semen from individual males.  相似文献   

11.
The objective of this study was to investigate whether butylated hydroxytoluene (BHT) could be used as a suitable supporter or alternative of egg yolk during preservation of goat spermatozoa. Three in vitro experiments and a fertility test were conducted to evaluate the effect of BHT on viability of chilled‐stored semen as well as motility and kidding rate of frozen‐thawed spermatozoa. In the first two experiments, ejaculates (n = 30/experiment) were collected from 10 bucks, split, diluted with egg yolk‐based and egg yolk‐free extenders supplemented with or without 0.3, 0.6, 2, 5 and 8 mm BHT and stored at 5°C for 168 h. In the third experiment, 30 ejaculates were collected from the above‐mentioned bucks, split and diluted with egg yolk‐free extenders supplemented with or without 0.3, 0.6 and 0.9 mm BHT and egg yolk‐based extenders supplemented with or without 5 mm BHT. Diluted semen was cooled to 5°C over a period of 4 h, frozen and thawed in the form of 0.3‐ml pellets. In the fertility test, 75 ejaculates were collected from two proven fertile bucks, split, diluted with egg yolk‐free extenders containing 0.6 mm BHT and egg yolk‐based extenders supplemented with or without 5 mm BHT, frozen and thawed as described above. An insemination volume of 0.6 ml containing 120–140 × 106 progressively motile spermatozoa was used for a single cervical insemination of cloprostenol‐synchronized does (n = 230). The results showed that addition of 5 mm BHT to egg yolk‐deficient (2.5%) extenders significantly improved viability of chilled‐stored semen together with motility (48.5%) and fertility (62.5%) of frozen‐thawed spermatozoa. Replacement of egg yolk in semen extenders by 0.6 mm BHT could sustain not only viability of chilled‐stored semen but also post‐thaw motility (47.5%) and fertility (53.75%) of frozen‐thawed spermatozoa. In conclusion, supplementation of semen diluents with BHT can ameliorate preservability of goat sperm.  相似文献   

12.
The objectives of this study were to investigate the influence of ram age on structural and functional competence of frozen–thawed spermatozoa and to test the hypothesis that increasing number of sperm bound to the zona pellucida in vitro was associated with decreasing in vivo fertility of frozen semen. Rams were allocated into two groups. Each group consisted of five rams aged either 1–2 years (young) or 4–5 years (mature). Three successive ejaculates were collected from each ram using an artificial vagina. Only ejaculates of ≥ 2.5 × 109 sperm/ml and 80% sperm progressive motility were pooled per ram, diluted with Bioxcell® medium and frozen in 0.25 ml straws. The end points of post‐thawing semen evaluation were computer‐assisted cell motility analysis, sperm capacitation (chlortetracycline assay), simultaneous assessment of plasma membrane integrity, mitochondrial membrane potential and condensation status of nucleus, per‐cell analysis of lipid peroxidation using C11‐BODIPY581/591, sperm‐hemizona binding (HZB) ability and sperm fertility after laparoscopic insemination of ewes (n = 114) in the progestagen‐synchronized oestrus. The results showed that mature rams had significantly lower values of sperm hyperactivated motility and peroxidized sperm, higher percentages of live non‐capacitated sperm and sperm cells with intact plasma membrane, functional mitochondria and condensed chromatin, as well as, greater lambing rate and ewe prolificacy. Sperm HZB binding ability was higher (p < 0.05) for young than for mature rams. Significant correlations were found between number of spermatozoa bound to the zona pellucida and semen fertility (r = ?0.63 to ?0.71). In conclusion, mature rams have better semen quality and in vivo fertility than young rams. Cryocapacitation can be involved in decreasing ram semen fertility as evidenced by the high number of spermatozoa bound to the zona pellucida in vitro.  相似文献   

