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.