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 31 毫秒
1.
The aim of this work was to study the effect of progesterone (P4) on capacitation and acrosome reaction (AR) of post-thaw bovine spermatozoa in vitro. Spermatozoa were incubated (0-180 min) in capacitation medium supplemented with 0, 0.1, 1.0 and 10.0 microg/ml of P4. At different time intervals aliquots were taken to determine sperm plasma membrane lipid destabilization, or capacitation (AR induced by lysophosphatidylcholine) in spermatozoa. The second experiment aimed to study the effects of P4, as potential inducer of AR in heparin-capacitated spermatozoa. The acrosomal status and viability of spermatozoa were evaluated under an epifluorescence microscope using Ethidium homodimer/peanut agglutinin fluorescein isothiocyanate staining method. Plasma membrane scrambling in spermatozoa was assessed by a flow cytometer, using merocyanine staining. The results show that P4 at the concentrations used had no negative effects on sperm viability. Progesterone significantly enhanced sperm capacitation (p < 0.001), but had no effect on plasma membrane lipid stability (p > 0.05) and did not significantly increase the AR of heparin-capacitated spermatozoa (p > 0.05). Progesterone displayed its effects in a dose-dependent manner with a maximum effect of 10 microg/ml P4 at 180 min of incubation. The results demonstrate that in cryopreserved bovine semen, P4 acts as capacitating, but not as an AR-inducing agent.  相似文献   

2.
A 4-year-old Basque Shepherd male dog was presented for breeding soundness evaluation after the dog failed to impregnate the three bitches he had mated. Clinical examination showed no anomaly of the reproductive system. Semen evaluation showed normal sperm count (640 x 10(6)), 80% had progressively motile spermatozoa, and 96% had morphologically abnormal sperm of which 84% had proximal cytoplasmic droplet and 12% had proximal droplet plus other anomaly. A zona pellucida-binding assay, using canine oocytes derived from frozen-thawed ovaries, was performed in order to investigate the zona-binding ability of dog spermatozoa with proximal cytoplasmic droplets. For the zona pellucida-binding assay, ovaries were thawed and minced in phosphate-buffered saline + 0.4% bovine serum albumin, the oocytes recovered were divided into two groups of 35-40 oocytes to be, respectively, used with the infertile dog and with a control fertile dog. Spermatozoa were capacitated in Canine Capacitating Medium (CCM) at 38.5 degrees C and 5% CO(2) in air for 2 h before oocyte insemination. Groups of five to six oocytes placed in 45 microl droplets of CCM were incubated for 1 h. Afterwards, 5 microl of CCM containing 25,000 spermatozoa were added to each droplet and co-incubated for 2 h before fixation and evaluation of the complexes. After oocyte insemination, sperm motility and viability were evaluated: the sample from the infertile dog had 85% sperm motility with fast and linear progressive movement, and sperm viability of 92%. The sample from the control dog showed 40% sperm motility with fast and highly curvilinear and erratic movement, high degree of sperm agglutination and sperm viability of 32%. For the infertile dog the mean number of bound spermatozoa/oocyte was 0.33 whereas for the control dog it was 1.80. It was concluded that dog sperm with proximal cytoplasmic droplets seem to lack normal capacitating ability in vitro, and consequently, they may have reduced capacity to bind to the zona pellucida of canine oocytes.  相似文献   

