Polyamines in human semen: presence of S-adenosyl-L-methionine decarboxylase.

The presence of S-adenosyl-l-methionine decarboxylase in human semen has been demonstrated. The activity of the S-adenosyl-l-methionine decarboxylase was high in the semen samples with less than 30 million sperm count per ml. In semen with sperm counts between 30 to 60 million/ml, activity of the enzyme was low and increased at high concentrations of spermatozoa (above 60 million/ml). Studies were also carried out to determine the possible site of origin of this enzyme in the semen. This investigation on the split ejaculates of the semen indicated that the seminal vesicles contribute the major amount of this enzyme to the seminal plasma pool.