Objective: To examine potential methods for distinguishing between the acro
some reaction and acrosomal loss.
Design: Prospective randomized study.
Setting: Department of Obstetrics and Gynecology, Osaka University Hospital
, Suita, Japan.
Patient(s): Five healthy volunteers and 34 patients with normozoospermia wh
o were participating in an IVF program.
Intervention(s): Semen samples were collected from the volunteers before th
e hamster egg penetration assay and from the patients at the time of IVF.
Main Outcome Measure(s): The numbers of oocytes penetrated and spermatozoa
bound were determined with the hamster egg penetration assay. Acrosomal sta
tus was assessed with two-color fluorescence staining using fluorescein iso
thiocyanate-conjugated Pisum sativum agglutinin (FITC-PSA) and MH61 (anti-C
D46 monoclonal antibody) with Texas red-conjugated antimouse immunoglobulin
G antiserum.
Result(s): The MH61 monoclonal antibody inhibited the penetration of human
spermatozoa into hamster oocytes but did not reduce the number of spermatoz
oa bound to the zona-free hamster oocytes. Two-color fluorescence staining
revealed four staining patterns of the acrosomal region. The percentage of
PSA-negative/CD46-positive spermatozoa increased to a greater extent than t
hat of PSA-negative/CD46-negative spermatozoa with an increase in the incub
ation time.
Conclusion(s): Two-color fluorescence staining with FITC-PSA and the anti-C
D46 monoclonal antibody may be useful for distinguishing between the acroso
me reaction and acrosomal loss. (Fertil Steril(R) 1999;71:497-501. (C)1999
by American Society for Reproductive Medicine.).