Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SPERMATOZOA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed1996

Effect of homologous and heterologous seminal plasma on the fertilizing ability of ejaculated bull spermatozoa assessed by penetration of zona-free bovine oocytes.

The ability of seminal plasma to influence the fertility of ejaculated bull spermatozoa was examined using a sperm penetration assay for zona-free bovine oocytes. Washed, ejaculated spermatozoa from bulls of below (low) or above average (high) fertility were mixed with seminal plasma from the same bull, or with seminal plasma from a bull of contrasting fertility. Treated spermatozoa were stained with different fluorochromes and competed to penetrate oocytes after heterospermic insemination in vitro. Washed spermatozoa exposed to seminal plasma from bulls of high fertility penetrated more oocytes than those spermatozoa mixed with seminal plasma from bulls of low fertility (P < 0.01). Mixing low fertility spermatozoa with high fertility seminal plasma generally improved penetrating ability compared with low fertility spermatozoa mixed with low fertility seminal plasma (P = 0.05). Washed spermatozoa from a bull of low fertility mixed with his own seminal plasma had greater ability to penetrate oocytes than did washed spermatozoa from a bull of high fertility mixed with seminal plasma from a bull of low fertility (P < 0.01). The bias associated with using low fertility seminal plasma from the bull providing the spermatozoa was removed by repeating this experiment using pooled seminal plasma from different subfertile bulls. After combination with pooled seminal plasma from bulls of low fertility spermatozoa from bulls of high or low fertility penetrated oocytes in a similar way, but high fertility spermatozoa had a slightly higher penetration rate (P = 0.12). In conclusion, the penetration of zona-free oocytes by ejaculated spermatozoa from bulls of low fertility was marginally improved by seminal plasma from bulls of high fertility, but penetration by high fertility spermaotoza was decreased by exposure to low fertility seminal plasma. Seminal plasma from bulls of low fertility similarly affected the penetrating ability of high and low fertility spermatozoa if the seminal plasma used was foreign to the spermatozoa being tested.

Animals↗
PubMed2001

Generation of reactive oxygen species by equine spermatozoa.

OBJECTIVE: To characterize generation of reactive oxygen species (ROS) by equine spermatozoa. SAMPLE POPULATION: Multiple semen samples collected from 9 stallions. PROCEDURE: Equine spermatozoa were separated from seminal plasma on a discontinuous polyvinylpyrrolidone (PVP)-coated silica gradient and resuspended in a modified Tyrode albumin-lactate-pyruvate medium. Amount of hydrogen peroxide (H2O2) generated was assayed by use of a 1-step fluorometric assay, using 10-acetyl-3,7-dihydroxyphenoxazine as a probe for detection of H2O2 in a microplate assay format. Concentration of H2O2 was determined by use of a fluorescence microplate reader. RESULTS: Amount of H2O2 generated increased significantly with time and spermatozoa concentration for live and flash-frozen spermatozoa, and amount of H2O2 generated was significantly greater for flash-frozen than for live spermatozoa. Addition of the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) significantly increased generation of H2O2 by live and flash-frozen spermatozoa. Addition of a calcium ionophore also significantly increased the amount of H2O2 generated by live spermatozoa but did not have an effect on amount of H2O2 generated by flash-frozen spermatozoa. Abnormal equine spermatozoa generated significantly greater amounts of H2O2 than did normal spermatozoa. CONCLUSIONS AND CLINICAL RELEVANCE: Equine spermatozoa generate ROS in vitro, possibly via a NADPH-oxidase reaction. Spermatozoa damaged during flash-freezing or morphologically abnormal spermatozoa generated significantly greater amounts of ROS than did live or morphologically normal spermatozoa. Damaged and abnormal spermatozoa generate greater amounts of ROS that may contribute to reduced fertility or problems related to semen preservation.

Animals↗
PubMed2002

Segregation of spermatozoa within sperm storage tubules of fowl and turkey hens.

