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Presence of ribonucleic acid in human spermatozoa: differences in content between normal and abnormal spermatozoa.

OBJECTIVE: Our purpose was to determine whether there are any differences in total ribonucleic acid content between normal and abnormal human spermatozoa. STUDY DESIGN: Spermatozoa were obtained from men undergoing routine semen analysis at a university-based reproductive genetics laboratory. Specimens were classified as normal or abnormal according to World Health Organization criteria. Total ribonucleic acid was removed by acid-phenol extraction, and ribonucleic acid expression levels were determined by spectrophotometric analysis. RESULTS: Abnormal spermatozoa were found to have significantly more ribonucleic acid (0.14 +/- 0.02 mg/10(6) spermatozoa) than normal spermatozoa (0.05 +/- 0.01 mg/10(6) spermatozoa; P <.001). CONCLUSION: Ribonucleic acid content is significantly altered in abnormal spermatozoa, and this alteration may be the result of some defect in the posttranscriptional pathway.

Humans↗

Comparison of neutral proteinase activities in cock and ram spermatozoa and observations on a proacrosin in cock spermatozoa.

Cock spermatozoa, like trypsin, induced a rapid fall in the viscosity of gelatin solutions but ram spermatozoa and inhibitor-free ram acrosin were ineffective. The gelatin-hydrolysing activity in cock spermatozoa was solubilized at pH 8 in the presence of calcium ions but comparable extracts of ram spermatozoa were inactive. Both extracts showed acrosin activity (assayed with benzoylarginine ethyl ester). The two catalytic activities of cock spermatozoa were each susceptible to the same trypsin inhibitors and during fractionations they were not separable. We deduce that cock acrosin, and probably some other avian acrosins, have the power to degrade dissolved gelatin while ram acrosin does not. The acrosin in cock spermatozoa, unlike that in ram spermatozoa, was inactivated at pH 2-7. Acid extracts of the former contain an inactive precursor of acrosin which undergoes spontaneous re-activation in buffers, pH 8, containing calcium ions. In this respect it resembles the proacrosin of rabbit testis.

Acrosin↗

Intracellular free Ca2+ concentration in fowl spermatozoa and its relationship to motility and respiration in spermatozoa.

The ability of fowl spermatozoa to accumulate and de-esterify the intracellular fluorescent Ca2+ indicator fura-2 was established. The cytosolic Ca2+ concentrations, measured by this technique, did not change after the addition of 1 mmol EGTA l-1. Subsequently, addition of the calcium ionophore A23187 caused a reduction in cytosolic Ca2+ concentrations, presumably by efflux of Ca2+ from the spermatozoa. Intracellular free Ca2+ concentrations were then significantly increased by the addition of 1 mmol CaCl2 l-1. The motility of demembranated spermatozoa gradually decreased after the addition of EGTA alone or EGTA with A23187, but was instantly restored by the addition of CaCl2 in the presence of both EGTA and A23187. Unlike demembranated spermatozoa, intact spermatozoa maintained their motility, even after the addition of EGTA, but their motility was reduced by the addition of A23187 in the presence of EGTA. The addition of A23187 also reduced the rate of oxygen consumption, but not the ATP concentrations in intact spermatozoa. These results demonstrate that the motility and respiration of fowl spermatozoa are strongly influenced by their intracellular Ca2+ concentrations.

Animals↗

Spermatozoa ultrastructure in Sciaenidae and Polynemidae (Teleostei:Perciformes) with some consideration on Percoidei spermatozoa ultrastructure.