3.
Orchiopexy of the cryptorchid (CR) testis and castration of the scrotal testis were performed in three unilaterally CR beagles at six months of age. Induction rates for ejaculated sperm hyperactivation (HA) and the acrosome reaction (AR) in vitro in these orchiopexied dogs were compared with five those in normal beagles one year later. Canine spermatozoa were incubated for 9 hr at 38 degrees C under 5% CO2 in air in canine capacitation medium at a concentration of 30 x 10(6) sperm/ml. HA was observed using high-speed videomicrography. The AR spermatozoa were evaluated by the triple stain technique. As a result, there was no significant difference between 'the CR dogs after orchiopexy' (CDO) and the normal dogs (ND) with respect to sperm motility just after ejaculation. However, sperm motility of CDO decreased markedly during incubation. There was a significant difference in sperm motility between CDO (Mean +/- SD; 47 +/- 12%) and ND (80 +/- 9%) after three hours of incubation (p less than 0.01). No significant difference was observed between CDO and ND with respect to the HA rate of motile spermatozoa throughout the incubation period. The peak of HA rate was found in both CDO (58 +/- 5%) and ND (61 +/- 16%) after seven hours of incubation. The AR rate of spermatozoa in CDO was lower than that in ND after six hours of incubation. The AR rate of CDO (26 +/- 4%) was significantly lower than ND (46 +/- 5%) after eight hours of incubation (p less than 0.01). It is assumed that there might be relation between a rapid decrease of motility and low AR rate in spermatozoa of CDO during incubation.  相似文献   

4.
Acrosin is an acrosomal protease synthesized as an inactive precursor, proacrosin, which is processed via autoproteolysis into active forms alpha- and beta-acrosin. In this paper, a comparative study on the immunoreactivity of acrosin during in vitro capacitation of frozen and fresh (control) canine sperm using Western blot analysis is reported. Semen samples were obtained by digital stimulation and ejaculates processed as fresh and frozen samples and then capacitated for 0, 30, 60 and 90 min. At each time period, samples were analyzed with monoclonal antibody C5F10 by Western blot. The antibody specifically recognized, in fresh and frozen/thawed spermatozoa, a 40-, 32- and 27-kDa bands corresponding to proacrosin, alpha- and beta-acrosin, respectively, during capacitation. Western immunoblots showed that the beta-acrosin reactivity in fresh sperm was directly proportional to the time of capacitation, whereas a decreased reactivity of active form of acrosin was observed with frozen-thawed sperm (p   < 0.05). These results suggest that proacrosin is activated to beta-acrosin earlier in frozen/thawed dog spermatozoa than in fresh dog spermatozoa.  相似文献   

5.
The aim of this study was to estimate the effects of Equex STM on sperm motion characteristics in chilled dog semen extended in Tris-based diluent. Thirty-two ejaculates were collected from 12 proven German shepherd stud dogs. The sperm-rich fractions were diluted in Tris-based extender with 1% (v/v) Equex STM (sample A) and in Tris-based extender with no addition of detergent (sample B). The extended semen was incubated for 240 h at 5°C and the motility parameters were evaluated by CASA system at 24-h intervals. Addition of Equex STM to Tris-based extender led to an initial activation of motion activity of spermatozoa, followed by a rapid decrease, shortening the lifespan of spermatozoa incubated at 5°C. Computer-assisted sperm analysis clearly showed that Equex STM-induced changes of sperm motion characteristics resemble the hyperactivation (HA) of spermatozoa associated with the capacitation process.  相似文献   

6.
The aim of this work was to determine the enzymatic activity of phosphofructokinase (PFK), malate dehydrogenase (MDH) and isocitrate dehydrogenase (IDH) in boar spermatozoa and study their participation in bicarbonate‐induced capacitation and follicular fluid‐induced acrosome reaction. Enzymatic activity of these enzymes was determined spectrophotometrically in extracts of boar spermatozoa. Sperm suspensions were incubated in the presence of bicarbonate (40 mM), a well‐known capacitation inducer, or follicular fluid (30%), as an acrosome reaction inducer, and different concentrations of oxoglutarate, oxalomalate and hydroxymalonate, inhibitors of PFK, IDH and MDH, respectively. Capacitation percentages were determined by the fluorescence technique of chlortetracycline (CTC), and true acrosome reaction was determined by trypan blue and differential–interferential contrast, optical microscopy. The activity of PFK in boar spermatozoa enzymatic extracts was 1.70 ± 0.19 U/1010 spermatozoa, the activity of NAD‐ and NADP‐dependent IDH was 0.111 ± 0.005 U/1010 and 2.22 ± 0.14 U/1010 spermatozoa, respectively, and the activity of MDH was 4.24 ± 0.38 U/1010 spermatozoa. The addition of the specific inhibitors of these enzymes prevented sperm capacitation and decreased sperm motility during capacitation and inhibited the acrosome reaction (AR), without affecting the sperm motility during this process. Our results demonstrate the participation of PFK, IDH and MDH in bicarbonate‐induced capacitation and follicular fluid‐induced acrosome reaction in boar spermatozoa, contributing to elucidate the mechanisms that produce energy necessary for these processes in porcine spermatozoa.  相似文献   