In avian species, spermatozoa reside in the oviduct for prolonged periods in specialized structures known as sperm storage tubules, but little is known about the relative distribution of spermatozoa in these tubules after successive inseminations by different males. The staining efficacies of various fluorescent dyes for fowl and turkey spermatozoa were evaluated to investigate one proposed mechanism of sperm competition. Hens were then inseminated at different intervals with stained and unstained spermatozoa to observe the spatial distribution of spermatozoa within the storage tubules. Several novel fluorescent lipophilic tracers that successfully stain mammalian spermatozoa either did not stain fowl or turkey spermatozoa, or greatly impaired sperm motility. In contrast, Hoechst 33342 readily stained sperm nuclei (fowl: 25 nmol l-1; turkey: 77 nmol l-1) within 4 h without inhibiting sperm motility, or affecting fertility or the hatching ability of the eggs. Hens were tandemly inseminated with equal numbers of stained or unstained spermatozoa at 24 h intervals and were killed 24 h after the final insemination to study sperm entry and storage within the tubules. Oviductal mucosa containing sperm storage tubules was removed, and individual tubules were classified as containing stained spermatozoa, unstained spermatozoa, a mixture of stained and unstained spermatozoa, or as not containing spermatozoa. Results from the present study indicate that spermatozoa from two different inseminations generally segregate into different storage tubules in both fowl and turkey hens. Storage tubules containing mixed populations of spermatozoa were found in only 4% of fowl and 12% of turkey storage tubules examined. Thus, the mechanism of last-male precedence does not appear to be due to the stratification of spermatozoa within the tubules.

Animals↗
PubMed2005

Relation between storage temperature and fertilizing ability of freeze-dried mouse spermatozoa.

The advantage of freeze-dried mouse spermatozoa is that samples can be stored in the refrigerator (+4 degrees C). Moreover, the storage of freeze-dried spermatozoa at ambient temperature would permit spermatozoa to be shipped easily and at low cost around the world. To examine the influence of the storage temperature on freeze-dried spermatozoa, we assessed the fertilizing ability of spermatozoa stored at different temperatures. Cauda epididymal spermatozoa were freeze-dried in buffer consisting of 50 mM ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, 50 mM NaCl, and 10 mM Tris-HCl (pH 8.0). Samples of freeze-dried spermatozoa were stored at -70, -20, +4, or +24 degrees C for periods of 1 week and 1, 3, and 5 months. Sperm chromosomes were maintained well at -70, -20, and + 4 degrees C for 5 months, and oocytes fertilized with these spermatozoa developed to normal offspring. Moreover, the chromosomal integrity of spermatozoa stored at -20 or + 4 degrees C did not decrease even after 17 months. In contrast, the chromosomes of spermatozoa stored at +24 degrees C were maintained well for 1 month but became considerably degraded after 3 months. In addition, to investigate the cause of deterioration of sperm chromosomes during storage at +24 degrees C, spermatozoa were freeze-dried in buffer containing DNase I. The chromosomes of spermatozoa freeze-dried with 1 or 0.2 units/ml of DNase I, 100% or 72%, respectively, exhibited chromosomal abnormalities. Our findings suggest that freeze-dried spermatozoa can be stored long-term with stability at +4 degrees C, and the suppression of nucleases present in the buffer or spermatozoa during storage led to the achievement of long-term storage of freeze-dried spermatozoa.

Animal Husbandry↗
PubMedDate not supplied

Relationships between computerized measurements of motion of frozen-thawed bull spermatozoa and fertility.

A computerized system (CellSoft, CRYO Resources, Ltd.) was validated using video tapes of frozen-thawed bull spermatozoa diluted in filtered (0.2 micron) egg yolk-citrate extender (8 X 10(6) spermatozoa/ml) and analyzed at 30 frames/sec for the percentage of motile spermatozoa (greater than or equal to 20 microns/sec) and linear velocity of motile spermatozoa. Virtually all motile spermatozoa were detected and debris rarely were classified as immotile spermatozoa if the extender had been filtered. Variation about the mean for percent motile cells was similar when only 12 rather than 20 or 30 frames/field were analyzed. Use of 20 frames/field was adequate to determine the percentage of motile bull spermatozoa. Five mixtures of live and killed spermatozoa were analyzed (four bulls) to evaluate accuracy. Percent motile spermatozoa was correlated (r = 0.97) with the ratio of live:killed spermatozoa. Mean linear velocity of motile spermatozoa was similar for each mixture (P greater than 0.05). To further evaluate accuracy, percent motile spermatozoa was determined by computer and by "track motility" (20 samples; 0 to 63% motile spermatozoa); values were correlated (r = 0.95). The system was precise (CV of 6% based on triplicate analyses of the same samples) and reasonably accurate for evaluating bull sperm motility if the extender had been filtered and 20 to 25 fields (greater than or equal to 200 spermatozoa) were evaluated. Correlations between measurements of sperm motion and fertility were studied using cryopreserved semen from two fertility trials. For the first, 75-day nonreturn rate data for 20 samples of bull semen (10 bulls) were not significantly correlated with evaluations made by CellSoft. For the second fertility trial, the competitive fertility index (a measure of relative fertility) for nine bulls was correlated (r greater than or equal to 0.68; P less than 0.05) with percent motile spermatozoa, linear velocity and straight-line velocity. Multiple correlations based on six characteristics evaluated by CellSoft, at 0 or 1.5 hours, and the competitive fertility index were greater than or equal to 0.94. Based on the latter data, the system may facilitate prediction of the relative fertility of bull spermatozoa.

