introduction the cryopreservation of spermatozoa has provided special opportunities for the preservation of genetic resources and improving breed programs by the artificial insemination technique (holt, 1996). sperm cryopreservation stimulates intracellular ice crystals formation, increasing osmotic and chilling injury that causes sperm cell damage (isachenko et al. 2003). freezing and thawing ...

We used a cell-free system to study membrane fusion during sperm exocytosis (acrosome reaction). Extracted bovine sperm plasma and outer acrosomal membranes were labeled with chlorophyll a or DCY, respectively. The occurrence of membrane fusion is indicated by the ability of the probes to diffuse from one membrane species to another which is revealed by resonance energy transfer between the two...

Objective Metals can cause male infertility through affection of spermatogenesis and sperm quality. Strong evidences confirm that male infertility in metal-exposed humans is mediated via various mechanisms such as production of reactive oxygen species (ROS). Flavonoids have antioxidant and metal chelating properties which make them suitable candidates for neutralizing adverse effects of metals ...

Sperm competition is a prevalent phenomenon that drives the evolution of sperm function. High levels of sperm competition lead to increased metabolism to fuel higher sperm velocities. This enhanced metabolism can result in oxidative damage (including lipid peroxidation) and damage to the membrane. We hypothesized that in those species experiencing high levels of sperm competition there are chan...

The epididymis is a long, tightly coiled tube within the lumen of which sperm matures. Sperm maturation involves morphological and biochemical changes in the sperm plasma membrane in response to epididymal secretions and their various proteins. Some of these proteins become outer membrane components while others become integral membrane proteins; transfer of some proteins to the sperm plasma me...

Objective(s): Increased levels of nitric oxide (NO) in the testicular veins of people suffering from varicocele have already been reported. However, the role of NO-synthase (NOS) isozymes and their inhibitors have not been extensively studied. We aimed to evaluate the inhibitory effects of aminoguanidine (AG), on sperm motility, vitality, and mitochondrial membrane potential (MMP) in varicoceli...

"Capaci ta t ion" is a physiological event which alters sperm to permit rapid penetration through oocyte investments and fusion between gametes. Acrosomal "reaction," the physiological release of acrosomal contents, occurs after this facilitating process. In this study, acrosomal "disruption" of guinea pig and rat sperm was achieved in vitro by incubating sperm together with the follicular cont...

Background: Fertilization and fecundation obviously are the phenomenon in which several factors are involved. Sperm membranous proteins are a series of these important elements. CD9, an inner acrosomal membrane protein, is one of the tetraspanin members that involved in sperm-egg fusion. CD52, is a GPI anchor protein which is expressed in the epididymal cells and during passage of sperms throug...

spermatozoa generate reactive oxygen species (ros) in physiological amounts which play a role in sperm functions during sperm capacitation acrosome reaction (ar) and oocyte fusion. in addition damaged sperm are likely to be the source of ros. the most important ros produced by human sperm are hydrogen peroxide superoxide anion and hydroxyl radicals. besides human seminal plasma and sperm posses...