DOSE-RESPONSE EFFECTS OF GRAMICIDIN-D, EDTA AND NONOXYNOL-9 ON SPERM MOTION PARAMETERS AND ACROSOME STATUS

Previous reports showed that gramicidin-D (G-D), a polypeptide with an tiviral and antimicrobial properties, nonoxynol-9 (N9), a common sperm icidal detergent, and EDTA, a Ca-Mg chelating agent, inhibited sperm m otility and cervical mucus penetration. The purpose of this study was to determine the dose-response effects of G-D, N9, EDTA and G-D + EDTA on sperm motion parameters and acrosome status. Semen specimens from known fertile donors were subjected to computer-assisted semen analysi s of motility, path velocity, progressive velocity, and hyperactivatio n prior to and after incubation with varying concentrations of gramici din-D, EDTA and nonoxynol-9. Each specimen was also prepared for acros ome status using rhodamine isothiocyanate conjugated pisum sativum agg lutinin (RITC-PSA). There was a significant decrease in motility by G- D, EDTA, G-D + EDTA, and N9 at all doses as compared to the fresh spec imen. N9 completely immobilized all sperm at each dose. Progressive ve locity and path velocity also decreased in a dose-response manner. Spe rm hyperactive motility also significantly decreased in all groups. Th e majority of sperm remained acrosome intact following exposure to all doses tested, whereas N9 resulted in complete breakdown/release of th e acrosomal contents. This study confirms previous reports that G-D, E DTA, and N9 significantly impair sperm motility and motion parameters. The effective 100% inhibitory concentration was seen only with N9, wh ereas G-D, EDTA, and G-D + EDTA resulted in incomplete impairment of s perm motion parameters. At the concentrations used, N9 demonstrated po tent spermostatic activity. Gramicidin-D and EDTA should be further st udied for their potential contraceptive spermostatic activity. (C) 199 8 Elsevier Science Inc. All rights reserved.