Animals↗
PubMed1994

Computerized analysis of the motility parameters of hamster spermatozoa during maturation.

A computer-aided semen analysis system was used for the objective assessment of hamster spermatozoa during epididymal maturation. The caput epididymal spermatozoa were extremely sluggish, achieved very little progression, and the three velocity parameters, namely curvilinear velocity (VCL), progressive velocity (VSL), and path velocity (VAP), were low. These spermatozoa during progressive movement alternated between the linear shape and "U" shape or attained an "S" shape prior to changing to the "U" shape. The corpus epididymal spermatozoa were faster, displayed greater VSL, VAP, and VCL compared to caput epididymal spermatozoa, and during forward motility, attained "U," "C," and (or) "?" shape as in the wriggling motility pattern. The proximal cauda epididymal spermatozoa were actively motile and VSL, VAP, and VCL in these spermatozoa were more than 10 times greater compared to the caput epididymal spermatozoa. The proximal cauda epididymal spermatozoa predominantly moved in circles and with time became slower and more circular in their trajectories and exhibited a reduction in LIN (linearity). The distal cauda epididymal spermatozoa were very similar to the proximal cauda epididymal spermatozoa with respect to their fast motility (VSL, VAP, and VCL are similar) and beat cross frequency (BCF), but showed larger values for STR (straightness) and LIN and moved along curved trajectories. The amplitude of lateral head displacement (ALH) was also considerably lower in the distal cauda epididymal spermatozoa compared to the proximal cauda epididymal spermatozoa. Thus, this study provides for the first time data related to seven motility parameters for caput and corpus epididymal spermatozoa of hamster. It also provides additional data with respect to VCL, LIN, BCF, and ALH for proximal and distal cauda epididymal spermatozoa of hamster.

Animals↗
PubMed2001

Enrichment of non-apoptotic human spermatozoa after cryopreservation by immunomagnetic cell sorting.

Cryopreservation increases the rate of apoptotic spermatozoa with decreased capability to fertilise oocytes. In order to optimise the fertilisation rates, especially in assisted reproduction the use of apoptotic sperms should be avoided. Early events of apoptosis in cryopreserved spermatozoa are not detectable by conventional methods. However, the surface of apoptotic spermatozoa is characterised by externalisation of phosphatidylserine (PS), which has a high affinity to Annexin V. Therefore, colloid paramagnetic Annexin-V-conjugated microbeads (AN-MB) were tested for their ability to eliminate apoptotic spermatozoa from a total of 40 fresh and in TEST yolk buffer cryopreserved semen samples which were provided by 15 healthy volunteers. By passing through a magnetic field (MiniMACS, Miltenyi Biotec) the sperm suspensions were divided into 2 sperm fractions depending on bound magnetic Annexin V-microbeads (AN-MB) to spermatozoa. As additional markers of apoptosis CD95 (Fas, APO-1) on the sperm surface and activated caspases in the cytosol were detected in both fractions. Supplementary investigations comprised eosin-supravital staining and computer assisted sperm motion analysis. The separation was supervised by flow cytometric analysis of spermatozoa labelled with FITC-conjugated anti Annexin V-antibodies. Analyses of the magnetic inactive sperm fraction (AN-MB-negative) showed CD95 on 0.6 +/- 0.3% (X +/- SEM) of spermatozoa and only 3.2 +/- 0.5% were stainable with eosin, whereas, 40.6 +/- 6.7% of the remaining cells in the column appeared to be CD95 positive and 99.8 +/- 0.1% stainable with eosin after cryopreservation. Indeed the overall amount of CD95 positive spermatozoa did not significantly increase after cryopreservation (2.5 +/- 0.5% vs. 4.3 +/- 1.2%; p > 0.05). Activated caspases were found in 21.8 +/- 2.6% of the spermatozoa in fresh and in 47.7 +/- 5.8% of cryopreserved semen samples (p < 0.01). The separation procedure of the cryopreserved spermatozoa reduced significantly the quantity of those containing activated caspases to 9.3 +/- 2.2% within the AN-MB-negative fraction. In contrast 89.1 +/- 2.3% of AN-MB-positive sperms showed activation of these proteolytic enzymes. Flow cytometric analyses using FITC-conjugated anti Annexin V-antibodies for monitoring of AN-MB-binding to spermatozoa showed 5.2 +/- 1.0% labelled spermatozoa in the AN-MB negative fraction and 72.6 +/- 2.7% labelled spermatozoa in the AN-MB positive one. There was no significant influence of the separation column and the magnetic field on the sperm functions. The passage through the column led to a sperm loss of 0.8 +/- 1.2%. Conclusion: The binding of paramagnetic Annexin V-conjugated microbeads is an excellent method to eliminate spermatozoa at early apoptotic stages from cryopreserved semen samples. A deleterious influence of the separation column and the magnetic field on the spermatozoa was not observed.