Spermatozoa ultrastructure was studied in five marines (Paralonchurus brasiliensis, Larimus breviceps, Cynoscion striatus, Micropogonias furnieri, Menticirrhus americanus, Umbrina coroides, Stellifer rastrifer), and one freshwater (Plagioscion squamosissimus) species of Sciaenidae and one species of Polynemidae (Polydactylus virginicus). The investigation revealed that, in all species, spermatozoa display a round head, a nucleus containing highly condensed, filamentous chromatin clusters, no acrosome, a short midpiece with a short cytoplasmic channel, and a flagellum showing the classic axoneme structure (9+2) and short irregular lateral fins. In Sciaenidae, the spermatozoa are type II, the flagellar axis is parallel to the nucleus, the lateral nuclear fossa is double arched, the centriolar complex is outside the nuclear fossa, the proximal centriole is anterior and perpendicular to the distal centriole, and no more than ten spherical (marine species) or elongate (freshwater species) mitochondria are observed. Polynemidae spermatozoa are of the intermediate type with the flagellar axis eccentric to the hemi-arc-shaped nucleus, and exhibit no nuclear fossa, the centriolar complex close to the upper nuclear end, the proximal centriole lateral and oblique to the distal centriole, and one large ring-shaped mitocondrion. The data available show that no characteristic is exclusively found in the spermatozoa of members of the Sciaenidae family when compared to other Percoidei with type II spermatozoa. However, three characteristics were exclusively found in Polynemidae: (1) the hemi-arched nucleus; the positioning of the centrioles; and (2) the ring-shaped mitocondrion. The interrelationships between Sciaenidae and Polynemidae as well as between these two families and other Percoidei are herein discussed.

Acrosome↗

Lectin histochemistry during in vitro capacitation and acrosome reaction in boar spermatozoa: new lectins for evaluating acrosomal status of boar spermatozoa.

Six peroxidase (HRP)-conjugated lectins have been used to analyze the distribution of carbohydrates in ejaculated boar spermatozoa during in vitro capacitation and acrosome reaction in air-dried preparations. The membranes of boar spermatozoa were positive to WGA and Con-A in the acrosome, middle piece and principal piece. PNA labelled the acrosomal region. DBA, UEA-I and LTA bound weakly or not to the spermatozoa. The lectin labelling pattern did not change during the in vitro capacitation. A diminution in the proportion of spermatozoa with acrosome positive to lectins PNA, WGA and Con-A was observed after coincubation with homologous immature oocytes. A positive correlation existed between the percentages of lectins bound to spermatozoa and the triple stain technique. The results show that peroxidase-conjugated lectins may be useful in determining acrosomal integrity of boar spermatozoa during in vitro capacitation and acrosome reaction.

Acrosome↗

Chromatin packaging and morphology in ejaculated human spermatozoa: evidence of hidden anomalies in normal spermatozoa.

This study aimed to investigate the association between anomalies in sperm chromatin packaging, morphology and fertilization in patients undergoing routine in-vitro fertilization (IVF) or subzonal insemination (SUZI). Sperm chromatin packaging was assessed using chromomycin A3 (CMA3), a fluorochrome specific for guanine-cytosine rich sequences of DNA. One hundred to 150 sperm cells were assessed in 55 patients to compare sperm chromatin packaging and morphology to fertilization after IVF or SUZI. When the morphology and CMA3 fluorescence of individual spermatozoa was assessed, > 75% of the macrocephalic sperm fluoresced in all patients. In contrast, a mean of 37% of the spermatozoa with normal morphology fluoresced in IVF patients compared with 58% of the normal spermatozoa in male factor patients treated by SUZI. SUZI patients displaying a high fluorescence (> 70%) in their spermatozoa also had a significantly lower fertilization rate. Lower packaging quality in morphologically normal spermatozoa may represent a major limiting factor in the fertilizing ability of male factor patients. This study confirms that a high percentage of CMA3 positivity is present in certain forms of male factor infertility and that such a test may be used to distinguish separate populations in morphologically normal spermatozoa.

Chromatin↗

Influence of spermatozoa characteristics on gamete intra-fallopian transfer procedures: analysis of results obtained utilizing normozoospermic, oligoasthenozoospermic and donor spermatozoa.

