Endocrine Abstracts

It has been previously shown that human spermatozoa produce nitric oxide (NO), a short-lived free radical synthesised by three isoforms of NO synthase (NOS): endothelial (eNOS), neuronal (nNOS), and inducible (iNOS), which are responsible for the conversion of L-arginine to L-citrulline and NO. Spermatozoa of fertile men express both eNOS and nNOS. The specific roles of NOS isoforms in gametes are not well understood, even if iNOS seems to ...

Objective(S): Single nucleotide polymorphism (SNP) in endothelial nitric oxide synthase (eNOS) G894T may affect the oxidative stress response. Our objective was to examine G894T SNP eNOS genotype frequencies and its potential role with sperm motility in infertile men. Through this prospective controlled study in the Andrology Unit, we have enrolled infertile (n=70) and healthy (n=60) men. Sperm motion kinetics assessed by computer assisted semen analysis (CASA), ...

Spermatozoa generate small amounts of O2°- and NO°. Under physiological condition these compounds exist at very low concentration and the formation of peroxynitrite (ONOO−) appears likely. Peroxynitrite reacts rapidly with proteins, lipids and DNA. Moreover, tyrosine nitration is a widely used marker of peroxynitrite. The nitration of protein residues gives rise to 3-nitrotyrosine which represents a protein modification specific for ONOO− formation in ...