The Factors that Modify Agglutination of Ageing Sperm

Abstract

The previous studies demonstrated that ageing “dry” or concentrated sperm gave rise to a marked increase, then decrease in agglutination, provided, however, the sperm were not overripe when shed. In the present study, the sperm were overripened in a standard 1% suspension at 22° C. and tested at each age by samples of the same egg water. There was the same, but quicker, cyclical change. The first phase began in 5 to 20 minutes after the initial test. The second phase ended in 15 to 125 minutes. The third phase ended in 260 minutes. The increase in agglutination was from 77 to 328%.

The greater the overripeness of the dry sperm when shed, the earlier the maximum values, and the sooner was the cycle ended. When sperm was not overripe when shed, subsequent ageing gave rise to very little or no increased phase, followed by a decreasing phase.

The experiments were so devised as to eliminate such factors as a change in agglutinin, change in jelly content, change in temperature, or H ion concentration of the medium.

To determine whether the increase in agglutination was due to a substance or substances liberated by the sperm, increasing concentrations of sperm were tested with the same egg water solutions. The concentrations of sperm ranged from 1% to 25%. More concentrated suspensions could not be used, on account of the difficulty in distinguishing the agglutinated clusters in the thick medium. Sufficient time was allowed for the substance if present to be liberated. There was no change in agglutination values with the marked increase in concentration of sperm whether ripe or overripe.

The CO₂ liberated by the eggs and the active sperm plays a large role in decreasing the activity of the sperm, in clumping the sperm into aggregations, but plays no role in increasing the agglutination of ageing sperm.