Creatine kinase in seminal plasma of infertile men: activity and isoenzymes.

Creatine kinase (CK) activity was determined in the seminal plasma of 169 men divided in a) 11 groups according to etiological diagnosis of infertility and b) 2 groups on the basis of the normal or abnormal spermiogram. Electrophoretic separation of CK isoenzymes on agarose gel was also performed. We found that: 1) in seminal plasma enzyme activity is 4.2 times higher than the upper limit in normal serum, 2) CK activity in seminal plasma is exclusively due to the isoenzyme BB (CK1). 3) there is a statistically significant difference of the enzyme levels between men with normal spermiogram and oligo-asthenozoo-spermics, yet with wide overlapping of the individual values, 4) there is no correlation between CK activity and the variables of the spermiogram, as well as between enzyme activity and fructose or acid phosphatase in seminal plasma.