7.
The present experiment was designed to determine the effects of various biologically active substances, such as oestradiol (OE), progesterone (P4) and heparin (Hep) alone or in combination on sperm plasma membrane scrambling, capacitation and acrosome reaction (AR) of post-thaw bovine spermatozoa. Spermatozoa were incubated for 180 min in capacitation medium supplemented with (i) 1 mug/ml OE; (ii) 1 mug/ml P4; (iii) 1 mug/ml OE and 1 mug/ml P4; (iv) 1 mug/ml OE and 5 mug/ml Hep; (v) 1 mug/ml P4 and 5 mug/ml Hep; (vi) 1 mug/ml OE, 1 mug/ml P4 and 5 mug/ml Hep. At predetermined time intervals aliquots were taken to assess sperm plasma membrane scrambling, or capacitation (AR induced by lysophosphatidylcholine) in spermatozoa. The second experiment was aimed to study the effects of OE, P4 and OE/P4 as potential inducers of AR in Hep-capacitated spermatozoa. Plasma membrane scrambling was assessed by a flow cytometer, using Merocyanine staining. Acrosomal status and viability of spermatozoa were evaluated under epifluorescence microscope with Ethidium homodimer-1/peanut agglutinin fluorescein isothiocyanate staining method (EthD-1/PNA-FITC). The results show that OE, P4 and a combination of OE/P4 at concentrations used did not affect sperm viability. Heparin significantly (p < 0.001) increased sperm plasma membrane scrambling of OE and P4-treated spermatozoa. P4 significantly affected the rate of sperm capacitation (p < 0.001) and AR (p < 0.05), but OE expressed membrane-stabilizing properties (p < 0.05). It can be concluded that in frozen-thawed bovine spermatozoa OE presents plasma membrane stabilizing properties that can be abolished by Hep, but not by P4. Progesterone possesses capacitating and AR-inducing properties in frozen-thawed bovine spermatozoa that can be alleviated by OE.  相似文献   

8.
Microencapsulation of bovine spermatozoa   总被引：1，自引：0，他引：1  
Two experiments were conducted to examine the efficacy of microencapsulation of bovine spermatozoa for use in artificial insemination. In Exp. 1, sperm were encapsulated at three different concentrations (45, 90 and 180 X 10(6) sperm/ml) in either .75- or 1.5-mm (diameter) microcapsules and incubated in vitro for 24 h at 37 C. Unencapsulated samples of each concentration served as controls. Capsule contents were evaluated for percentage of sperm motility and intact acrosomes at 2, 12 and 24 h of incubation. Capsule fragility was evaluated after 24 h incubation. Viability of spermatozoa was not influenced by sperm concentration or capsule size, and compared with controls, cellular injury after encapsulation was not apparent. Fragility of capsules was unaffected by capsule size; however, as the sperm concentration increased, integrity of the capsules decreased (P less than .05). In Exp. 2, using frozen-thawed semen, the effect of egg yolk content, presence of glycerol and viability of spermatozoa on the success of microencapsulation was measured. The extender was 2.9% sodium citrate with glycerol (7% v/v) and either 0, 5, 10 or 15% egg yolk (v/v). Uniformity of capsules in size and shape was evaluated subjectively. Capsule integrity and uniformity were unaffected by glycerol, sperm viability or egg yolk level up to 10% v/v; however, encapsulation of spermatozoa in 15%-yolk buffer increased the heterogeneity in capsule size and shape. Viability of encapsulated spermatozoa was maximal for extenders containing 10 or 15% yolk v/v. Reduced viability for the 5% yolk extender was due to pre-encapsulation injury associated with freezing. Microencapsulation procedures are compatible with sperm viability and can be adapted to an acceptable extender system used in artificial insemination.  相似文献   

