Results 191 to 200 of about 5,280,557 (249)
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The ionophore‐induced acrosome reaction differs structurally from the spontaneous acrosome reaction
Journal of Experimental Zoology, 1992AbstractThe ultrastructure of the spontaneous acrosome reaction in ram spermatozoa has been compared with that induced by the ionophore, A23187. The spontaneous event was dependent on incubation for 4 h, on the temperature, and on dilution. Apart from the more rapid occurrence of the ionophore‐induced event, the mean diameter and distribution of ...
P F, Watson, J M, Plummer, P S, Jones
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The acrosome reaction in boar spermatozoa*
Human Reproduction, 1988In order to gain more insight into the molecular alterations of the acrosome, boar spermatozoa were incubated in a calcium-containing medium in the presence of the ionophore A23187. The time-course of the acrosome reaction was assessed by phase-contrast microscopy.
E, Töpfer-Petersen +2 more
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Absence of Acrosome Reaction in Polyzoospermia*
Andrologia, 2009Using the recently described triple-stain technique the time course of the acrosome reaction in a group of patients with polyzoospermia was evaluated and was compared to that of a group of normozoospermic men and a group of men with proven fertility. Polyzoospermia (greater than 250 Mill. spermatozoa/ml) has been repeatedly associated with subfertility.
E, Töpfer-Petersen +3 more
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Induced acrosome reactions as fertility predictor
Journal of Assisted Reproduction and Genetics, 1994This study was conducted to determine the fertility predictive value of acrosome reaction rates and indices (induced minus control) of human spermatozoa. By comparison these outcomes with in vitro fertilization success. The effect of oocyte-cumulus complex exposure on the induction of the acrosome reaction was also analyzed.
K, Coetzee, J, Olmedo, C J, Lombard
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Fertility and Sterility, 1993
To test a new method for evaluation of stimulus-induced acrosome reaction (AR). To determine whether this method, based on the definition of a specific staining pattern of recently reacted spermatozoa, brings an advantage of increased sensitivity as compared with a standard procedure.The hypothesis that a specific staining pattern with fluorescein ...
J, Tesarik, C, Mendoza, A, Carreras
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To test a new method for evaluation of stimulus-induced acrosome reaction (AR). To determine whether this method, based on the definition of a specific staining pattern of recently reacted spermatozoa, brings an advantage of increased sensitivity as compared with a standard procedure.The hypothesis that a specific staining pattern with fluorescein ...
J, Tesarik, C, Mendoza, A, Carreras
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The acrosome reaction in human spermatozoa
Biology of the Cell, 2000During gamete interaction, sperm acrosome reaction (AR) induced by oocyte investment is a prerequisite event for the spermatozoa to pass through the zona pellucida (ZP), fuse with and penetrate the oocyte. Progesterone (P4), secreted by cumulus cells, is an important cofactor for the occurrence of this exocytosis event.
C, Patrat, C, Serres, P, Jouannet
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Physiological inducers of the acrosome reaction
Cell Differentiation and Development, 1988This article reviews recent studies on physiological inducers of the acrosome reaction in starfish. Upon encountering the jelly coat of eggs, starfish sperm undergo the acrosome reaction in response to a cooperation of three jelly components: a sulfated glycoprotein named acrosome reaction-inducing substance (ARIS), a group of steroidal saponins named ...
M, Hoshi +4 more
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Mammalian Sperm Acrosomal Enzymes and the Acrosome Reaction
1991The sperm acrosome is an intracellular membrane-limited organelle that surrounds the anterior portion of the nucleus. It consists of an inner acrosomal membrane that is closely associated with the nucleus and is continuous with the outer acrosomal membrane. The acrosomal matrix proper is located between the two membranes.
L. J. D. Zaneveld, C. J. De Jonge
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1956
Publisher Summary The reaction of the acrosome holds a general significance in connection with the fertilization process. This chapter discusses the structural aspects of the acrosome reaction including groups of Echinoidea, Asteroidea, Holothuroidea, Ophiuroidea, and Mollusca—Pelecypoda, Gastropoda, and Annelida.
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Publisher Summary The reaction of the acrosome holds a general significance in connection with the fertilization process. This chapter discusses the structural aspects of the acrosome reaction including groups of Echinoidea, Asteroidea, Holothuroidea, Ophiuroidea, and Mollusca—Pelecypoda, Gastropoda, and Annelida.
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1977
No morphological change has been observed in mouse (Bryan, 1974) or rabbit (Bedford, 1969) spermatozoa lying free in the ampulla of the oviduct. However, as the spermatozoa pass through the cumulus oophorus the outer acrosomal membrane may invaginate to form membrane-bound vesicles within the acrosome followed by loss of the plasma membrane (Jones ...
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No morphological change has been observed in mouse (Bryan, 1974) or rabbit (Bedford, 1969) spermatozoa lying free in the ampulla of the oviduct. However, as the spermatozoa pass through the cumulus oophorus the outer acrosomal membrane may invaginate to form membrane-bound vesicles within the acrosome followed by loss of the plasma membrane (Jones ...
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