The objective of this study was to analyze the efficacy of the gamete intra-Fallopian transfer (GIFT) procedure in relation to spermatozoa characteristics. A total of 268 infertile couples enlisted for GIFT were categorized into three groups on the basis of semen characteristics in the husband. These included oligoasthenozoospermic men in 88 retrieval cycles (group 1), normozoospermic men in 116 cycles (group 2) and azoospermic partners who needed donor semen in 86 cycles (group 3). All female patients had ovarian stimulation and laparoscopic GIFT. Pregnancy rates were significantly higher with donor spermatozoa than with oligoasthenozoospermic or normozoospermic spermatozoa, i.e. 51.1% versus 15.9% (P < 0.001), and 32.7% (P < 0.005). Implantation rates were significantly higher with donor spermatozoa than with normo- or oligoasthenozoospermic spermatozoa (P < 0.01). These data suggest that GIFT does not give good results with male factor infertility. Donor cryopreserved semen gives higher pregnancy and implantation rates than normozoospermic semen, and GIFT with donor spermatozoa gives a good chance of pregnancy to couples previously treated with artificial insemination using donor semen.

Female↗

Antibody directed against plasma membrane components of equine spermatozoa inhibits adhesion of spermatozoa to oviduct epithelial cells in vitro.

Before fertilization, equine spermatozoa adhere to oviduct epithelial cells (OEC) of the mare. The biochemical basis for this adhesion has not been determined. Our objective was to produce an antiserum to block this interaction. Ejaculated spermatozoa were subjected to nitrogen cavitation and spermatozoal plasma membranes enriched by sucrose density gradient centrifugation; membrane enrichment was confirmed by comparative alkaline phosphatase analysis, electron microscopy, and one- and two-dimensional PAGE. Periacrosomal plasma membrane was used as an immunogen for the production of an antiserum, which recognized several components of spermatozoal plasma membrane on Western blots. Antigen-binding fragments (Fab) were isolated by papain digestion from a specific antiserum and from nonimmunized rabbit IgG (control). The periacrosomal regions of epididymal and ejaculated spermatozoa were immunolabeled with antiserum Fab but not control Fab. The immunoneutralizing activity of antiserum Fab was tested in fluorescent cell-binding assays by competitive inhibition of the binding of spermatozoa to OEC monolayers or explants. In both assays, binding of spermatozoa to OEC was reduced as the concentration of specific Fab increased. These results suggest that one or more protein or glycoprotein components of the rostral spermatozoal plasma membrane mediate adhesion between spermatozoa and oviduct epithelium in vitro.

Acrosome↗

Relation between number of immobile spermatozoa and pregnancies obtained during a twenty-year follow-up period immobile spermatozoa and fertility.

The clinical fertility of 1077 men examined with semen analysis including detection of number of immobile spermatozoa during the years 1950-52 was studied twenty years later with a questionnaire replied by 785 (72.9%). There was a significant relation (p less than 0.01) between decreasing number of immobile spermatozoa and increasing chance of getting living children, but no relation to abortions and pathological pregnancies. Furthermore, decreasing number of immobile spermatozoa was correlated to shorter time-interval between attempt to impregnate and first pregnancy obtained (p less than 0.01). Mean values for those obtaining living children was 34.7% immobile spermatozoa compared with 38.2% for those not doing so. Over 80% immobile spermatozoa, fertility was considerably reduced, and the borderline between normal and reduced male fertility should therefore be defined to 80% immobile spermatozoa.

Abortion, Spontaneous↗

Reactive oxygen species and human spermatozoa. I. Effects on the motility of intact spermatozoa and on sperm axonemes.

Mammalian spermatozoa are sensitive to oxygen-induced damages mediated by lipid peroxidation of the cell membrane. The aim of this study was to evaluate whether reactive oxygen species (ROS) could also induce axonemal damage. When Percoll-separated spermatozoa were treated with hydrogen peroxide, or the combination xanthine and xanthine oxidase (X + XO), there was a progressive decrease, leading to a complete arrest, in sperm flagellar beat frequency. Once demembranated in a medium containing magnesium adenosine triphosphate (Mg.ATP), ROS-immobilized spermatozoa still reactivated motility; however, the percentage and duration of motility obtained in these tests gradually decreased to zero in the next hour. In 50% of the cases, motility of intact spermatozoa spontaneously reinitiated after 6 to 24 hours of immobilization due to ROS treatment, although with percentages and beat frequencies lower than those of untreated spermatozoa. Studies using ROS scavengers (such as catalase, superoxide dismutase, and dimethylsulfoxide) indicated that hydrogen peroxide was the most toxic of the ROS involved, but that .O2- and .OH probably also played a role in immobilization of spermatozoa by ROS. The data suggest that ROS induce a chain of events leading to sperm immobilization, that axonemes are affected, and that limited endogenous repair mechanisms exist to reverse these damages.

