نتایج جستجو برای: coated spermatozoa

تعداد نتایج: 61749  

2016
Malgorzata Kotwicka Izabela Skibinska Magdalena Jendraszak Piotr Jedrzejczak

BACKGROUND It is assumed that spermatozoa are target cells for estrogens however, the mechanism of their action is not fully understood. The aim of this study was to investigate the influence of 17β-estradiol (E2) on the human spermatozoa mitochondrial function. METHODS The effects on spermatozoa of E2 at final concentrations of 10(-10), 10(-8) and 10(-6) M were studied regarding the followin...

Journal: :Folia biologica 2012
Stanisław Kondracki Dorota Banaszewska Anna Wysokńjska Maria Iwanina

Experiments were performed on 75 ejaculates obtained from 19 bulls representing different cattle breeds used at the Masovian Centre for Animal Breeding and Reproduction in Łowicz. Fresh ejaculates were measured in respect to their volume and sperm count in the ejaculates was determined. The ejaculates were classified based on the criterion of sperm concentration and divided into five groups. Sp...

Journal: :Human reproduction 2007
Rony Oren-Benaroya Jonathan Kipnis Michael Eisenbach

BACKGROUND Earlier studies demonstrated that macrophages phagocytize spermatozoa in the female genital tract of mammals. In spite of this phagocytosis, fecundity is not affected, raising questions of how the resulting decrease in the number of spermatozoa does not reduce the fertilization rate and of the role of this phagocytosis. We hypothesized that its role is to rid the female genital tract...

Journal: :Human reproduction 1996
G D Palermo P N Schlegel L T Colombero N Zaninovic F Moy Z Rosenwaks

This study was conducted to determine whether the mode of sperm immobilization prior to intracytoplasmic sperm injection (ICSI) influences fertilization by immature spermatozoa. Of the 837 ICSI cycles evaluated, 81 were performed with epididymal or testicular spermatozoa; 35 cycles with epididymal spermatozoa immobilized in the standard fashion resulted in fertilization and pregnancy rates of 4...

Journal: :Human reproduction 1997
M Vandervorst H Tournaye M Camus Z P Nagy A Van Steirteghem P Devroey

The microinjection of completely immotile spermatozoa may impair the outcome of intracytoplasmic sperm injection (ICSI). Eleven couples underwent an initial ICSI cycle with 100% immotile freshly ejaculated spermatozoa. Two-pronuclear fertilization ensued in 18 of 145 (12.4%) successfully injected oocytes. None of these cycles resulted in a pregnancy. Nine couples underwent ICSI in subsequent cy...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2006
Montserrat Gomendio Juan Martin-Coello Cristina Crespo Concepción Magaña Eduardo R S Roldan

When females mate promiscuously, sperm from rival males compete within the female reproductive tract to fertilize ova. Sperm competition is a powerful selective force that has shaped sexual behavior, sperm production, and sperm morphology. However, nothing is known about the influence of sperm competition on fertilization-related processes, because it has been assumed that sperm competition onl...

2015
Caroline Flegel Felix Vogel Adrian Hofreuter Benjamin S. P. Schreiner Sandra Osthold Sophie Veitinger Christian Becker Norbert H. Brockmeyer Michael Muschol Gunther Wennemuth Janine Altmüller Hanns Hatt Günter Gisselmann

The detection of external cues is fundamental for human spermatozoa to locate the oocyte in the female reproductive tract. This task requires a specific chemoreceptor repertoire that is expressed on the surface of human spermatozoa, which is not fully identified to date. Olfactory receptors (ORs) are candidate molecules and have been attributed to be involved in sperm chemotaxis and chemokinesi...

Journal: :Molecular endocrinology 2005
G Livera F Xie M A Garcia B Jaiswal J Chen E Law D R Storm M Conti

Mammalian spermatids and spermatozoa express functional G protein-coupled receptors. However, bicarbonate-regulated soluble adenylyl cyclase (AC), the major AC present in these cells, is not directly coupled to G proteins. To understand how G protein-coupled receptors signal in spermatozoa, we investigated whether a conventional transmembrane cyclase is present and biologically active in these ...

Journal: :Reproduction, nutrition, developpement 1988
C Radigue J C Soufir M L Couvillers M C Dantec R Folliot

In a previous study we showed that the administration of gossypol to rats for 34 days caused 2 types of modification of the epididymis: (1) the secretion of carnitine and inositol were reduced in the fluid, (2) the spermatozoa lost their motility and showed major morphological changes (head-flagella dissociation). We wished to clarify the early effects of gossypol on the epididymis. Sprague Daw...

Journal: :Indonesian Journal of Health Science 2022

In Vitro Fertilization (IVF) is the penetration of ovum cells by spermatozoa in a culture system and reproductive technique that useful for increasing efficiency sperm utilization. vitro fertilization applied to overcome problem infertility prevent birth defects. The success IVF influenced quality spermatozoa. order fulfill this, it necessary select spermatozoa, which separate good from total p...

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