نتایج جستجو برای: stability of sperm membrane
تعداد نتایج: 21215794 فیلتر نتایج به سال:
The sperm cell has a characteristic polarized morphology and its surface is also highly differentiated into different membrane domains. Junctional protein ring structures seal the surface of the mid-piece from the head and the tail respectively and probably prevent random diffusion of membrane molecules over the protein rings. Despite the absence of such lateral diffusion-preventing structures,...
The early events of fertilization that precede and cause activation of an egg have not been fully elucidated. The earliest electrophysiological change in the sea urchin egg is a sperm-evoked increase of the egg's membrane conductance. The resulting depolarization facilitates entry of the fertilizing sperm and precludes the entry of supernumerary sperm. The sequence of the increase in the egg's ...
Sperm-egg plasma membrane fusion is preceded by sperm adhesion to the egg plasma membrane. Cell-cell adhesion frequently involves multiple adhesion molecules on the adhering cells. One sperm surface protein with a role in sperm-egg plasma membrane adhesion is fertilin, a transmembrane heterodimer (alpha and beta subunits). Fertilin alpha and beta are the first identified members of a new family...
background: nitric oxide (no) is synthesized from l-arginine by a family of enzymes known as nitric oxide synthases. low concentrations of no is essential in biology and physiology of spermatozoa, but high amounts of no is toxic and has negative effects on sperm functions. moreover, sperm membrane contains high concentrations of polyunsaturated fatty acids that are highly susceptible to oxidati...
this study was carried out to investigate effects of copper sulphate (cuso4) additive to semen extenders on sperm parameters: progressive motility, viability, membrane integrity and dna damage, after semen dilution and cryopreservation. semen samples of 5 buffalo bulls of 3-5 years old were collected at 5 different occasions during the autumn 2011. a total number of 25 samples were used in each...
Background and Objectives: Reactive oxygen species (ROS) are essential for sperm physiological functions including capacitation, acrosome reaction, fertilization, and etc. Sperm cell in comparison with other cells is highly prone to oxidative attack due to high level of membrane unsaturated fatty acids and low volume of cytoplasmic space. Therefore, the aim of this review article was to underst...
this study was carried out to evaluate the changes in some important cell parameters under water limitation in sorghum genotypes. a factorial experiment was conducted based on randomized completely design in greenhouse, in university of mohaghegh ardabili in 2014. treatments were water stress at levels of 85, 65, 45 and 25 percent field capacity in and three genotypes of forage sorghum (kfs2, k...
the aim of the present study was to evaluate the antioxidant effects of aqueous fruit extract of ziziphusjujuba on ethanol-induced oxidative stress and to examine its protective effects on sperm motility and plasma membrane integrity of male wistar rats. adult male rats (n = 28) were divided into four equal groups: the first group served as untreated controls, the second group of rats was given...
heteropoly acids (hpa) and their salts have advantages as catalysts which make them both economically and environmentally attractive, strong br?nsted acidity, exhibiting fast reversible multi-electron redox transformations under rather mild conditions, very high solubility in polar solvents, fairly high thermal stability in the solid states, and efficient oxidizing ability, so that they are imp...
abstract ion selective electrodes (ises) are electrochemical sensors that respond selectivity to the activity of ionic species. an ion-selective electrode is an electrochemical device that uses a thin selective membrane or film as the recognition element, and is an electrochemical half-cell equivalent to other half-cells of the zeroth (inert metal in a redox electrolyte). in common methods o...
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