Increased acrosome-reaction inducing activity of glycosaminoglycans by partial hydrolysis

The possibility that partial hydrolysis of glycosaminoglycan-sulfates (GAGs) such as occurs during the last phases of follicular maturation could play some role in the activity of follicular fluid as an inducer of the acrosome reaction was explored. Hydrolysis of follicular fluid GAGs (ff-GAGs) for 30 min with low-pH HNO2 substantially increased (more than 3 times) its capacity to induce the acrosome reaction. This increase was significantly reduced when the time of hydrolysis was either shorter (10 min) or longer (60 min). Partial hydrolysis of spermatozoa GAGs by direct incubation of sperm cells with chondroitinase ABC was also capable of inducing the acrosome reaction.