RESUMO
New approaches need to be pursued towards the assessment of sperm quality using biochemical markers. In order to help develop a good biochemical marker to assess sperm-membrane integrity, the enzyme creatine kinase (CK) was studied in semen of normal, oligospermic and azoospermic samples and correlated with sperm concentration, lipid-peroxidation (LP) and water test. Presence of isoforms of creatine kinase (CK-MB) was also seen. An inverse correlation was observed between CK activity and sperm concentration (p<0.001). Water test was seen to be inversely correlated with CK activity (p<0. 001). Lipid peroxidation showed positive correlation with CK activity (p<0.001). A significant correlation between loss of sperm function meditated by induction of peroxidative damage to sperm plasma membrane is indicated. Enzymes like CK can serve as good biochemical marker along with lipid peroxidation to confirm loss of sperm membrane integrity. The water test can be used as a preliminary screening test for sperm membrane integrity.