Journal Article↗
PubMed2005

Proacrosin/acrosin quantification as an indicator of acrosomal integrity in fresh and frozen dog spermatozoa.

The scope of the present study was to evaluate the presence and activation of proacrosin/acrosin as a tool to determine the acrosomal status of fresh and frozen/thawed dog spermatozoa. Monoclonal antibody C5F11, directed against human acrosin, cross-reacted with dog spermatozoa and labeled the acrosome of both fresh and frozen/thawed dog spermatozoa. Frozen/thawed spermatozoa had a lesser proportion of labeled spermatozoa than fresh spermatozoa (P<0.05). When live spermatozoa were labeled with soybean trypsin inhibitor conjugated with Alexa 488 (SBTI-Alexa 488), the proportion of acrosome-labeled fresh spermatozoa was less than frozen/thawed spermatozoa (P<0.05). By using Western blots and enzymatic activity, frozen/thawed spermatozoa had a greater proportion of active acrosin than fresh spermatozoa. In addition, beta 1,4-galactosyl-transferase (GalT), a plasma membrane bound protein, remained attached to frozen/thawed spermatozoa. Proacrosin is activated during freezing/thawing of dog spermatozoa, and that proacrosin/acrosin may be a good indicator of acrosomal integrity of frozen/thawed spermatozoa.

Acrosin↗
PubMed2000

The interaction of fresh and frozen-thawed ram spermatozoa with oviducal epithelial cells in vitro.

In order to investigate the interaction of fresh and frozen-thawed spermatozoa with oviduct epithelial cells, spermatozoa were co-incubated with ovine oviduct epithelial cell monolayers (OECM) derived from either complete oviducts, at any stage of the oestrous cycle (Experiments 1 and 2), or from different regions of the oviduct at different stages of the cycle (Experiment 3). Fresh and frozen-thawed spermatozoa displayed different patterns of binding to, and release from, the OECM. Frozen-thawed spermatozoa immediately bound to the complete oviduct OECM and were released after 2 h. A small proportion of fresh spermatozoa bound immediately, increasing to a maximum after 2 h, and were gradually released thereafter. When only the cells that were released from the OECM were observed by chlortetracycline staining in Experiment 2, it was found that the presence of an OECM increased the number of capacitated fresh spermatozoa while decreasing the number of capacitated frozen-thawed spermatozoa. Overall, the OECM advanced the membrane state of both types of spermatozoa from uncapacitated to acrosome-reacted. Fresh and frozen-thawed spermatozoa bound to OECM derived from the cells of the isthmus and the ampulla in similar proportions. However, more spermatozoa were capacitated when incubated with OECM derived from isthmic rather than ampullary cells. Higher proportions of fresh spermatozoa bound to, and were acrosome-reacted following incubation with OECM derived from post- rather than pre-ovulatory tracts. Such differences were not observed for frozen-thawed spermatozoa. The findings reported in this study show that fresh and frozen-thawed spermatozoa behave differently when in contact with oviduct cells in vitro. This may be a consequence of the more advanced membrane state of the frozen spermatozoa upon thawing.

Animals↗
PubMed1996

Fertilizing ability of immotile spermatozoa after intracytoplasmic sperm injection.

