Dynamics of ATP and movement in Eurasian perch (Perca fluviatilis L.) sperm in conditions of decreasing osmolality.

Repetitive activation of perch (Perca fluviatilis L.) sperm motility was investigated in this study. The first phase of sperm motility activation was initiated by dilution in a 260 mM glucose solution (75% motility). The second phase of motility was achieved by adding water to previously activated sperm, so that the glucose concentration dropped to 220 mM (24% motility). Finally, the third phase was obtained by further addition of water (down to 90 mM glucose) to the activated sperm suspension (15% motility). Parallel measurements of sperm ATP content were also made. The median value for nonactivated sperm was 43.9 nmol ATP/10(9) spermatozoa. The ATP concentration decreased significantly from 35 to 7 nmol ATP/10(9) spermatozoa after successive activations of motility in the above glucose solutions. Sperm velocity ranged in value from 25 to 330 microm/sec at 10 sec postactivation, from 10 to 290 microm/sec at 30 sec, and from 0 to 200 microm/sec at 45 sec. A model postulating several classes in the population of spermatozoa is developed, tentatively accounting for such successive activation. Possible further application of multiple sperm activation is discussed.