[Effect of seminal vesicles and dithiotritol [DTT] on stability of sperm chromatin in IVF and ICSI patients]

ABSTRACT

Different studies have shown that there is no relation between sperm chromatin stability andfertilization rate in both IVF and ICSI patients. However, the relation between SDS tests, as a detergent, alongwith DTT as reducer of disulphide bridges has not been studied so far in ICSI patients. Since differentconcentrations of DTT can induce different degrees of sperm chromatin decondensation, the aim of this studywas to evaluate the effect of different concentrations of DTT on sperm chromatin decondensation in IVF andICSI cases.During this study, 85 patients were divided into two groups according to their treatment procedure[IVF or ICSI].Semen samples of each patient was evaluated for sperm chromatin tests including SDS,SDS+EDTA and SDS+DTT for assessment of free thiole groups level [-SH], amount of non covalent bondbetween Zn and thioles[-SH Zn SH-] and levels of disulfide bond [-S-S-] in sperm chromatin, respectively. Inthis study, seminal fructose concentration, corrected seminal fructose level and true corrected fructose level asindicators of seminal vesicle function on sperm chromatin stability were assessed.No correlation was observed between any of the above tests and rate of fertilization, both in IVF andICSI cases. However, in IVF patients, a significant correlation was observed between SDS, SDS+DTT test andseminal fructose level, while in ICSI patients, only a significant correlation was observed between SDS+DTTand corrected or true fructose concentration.Since no correlation was observed between sperm chromatin test and fertilization rate, it issuggested that the chromatin status of these samples are adequate for fertilization to take place and extent ofdisulphide bridges has no effect on fertilization rate. However, the amount of disulphide bound present in spermsof ICSI and IVF patients are different, and this difference is related to seminal vesicle performance in thesepatients