Sometimes spermatozoa from ejaculate, epididymis or testis show a total absence of motility. For some patients, however, very few spermatozoa with very poor motility can be found after several hours of incubation (initially immotile spermatozoa). Other samples show no motility at all even after extended culture (totally immotile spermatozoa). Intracytoplasmic sperm injection (ICSI) is the only method available to select and retrieve a single immotile or initially immotile spermatozoon and inject it into the oocyte. A total of 103 patients with asthenozoospermia underwent ICSI in this study. It was shown that initially immotile and totally immotile spermatozoa, whatever their origin, have the capacity to fertilize an oocyte after ICSI. No significant difference could be observed between the fertilizing capacity of testicular or epididymal spermatozoa. Totally immotile ejaculated spermatozoa, however, fertilized significantly fewer oocytes after ICSI when compared with initially immotile ejaculated spermatozoa. Embryos of lower quality tended to be produced when totally immotile spermatozoa of any origin were used, compared with embryos resulting from initially immotile spermatozoa. Ongoing pregnancies were conceived after ICSI with initially immotile spermatozoa from any origin and totally immotile spermatozoa retrieved from testis only. One biochemical pregnancy was the result of embryo transfer after ICSI with totally immotile ejaculated spermatozoa. No supernumerary embryos could be cryopreserved for patients with totally immotile spermatozoa from ejaculate or epididymis. For a Kartagener patient, subzonal insemination (SUZI) seemed to be a better approach for obtaining fertilization and pregnancy than ICSI because no fertilization occurred after ICSI on sibling oocytes. Hence a healthy pregnancy was obtained after SUZI.

Cryopreservation↗
PubMed1999

Presence of platelet-activating factor in rhesus (Macaca mulatta) spermatozoa.

Platelet-activating factor [1-O-alkyl-2-acetyl-sn-glycero-phosphocholine; PAF] is a unique signaling phospholipid which has been implicated in a number of biological activities (e.g., reproduction). PAF has been detected in the spermatozoa from a number of laboratory and domestic species, including, but not limited to, rabbit, bovine, and the mouse. The concentration of PAF is inversely related to human (Homo sapien) spermatozoal quality. Additionally, PAF levels are significantly higher in Bolivian squirrel monkey (Saimiri sciureus) spermatozoa obtained during the breeding season than spermatozoa obtained during the nonbreeding season. There are no reports on the presence of PAF in rhesus (Macaca mulatta) spermatozoa. Therefore, the primary objective of this study was to detect the presence of PAF in rhesus spermatozoa. A second objective was to determine if PAF spermatozoa levels differ between animals housed individually (single-caged) versus free-ranging (open corrals). Semen were collected from mature rhesus via electro-ejaculation. Spermatozoa were washed free of ejaculatory plug and quick frozen in PBS. Endogenous lipids were extracted from thawed spermatozoa and ejaculatory plugs then assayed for the presence of PAF by [125I]-radioimmunoassay. PAF was not detected in any ejaculatory plugs. PAF levels were significantly higher (P < 0.01) in spermatozoa obtained from free-ranging males (mean: 1.16 pmol/10(6) spermatozoa) than males housed individually in single cage units (mean: 0.53 pmol/10(6) spermatozoa). PAF was present in rhesus spermatozoa. Additionally, PAF levels were higher in spermatozoa obtained from corral-housed animals. Additional studies are warranted to elucidate the role of PAF in spermatozoa function.

Animals↗
PubMed1996

Factors affecting motion characteristics of frozen-thawed stallion spermatozoa.

