Increase of intracellular calcium is not a cause of pentoxifylline-induced hyperactivated motility or acrosome reaction in human sperm.
OBJECTIVE
To investigate the effects of the phosphodiesterase inhibitor pentoxifylline on hyperactivated motility and acrosome reaction in human sperm and to determine whether its stimulatory effects occur via increased intracellular calcium levels.


METHODS
Prospective study.


METHODS
Academic tertiary care facility.


METHODS
Healthy male donors.


METHODS
The effects of pentoxifylline on hyperactivated motility, acrosome reaction, and intracellular calcium were studied and compared with the effects of progesterone. Thapsigargin, a known mobilizer of intracellular calcium, also was used as positive control.


METHODS
Hyperactivated motility was assessed by computer-assisted sperm motion analysis using the HTM-IVOS, acrosome reaction was evaluated with the fluorescent probe fluorescein isothiocyanate-labeled Pisum sativum agglutinin, and intracellular calcium was determined by fura-2 using spectrofluorometry.


RESULTS
Pentoxifylline significantly increased both hyperactivated motility and acrosome reaction. Enhancement of hyperactivated motility by pentoxifylline in the capacitation medium persisted for up to 5 hours after pentoxifylline was washed from the medium. It also enhanced the percentage of acrosome-reacted spermatozoa after 4 hours of incubation. These effects occurred in the presence of a marginally significant decrease in intracellular calcium.


CONCLUSIONS
Pentoxifylline stimulates hyperactivated motility and acrosome reaction in spermatozoa from fertile men. Its stimulatory effects occur through mechanism(s) other than increase in intracellular calcium.
Nassar
A
A
The Jones Institute for Women's Health, Department of Obstetrics and Gynecology, Eastern Virginia Medical School, Norfolk 23507, USA.
Mahony
M
M
Blackmore
P
P
Morshedi
M
M
Ozgur
K
K
Oehninger
S
S
D000177:Acrosome / Q000187:drug effects* / Q000502:physiology; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007424:Intracellular Fluid / Q000378:metabolism; D007476:Ionophores / Q000494:pharmacology; D008297:Male; D010431:Pentoxifylline / Q000494:pharmacology*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D011374:Progesterone / Q000494:pharmacology; D011446:Prospective Studies; D013081:Sperm Motility / Q000187:drug effects* / Q000502:physiology; D013094:Spermatozoa / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D019284:Thapsigargin / Q000494:pharmacology; D013997:Time Factors
D004791:Enzyme Inhibitors; D007476:Ionophores; D010726:Phosphodiesterase Inhibitors; D000001:Calcimycin; D011374:Progesterone; D019284:Thapsigargin; D010431:Pentoxifylline; D002118:Calcium