Assessment of progesterone-induced acrosome reaction by biotinylated monoclonal antibody probes.
OBJECTIVE
To develop an immunohistochemical assay for determination of acrosome-reacted human sperm and to study the effects of progesterone and cholesterol treatment on human sperm acrosome reaction.


METHODS
Three distinct anti-sperm monoclonal antibodies were biotinylated and used as probes for assessment of acrosome reaction in a 30-min immunohistochemical assay. Progesterone and/or cholesterol were added to sperm preparation to influence the acrosome reaction in different experimental conditions.


RESULTS
Percentages of acrosome-intact sperm decreased significantly during the 18-hr incubation. Acrosome reaction could be induced by progesterone as early as 2 hr after sperm incubation in human tubal fluid. The degree of progesterone-induced acrosome reaction was time dependent and the optimal effect was reached by adding 10 micrograms/ml progesterone for 30 min incubation. Progesterone-induced acrosome reaction was shown to be hormone-concentration dependent with 50% stimulation at 1 microgram/ml. Cholesterol (1 microgram/ml) was found to inhibit progesterone-induced acrosome reaction either by co-incubation with human sperm during capacitation, or by simultaneous incubation with progesterone during acrosome reaction induction.


CONCLUSIONS
Assessment of human sperm acrosomal status by avidin-biotin immunohistochemical assay can be a routine in clinical laboratories for male infertility services. Cholesterol can inhibit progesterone-induced acrosome reaction, possibly by its modifications of sperm plasma membrane and/or interference of progesterone binding to its surface receptors.
Lee
C Y
CY
Department of Obstetrics and Gynecology, University of British Columbia, Vancouver, Canada.
Khorasani
A M
AM
Dorjee
S
S
D000177:Acrosome / Q000187:drug effects*; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D000918:Antibody Specificity; D001710:Biotin / Q000494:pharmacology*; D002784:Cholesterol / Q000494:pharmacology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D011374:Progesterone / Q000494:pharmacology*; D013094:Spermatozoa / Q000187:drug effects
D000911:Antibodies, Monoclonal; D011374:Progesterone; D001710:Biotin; D002784:Cholesterol