Oxidative stress on sperm motility
Thursday, 15 May 2008 - At the 23rd EAU annual congress held in Milan, March 2008, El-Taieb et al. presented a more stable and reliable sensitive carbonyl protein (CP) detection method in seminal plasma from patients with oligoasthenoteratozoospermia (OAT) syndrome to clarify the effect of oxidative stress on spermatozoa in terms of protein dysfunction.
In total 675 patients were examined between September 2006 and July 2007 because of unfulfilled parenthood. Of them 60 patients with pathological sperm count, presenting without leukospermia and sterile ejaculate culture and samples of 10 controls with normal sperm count were enrolled into this pilot study. All subjects underwent andrological examination. Semen samples were analysed according to the WHO (1999, World Health Organization) guidelines. Seminal plasma was stored at -70°C until analyzed. Carbonyl protein content was measured after incubation with 2,4-dinitrophenylhydrazine with the sensitive chemo- luminescence ELISA technique.
The normal value for CP in semen was 501,4 pmol/mg (+233,0 pmol/mg) in the 10 controls. The mean of CP in the 60 OAT syndrome patients was 1747,35 pmol/mg (± 396,92 pmol/mg). A statistically significant negative correlation (p = 0.01) could be found between rapid, as well as with A+B class sperm and CP level in seminal plasma. Furthermore, statistically significant increase in midpiece abnormalities (p = 0.006) could be detected in patients with CP levels over a cut-off level of 1000 pmol/mg. A significant correlation (p = 0.011) could be found between midpiece deformities and CP.
The authors concluded that CP is a highly sensitive marker with the advantage of being more stable than ROS. The motility of sperm is essentially regulated in the midpiece of sperm. ROS respectively CP are originated in mitochondria, which are located in the midpiece of sperm. A significant negative correlation could be detected between rapid and A+B class sperm on one hand and CP level on the other hand. Furthermore, with increasing CP levels a statistical significant increase in midpiece deformities could be detected. Therefore, the analysis of CP reveals an important effect of oxidative stress on motility and midpeace deformities according to its level in seminal plasma. This finding may lead to a better differentiation of the underlying cause and a better stratification of OAT-Syndrome patients for targeted therapy with antioxidative agents.
Author: El-Taieb et al. presented at the 23rd Annual EAU Congress, 26-29 March 2008, Milan, Italy