Inhibition of the hamster sperm acrosome reaction by transmethylation inhibitors.
Two inhibitors of somatic cell transmethylation, homocysteine thiolactone (Hcy) and 3--deazadenosine (3--DZA), inhibited the acrosome reactions of hamster sperm in vitro. Hcy (250 microM) or 3--DZA (200 microM) inhibited acrosome reactions by approximately 30% after 4 hours of incubation with washed sperm in a capacitating medium containing epinephrine, taurine, and bovine serum albumin. Inhibition by 3--DZA decreased by 5 hours, but inhibition by Hcy did not. Incubation of sperm with the combination of both inhibitors inhibited acrosome reactions by nearly 60% at 4 hours, and did not appreciably decrease with time up to 5 hours. These results are the first to demonstrate that such inhibitors can interfere with the acrosome reaction and taken together with the effects of Hcy and 3--DZA on somatic cells, suggest that sperm protein and/or phospholipid transmethylation is/are involved in capacitation and/or the acrosome reaction.
D000177:Acrosome / Q000187:drug effects*; D000818:Animals; D006224:Cricetinae; D006710:Homocysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D008647:Mesocricetus; D008745:Methylation; D012263:Ribonucleosides / Q000494:pharmacology*; D013075:Sperm Capacitation; D013081:Sperm Motility; D013094:Spermatozoa / Q000187:drug effects*; D014372:Tubercidin / Q000494:pharmacology*
D012263:Ribonucleosides; C018258:3-deazaadenosine; D006710:Homocysteine; C007957:homocysteine thiolactone; D014372:Tubercidin