MECHANISM FOR PROCAINE-MEDIATED HYPERACTIVATED MOTILITY IN GUINEA-PIGSPERMATOZOA

Hyperactivated motility was studied in guinea pig spermatozoa. In the presence of the local anesthetic procaine, a high number of sperm cell s (64%) showed hyperactivation when incubated in minimal culture mediu m with pyruvate, lactate, and glucose. Hyperactivated motility was dep endent on glucose in the medium. Sperm ATP concentration was increased twofold in hyperactivated sperm when compared to procaine-treated non -hyperactivated cells, cAMP levels were also higher in hyperactivated cells than in control spermatozoa. Thus, in living spermatozoa high re vels of ATP appear to be needed to generate hyperactivation, cAMP is p resent at a high concentration in hyperactivated spermatozoa, therefor e a role of cAMP in hyperactivation cannot be excluded. Depletion of e xternal Ca2+ did not inhibit procaine-induced hyperactivated motility. Hence, procaine canceled the requirement of external Ca2+ for sperm t o express hyperactivated motility. (C) 1994 Wiley-Liss, Inc.