Five experiments were conducted to evaluate damage incurred in each processing step for cryopreservation of stallion spermatozoa. In Experiment 1, semen was centrifuged for 9 centrifugation times and the percentage of spermatozoa recovered after each treatment was calculated and spermatozoal motion characteristics analysed. Recovery of spermatozoa was > or = 80% when spermatozoa were centrifuged for > or = 10 min. Experiment 2 evaluated spermatozoa cryopreserved at 5 different concentrations in each of 2 extenders (skim milk-egg yolk-glycerol, SM-EYG; and lactose-EDTA, LAC). In SM-EYG, TMOT and PMOT were higher at spermatozoal concentrations of 20, 200 and 400 x 10(6)/ml (51%/41%, 52%/44%, 50%/43%, respectively) than for samples frozen at > or = 800 x 10(6) spermatozoa/ml (41%/35%, 32%/27%; P < 0.05). Spermatozoa frozen in LAC at a concentration of 20 x 10(6)/ml resulted in the highest TMOT and PMOT (43% and 30%, respectively, P < 0.05). The effect of freezing rate on motion characteristics of spermatozoa was evaluated in Experiment 3. The VCL of spermatozoa frozen in SM-EYG was the only parameter affected by freezing rate (P < 0.05). Experiment 4 evaluated motion characteristics after cryopreservation of spermatozoa in different sized straws (0.5 or 2.5 ml) in each of 2 extenders (SM-EYG and LAC). In SM-EYG, PMOT (38%) and VCL (109 microns/s) were highest when spermatozoa were frozen in 0.5 ml straws (P < 0.05). In Experiment 5, spermatozoa thawed immediately after cryopreservation or thawed after storage in liquid nitrogen for 24-48 h were evaluated. There was no effect of length of storage in liquid nitrogen on spermatozoal motion characteristics (P < 0.05). Experiment 6 evaluated the effects of cooling time to 5 degrees C (0, 2.5 and 5 h) on motion characteristics of spermatozoa cryopreserved in 2 extenders (SM-EYG and LAC). TMOT and PMOT were effected by cooling time, and there was a cooling-time-by-extender interaction (P < 0.05). In SM-EYG, TMOT and PMOT were higher if spermatozoa were cooled to 5 degrees C prior to initiation of freezing than if freezing was initiated at 20 degrees C (P < 0.05). A suggested protocol for cryopreservation of stallion spermatozoa would include: 1) centrifugation at 400 g for 14 to 16 min; 2) extension at 23 degrees C with SM-EYG to 400 x 10(6) spermatozoa/ml; 3) cool to 5 degrees C for 2.5 h; 4) package in 0.5 ml straws at 5 degrees C; 5) freeze in liquid nitrogen vapour at -160 degrees C; and 6) thaw for 30 s in 37 degrees C water.

Animals↗
PubMed1976

In-vitro fertilization of hamster eggs in different media and the stimulating effect of heterologous and homologous spermatozoa.

Hamster eggs with follicular cells were fertilized by epididymal spermatozoa in two chemically defined media. The proportion of penetrated eggs was significantly higher in a medium for rabbit (16%) than in a medium for rat eggs (6%), but much lower than in Tyrode's solution containing follicular fluid or blood serum as reported by others. The optimal sperm concentration for sperm penetration ranged from 0.5 to 5 X 10(6)/ml but penetration of denuded eggs failed in these media. When exposed to hamster spermatozoa in the rabbit medium containing living or dead spermatozoa of guinea-pig, rat, mouse or hamster, high proportions of denuded eggs (24-96%) and eggs with follicular cells (93%) were penetrated. By exposure of denuded hamster eggs to hamster spermatozoa in supernatant fluid of frozen-thawed guinea-pig spermatozoa, 97% of eggs were penetrated in 8 hr compared to 0% in the control group. Sperm capacitation was also efficiently induced by preincubation of hamster spermatozoa in the supernatant fluid. The fertilizing capacity of hamster spermatozoa was maintained for 12 hr during incubation with frozen-thawed guinea-pig spermatozoa when the concentration of hamster spermatozoa ranged between 10 and 20 X 10(6)/ml. The beneficial factor of guinea-pig spermatozoa appeared to be from spermatozoa themselves, not from the vasal or epididymal fluids. The presence of follicular cells, blood serum, bovine serum albumin, or even polyvinylpyrrolidone in the media is essential for the capacitation and acrosome reaction of hamster spermatozoa. The components of guinea-pig spermatozoa appear to maintain the fertilizing capacity of hamster spermatozoa and stimulate the process of capacitation.

Animals↗
PubMed1983

The activity of glyceraldehyde 3-phosphate dehydrogenase in spermatozoa from different regions of the epididymis in laboratory rodents treated with alpha-chlorohydrin or 6-chloro-deoxyglucose.