9.
The purpose of this study was to investigate effects of addition of lactoferrin on characteristics and functions of bovine epididymal, ejaculated, and frozen-thawed sperm. The addition of lactoferrin was significantly (p < .05) effective on increasing values of progressive motility, straightness, and linearity in caput epididymal sperm and values of motility in cauda epididymal sperm. When ejaculated sperm were incubated in capacitation medium, percentages of motile and progressively motile sperm decreased largely within the first period of 30 min, followed by only minor changes. However, the addition of lactoferrin significantly lessened the early decreases of these parameters and additionally promoted capacitation-dependent changes of chlortetracycline staining patterns (from F pattern to B pattern). In other experiments, when ejaculated sperm were exposed to oxidative stress with 100-µM H2O2, the addition of lactoferrin partially protected them from dysfunction of flagellar movement and loss of progressive movement. In final experiments with frozen-thawed samples incubated in the capacitation medium, the addition of lactoferrin effectively survived dying sperm and suppressed occurrence of sperm agglutination. These results may suggest biological and biotechnological potentials of lactoferrin for modulation of bovine sperm viability, motility, capacitation state, and preservation in vitro.  相似文献   

10.
Computerized motility analysis (CASA) shows that four separate subpopulations of spermatozoa with different motility characteristics co-exist in rabbit ejaculates. There were significant (p < 0.01) differences in the distribution of these subpopulations among separate genetic lines, total sperm abnormalities and the percentage of altered acrosomes. Furthermore, logistic and linear multivariate regressions among several parameters of rabbit semen quality analysis were tested for use as predictive tools for the fertilizing ability of a specific artificial insemination semen sample. Logistic regression analysis rendered two mathematical, significant (p < 0.01) models: one between sperm viability and conception rate and the other between total sperm abnormalities and conception rate. Multiple linear regression analyses also yielded some significant relationships between both fertility (p < 0.001) and litter size (p < 0.05), with respect to some semen characteristics. Our results support the hypothesis that the predictive in vivo fertility use of the standard rabbit semen quality analysis coupled with a CASA determination could be reasonably achieved by applying linear and logistic regression analyses among several parameters of rabbit semen quality analysis.  相似文献   

11.
To evaluate effects of different concentrations of pentoxifylline, as phosphodiesterase inhibitor, on quality of motility, capacitation and acrosome reaction, Ejaculated spermatozoa were collected from crossbred dogs. The sperm were incubated at concentrations of 0.1, 1, 10 and 100 mM pentoxifylline for 2 h. Conventional assessment was also made on the percentage of motility and quality of motility of spermatozoa; values were expressed as sperm motility index (SMI). Capacitation and acrosome reaction were also evaluated by chlortetracycline fluorescence staining. SMI as quality index of sperm was significantly increased in concentrations of 10 and 100 mM pentoxifylline during 1 and 2 h compared to control. The number of capacitated or acrosome reacted spermatozoa significantly (P < 0.05) were higher than controls at high concentrations of pentoxifylline (10 and 100 mM) during 1 and 2 h. In conclusion, high concentration of pentoxifylline is able to induce capacitation and acrosome reaction and improves quality of motility in canine ejaculated spermatozoa.  相似文献   