13.
In the present study, an automated system for sperm analysis, the Sperm Quality Analyzer (SQA II‐C), was tested as a potential tool for the assessment of dog sperm quality. In the first experiment the device displayed a good repeatability of measurements for semen of medium and high quality, as evidenced by a low coefficient of variance (CV; 0.08), whereas a high CV (0.46) was obtained for one dog with semen of inferior quality. In the second experiment, seven different sperm concentrations (25–300 ×106/ml), obtained by dilutions in Hepes‐TALP medium were stored for 48 h at room temperature. A concentration dependent increase in sperm motility index (SMI) was shown, reaching a plateau at 150×106 spermatozoa/ml. For all sperm concentrations, the SMI value decreased significantly after 24 h, indicating the importance of sperm motility for SMI values. For sperm concentrations lower than 150×106/ml, highly significant correlations [r=0.80;p<0.05] were established between SMI values on one hand and sperm concentration, and semen parameters expressing the overall semen sample quality on the other hand (experiment 3) while non‐significant or low correlations were found between SMI values and other individual sperm parameters. In experiment 4, significantly high correlations (r=0.97) were found between mean SMI values and post‐thaw motility and progressive motility assessed subjectively. In conclusion, our study indicates that both motility and concentration largely influence SMI values and that the SQA II‐C saturates at 150×106 fresh spermatozoa/ml. In our opinion, the SQA II‐C may be a useful and objective device to assess the post‐thaw motility of dog sperm.  相似文献   

14.
This study assessed the effects of different incubation temperatures on semen viability and the influence of pooling on semen longevity. In experiment 1, semen samples were collected from five dogs, individually processed (individual semen: IS) and then aliquots from each male were pooled (pooled semen: PS). Semen samples (IS and PS) were diluted in a Tris‐glucose‐yolk extender and preserved as fresh (37 and 25°C) and chilled semen (4°C). Sperm motility and the percentages of sperm abnormalities and acrosome membrane integrity were assessed for 24 h. Storage at 25 or 4°C for the first 24 h yielded similar semen quality, but incubation at 37°C caused drastic reduction in sperm motility from 8 h of incubation onwards. In experiment 2, the semen was processed in the same way to that of experiment 1 and then preserved at 25 or 4°C until semen inactivation. Semen that was incubated at 25°C became completely inactive after 3–4 days of storage, while semen that was preserved at 4°C presented with more gradually decreased sperm motility (mean values of 40–60% for the first 8 days). In addition, the mixing of semen was only observed to influence the sperm quality of the samples stored at 4°C. In experiment 3, semen was collected from five dogs, pooled and frozen in liquid nitrogen; after thawing, it was preserved at 37, 25, 15 and 4°C, and the sperm quality was defined. The motility of the freeze‐thawed semen samples decreased quickly in the first 4 h after thawing, regardless of the preservation temperature of the thawed semen. This study confirmed that semen preserved at 37°C should be used within a maximum of 12 h, while the semen stored at 25°C shows acceptable quality for 24 h. Chilled semen presented highest most sustainable quality, especially when semen is processed as pooled semen.  相似文献   

15.
Epigallocatechin gallate (EGCG) is the major polyphenol in green tea (Camellia sinensis) and is known for its antioxidant effects. The objective of the present study was to examine the effects of EGCG during in vitro fertilization (IVF) on the sperm quality and penetrability into oocytes. In the first experiment, the effects of concentration and incubation period of EGCG on the motility and penetrability of spermatozoa were examined. When frozen–thawed spermatozoa were incubated in IVF medium supplemented with 0 (control), 1, 50 and 100 μm EGCG for 1, 3 and 5 h, supplementation with 50 and 100 μm EGCG improved motility of the spermatozoa (p < 0.05), but not viability, as compared with the control group. When frozen–thawed spermatozoa were co‐incubated with in vitro‐matured (IVM) oocytes in IVF medium supplemented with 50 and 100 μm EGCG for 5 h, supplementation of EGCG had positive effects on sperm penetration rates. In the second experiment, the effects of supplementation of EGCG in IVF medium on penetrability of sperm from different boars and development of fertilized oocytes were evaluated. When frozen–thawed spermatozoa from six boars were co‐incubated with IVM oocytes in IVF medium supplemented with 50 μm EGCG, the effect of EGCG on sperm penetration and development of oocytes after fertilization was found to vary with individual boar. Our results indicate that motility and penetrability of boar spermatozoa are improved by co‐incubation with 50 μm EGCG, but the effects vary with individual boars.  相似文献   

