Oxidative Stress in Testicular Tissue Before and After Cryopreservation
Oxidative Stress in Testicular Tissue Before and After Cryopreservation
The absence of sperms in ejaculated semen, is the most severe form of male-factor infertility
 and is present in approximately 5 % of all investigated infertile couples.
Obstructive azoospermia is defined as the absence of spermatozoa in the ejaculate despite
 normal spermatogenesis.Infection, Iatrogenic injury, Vasectomy and congenital atresia are the
 possible causes of it. Non obstructive or functional azoospermia results from testicular
 failure, which is the absence or inadequate production of fully developed spermatozoa within
 the testes.

 Etiologies for testicular failure include genetic disorders such as sexual chromosomal
 abnormalities ; translocations and microdeletions of the Y chromosome; cryptorchidism;
 testicular torsion; radiation and toxins.

 The advent of intra-cytoplasmic sperm injection has transformed the treatment of this type of
 severe male-factor infertility.

 Surgical techniques for sperm retrieval:Testicular sperm aspiration: In men with obstructive
 azoospermia ,testicular sperm aspiration invariably generates enough sperm for
 intra-cytoplasmic sperm injection.

 Testicular sperm extraction:This conventional method of surgical sperm extraction generally
 offers the best chance of retrieving spermatozoa, especially in functional cases and when
 guided by surgical microscope. However, it can be done by simple open conventional biopsy and
 closed surgical extraction resembling Trucut biopsy using a special cannula.

 Cryopreservation Cryopreservation of human testicular tissue obtained by biopsy can be used
 as a potential future source of sperms. For adult cancer survivors, cryopreservation of
 testis biopsies may be the only option remaining if they prefer to father their own
 biological progeny.

 There are 4 types of cryopreservation :

 Slow freezing: involves step-wise programmed decrease in temperature. Rapid freezing: was
 first proposed by . Ultra-rapid freezing :can be considered midway technique between slow
 freezing and vitrification.

 Vitrification: solidifies the sample into a glass-like state. During the freezing
 process,increasing in susceptibility of spermatozoa to lipid peroxidation,as affected by cold
 shock, plays an important role in ageing of spermatozoa ,shortening their lifespan and
 affecting the preservation of semen.The major susceptibility is related in, part to the
 content of polyunsaturated fatty acids.

 Oxidative stress and antioxidants: Oxygen is required to support life, but its metabolites,
 such as reactive oxygen species, can modify cell functions and endanger cell survival. For
 this reason,reactive oxygen species is inactivated continuously to maintain only the small
 amount necessary to maintain normal cell function. There is a balance between the different
 antioxidants and oxidants at normal status. Oxidative stress is a cellular condition
 associated with an imbalance between the production of free radicals, mainly reactive oxygen
 species, and the scavenging capacity of antioxidants.

 Superoxide dismutase and catalase are endogenous antioxidants, which protect cells from
 oxidative stress. Scavengers of reactive oxygen species and antioxidants are important in
 treating and preventing the damage caused by such stress.

 Catalase has been reported from testis, seminal plasma, and spermatozoa Tissue level of
 malondialdehyde is proven indicator of oxidative stress resulting from lipid peroxidation .

 The process of cryopreservation is known to cause more production and/or accumulation of
 reactive oxygen species, as antioxidant defenses are reduced in the process.
Inclusion Criteria:

 - Men with azoospermia at reproductive age .

 Exclusion Criteria:

 -  Pyospermia.

 -  Previous trial of cryopreservation.

 -  Systemic diseases.

 -  Cryptorchidism history.

 -  Smoking