Evaluation of poly(ADP-ribose) polymerase cleavage (cPARP) in ejaculated human sperm fractions after induction of apoptosis.

OBJECTIVE To examine the presence of cleaved poly(ADP-ribose) polymerase(s) (cPARP) in ejaculated spermatozoa and determine cPARP levels following exposure to chemical or oxidative stress. DESIGN Prospective pilot study. SETTING Tertiary care academic hospital. PATIENT(S) Eight healthy men. INTERVENTION(S) Semen specimens were collected, prepared with double-density-gradient centrifugation, and divided into control, hydrogen peroxide (H(2)O(2)), H(2)O(2) + 3-aminobenzamide (3-ABA), staurosporine (STS), and STS + 3-ABA treated groups. MAIN OUTCOME MEASURE(S) Cleaved PARP and apoptosis markers by flow cytometry. RESULT(S) Cleaved PARP was detected in both neat and mature fractions. The cPARP levels were similar in both mature and immature spermatozoa. In combined mature and immature fractions, a higher percentage of late apoptotic sperm was seen in STS + 3-ABA versus STS. Higher levels of late apoptotic spermatozoa were seen in immature versus mature fractions within STS and STS + 3-ABA groups. Lower levels of cPARP were seen in immature versus mature fractions in H(2)O(2) and H(2)O(2) + 3-ABA treated groups. Cleaved PARP was related to activated caspase-3. CONCLUSION(S) Cleaved PARP is present in ejaculated human spermatozoa. Poly(ADP-ribose) polymerase inhibitors may play a different role in chemical versus oxidative stress-induced sperm damage.