The activity of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) (mUnits/10(6) spermatozoa: mean +/- s.e.m., N = 12) in spermatozoa from the rat epididymis declined from 22.0 +/- 1.4 in the caput to 14.1 +/- 1.3 in the corpus region but there was no further decrease in the cauda region. In hamsters (N = 4), GAPDH activity in spermatozoa declined from 24.8 +/- 2.2 in the caput to 15.2 +/- 1.2 in the distal cauda epididymidis with the greatest decrease between the corpus and proximal cauda regions. In guinea-pigs (N = 4) GAPDH activity in spermatozoa increased from 11.4 +/- 0.79 in the caput to 18.0 +/- 0.7 in the corpus and cauda regions of the epididymis. The activity of GAPDH in spermatozoa therefore changes during maturation in a species dependent manner. GAPDH in spermatozoa from the distal cauda epididymidis of rats given alpha-chlorohydrin (4, 8 or 25 mg/kg/day by mouth) or 6-chloro-6-deoxyglucose (24 or 96 mg/kg/day by mouth) for 10 days was inhibited by greater than 80% but was only inhibited by 25-45% in spermatozoa from the caput epididymidis. The enzyme was inhibited to an intermediate and dose-dependent extent in spermatozoa from the corpus region. A similar pattern of inhibition was seen in spermatozoa from hamsters given alpha-chlorohydrin (50 or 100 mg/kg/day) for 10 days. alpha-Chlorohydrin (66 mg/kg/day s.c.) for 10 days inhibited GAPDH in spermatozoa from the caput or corpus epididymidis of the guinea-pig by less than 20% but decreased GAPDH activity by almost 90% in the cauda region. In rats the greater effect of alpha-chlorohydrin on spermatozoa from the cauda region of the epididymis occurred even after short periods of treatment or when the passage of spermatozoa through the duct was interrupted by a ligature around the corpus region, indicating that the effect is not simply a reflection of the length of time the spermatozoa have spent in the epididymis. It is concluded that either spermatozoa undergo a maturational change which increases their sensitivity to alpha-chlorohydrin or that alpha-chlorohydrin (or an active metabolite) is concentrated in the lumen of the cauda epididymidis.

Animals↗
PubMed2001

Glycoconjugates on the surface of epididymal spermatozoa in a marsupial, the brushtail possum, Trichosurus vulpecula.

Variation in localization and distribution of saccharides on the sperm surface of a marsupial, the brushtail possum, Trichosurus vulpecula, was compared between spermatozoa from the caput and cauda epididymides. Spermatozoa were subjected to the following treatments: (i) unfixed and fixed spermatozoa were stained with fluorescein-labelled lectins; (ii) unfixed spermatozoa were incubated with lectins for determination of agglutination; and (iii) spermatozoa were incubated with detergent to remove the plasmalemma, the glycoproteins were separated on SDS-PAGE and western blots were stained with biotinylated lectins. Many of the fluorescein isothiocyanate (FITC)-labelled lectins bound selectively to the sperm surface, and marked differences were found in lectin staining affinity between caput and cauda epididymal spermatozoa. Incubation of spermatozoa from the cauda epididymidis with neuraminidase reversed many of the differences in staining of the cauda epididymal spermatozoa, indicating masking of some terminal saccharides by sialic acid. Agglutination of spermatozoa from the caput epididymidis occurred after incubation with Concanavalin A (ConA) and soybean agglutinin (SBA), but agglutination was less extensive for spermatozoa from the cauda epididymidis. Western blot analysis indicated several ConA-positive bands in caput sperm extracts, but fewer positive bands in the cauda sperm extracts, whereas SBA stained four bands from caput but none from the cauda epididymal spermatozoa. These results demonstrate extensive glycosylation of the surface proteins of spermatozoa from the caput epididymidis and significant differences in spermatozoa from the cauda epididymidis. In general, the findings indicate similar glycosylation of the surface of marsupial spermatozoa to those from eutherian mammals despite marked differences in their morphology and early divergence of marsupials from eutherian mammals. It would appear that this situation differs markedly from that in sub-mammalian vertebrates.

Animals↗
PubMed2001

Generation of live rat offspring by intrauterine insemination with epididymal spermatozoa cryopreserved at -196 degrees C.

This study reports the development of a reliable method for cryopreservation of rat epididymal spermatozoa and the production of live young by artificial insemination using these cryopreserved spermatozoa. The motility and membrane integrity of rat spermatozoa were investigated after spermatozoa had been subjected to physical stress and frozen with various concentrations of glycerol (0, 3 and 6%) either in the presence or absence of Equex Stem as cryoprotective agents. The ability of cryopreserved spermatozoa to generate normal offspring by intrauterine insemination was also evaluated. Rat spermatozoa that had been centrifuged at 700 g for 5 min showed a significant decrease in motility compared with non-centrifuged spermatozoa. In addition, after centrifugation three times the percentage of membrane-intact spermatozoa decreased to approximately 0%. The percentage of membrane-intact spermatozoa was significantly higher (P < 0.01) in semen samples that had been frozen in medium without glycerol than in samples frozen in medium with 3% glycerol. Although the addition of 0.7% Equex Stem to medium without glycerol or with 3% glycerol did not influence rates of sperm motility after freezing and thawing, the percentage of membrane-intact spermatozoa was improved by the presence of 0.7% Equex (P < 0.05). Therefore, rat spermatozoa were handled gently to avoid physical stress and were frozen in medium containing 23% egg yolk, 8% lactose monohydrate and 0.7% Equex Stem, at pH 7.4 adjusted with 10% Tris(hydroxymethyl)aminomethane solution. Thirteen female rats were inseminated into the oviductal end of both uterine horns with frozen-thawed spermatozoa. Forty-one normal live offspring were obtained from nine of the inseminated females. These results indicate that frozen-thawed rat spermatozoa can generate normal offspring. To our knowledge, this procedure is the first successful production of offspring using spermatozoa cryopreserved in liquid nitrogen.