16.
Oxidative stress represents a challenge during sperm manipulation. We have tested the effect of increasing hydrogen peroxide (H2O2) levels on red deer spermatozoa after cryopreservation, and the role of male‐to‐male variation in that response. In a first experiment, eight thawed samples were submitted to 0, 25, 50, 100 and 200 μm H2O2 for 2 h at 37°C. Intracellular reactive oxygen species (H2DCFDA‐CM) increased with H2O2 concentration, but we only detected a decrease in sperm function (motility by CASA and chromatin damage by sperm chromatin structure assay) with 200 μm . Lipoperoxidation assessed by the thiobarbituric acid reactive substance (TBARS) method increased slightly with 50 μm H2O2 and above. In a second experiment, samples from seven males were submitted to 0 and 200 μm H2O2 for 2 h, triplicating the experiment within each male. Males differed at thawing and regarding their response to incubation and H2O2 presence. We found that the kinematic parameters reflected male‐to‐male variability, whereas the response of the different males was similar for lipid peroxidation and viability. A multiparametric analysis showed that males grouped differently if samples were assessed after thawing, after incubation without H2O2 or after incubation with H2O2. Red deer spermatozoa are relatively resilient to H2O2 after thawing, but it seems to be a great male‐to‐male variability regarding the response to oxidative stress. The acknowledgement of this individual variability might improve the development of optimized sperm work protocols.  相似文献   

17.
Routinely, swim‐up method is used to separate high‐quality sperm; however, long processing time and close cell‐to‐cell contact during the centrifugation step are inevitable elements of oxidative stress to sperm. The objective was to evaluate Sephadex? and glass wool filtration to separate motile, intact and viable sperm for in vitro fertilization in buffalo. The cumulus–oocyte complexes (COC s) were collected from ovaries of slaughtered buffaloes by aspiration and matured for 24 hr in CO 2 incubator at 38.5°C and 5% CO 2. Matured COC s were rinsed twice in fertilization TALP and placed in the pre‐warmed fertilization medium without sperm. Cryopreserved buffalo semen was thawed at 37°C for 30 s and processed through Sephadex?, glass wool filtration and swim‐up (control). Total and motile sperm recovery rates were assessed, resuspended in fertilization TALP and incubated for 15–20 min in CO 2 incubator. Samples prepared by each method were divided into two aliquots: one aliquot was studied for sperm quality (progressive motility, membrane integrity, viability, liveability), while the other was subjected to co‐incubation with sets of 10–15 in vitro matured oocytes. Data on sperm quality were analysed by ANOVA , while in vitro fertilizing rates were compared by chi‐squared test using SPSS ‐20. Least significant difference (LSD ) test was used to compare treatment means. Glass wool filtration yielded higher total and motile sperm recovery rate, while Sephadex? filtration improved (p  <  .05) sperm quality (progressive motility, membrane integrity, viability, liveability). Sperm preparation through Sephadex filtration yielded higher in vitro fertilization rate in terms of cleavage rate compared to glass wool filtration and swim‐up (control). In conclusion, cryopreserved Nili‐Ravi buffalo sperm selected through Sephadex filtration showed improved quality and yielded better fertilization rates (cleavage rate) of in vitro matured/fertilized oocytes. Sephadex filtration could be a promising technique for use in in vitro fertilization in buffalo.  相似文献   

18.
This study investigated the effects of long‐term extenders on post‐thaw sperm quality characteristics following different holding times (HT) of boar semen at 17 and 10°C. Sperm‐rich fractions, collected from five boars, were diluted in Androhep® Plus (AHP), Androstar® Plus (ASP), Safecell® Plus and TRIXcell® Plus (TCP) extenders. The extended semen samples were held for 2 hr at 17°C (HT 1) and additionally for 24 hr at 10°C (HT 2), after they were evaluated and frozen. CASA sperm motility and motion patterns, mitochondrial membrane potential (MMP), plasma membrane integrity (PMI) and normal apical ridge (NAR) acrosome integrity were assessed in the pre‐freeze and frozen‐thawed semen. The Vybrant Apoptosis Assay Kit was used to analyse the proportions of viable and plasma membrane apoptotic‐like changes in spermatozoa. Results indicated that boar variability, extender and HT significantly affected the sperm quality characteristics, particularly after freezing‐thawing. Differences in the pre‐freeze semen were more marked in the sperm motion patterns between the HTs. Pre‐freeze semen in HT 2 showed significantly higher VCL and VAP, whereas no marked effects were observed in the sperm membrane integrity and viability (YO‐PRO‐1?/PI?) among the extenders. Post‐thaw sperm TMOT and PMOT were significantly higher in the AHP and ASP extenders of HT 2 group, whereas VSL, VCL and VAP were markedly lower in the TCP extender. Furthermore, spermatozoa from the AHP‐ and ASP‐extended semen of HT 2 group were characterized by higher MMP, PMI and NAR acrosome integrity following freezing‐thawing. In most of the extenders, the incidence of frozen‐thawed spermatozoa with apoptotic‐like changes was greater in HT 1. The findings of this study indicate that holding of boar semen at 10°C for 24 hr in long‐term preservation extenders modulates post‐thaw sperm quality characteristics in an extender‐dependent manner. These results will further contribute to the improvement in the cryopreservation technology of boar semen.  相似文献   

