Effects of phosphodiesterase inhibitors caffeine and pentoxifylline on spontaneous and stimulus-induced acrosome reactions in human sperm.
OBJECTIVE
To determine whether the phosphodiesterase inhibitors caffeine and pentoxifylline influence the acrosome reaction in the conditions in which they are currently used as sperm movement enhancers.


METHODS
The frequency of acrosome reaction occurring spontaneously in capacitating media or induced by physiological (follicular fluid [FF]) and artificial (ionophore A23187) stimuli was compared in the presence and absence of the phosphodiesterase inhibitors.


METHODS
Private hospital and research laboratory.


METHODS
Patients undergoing routine semen examination before in vitro fertilization (no pathology detected) and healthy sperm donors.


METHODS
None.


METHODS
Percentage of acrosome-reacted sperm determined with the use of fluorescein-labeled Pisum sativum agglutinin as acrosomal stain.


RESULTS
Caffeine alone augmented the frequency of acrosome reaction, but this effect was not observed with pentoxifylline alone. However, pentoxifylline increased sperm responsiveness to the acrosome reaction-inducing stimuli, FF and ionophore A23187.


CONCLUSIONS
The promotion of spontaneous acrosome reaction may counteract the benefits from application of caffeine as motility stimulant. On the other hand, the sensitization to physiological acrosome reaction stimuli is expected to contribute to the improvement of sperm fertilizing ability by pentoxifylline and make this drug a potential candidate for the treatment of acrosome reaction anomalies.
Tesarik
J
J
Centre for Reproductive Biology and Medicine, American Hospital of Paris, Neuilly Sur Seine, France.
Mendoza
C
C
Carreras
A
A
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors*; D000177:Acrosome / Q000187:drug effects* / Q000502:physiology*; D002110:Caffeine / Q000494:pharmacology*; D000001:Calcimycin / Q000494:pharmacology; D005260:Female; D015571:Follicular Fluid / Q000502:physiology; D006801:Humans; D008297:Male; D010431:Pentoxifylline / Q000494:pharmacology*
D000001:Calcimycin; D002110:Caffeine; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D010431:Pentoxifylline