Adult↗

Plasma membrane structure of bat spermatozoa: observations on epididymal and uterine spermatozoa in Myotis lucifugus.

Plasma membrane structure of bat spermatozoa was examined utilizing electron microscopy of thin sections and freeze-fracture replicas. Notable membrane features observed in replicas from cauda epididymal spermatozoa included specialized particle aggregates at the junction between the acrosomal and postacrosomal region of the head (a membrane structure not previously described in mammalian spermatozoa) and another row of rod-like particles just anterior to the posterior ring. Both of these specializations in fractured plasma membranes correspond with regions where the membrane is closely apposed to underlying structures when viewed in thin sections. The postacrosomal sheath appears to be composed of an array of longitudinally oriented filamentous components. Characteristic ordering of intramembranous particles was also noted in replicas from the midpiece region and the annulus. Major changes in plasma membrane structure were not seen in spermatozoa stored in the female reproductive tract; however, the appearance of linear particle aggregations in the principal piece membrane was noted. No evidence was obtained to suggest that an acrosome reaction had occurred in spermatozoa stored in females.

Animals↗

Oxygen metabolism of mammalian spermatozoa. Generation of hydrogen peroxide by rabbit epididymal spermatozoa.

Rabbit spermatozoa from the cauda epididymis produced 0.7-0.8nmol of H(2)O(2)/min per 10(8) cells at cell concentrations below 10(7) cells/ml with linear dependence on cell concentration. Above 2 x 10(7) cells/ml, the rate again became linear with cell concentration but decreased to 0.1-0.2nmol/min per 10(8) cells. Spermatozoa treated with amphotericin B, which makes the plasma membrane highly permeable to low-molecular-weight compounds, showed a similar dependence of H(2)O(2) production rate on cell concentration; below 10(7) cells/ml the rate was 0.3-0.4nmol/min per 10(8) cells; above 2 x 10(7) cells/ml, the rate was 0.1-0.2nmol/min per 10(8) cells. Hypo-osmotically treated rabbit epididymal spermatozoa, a preparation useful for studying mitochondrial function in sperm [Keyhani & Storey (1973) Biochim. Biophys. Acta305, 557-565] produced 0.1-0.2nmol/min per 10(8) cells in the absence of added substrates. The dependence of rate on cell concentration was linear from 10(7) to 2.2 x 10(8) cells/ml. This endogenous rate was unaffected by rotenone, but stimulated 4-fold by antimycin A. Addition of the mitochondrial substrates lactate plus malate increased the rate of H(2)O(2) production to 0.3nmol/min per 10(8) cells. The decreased rate of H(2)O(2) production observed with intact sperm at high cell concentrations is attributed to reaction of H(2)O(2) with the cells, possibly with the plasma membrane, which is lost after hypo-osmotic treatment. Rabbit spermatozoa have glutathione peroxidase and glutathione reductase activities, but these seem to play little role in removal of H(2)O(2) generated. The rate at low cell concentration is taken to be the unperturbed rate. The sources of H(2)O(2) production in rabbit spermatozoa have been tentatively resolved into a low-molecular-weight component, lost after amphotericin treatment, a mitochondrial component and a rotenone-insensitive component that has not been identified.

Amphotericin B↗

Intracytoplasmic injection of human spermatozoa into mouse oocytes: a useful model to investigate the oocyte-activating capacity and the karyotype of human spermatozoa.

