Sperm DNA damage has a negative effect on early embryonic development following in vitro fertilization

Sperm DNA damage is recognized as an important biomarker of male infertility. To investigate this, sperm DNA damage was assessed by the sperm chromatin dispersion （SCD） test in semen and motile spermatozoa harvested by combined density gradient centrifugation （DGC） and swim-up in 161 couples undergoing in vitro fertilization （IVF）. Semen analysis and sperm DNA damage results were compared between couples who did or did not achieve pregnancy. The sperm DNA damage level was significantly different between the two groups （P 〈 0.05） and was negatively correlated with IVF outcomes. Logistic regression analysis confirmed that it was an independent predictor for achieving clinical pregnancy. The effects of different levels of sperm DNA damage on IVF outcomes were also compared. There were significant differences in day 3 embryo quality, blastocyst formation rate, and implantation and pregnancy rates （P 〈 0.05）, but not in the basic fertilization rate between the two groups. Thus, sperm DNA damage as measured by the SCD appears useful for predicting the clinical pregnancy rate following IVF.

Chloride channels are involved in sperm motility and are downregulated in spermatozoa from patients with asthenozoospermia

Human spermatozoa encounter an osmotic decrease from 330 to 290 mOsm I-z when passing through the female reproductive tract. We aimed to evaluate the role of chloride channels in volume regulation and sperm motility from patients with asthenozoospermia. Spermatozoa were purified using Percoll density gradients. Sperm volume was measured as the forward scatter signal using flow cytometry. Sperm motility was analyzed using computer-aided sperm analysis （CASA）. When transferred from an isotonic solution （330 mOsm I-z） to a hypotonic solution （290 mOsm I-Z）, cell volume was not changed in spermatozoa from normozoospermic men; but increased in those from asthenozoospermic samples. The addition of the chloride channel blockers, 4,4＇-diisothiocyanatostilbene-2,2＇- isulfonic acid （DIDS） or 5-nitro-2-（3-phenylpropylamino） benzoic acid （NPPB） to the hypotonic solution caused the normal spermatozoa to swell but did not increase the volume of those from the asthenozoospermic semen. DIDS and NPPB decreased sperm motility in both sets of semen samples. The inhibitory effect of NPPB on normal sperm motility was much stronger than on spermatozoa from the asthenozoospermic samples. Both sperm types expressed CIC-3 chloride channels, but the expression levels in the asthenozoospermic samples were much lower, especially in the neck and mid-piece areas. Spermatozoa from men with asthenozoospermia demonstrated lower volume regulating capacity, mobility, and CIC-3 expression levels （especially in the neck） than did normal spermatozoa. Thus, chloride channels play important roles in the regulation of sperm volume and motility and are downregulated in cases of asthenozoospermia.

Change of Accessory Genital Glands Markers in the Patients with Oligoasthenospermia

Objective To evaluate the effect of the accessory gential gland on the male fertility. Methods The relevant seminal parameters of 32 normal donors and 35 patients with olioasthenospermia were measured by seminal routine analysis, sperm morphology and accessory, gentital glands markers.Results The percentage of normal spermatozoa, the function of sperm penetration through cervical mucus and the enzyme activity of neutral α-1,4-glucosidase significantly declined as compared with the control. There was a significant negative relationship between the semen volume and the sperm motility for the oligoasthenospermia （r= -0.415, P〈0.05）, and a significant positive relationship between the sperm count and the percentage of normal sperm （r=0.393, P〈0.05）.Conclusion The abnormal function of epididymis exists in patients with oligoasthenospermia. Sperm function,for the oligoasthenospermia declines with an increase of the percentage of the abnormal sperm. The poorer the spermatogenises function of the testis is, the higher the percentage of the abnormal sperm appears.