الفهرس 
MALE GENITAL TRACTOnly 14 pages are availabe for public view
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Abstract
Infertility is defined as the inability to conceive after one year of unprotected intercourse. Approximately 30% of cases of couple infertility are due to a male factor.
Evaluation of subfertile male in the past and recent studies has revealed a wide range of causes contributing to male infertility. Presence of varicocele, idiopathic oligospermia and past undescended testes are some of the common finding. Causes may also be secondary to structural abnormalities, such as ductal obstruction, or even due to life style factors such as diet, alcohol, tobacco and recreational drug use. In recent year, however, research has revealed multiple genetic etiologies of male infertility.
The corner stone of the evaluation of infertile man is careful history and physical examination with special emphasis on the reproductive organs for evidence of proper androgenization.
The semen analysis remains the staring point in the laboratory evaluation of the infertile men. A complete semen analysis involves the measurement of multiple parameters (count, motility, pH, vitality, morphology). WHO defines the normal semen as having a sperm concentration greater than 20 million sperm per milliliter and sperm motility of more than 50%.
The main constituent of endocrine laboratory diagnosis of testicular disorders is the determination of the gonadotropin LH and FSH as secretions of anterior pituitary, testosterone as the most important secretion of leydig cells.
Most important markers of infertility include seminal vesicular markers, biochemical markers (acrosin, carnitine, elastase and inhibin), oxidative stress markers and genetic markers.
Seminal vesicular secretion is important for semen coagulation, sperm motility, stability of sperm chromatin and suppression of the immune activity in the female reproductive tract. The function of seminal vesicle is important for fertility. Parameters as sperm motility, sperm chromatin stability, and immuno-protection may be changed in case of its hypofunction. Measurement of seminal fructose has been used in almost all laboratories of the world as a marker of the seminal vesicular function. The WHO includes the measurement of this sugar to assess the function of these glands.
Acrosin is an important enzyme enabling the penetration of spermatozoa through the zona pellucida of the oocyte by limited proteolysis of ZP glycoproteins, so measurement of total acrosin activity may be considered as a sensitive biochemical marker for clinical evaluation of unexplained infertility in males.
The level of L-carnitine in seminal plasma may be taken as one of important markers for diagnosis and treatment of male infertility. Therefore, it is necessary to determine carnitine concentrations in human seminal fluid samples for the study of the pathology of male infertility especially in patients with asthenozoospermia.
The demonstration that inhibin B is the relevant inhibin form in man prompted a number of clinical investigations aiming at the analysis of this new endocrine parameter in several pathophysiological conditions, such as infertility, hypogonadism, gonadotrophin administration, hormonal contraception and testicular damage resulting from radiation or chemotherapy.
Limited amount of free radicals and oxidative stress have an important role in modulating many physiological functions in reproduction. ROS are being constantly produced in small controlled amounts in the reproductive tract and by a variety of semen components. Many scavenging enzymes and molecules (antioxidants) control the damaging effects of ROS to keep the normal physiological balance. However, when ROS production exceeds the scavenging capacity of the antioxidant a state referred to as oxidative stress is generated that become toxic to sperm. High levels of ROS and OS in reproductive tract and semen are associated with sperm dysfunction and damage to sperm nuclear DNA. Although routine semen analysis remains the backbone of evaluating male infertility, determining the levels and sources of excessive ROS generation in semen may be useful in developing future diagnosis strategies for male infertility.
Many cases of idiopathic infertility have a genetic or molecular basis. The most frequent pathogenic genetic causes of male infertility are Y chromosomal microdeletions and obstructive azoospermia due to CAVD in the presence of mutations in the cystic fibrosis transmembrane conductance regulator CFTR gene.
Finally, we concluded that the biochemical markers such as acrosin, carnitin, elastase, inhibin and oxidative stress markers are important complementaty tools for the proper diagnosis of fertility disorders.