12.
Basic characteristics of European bison (Bison bonasus) semen were described and the efficacies of two extenders-Triladyl, containing egg yolk, and a synthetic extender, containing soybean lipids-were tested for semen cryopreservation. Seven ejaculates were collected by electroejaculation from a 10-yr-old, European bison bull. Each ejaculate was diluted at 37 degrees C to a final concentration of 200 x 10(6) sperm/ml with Triladyl or the synthetic extender. Extended semen samples were frozen according to a standard bull semen freezing protocol. After 2 wk of storage, one straw from each extender and ejaculate was thawed, and postthaw quality was evaluated by individual sperm motility and movement rate, numbers of sperm morphologic abnormalities and intact acrosomes, functional integrity of the sperm membranes determined by hypoosmotic swelling test (HOST), viability (live-dead, eosin-nigrosin stain), and a heterologous in vitro sperm penetration assay (SPA). A total of 600 in vitro-matured bovine oocytes were inseminated with 1 X 10(6) spermatozoa of Holstein semen frozen-thawed in Triladyl (control) or of European bison semen frozen in Triladyl or the synthetic extender. Nuclear status of the oocytes was determined after 18 h of sperm-oocyte coincubation. Extender had no effect on any evaluated parameters of semen after dilution and cooling (4 hr at 5 degrees C) or in postthaw individual motility, quality of movement, and sperm morphology. However, significantly (P < 0.05) higher numbers of spermatozoa with intact acrosomes, intact membranes (HOST), and viable sperm (P < 0.01) were in semen frozen in Triladyl than in the synthetic extender. Mean values for heterologous SPA for bull (control) and for bison semen frozen in the synthetic extender were very much alike-63.3+/-10.6% and 63.1 +/- 15.9%, respectively; bison semen frozen in Triladyl was lower, 43.0+/-24.2% but not significantly different. Cumulative results from a variety of viability assays of diluted/cooled and frozen-thawed semen, including the heterologous SPA, suggest that European bison semen can be successfully frozen in both extenders tested in this study.  相似文献   

13.
The function of prion‐like protein Doppel was suggested to be related to male fertility. In this study, the importance of ovine Doppel polypeptide on spermatozoa capacitation and fertilization was evaluated. After refolding, recombinant Doppel (rDpl) was supplemented with different concentrations (40, 80 or 190 ng/ml) to ovine spermatozoa during the capacitation process. In experiment 1, post‐thawed ovine spermatozoa were incubated with different concentrations of rDpl during 1 h for swim‐up, and changes in sperm motility, concentration, vigour, viability and capacitation were monitored (10 replicates). In experiment 2, the fertilization ability of post‐swim‐up spermatozoa incubated as above was tested through heterologous fertilization of bovine in vitro matured oocytes (n = 423, three replicates). Regardless of dosage, rDpl improved (p ≤ 0.03) spermatozoa viability. Sperm individual motility and vigour were the highest (p ≤ 0.04) for the group receiving 190 ng/ml rDpl. Sperm supplemented with the highest doses of rDpl achieved higher (p = 0.02) fertilization rates (56.0 ± 3.0%) than control (39.1 ± 2.2%) and 40 ng/ml rDpl (39.8 ± 2.7%). Preliminary data suggest that Doppel protein may enhance in vitro spermatozoa fertilizing ability.  相似文献   

14.
In this study, the relations between fertility (56‐day non‐return rates, 56‐day NRR) after artificial insemination (AI) and bull sperm characteristics post‐thaw, after swim‐up and after co‐incubation with heparin (Hep) and hyaluronan (HA), respectively, were determined, attempting to determine if such a procedure could be of value to evaluate the potential fertilizing ability of frozen‐thawed AI bull spermatozoa. Spermatozoa from 20 semen batches derived from 20 Swedish Red and White AI bulls ranging widely in their field fertility after AI (55–79% 56‐day NRRs) were evaluated with regards to post‐thaw motility, membrane integrity, and migration through a simple swim‐up procedure. Sperm viability and capacitation status were evaluated by two different vital staining procedures and chlortetracycline hydrochloride staining. Sperm motility and membrane integrity post‐thaw (e.g. indicators of sperm viability) were significantly correlated (r = 0.53, p < 0.05 and r = 0.59, p < 0.01, respectively) with fertility. Heparin (5 µg/ml) significantly (p lt; 0.001) increased the frequencies of capacitation and acrosome‐reaction (AR) among swim‐up separated spermatozoa, whereas HA at a concentration of 50 ng/ml did not have any significant capacitating effect. The incidences of capacitated or AR‐spermatozoa following Hep‐treatment were not correlated with fertility. On the other hand, the percentage of viable spermatozoa was significantly (p < 0.001) lower in Hep‐treated samples than in control and HA‐treated samples and was significantly (r = 0.49, p < 0.05) correlated with fertility after AI (56‐day NRR). The results indicate that the percentage of viable spermatozoa after swim‐up separation and heparin‐exposure from a selected population of AI bulls were significantly and positively related to the AI fertility of the donors and thus could be used as a parameter to determine the fertilizing ability of frozen—thawed AI bull spermatozoa.  相似文献   

