Experiments were designed to test the effects of simple sugars andcomplex polysaccharides on the attachment of human spermatozoa withthe zona pellucida. For this in vitro system the salt-stored humaneggs (Yanagimachi et al. 1979) were used.The attachment of capaciated spermatozoa to the zona pellucida wasinhibited by fucoidin. Fucoidin was a very potent inhibitor, completelyblocking attachment at a concentration of 0.1 mg/ml.When the spermatozoa were treated with 1 mg/ml fucoidin and weremixed with ova in fucoidin-free medium, they barely attached to thezona. However, pretreatment of the zonae identicaly, prior tomixing with untreated spermatozoa, did not inhibit attachment.These results suggest that fucoidin probably reacted with spermatozoa, not with zonae.
