Seminal plasma albumin: origin and relation to the male reproductive parameters

We wanted to investigate the origin of seminal plasma albumin and its relation to the male reproductive parameters. Semen samples from 916 men, under infertility assessment, were analysed according to guidelines of the World Health Organization. Seminal plasma constituents, i.e. albumin, markers of the epididymal (neutral alpha-glucosidase, NAG), prostatic (prostate-specific antigen, PSA, and zinc) and seminal vesicle function (fructose), as well as levels of reproductive hormones in plasma were measured. The sperm chromatin structure assay (SCSA) was applied on 267 of the 916 samples. A negative correlation was seen for seminal albumin and plasma follicle-stimulating hormone (r=-0.1, P=0.02) and a positive correlation for seminal albumin and serum inhibin B (r=0.2, P=0.004). Albumin exhibited positive correlations with the epididymal marker, NAG (r=0.5, P<0.001) and with the prostatic markers, PSA and zinc (r=0.1, P=0.001; r=0.2, P<0.001 respectively) as well as with age (r=0.2, P<0.001). A negative significant association was seen for seminal albumin and semen volume (beta=-0.60; 95% CI -0.80 to -0.30). The opposite trend was found regarding sperm concentration (beta=0.34; 95% CI 0.30-0.40), total sperm count (beta=0.30; 95% CI 0.20-0.40), and percentage morphologically normal spermatozoa (beta=0.70; 95% CI 0.10-1.0). No association was found between albumin and sperm motility, SCSA parameters, or fructose, the marker of seminal vesicles. Our results suggest testicular, epididymal and prostatic origin of seminal plasma albumin, in addition to the contribution from blood. This is the first study to demonstrate an association between seminal plasma albumin and sperm morphology. Further studies are needed to elucidate the role of seminal albumin in sperm morphology.