15.
The purpose of this study was to evaluate the ability of various chemicals to induce capacitation of stallion spermatozoa using 2 different assay systems. In Experiment 1, freshly ejaculated spermatozoa were treated for 0, 3 and 6 h with 10 μ g/ml heparin, 0.5 mM hypotaurine or 5 mM caffeine, or were incubated for 0, 3 and 6 h following 1 min exposure to 0.1 μ M ionophore A23187. The acrosome reaction (AR) in the capacitated spermatozoa was induced by 15 min challenge with 100 μ g/ml lysophosphatidylcholine (LPC). In the BO/BSA-control medium (Brackett and Oliphant medium with 0.3% BSA), mean percentage of AR spermatozoa at 0 h was 30%, and the AR rates increased to 40 and 48% after 3 and 6 h incubation, respectively. There was no significant further increase of the AR rates in the spermatozoa treated with heparin (50% at 6 h) and hypotaurine (58% at 6 h) when compared to the control. Caffeine had a beneficial effect on inducing sperm capacitation after 3 and 6 h incubation (AR rates; 61 and 66%, respectively, P<0.01). Immediately after ionophore A23187 treatment, the AR rate increased to 56%, and reached 68 and 67% after 3 and 6 h incubation, respectively (P<0.01). Spermatozoal motility at any time points did not differ between control and any chemical treatment groups, except one treatment (ionophore; 3 h group).In Experiment 2, frozen-thawed spermatozoa were treated with 4 different chemicals as described above. Aliquot of spermatozoa was added to a microdrop of BO/BSA medium in which 6 to 10 in vitro-matured, zona-free mare oocytes were placed, and the oocytes were fixed and stained 20 h after insemination. The penetration rate by BO/BSA-treated spermatozoa was 76%, which was comparable to the results with heparin (73%), hypotaurine (78%) and caffeine (58%). In contrast, treatment of spermatozoa with ionophore A23187 gave a significantly lower penetration rate (30%) than the control value. Surprisingly these two experiments had different conclusions in assessing capacitation of stallion spermatozoa.  相似文献   

16.
The aim of this study was to evaluate how different protein profiles of seminal plasma (SP) fractions affect sperm functionality in vitro. Ejaculates from three boars were separated into six fractions. The fractions differed from each other in their sperm content, in their total SP protein content, and their spermadhesin PSP-I/PSP-II and heparin-binding protein (HBP) concentrations. Spermatozoa were mainly recovered in fraction 2 (sperm-rich fraction, >1800 × 106 spermatozoa/ml), whereas the pre-sperm fraction 1 and the post-sperm fractions 4–6 contained low numbers of spermatozoa (<500 × 106/ml). Except in fraction 2, the total SP protein concentration and the concentration of both, spermadhesin PSP-I/PSP-II and the HBPs increased with fraction order. Distinct time-dependent effects were observed on motility characteristics and membrane integrity of highly diluted boar spermatozoa upon incubation with a 10% dilution of the SP from each fraction. The highest sperm viability was recorded after exposure for 5 h to fraction 2, followed by fractions 1 and 3. The percentages of motile spermatozoa also differed significantly among fractions after 5 h of incubation. Spermatozoa incubated with SP of fractions 1–3 showed the highest percentage motility. We conclude that different SP fractions exert distinct effects on the functionality of highly diluted boar spermatozoa. Fractions 1–3 appear to promote sperm survival, whereas fractions 4–6 seem to be harmful for preserving the physiological functions of highly diluted boar spermatozoa.  相似文献   

