PENTOXIFYLLINE POTENTIATES IONOPHORE (A2318T) MEDIATED ACROSOME REACTION IN HUMAN SPERM - FLOW CYTOMETRIC ANALYSIS USING CD46 ANTIBODY

The study was designed to investigate the effects of pentoxifylline on the acrosome reaction of human spermatozoa in vitro, and to determine whether the reaction is differently modulated after sperm selection b y multiple tube swim-up and Percoll buoyant density centrifugation. Th e acrosome reaction was induced in vitro by using calcium ionophore (A 23187) and was detected by measuring the fluorescence of FITC-conjugat ed goat anti-mouse immunoglobulin bound to CD46 antibody (which binds to the CD46 receptor site on the inner acrosomal membrane) by flow cyt ometry. Spermatozoa separated on Percoll displayed significantly lower spontaneous acrosome reactions (P = 0.002) than did those separated b y the swim-up technique. Pentoxifylline did not, by itself, induce acr osome reaction, but after induction with ionophore, it significantly i ncreased the reaction (P = 0.0003) and this increase was seen to be gr eater when Percoll separation was used as compared to the swim-up tech nique (P = 0.0002). We therefore conclude that Percoll selection of mo tile spermatozoa together with pentoxifylline treatment may be of valu e in assisted reproductive techniques, as an increased ARIC score aros e after both treatments, and that flow cytometry allows a precise and rapid quantification of the acrosome reaction.