INTRODUCTION: The assessment of creatine kinase (CK) in human sperm cells is an unbiased indicator of sperm maturity and fertilization potential. Elevated CK values are associated with an increased number of functional abnormalities and increased cytoplasmic residues. The CK-Mi isoenzyme in human sperm is of mitochondrial origin. Increased spermatozoal CK activity is associated with high CK cell levels. The objective of the present study was to compare the biochemical marker CK with morphological changes of the head, neck, and tail. The authors also investigated the assessment of CK activity in human sperm to obtain an objective biochemical marker of sperm maturity and fertilization potential.
METHODS: The activity of CK was assessed for seminal plasma-deprived spermatozoa in 126 men. The participants were divided into 2 groups. Patients in group 1 (n = 64) had reduced spermatozoa count. They were subdivided into: group 1a (n = 28) patients with moderate oligospermic characteristics (spermatozoa count 5.1 - 20 x 106/mL), and group 1b (n = 36) patients with severe oligospermic characteristics (spermatozoa count < 5 x 106/mL). Group 2 (n = 62) was a comparison group of patients with normospermic characteristics (spermatozoa count > 20 x 106/mL; motility > 0.30). Semen analysis was performed according to World Health Organization guidelines. The CK-Mi isoenzyme was separated from CK-B using DEAE Sephadex™ A-50 columns, and agarose gel electrophoresis was used for separating the CK-Mi isoenzyme. The total CK activity was assessed with a spectrophotometer.
RESULTS: CK was significantly higher in the group with severe oligospermia (mean [SD] = 1.9 [2.2] UI/108 sperm cells) than in the group with normospermia (0.097 [0.026] UI/108 sperm cells) (P < .01). The group with oligospermia had a significantly lower CK-Mi/CK ratio (0.16 [0.10]) than the group with normospermia (0.36 [0.12]) (P = < .01).
DISCUSSION: The concentration of CK and synthesis of CK-Mi isoforms reflect normal spermatogenesis and can be used for predicting human sperm maturity and fertilization potential. CK appears to be a sensitive indicator of spermatozoa quality and maturity for men with male-factor infertility.
KEYWORDS: Oligospermia; Normospermia; Creatine kinase; Isoenzyme CK-Mi
CORRESPONDENCE: Professor Sava Micic, MD, PhD, Institute of Urology and Nephrology, Resavska 51, Belgrade 11000, Serbia ( ).
CITATION: UroToday Int J. 2010 Jun;3(3).
doi:10.3834/uij.1944-5784.2010.06.08