Effect of ionophore challenge on hamster egg penetration and acrosome reaction of antibody-coated human sperm.
OBJECTIVE
Following the demonstration that antisperm antibodies do not affect the spontaneous acrosome reactions (AR) of human sperm used for the hamster egg penetration assay (HEPA), we evaluated the effect of the ionophore challenge on HEPA and AR of antibody-coated sperm.


METHODS
Motile sperm suspensions from donors were exposed to serum and seminal plasma samples with sperm-head-directed antibodies, washed, capacitated, and challenged with ionomycin.


RESULTS
The proportion of acrosome-reacted sperm, assessed by fluoresceinated Pisum sativum agglutinin and supravital stain Hoechst 33258, was significantly higher in the antibody-exposed sperm than in the controls (47.0 +/- 13.2% vs. 39.3 +/- 12.1, respectively; P < 0.05). However, the hamster egg penetration rate and index were not significantly different between antibody-exposed sperm and controls (98.0 +/- 3.7% vs. 85.9 +/- 16.2% and 6.64 +/- 4.1 vs. 6.81 +/- 4.8, respectively). Only one of eight test samples with antisperm antibodies, where the highest increase of AR rate compared with controls was observed (55.0% vs. 35.6%) produced a substantial increase of penetrations per oocyte (7.4 vs. 4.1).


CONCLUSIONS
The ionophore challenge enabled us to recognize a subtle effect of anti-sperm antibodies on the dynamics of acrosomal loss, the clinical relevance of which needs to be elucidated.
Department of Internal Medicine, University of L'Aquila, Medical School, Italy.
R
R
Romano
R
R
Santucci
V
V
Marrone
F
F
Francavilla
D000177:Acrosome / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D000906:Antibodies / Q000276:immunology*; D006224:Cricetinae; D005260:Female; D006801:Humans; D007476:Ionophores / Q000494:pharmacology*; D008297:Male; D013084:Sperm-Ovum Interactions / Q000187:drug effects*; D013094:Spermatozoa / Q000276:immunology*
D000906:Antibodies; D007476:Ionophores