When intracytoplasmic sperm injection (ICSI) is performed, it is important to know the capacity of sperm cells to activate the oocytes, although knowledge of their ability to fuse with the oocytes is not vital. Hamster oocytes are not suitable for this purpose because they are easily activated by the injection procedure Itself. We therefore investigated whether mouse oocytes could be used to assess the activation properties of human spermatozoa. Mouse oocytes were randomized for injection with initially motile spermatozoa, medium, heat-treated or salt-extracted spermatozoa, and the survival and activation rates were examined. About half of the mouse oocytes survived the intracytoplasmic injection of a human sperm cell. Unlike hamster oocytes, the rate of activation provoked by the injection procedure itself was acceptably low (20%), resembling in this respect the behaviour of human oocytes. Following the injection of initially motile human spermatozoa, all mouse oocytes were activated. The injection of heat-treated or salt-extracted human spermatozoa resulted in activation rates of 14 and 15% respectively, comparable with the results following sham ICSI. These data support the hypothesis of a sperm-associated oocyte activation factor. In most activated oocytes, the human sperm nucleus decondensed to form a male pronucleus. Cytogenetic analysis at the first metaphase revealed that human sperm chromosomes were able to undergo replication in a heterologous environment.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Vitality and morphology of human spermatozoa. Studies on the resistance to storage and centrifugation and on the removal of dead spermatozoa.

The effect of storage of human spermatozoa at room temperature and in the refrigerator was studied. Loss of vitality was found to be linear and the same within the temperature range studied. Vitality was reduced by 0,9% per hour on average. The rate of this loss did not show much variation. The morphology of both all spermatozoa and the living sperm population studied separately was only slightly impaired by storage. The effect of centrifugation and resuspension of spermatozoa was studied separately. Vitality was found to be reduced by gravitation forces of 800 g for 20 minutes whereas no effect on morphology was noted by this treatment. Gravitation forces of 600 g and below did not significantly affect the spermatozoa. Two methods of separation of spermatozoa with better motility and morphology from the rest of the semen sample were studied, (1) filtration through a layer of glass beads, (2) "sperm rise" after centrifugation at low gravitation force. The clinical value of these procedures is probably limited to selected cases.

Cell Separation↗

Type I and II cAMP-dependent ecto-protein kinases in goat epididymal spermatozoa and their enriched activities in forward-motile spermatozoa.

Several lines of evidence have demonstrated conclusively the presence of cAMP-dependent protein kinase (ecto-RC) activity on the external surface of goat cauda-epididymal intact spermatozoa. The intact-cell ecto-kinase that caused transfer of the terminal phosphate of exogenous ATP to the serine and threonine residues of exogenous histone was specifically activated by cAMP. As well, the ecto-kinase caused phosphorylation of the synthetic peptide Kemptide. The isolated spermatozoa, before or after incubation with reaction mixture for ecto-kinase assays, were approximately 99.5% viable, as shown by the analyses of ethidium bromide fluorescence and the cytosolic marker enzymes lactic dehydrogenase and 3-phosphoglycerate kinase. The ecto-kinase activity was not due to contamination of epididymal plasma and damaged cells or to protein kinase that may have leaked from the cells. There was little uptake of ATP and histone by the cells. The intact-cell kinase activity was strongly (80-90%) inhibited by treatment with membrane nonpenetrating surface probes: p-chloromercuriphenylsulfonic acid (2 microM), diazonium salt of sulfanilic acid (DSS, 0.5 mM), and proteases such as trypsin, chymotrypsin, and pronase (each 125 micrograms/mL). Disruption of sperm plasma membrane by sonication or Triton X-100 (0.2%) caused about a fivefold increase of the intact sperm kinase activity. Highly purified sperm plasma membrane (PM) possessed ecto-kinase activity that was resolved into type I and II kinases by DEAE-cellulose chromatography, the type I isoenzyme being the major (approximately 70%) enzymic species. Treatment of the intact spermatozoa with DSS prior to isolation of PM caused a marked loss of the activities of both the isoenzymes, indicating thereby the "ecto" nature of the PM-bound type I and II kinases. Preparations of vigorously forward-motile spermatozoa with 100% intactness had approximately fourfold higher specific activity of the ecto-kinase than the "composite" cells from which the former cells were isolated. However, the profiles of the type I and II ecto-kinases of the composite, as well as forward-motile spermatozoa, were nearly identical. The data are consistent with the view that ecto-kinases may have role in the regulation of flagellar motility.

