نتایج جستجو برای: sperm concentrations
تعداد نتایج: 341865 فیلتر نتایج به سال:
The objectives of this study were to determine whether (i) the presence and concentration of ovarian fluid (OF) affects sperm performance traits, and (ii) variation in sperm performance traits is due to male identity, female identity, and/or male×female interactions in lake trout, Salvelinus namaycush. Spermatozoa from four males were activated in river water and OF from four females at two con...
The sea urchin sperm fertilization bioassay is an approved U.S. Environmental Protection Agency (U.S. EPA) biomonitoring tool for regulatory and compliance purposes. The method adapted for the Hawaiian species Tripneustes gratilla recommends a sperm-to-egg ratio of 2,500. Using a fixed ratio for all tests does not sufficiently account for seasonal and individual variabilities of this organism. ...
PROBLEM The boar, as human, sequentially ejaculates sperm-rich and sperm-poor fractions. Seminal plasma (SP) spermadhesins (PSP-I/PSP-II) induce a primary endometrial inflammatory response in female sows, similar to that elicited by semen deposition in other species, including human. However, the SP is also known to mitigate such response, making it transient to allow for embryo entry to a clea...
background: nitric oxide (no) that plays important role in all sexual activities of animals is made from the amino acid l-arginine by the enzymatic action of no synthase (nos). no makes a band with sulfur-iron complexes, but due to production of steroid sexual hormones related to the enzymes involved in this complex, no can change the activity of these enzymes. no affects many cells including v...
Most of the general population is exposed to carbaryl and other contemporary-use insecticides at low levels. Studies of laboratory animals, in addition to limited human data, show an association between carbaryl exposure and decreased semen quality. In the present study we explored whether environmental exposures to 1-naphthol (1N), a metabolite of carbaryl and naphthalene, and 3,5,6-trichloro-...
Sixteen (mean age = 1.1 +/- 0.1 yr; mean BW = 478 +/- 34 kg) Brahman-influenced bulls were used to determine the influence of fescue type on sperm characteristics and serum concentrations of prolactin, cortisol, and testosterone. Bulls were blocked by BW, scrotal circumference (SC), and pregrazing sperm characteristics and randomly assigned to graze toxic endophyte-infected (EI; 4 bulls/pasture...
The volume of nanoparticles (NPs) used in various sectors human life is steadily increasing. Due to their unique properties, silicon dioxide (SiO2 NPs) are widely industrial production. However, ecotoxicological effect on marine biota extremely poorly understood. To highlight this problem, experiments were conducted with short-term SiO2 NPs exposure the sand dollar Scaphechinus mirabilis sperm,...
BACKGROUND Spermatozoa acquire the ability to fertilize an oocyte when they become capacitated. Capacitation takes place when sperm pass through the female reproductive tract, interacting with female fluids. Both tyrosine phosphorylation of sperm proteins and the ability to respond to acrosome reaction (AR) inducers have been associated with sperm capacitation. Recent data indicate that conditi...
Sperm must undergo a process termed capacitation in the female reproductive tract before they are capable of fertilization. Previous studies strongly suggest that capacitation of sperm occurs in the oviduct. The secreted extracellular matrix phosphoprotein osteopontin (OPN) has been positively correlated to fertility in Holstein bull seminal plasma and identified in the bovine oviduct, where we...
As the chemical environment of semen can have a profound effect on sperm quality, we examined the effect of pH on the motility, viability and capacitation of human sperm. The sperm in this study was collected from healthy males to avoid interference from other factors. The spermatozoa cultured in sperm nutrition solution at pH 5.2, 6.2, 7.2 and 8.2 were analyzed for sperm total motility, progre...
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