Animals↗
PubMed1984

Characteristics of bovine spermatozoa after migration through a bovine serum albumin gradient.

Experiments were conducted to determine the efficiency with which viable, morphologically normal bovine spermatozoa could be isolated using a discontinuous bovine serum albumin (BSA) gradient. In the first experiment, extended semen was layered on top of a BSA gradient (4% BSA over 10% BSA) contained in a 500-ml separatory funnel. When comparing 1, 3, 5, 7, 14 or 21 X 10(9) spermatozoa applied to the gradient, the percentage of spermatozoa recovered from the lower third of the 10% BSA ranged from 2.9 to 18.5%. The greatest recovery was achieved when 1 X 10(9) sperm cells were applied. Increasing the number of spermatozoa applied to the gradient increased the percentage of spermatozoa remaining in the upper portions of the gradient. Motility of spermatozoa immediately after collection from the 10% BSA layer of the gradient was greater than 90%, regardless of the number of spermatozoa applied. In a second experiment with freeze-thawed separated or unseparated spermatozoa, post-thaw motility (greater than 60%) and acrosomal integrity (greater than 85%) of separated spermatozoa (4 or 10% BSA layer) was greater (P less than .05) than that of unseparated spermatozoa (38 and 66%, respectively). The discontinuous gradient excluded decapitated spermatozoa and spermatozoa with mid-piece and principal piece abnormalities from entering the lower layers. Sperm cells with head abnormalities were not separated. These data indicate that a population of spermatozoa with a high frequency of viable, motile, morphologically-normal bovine spermatozoa can be isolated using a discontinuous BSA gradient.

Animals↗
PubMedDate not supplied

Effect on clinical outcome of the interval between collection of epididymal and testicular spermatozoa and intracytoplasmic sperm injection in obstructive azoospermia.

We wished to determine whether the interval between surgical retrieval of epididymal and testicular spermatozoa in obstructive azoospermia and their subsequent use in intracytoplasmic sperm injection (ICSI) has an effect on their fertilizing capacity and pregnancy rates in patients undergoing ICSI. This was a retrospective review of 164 consecutive cycles of ICSI in partners of men undergoing surgical sperm retrieval for obstructive azoospermia. Seventy-three cycles used fresh testicular spermatozoa; in 35 cycles ICSI was performed within 4 hours of sperm retrieval, and in 38 cycles spermatozoa were incubated overnight before ICSI. Epididymal spermatozoa were used in 29 cycles; 22 cases within 4 hours of retrieval and 7 cases following overnight culture. Cyropreserved testicular and epididymal spermatozoa were used in 42 and 20 ICSI cycles, respectively. Fertilization and clinical pregnancy rates were calculated for each treatment group. Fertilization rates for epididymal spermatozoa were 67% at 4 hours, 56% at 24 hours, and 63% for cryopreserved spermatozoa (P =.52). Fertilization rates for testicular spermatozoa were 63% at 4 hours, 71% at 24 hours, and 60% for cryopreserved spermatozoa (P =.16). Unlike testicular spermatozoa, cryopreserved epididymal spermatozoa showed a significant increase in clinical pregnancy rates with cryopreservation, with rates of 4 of 22, 1 of 7, and 10 of 20 at 4 hours, 24 hours, and cryopreservation, respectively (P =.049). This study confirms that fertilization and pregnancy rates following ICSI with motile spermatozoa are unaffected by the duration between surgical retrieval of spermatozoa and their injection into oocytes. It also demonstrates that of all treatment modalities, the use of frozen epididymal spermatozoa was associated with the greatest pregnancy rates.

Adult↗