Animals↗

Analysis of surface proteins of rat spermatozoa during epididymal transit and identification of antigens common to spermatozoa, rete testis fluid and cauda epididymal plasma.

Spermatozoa from the testis and cauda epididymidis of the rat were surface labelled with radioactive iodide, extracted with detergent, and the radioactive proteins separated by two-dimensional polyacrylamide gel electrophoresis. In some instances spermatozoa were also surface labelled with tritiated borohydride in the presence of galactose oxidase. Soluble proteins in blood serum, rete testis fluid and cauda epididymal plasma were also iodinated and separated by gel electrophoresis. In addition, aliquants of the radioactive sperm extracts, blood serum and reproductive tract fluids were each immunoprecipitated with polyspecific antisera directed against either testicular sperm membranes, caudal sperm membranes, blood serum, rete testis fluid or cauda epididymal plasma before gel electrophoresis. From the patterns of radioactive proteins detected on the resultant gels, a two-dimensional map was created for each of the sperm extracts and for the various fluids. Proteins which were nonhomologous between testicular and caudal spermatozoa were identified, as well as proteins which were common to spermatozoa and reproductive tract fluids. Epididymal transit was characterized by the loss of certain proteins from the sperm surface, including three borohydride-labelled proteins of Mr 130 000, and by the addition of others, most notably a highly abundant protein of Mr 42 000. Several of the proteins lost from spermatozoa accumulated in the epididymal plasma whilst some of those added to the sperm surface could be identified as direct secretory products of the epididymis. Rete testis fluid contained blood proteins in addition to others presumed to be testis-specific, whilst the composition of cauda epididymal plasma was markedly different from blood serum or rete testis fluid.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[The effect on penetration rate of human spermatozoa into the zona pellucida free hamster oocyte system of monoclonal antibodies against human spermatozoa].

The penetration rate of human spermatozoa in zona pellucida-free hamster oocytes was reduced by 4 monoclonal anti-sperm-antibodies (A-24, B-20, III-3, and VII-5) out of 6 tested. The other 2 (VI-1 and VI-16) left the penetration rates virtually unchanged. The extent of penetration rate reduction depended on the concentrations of antibodies A-24, B-20, III-3, and VII-5; if undiluted, they produced a significant reduction of penetration rates, the largest average reduction being almost 50% with undiluted antibody A-24. Decreasing concentrations of the monoclonal anti-sperm-antibodies resulted in significantly smaller reductions of sperm penetration rates. The reason for the reduced penetration rates observed may be a blockage of receptors on the sperm surface by the named monoclonal anti-sperm-antibodies. This can inhibit enzyme reactions of the spermatozoa, or interfere with the interaction between oocyte and spermatozoa membranes. It is noted that only the antibody III-3 caused agglutination of human spermatozoa in the micro-sperm-agglutination and immobilization tests. Therefore, the agglutination or immobilization of spermatozoa may not be held responsible for the reduced penetration rates after addition of monoclonar antibodies, as opposed to the findings with polyclonal antibodies (Steinberg - 1985&).

Animals↗

Heavy metals and human spermatozoa: II. The effect of seminal plasma on the toxicity of copper metal for spermatozoa.

The ability of copper metal to immobilize human spermatozoa was assessed in vitro. Copper (200 mm2) significantly decreased the percentage of progressively motile spermatozoa over a 3-hour incubation at 37 degrees C. The toxicity of the copper was potentiated by washing the spermatozoa free of seminal plasma. Once they had been immobilized, spermatozoa did not regain motility even after extensive washing, prolonged dialysis, or treatment with copper-specific chelating agents. Apparently copper induces a change in the properties of the spermatozoa which results in irreversible immobilization. The relevance of these observations to the action of intrauterine devices (IUD) bearing copper is discussed.

Copper↗