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  • 1
    Electronic Resource
    Electronic Resource
    Reaction of sperm with egg-derived hydrogen peroxide helps prevent polyspermy during fertilization in the sea urchin (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 365-377 
    Details
    ISSN: 0148-7280
    Keywords: block to polyspermy ; hydrogen peroxide ; sperm peroxidase ; sperm catalase ; cortical reaction ; fertilization ; phenylhydrazine ; 3-amino-1,2,4-triazole ; ovoperoxidase ; sea urchin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Recent evidence suggests roles for egg derived hydrogen peroxide (H2O2) and ovoperoxidase (secreted by cortical granules) in both fertilization envelope hardening and the block to polyspermy in sea urchins. Strongylocentrotus purpuratus eggs were found to release H2O2 during the cortical reaction at fertilization. Treatment of sperm with equivalent concentrations of H2O2 resulted in a rapid loss of sperm fertilizing ability. Attempts were made to induce polyspermy by utilizing ovoperoxidase inhibitors at concentrations known to inhibit fertilization envelope hardening. Eggs fertilized in phenylhydrazine became polyspermic, while 3-amino-1,2,4-triazole-treated eggs did not. These data suggested that a sperm peroxidase might be involved in preventing polyspermy. This hypothesis was tested by the addition of phenylhydrazine or 3-amino-1,2,4-trizaole to H2O2-treated sperm. Phenylhydrazine acted to protect sperm fertility from H2O2, while 3-amino-1,2,4-triazole increased the adverse effect of H2O2. Simultaneous addition of both inhibitors to sperm incubated in H2O2 gave an intermediate value of sperm fertility. These data indicate that (1) H2O2 generated by sea urchin eggs during the cortical reaction at fertilization is used for two separate processes, fertilization envelope hardening and the prevention of polyspermy; (2) ovoperoxidase is probably not involved in preventing polyspermy; and (3) egg-derived H2O2 reacts directly with sperm enzymes to prevent polyspermy. The phenylhydrazine-sensitive enzyme in the sperm is probably a peroxidase that acts to inactivate sperm, while the 3-amino-1,2,4-triazolesensitive enzyme is probably a catalase which protects sperm from H2O2. This hypothesis is consistent with model experiments on horseradish peroxidase and bovine liver catalase.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040502
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  • 2
    Electronic Resource
    Electronic Resource
    A separate catalase and peroxidase in sea urchin sperm (1984)
    New York, NY : Wiley-Blackwell
    Gamete Research 10 (1984), S. 267-281 
    Details
    ISSN: 0148-7280
    Keywords: sea urchin sperm ; catalase ; peroxidase ; phenylhydrazine ; 3-amino-1,2,4-triazole ; azide ; fertilization ; polyspermy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The release of hydrogen peroxide (H2O2) by the fertilized sea urchin egg has been shown to assist in the prevention of polyspermy [Coburn et al, 1981; Boldt et al, 1981]. Physiological data suggested that egg-derived H2O2 reacts with a phenylhydrazine-sensitive sperm peroxidase to inactivate sperm, while a 3-amino-1,2,4-triazole-sensitive catalase acts to protect sperm from H2O2 [Boldt et al, 1981]. Strongylocentrotus purpuratus sperm contain heat and pronase labile catalase and peroxidase activities. Differential extraction of sperm (hypotonic phosphate buffer for catalase and Triton X-100 at high ionic strength for peroxidase) results in complete separation of these enzyme activities. The catalase is highly sensitive to inhibition by azide and 3-amino-1,2,4-triazole, and less sensitive to inhibition by phenylhydrazine. The peroxidase is highly sensitive to inhibition by phenylhydrazine and relatively insensitive to 3-amino-1,2,4-triazole and azide. These results show that two distinct H2O2 reactive enzymes, catalase and peroxidase, are present in sea urchin sperm, and are consistent with our hypothesis concerning the biological functions of these enzymes in fertilization.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120100306
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  • 3
    Electronic Resource
    Electronic Resource
    Anti-inflammatory drugs promote polyspermic fertilization in sea urchins (1984)
    New York, NY : Wiley-Blackwell
    Gamete Research 10 (1984), S. 9-19 
    Details
    ISSN: 0148-7280
    Keywords: fertilization ; polyspermy ; sea urchin eggs ; sperm peroxidase ; anti-inflammatory drugs ; cyclooxygenase ; prostaglandins ; arachidonic acid cascade ; indomethacin ; flufenamic acid ; meclofenamate ; aspirin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Sea urchin eggs are known to release H2O2 during the cortical reaction at fertilization to help prevent polyspermy by inactivating excess sperm in the vicinity. This process resembles the peroxidatic killing of bacteria by phagocytic leukocytes during inflammation. Associated with these reactions in leukocytes, arachidonic acid is released from phospholipids and can be oxidized via the cyclooxygenase pathway to produce prostaglandins. Nonsteroidal anti-inflammatory drugs (NSAID) that are cyclooxygenase inhibitors in somatic cells were used to determine whether Arbacia punctulata and Strongylocentrotus purpuratus eggs use these processes to help prevent polyspermy. The potent cyclooxygenase inhibitor indomethacin causes a dose (10-100 μM) and sperm density dependent induction of polyspermy if added before the egg completes the cortical reaction. It does not retard elevation of the fertilization envelope and does not promote polyspermy by protecting sperm from peroxidatic inactivation by egg-derived H2O2. Other potent cyclooxygenase inhibitors, flufenamate and meclofenamate, also induce polyspermy at 10-60 μM. Aspirin, a weak cyclooxygenase inhibitor in somatic cells, does not cause polyspermy at 5 mM. These findings provide evidence that prostaglandins or other cyclooxygenase-derived metabolites may help assure monospermic fertilization in sea urchins.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120100103
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    Paper (German National Licenses)
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