ABSTRACT
Sterile semen of three brothers was investigated biochemically. Most strikingly was the strong similarity of both the amino acid and the carbohydrate composition of the semen. Inside the spermatozoa much more fructose and glucose was present than normally is found. It could be shown that in the seminal plasma peptides and proteins were present all containing more or less beta-alanine and all able to bind glucose and fructose. After incubation with labelled glucose it was evident that inside the spermatozoa enzymes requried for formation of lactic acid were lacking or inactive. Moreover labelled tyrosine and serine was found. Treatment with proviron did not improve carbohydrate metabolism but the amounts of present glucose and fructose inside the spermatozoa had strongly decreased. It is supposed that the sterility of the men is due to a disturbance in spermatogenesis.
