Motile Human Spermatozoa Research Articles

Effect of purification of bovine serum albumin on the interaction of human semen with mouse ova in vitro.

Mouse ova degenerate in medium containing untreated bovine serum albumin (BSA) when incubated for 18—24h with highly motile human spermatozoa not completely freed from a seminal plasma component. The human seminal plasma component also has a detrimental effect on the motility of human spermatozoa in the presence of untreated BSA, but both mouse ova and human spermatozoa are unaffected by human seminal plasma when the culture medium contains purified BSA as a protein source. The active component from human seminal plasma is most probably spermine. This polyamine reacts with the untreated BSA with a component that is pronase sensitive, heat labile and only partially dialyzable. The BSA component is not precipitated by trichloroacetic acid but is soluble in ethanol. Although the nature of the seminal plasma-BSAinteraction suggests that the effect of BSA may be due to amine oxidase activity, attempts to assay endogenous amine oxidase activity in the untreated BSA have failed to detect it.

REVIVAL OF MAMMALIAN SPERM AFTER IMMERSION IN LIQUID NITROGEN

1. A wide variety of procedures was used to test the motility of mammalian sperm after plunging them into liquid nitrogen at -195 degrees C. and later rapidly warming them to 35 degrees C. by plunging them into a suitable balanced and isotonic medium. 2. Using seminal fluid sperm from the same human donor, maximal numbers of motile sperm survived vitrification when the samples were (a) very fresh, (b) untreated with plasmolysing solutions, (c) plunged into the refrigerant in the form of a foam. The maximum yield of motile human sperm recoverable from the liquid nitrogen was 50 per cent. Since in this sample only 75 per cent of the sperm were alive before immersion, 67 per cent of the living sperm survived vitrification. 3. Experiments with sperm from 31 rabbits were made with a variety of conditions of pretreatment to obtain maximal yields of recoverable, motile sperm after vitrification by liquid nitrogen. (a) A consistent recoverable yield of about 0.5 per cent was obtained when the untreated suspension of sperm was smeared on cellophane and partially dried in air before immersing in liquid nitrogen. (b) On a few out of many occasions plasmolysis for several minutes with hypertonic Ringer solution gave a recoverable yield of 0.1 per cent as did (c) pretreatment with hypertonic Ringer and butyric acid.