SPONTANEOUS AND FOLLICULAR FLUID-INDUCED ACROSOME REACTION IN SPERM SAMPLES FROM IN-VITRO FERTILIZING AND NONFERTILIZING NORMOZOOSPERMIC PATIENTS

Purpose: One of the most challenging and intriguing groups of infertil e patients is that of normozoospermic men who have repeatedly not achi eved fertilization in vitro. These cases probably present a wide range of gamete disorders manifested at different stages of the fertilizati on process. The occurrence of spontaneous and follicular fluid (FF)-in duced acrosome reactions (ARs) in in vitro fertilizing and nonfertiliz ing specimens from normozoospermic NF patients was assessed, and the e ffect of Percoll and cryopreservation on the incidence of ARs was eval uated. Methods: Semen samples from 62 normozoospermic (15 in vitro non fertilizing and 47 fertilizing) patients were analyzed. Spermatozoa we re double-stained with FITC-conjugated Pissum sativum lectin, to asses s their acrosomal status, and propidium iodide, to evaluate their vita lity, using flow cytometry analysis. Results: A lower aver age of AR i ncidence was observed in the nonfertilizing than in the fertilizing gr oup with all treatments. Both groups exhibited an increase in the prop ortion of ARs following incubation with FF: This rise was most promine nt when Percoll-separated fractions were used (15.8 and 25.6% AR in th e nonfertilizing and fertilizing groups, respectively). Thawed cryopre served and fresh fertilizing samples exhibited similar AR rates. Concl usions: That normozoospermic recurrently nonfertilizing compared to fe rtilizing semen samples have a lower capacity to undergo ARs is sugges ted.