Protein content of human seminal plasma and spermatozoa in relation to sperm counts.

Semen samples were obtained from 61 subjects with fertility disorders but no endocrinological or obstructive disorders of the urogenital tract. Semen containing cells other than spermatozoa was excluded. Spermatozoa were separated by centrifugation and then by washing 3 times with Ringers buffer at pH 7.2. After another centrifugation the final pellet was suspended in .5 ml of buffer and cells recounted. Protein determinations were made in plasma and in homogenized spermatozoa. The protein content of seminal plasma ranged from 20 to 60 mg/ml. Protein concentrations of seminal plasma were unrelated to sperm counts. However the protein content of washed spermatozoa decreased with the increase of original sperm counts. This trend suggests an altered protein metabolism in the spermatozoa of oligospermic patients which might be related to fertility incompetence. Sediments from azoospermic patients had 4 times more protein than spermatozoa-free sediments from oligospermic specimens. It is suggested that in azoospermic disorders the seminiferous tubules secrete increased amounts of proteinaceous material. Destruction of immature cells may also contribute to the increased protein content.