17.
This study was carried out to assess the in vitro quality of canine semen frozen in an ultrafreezer at -152 degrees C and to evaluate the male-to-male variation of frozen semen in five male dogs of the Canarian Mastiff breed. Four ejaculates of each dog were processed individually (5% glycerol and 0.5% Equex) to reach a final concentration of 100 x 10(6) spermatozoa/ml. Then, two freezing techniques were tested to assess the seminal quality (sperm motility, live spermatozoa and abnormal sperm cell percentages) at 1, 30, 60, 120 and 360 days after freezing: (i) semen was frozen and stored in liquid nitrogen; (ii) semen was frozen and stored in the ultrafreezer at -152 degrees C. After freezing-thawing, both freezing protocols showed no significant differences in sperm motility and the percentages of live and abnormal spermatozoa. On the other hand, the microscopic characteristics of spermatozoa in fresh semen were practically similar among males; however, after the semen processing and freezing, significant differences were observed (p < 0.05) among males, especially as regards sperm motility. This inter-individual variability was detected in both freezing protocols, showing that the male-to-male variation in the seminal quality post-freezing was independent of the freezing technique used. The in vitro results obtained in the Canarian Mastiff breed confirmed that the use of ultra-freezers at -152 degrees C is a potential alternative to liquid nitrogen for storing canine semen for long periods of time.  相似文献   

18.
The addition of Orvus ES paste (OEP) to extender may be essential for preparing frozen dog semen. The major ingredient of OEP is sodium lauryl sulfate (SLS). In this study, we compared the effect of SLS on frozen dog semen with that of OEP. There were no significant differences between the 2-mg/ml SLS group and OEP group concerning sperm motility, viability and the percentage of viable sperm with intact acrosomes after freeze-thawing. These results suggest that the effectiveness of frozen dog semen extender containing 2 mg/ml of SLS is similar effective to that demonstrated for OEP.  相似文献   

19.
Progress of essential steps of the capacitation is coordinated in the oviductal isthmus, where sperm are stored in close contact with the epithelium. A crucial capacitational event is the phosphorylation of sperm membrane proteins. Regulation of the tyrosine phosphorylation by the oviduct has not been examined in dog sperm yet. The aim of this work was to study the effect of dog sperm binding to porcine oviductal epithelium on capacitation‐induced cellular and molecular changes. Epithelial cells were stripped from the oviducts of post‐puberal sows and cultured for 5–7 days at 39°C and 5% CO2 on Biomatrix‐covered Chamber slides. Sperm washed through Percoll was co‐incubated with the oviductal epithelium cell cultures in a bicarbonate Tyrode's medium. During co‐incubation, sperm membrane changes, the state of tyrosine phosphorylation and motility were determined after 3, 30, 90, 180, 240 and 360 min. Significant increases in the percentage of capacitated and dead cells were observed in unbound sperm, while bound sperm remained uncapacitated, live and motile. An increasing tyrosine phosphorylation of tail proteins in bound, unbound and control sperm suspensions and a subsequent phosphorylation of head proteins in unbound and control sperm suspensions were observed. A significant difference regarding head phosphorylation (p < 0.05) was found between sperm bound to oviductal epithelium and unbound sperm. Binding occurred mainly in sperm with non‐ phosphorylated heads, while higher proportions of phosphorylated cells were found in unbound populations. The head phosphorylation progressed significantly during incubation in unbound spermatozoa (p < 0.05); however, it was suppressed in population of sperm attached to oviductal epithelium. Significant correlations between motility parameters related to hyperactivation and tail phosphorylation were found in unbound sperm. These observations support the hypothesis that spermatozoa with non‐phosphorylated heads preferentially attach to epithelial cells. It can be concluded that tyrosine phosphorylation of head membrane proteins and capacitation are delayed in canine spermatozoa being in closed contact with oviductal epithelium.  相似文献   

20.
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   

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