Protamine 1 to protamine 2 ratio correlates with dynamic aspects of DNA fragmentation in human sperm.

Objective: To investigate the relationship between the protamine 1 to protamine 2 (P1/P2) ratio and the rate of sperm DNA fragmentation in sperm samples from human males with proven fertility and three different cohorts of male patients.

Design: P1/P2 ratio was analyzed using acid-urea polyacrylamide acid-urea gels electrophoresis (PAGE). Sperm DNA fragmentation using sperm chromatin dispersion methodology was analyzed after 0, 4, 8, and 24 hours of incubation at 37°C.

Setting: University medical school and hospital.

Patient(s): A total of 32 human males: six with proven fertility, seven carriers of chromosome reorganizations, nine clinical varicocele patients, and ten subclinical varicocele patients.

Intervention(s): None.

Main Outcome Measure(s): P1/P2 ratio, sperm DNA fragmentation (SDF) and the rate of sperm DNA fragmentation (rSDF).

Result(s): P1/P2 ratio correlated with SDF and rSDF. Statistical differences were detected between fertile controls and patients for the three pathologies studied. rSDF yielded information that differed from baseline SDF. No differences were detected for P1/P2 ratio among patient groups, in reference to the three pathologies studied.

Conclusion(s): SDF and rSDF correlates with P1/P2 ratio in human sperm, and statistical differences were detected when fertile controls were compared with three different cohorts of patients.