19.
Oxytocin (OXT) contained in boar semen is known to produce uterine contraction; therefore, we hypothesized that the co‐injection of OXT with sperm would improve artificial insemination (AI) using liquid or frozen‐thawed boar sperm. We initially examined whether OXT added to semen extender improved sperm transport to the oviduct. Although the addition of OXT did not affect the fresh or frozen‐thawed sperm motility or acrosomal integrity, it significantly increased the number of sperm in the oviduct at 6 h after AI injection with OXT, as compared with the control (P < 0.05). Moreover, some sperm were observed in the sperm reservoir of the isthmus in the OXT treatment group, whereas few sperm were observed in the control. When OXT was added to the semen extender immediately prior to AI, the conception rates were significantly higher in both fresh semen and frozen‐thawed semen than in the control group (P < 0.05: liquid, 87.5% vs. 70.5%; frozen‐thawed, 89.8% vs. 75.0%). From these results, we concluded that the addition of OXT to the semen extender assisted in sperm transportation from the uterus to the oviduct, which resulted in improved reproductive performance.  相似文献   

20.
The addition of 0.5% (v/v) of Equex STM Paste (Nova Chemical Sales, Scituate Inc., MA, USA), whose active ingredient is sodium dodecyl sulphate (SDS), to a Tris–egg yolk extender was demonstrated to improve the longevity of frozen–thawed dog spermatozoa during in vitro incubation at 38°C. The aim of the first experiment was to compare the effects of two SDS‐containing compounds, Equex STM Paste and Equex Pasta (Minitüb, Tiefenbach, Germany), when added to a Tris–egg yolk based extender, on the post‐thaw longevity of dog spermatozoa, as well as on the intracellular Ca2+ concentration of spermatozoa, during post‐thaw incubation at 38°C. The post‐thaw sperm survival and longevity, as well as the quality of the sperm movement, were significantly better when using Equex STM Paste. Such prolonged sperm longevity, however, was associated to a higher intracellular Ca2+ concentration in a large subpopulation of the live spermatozoa. A second experiment was aimed to evaluate the effects of sperm dilution immediately post‐thaw with a Tris buffer containing glucose or fructose. The two Tris buffers were no different for any of the sperm parameters studied. The aim of a third experiment was to evaluate the sperm longevity, motility patterns and intracellular Ca2+ concentration of cryopreserved dog spermatozoa during post‐thaw incubation in capacitating conditions [canine capacitating medium (CCM) with or without 5 μg/ml of heparin]. Heparin had no significant effects on any of the sperm parameters evaluated. During the first 8 h of incubation, the majority of the live spermatozoa had a high intracellular Ca2+ content. However, after 8–10 h of incubation, it had significantly declined. The highest proportion of fast motile sperm, and the highest curvilinear velocity, average path velocity and amplitude of lateral head displacement for the total motile sperm were observed during the 2–4‐h incubation period. It was concluded that: (a) the addition of 0.5% (v/v) of Equex STM Paste to a Tris–egg yolk based extender significantly improved the post‐thaw longevity of dog spermatozoa, but the same concentration of Equex Pasta had no significant beneficial effects; (b) sperm dilution after thawing with a Tris buffer containing glucose or fructose made no difference in post‐thaw sperm longevity; (c) the addition of 5 μg/ml of heparin to CCM had no significant capacitating effects on frozen–thawed dog spermatozoa.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号