objective: melatonin, the chief secretory product of the pineal gland, regulates dynamic physiological adaptations that occur in seasonally breeding mammals as a response to changes in daylight hours. because of the presence of melatonin in semen and the membrane melatonin receptor in spermatozoa, the impact of melatonin on the regulation of male infertility is still questionable. the aim of th...

BACKGROUND Sperm chromatin is highly condensed and relatively resistant to chemical and physical treatments. The purpose of this study was to explore the highest temperature that sperm can tolerate and still produce live offspring. METHODS Mouse sperm were heated in a water bath at 50, 65, 80 or 95°C for 30 min before they were microinjected into mouse oocytes. Fertilization, embryo developme...

Sperm cells are remarkably complex and highly specialized compared to somatic cells. Their function is to deliver to the oocyte the paternal genomic blueprint along with a pool of proteins and RNAs so a new generation can begin. Reproductive success, including optimal embryonic development and healthy offspring, greatly depends on the integrity of the sperm chromatin structure. It is now well d...

Background: During spermatogenesis the sperm nucleus exchange histones against cystein rich protamines, which stabilize the sperm chromatin and protects the DNA against damages. At ejaculation the age of the patient, handling routines, processing of the semen sample and the storage of the final sperm suspension might damage the DNA. Sperm chromatin stability and DNA damages are evaluated with d...

Background: Techniques of sperm preparation require centrifugation to separate spermatozoa from the seminal plasma. The centrifugation can induce damage to the spermatozoa and increase reactive oxygen species(ROS) productionspecially in leukospermic speciemens that are associated with impaired function and fertilizing capacity. However in ICSI, fertilization can occure with damage DNA sperm but...

BACKGROUND Acrylamide (AA) is an important industrial chemical primarily. AA is also found in carbohydrate-rich foods that are prepared at high temperatures, such as French fries and potato chips. It is demonstrated that AA is a carcinogen and reproductive toxin and has ability to induce sperm damage. OBJECTIVE The aim of this study was to observe the effects of AA on sperm parameters and eva...

BACKGROUND Arsenic as an environmental toxicant is able to exert malformations in male reproductive system by inducing oxidative stress. Vitamin E (Vit.E) is known as antioxidant vitamin. OBJECTIVE The aim of this study was to investigate the harmful effects of sodium arsenite on sperm parameters and the antioxidant effects of Vit.E on sperm anomalies in sodium arsenite treated rats. MATERI...

The scope of paternal contributions during early embryonic development has long been considered limited. Dramatic changes in chromatin structure throughout spermatogenesis have been thought to leave the sperm void of complex layers of epigenetic regulation over the DNA blueprint, thus leaving the balance of that regulation to the oocyte. However, recent work in the fields of epigenetics and mal...

BACKGROUND Etiology of more than half of Recurrent Spontaneous Abortion. The etiology of more than 50 percent of Recurrent Spontaneous Abortions (RSA) cases has been remained unexplained. It is supposed that RSA may have "paternal effect" due to supply 50% of embryonic genomic content by male gamete. OBJECTIVE The aim of present study was to evaluate the role of sperm apoptosis and protamine ...

The nuclear chromatin decondensation test (NCDT) detects the ability of the sperm chromatin to undergo decondensation following fertilization. The test does not have direct bearing with the fertilizing ability of the spermatozoa but only reflects the proportion of sperm that may swell following exposure to in vitro decondensing agents. The gross seminal parameters do not have any direct relatio...