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  • 1
    Electronic Resource
    Electronic Resource
    Regulation of calcium distribution in bovine sperm cells: Cytochemical evidence for motility control mechanisms (1982)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 2 (1982), S. 225-242 
    Details
    ISSN: 0886-1544
    Keywords: spermatozoa ; calcium ion transport ; motility regulation ; cholinergic agonists ; ouabain ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Behavioral responses of mature spermatozoa treated with neurotropic factors suggest that calcium entry and intracellular transport may be regulated by a cholinergic mediated program. To test the validity of this proposed mechanism, the effect of several agents on Ca distribution in the sperm cell was examined cytochemically.Sites of Ca accumulation were visualized in thin sections of bull spermatozoa by the application of a modification of Gomori's histochemical procedure for phosphatases. Intact bull sperm cells incubated at room temperature in a buffered balanced salt solution containing 5 mM/liter of CaCl2 showed small, randomly scattered deposits of the reaction product. Similarly treated sperm cells, plasmolyzed in hypoosmotic KCl, revealed a greatly increased amount of deposit associated with the cell membranes (mitochondrial surfaces and plasmalemma), the axonemal complex components, and satellite fibers adjacent to the outer dense fibers. Preincubation of intact cells in nicotine or eserine considerably enhanced the entry of calcium into the cell and its association with the membranes and other intracellular organelles. Decamethonium, an irreversible depolarizer and blocker of cholinergic receptors, interfered with the uptake and intracellular distribution of the calcium. Ouabain, the digitalis glycoside that decreases progressive motility of bull sperm and inhibits Na-, K-ATPase, appears to block Ca efflux, causing an intense accumulation of electron-opaque particles in the plasma membrane while smaller numbers of particles are distributed sparsely throughout the cell interior.The cytochemical results showing enhanced calcium entry in the presence of cholinergic agents, depressed intracellular calcium in cells treated with cholinergic receptor blocker, and intense accumulation of calcium within the cell membrane in the presence of ouabain are consistent with spermatozoan behavioral responses to these agents. These observations support the concept that neurotropic factors may be involved in regulating transmembrane and intracellular transport of ions in control of sperm cell function.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970020304
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  • 2
    Electronic Resource
    Electronic Resource
    Cationic probes: Specificity of distribution of metal-binding sites in bovine sperm (1986)
    New York, NY : Wiley-Blackwell
    Gamete Research 13 (1986), S. 339-351 
    Details
    ISSN: 0148-7280
    Keywords: calcium ; ligands ; metal-binding sites ; sperm ; flagella ; dynein ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Salts of transition elements that alter the rate of sperm cell movement act at or near calcium-binding sites. After living bull sperm cells had been preincubated in VO43-, Ni2+, Zn2+, Mn2+, and also La3+, they were then fixed. Crisply defined organelles and the absence of particulate deposits in the morphological controls contrasted sharply with the treated specimens; the latter contained regions of increased electron density, the nature and distribution of which depended on the test substance, reflecting the differential affinities of the specific ions. La3+ formed fine dense areas, mainly at the exocytic surface of the plasma membrane. VO43- marks the cell surface but also left particulate densities within the cell. Ni2+ caused a nearly uniformly dense deposit at the surface and on the satellite fibers and axonemal microtubules. Zn2+ formed less uniform but coarser deposits, while in Mn2+ the distribution was similar to that in Zn2+ but much denser in the axonemal matrix and on the satellite fibers. Verapamil restricted the size and number of the opacities, while procaine permitted a similar distribution of slightly larger size reaction product. The differences in size and distribution of the enhanced densities were consistent and replicable for the individual assay substances. Vanadate, which specifically inhibits Na, K-ATPase, bound to ouabain-sensitive enzyme loci, however, completely disrupting the axonemal complex. This suggests that an important role of dynein in flagellar motion may relate to intracellular transport of Ca2+.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120130408
    Library Location Call Number Volume/Issue/Year Availability
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    Paper (German National Licenses)
    Fulltext
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