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  • 1
    Electronic Resource
    Electronic Resource
    Maturation of hamster epididymal sperm motility and influence of the thiol status of hamster and rat spermatozoa on their motility patterns (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 38 (1994), S. 347-355 
    Details
    ISSN: 1040-452X
    Keywords: Diamide ; dithiothreitol ; CASA ; Sperm kinematics ; Motility maintenance ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: A method for objective quantification of hamster sperm movement parameters as an indicator of maturation along the epididymis was established using a computerised system. Analysis of spermatozoa released into medium from five epididymal regions showed that the most drastic increases in percentage motility and curvilinear velocity (VCL) occurred from the distal corpus to the beginning of the proximal cauda and in straight-line velocity (VSL) from the beginning to a more distal site within the proximal cauda region. Both high osmolarity (400 mOsm/kg) and the thiol-oxidising agent diamide (10 μM) increased flagellar straightness of distal corpus spermatozoa, but VSL was increased only with the latter. The thiol-reducing agent dithiothreitol (DTT, 1mM) stimulated and maintained percentage motility and velocities of spermatozoa from the caput, stimulated only percentage motility of distal corpus sperm, but decreased velocities of those from the proximal cauda in prolonged incubation. In rats, diamide increased path straightness but not velocities of caput spermatozoa and yet caused immotility within 15 min, whereas DTT prolonged the maintenance of in vitro motility. The slight increases in kinematic parameters in the presence of DTT were enhanced by a 2-min preincubation with diamide. The finding that the effects of DTT and diamide were not compensatory suggests that the influence of the SH/S-S status on sperm movement is multifaceted, with decreasing sensitivity to stimulation upon sperm maturation. © 1994 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080380317
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  • 2
    Electronic Resource
    Electronic Resource
    Osmotic swelling of maturing rat spermatozoa and Lysis of caput spermatozoa by acylcarnitines and acylcholines (1986)
    New York, NY : Wiley-Blackwell
    Gamete Research 14 (1986), S. 47-56 
    Details
    ISSN: 0148-7280
    Keywords: rat sperm ; osmotic swelling ; sperm maturation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The form that rat spermatozoa assume when swelling in hyposmotic media depends on the position of the cytoplasmic droplet, previous exposure to hypertonic media, and the stiffness of the flagellum. Bending at the end of the midpiece occurs when the swelling droplet is situated at this site; this occurs in midcaput cells, but sperm from more proximal sites do not bend in this fashion. Stiffening of caput sperm stored in vitro reduces the incidence of such midpiece bending but looping at the tip of the tail still occurs, and previous exposure of caput spermatozoa to hypertonic media also prevents hairpin bend formation. Mature sperm from the cauda are too stiff to form hairpin loops when placed in hypotonic media unless first treated with a penetrating disulphydryl-reducing agent, after which swollen spherical vesicles can result from very flexible flagella confined within an intact membrane. Long-chain acylcarnitines are more potent lytic agents than acylcholines, but, for both, chain lengths of 16 carbon atoms is optimal for preventing the swelling of rat caput sperm.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120140106
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  • 3
    Electronic Resource
    Electronic Resource
    The onset and maintenance of hyperactivated motility of spermatozoa from the mouse (1984)
    New York, NY : Wiley-Blackwell
    Gamete Research 9 (1984), S. 55-74 
    Details
    ISSN: 0148-7280
    Keywords: mouse ; sperm motility ; capacitation ; hyperactivation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Estimates were made of the proportion of freely motile mouse spermatozoa displaying hyperactivated motility by an objective photographic method employing stroboscopic illumination under dark-field conditions and examining displacements of the sperm head and bend angles of the sperm tail. In media known to support in vitro fertilisation hyperactivation gradually appeared reaching about 40% by 6 hr incubation, and it was not promoted by 2 mM caffeine or 0.1 mM Bt2 cAMP or washing the cells free of epididymal fluid. Raising the osmolarity of the medium to 400 mOSM with electrolytes, but not nonelectrolytes, did promote hyperactivation (60% by 2 hr) suggesting that the ionic strength of the medium was important. Hyperactivation in high ionic strength media could be prevented by removing or chelating Ca2+, or replacing Ca2+ with Ba2+ or Mg2+, when nonhyperactivated motility was maintained, but Sr2+, like Ca2+, permitted hyperactivated motility. Hyperactivation in low ionic strength medium could be promoted by the ionophore A23187, suggesting that Ca2+ movement into the cells is important. Of a range of glycolytic substrates tested supporting nonhyperactivated motility in the presence of lactate, only glucose supported hyperactivation. Addition to glucose -  or Ca2+  -  free, high ionic strength media after 2 hr increased hyperactivation immediately (glucose) or after a lag of 2 hr (Ca2+) suggesting that glucose acts on a Ca2+  -  primed system. Removal from high ionic strength medium, chelation of Ca2+ or inhibition of glucose metabolism did not prevent hyperactivation continuing once it had been initiated, indicating different requirements for initiation and maintenance of this form of motility.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120090106
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  • 4
    Electronic Resource
    Electronic Resource
    Effects of bovine mammary alpha-lactalbumin on hyperactivation and sperm-zona pellucida binding of mouse spermatozoa (1989)
    New York, NY : Wiley-Blackwell
    Gamete Research 24 (1989), S. 415-426 
    Details
    ISSN: 0148-7280
    Keywords: galactosyltransferase ; capacitation ; epididymis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The effects of bovine mammary alpha-lactalbumin on the motility and zona-binding characteristics of mouse sperm were investigated. Two properties of sperm associated with capacitation, hyperactivated motility, and the ability of sperm to bind to the zona pellucida of oocytes were shown to be suppressed by alpha-lactalbumin. These inhibitory effects were not accompanied by changes in the percentage of motile cells or by differences in the velocity parameters of the hyperactivated and non-hyperactivated spermatozoa. Bovine serum albumin prevented and reversed the alpha-lactalbumin-induced suppression of hyperactivation. Sperm-zona pellucida binding was partially restored by lowering the alpha-lactalbumin concentration in the medium in which sperm were allowed to bind to the zona pellucida. The results suggest that mouse sperm are decapacitated by bovine mammary alpha-lactalbumin. The counteracting effect of bovine serum albumin to the suppressive action of alpha-lactalbumin on the flagellum suggests the involvement of a mechanism different from the action of alpha-lactalbumin on the sperm head inhibiting binding to the zona pellucida.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120240408
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