The yield, motility and performance in the hamster egg test of human spermatozoa prepared from cryopreserved semen by four different methods

Abstract

Different procedures were investigated for the dilution of human cryopreserved semen and the preparation of an enriched population of motile spermatozoa for assisted reproduction. The dilution of a 0.25 ml straw of cryopreserved human semen by addition of 2.0 ml Ham's F-10 buffer in one step caused a large decrease in the proportion of motile spermatozoa. This was due to osmotic stress because many of the diluted spermatozoa exhibited swollen tails. To a large extent the damage could be avoided by adding the buffer in 0.10-ml aliquots at 30-s intervals. Spermatozoa obtained after such dilution of cryopreserved human semen were subjected to the swim-up procedure, to centrifugation on two-step gradients of Nycodenz or Percoll, or to filtration through glass fibre paper and compared with respect to yield, motility parameters and penetrating ability in the hamster egg test. The swim-up procedure yielded spermatozoa with excellent motility but only 12% of the available motile spermatozoa were recovered. On both Nycodenz and Percoll gradients, greater than 40% of the available motile spermatozoa were recovered and the average velocity of the spermatozoa was not significantly less than for the swim-up technique. When A23187 was used to promote acrosome reactions in the hamster egg test, Percoll-prepared spermatozoa achieved an average of 8.6 decondensed sperm heads/egg compared to 1.9 for Nycodenz and 1.3 for the swim-up procedure. The yield from glass fibre paper filtration was only 12% and the velocity of the spermatozoa and their performance in the hamster egg test was significantly poorer than in all the other methods.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of Ca‐ATPase inhibitors on the intracellular calcium activity and motility of human spermatozoa

“…Semen was obtained from healthy donors by masturbation and allowed to liquefy for 30–60 min at 37 °C. It was centrifuged (350 g × 20 min) through a 40 : 80% discontinuous ‘Percoll’ density gradient (Ford et al. , 1992) and the sperm pellet was washed twice (350 g × 10 min) in modified Biggers, Whitten and Whittingham (BWW) medium containing 3 mg/mL bovine serum albumin (Fraction V) (Biggers et al.…”

Functional Significance of the Pentose Phosphate Pathway and Glutathione Reductase in the Antioxidant Defenses of Human Sperm1

“…All the donors provided signed consent for their semen to be used for research and were recruited in accordance with local ethical guidelines. Semen was collected into sterile plastic pots and allowed to liquefy at 37ЊC for up to 1 h before being layered above 40%/80% discontinuous Percoll density gradients [20]. Gradients were centrifuged at 350 ϫ g for 25 min, and the resultant sperm pellet was washed twice (350 ϫ g, 10 min) in Biggers Whitten and Whittingham buffer (BWW) containing 3 mg/ml of BSA [21].…”

Multistep and single-step treatment of human spermatozoa with cryoprotectants

“…This also occurs with ovine spermatozoa, but they survive better a gradual reduction in osmolality (19). The addition and removal of glycerol cryoprotectant in multiple small steps, rather than in one step, improves the motility and fertilizing capacity of post-thaw human spermatozoa (20,21); this is thought to be because of the lesser extent of volume change under these conditions. The permeability of human spermatozoa toward glycerol is less than that of water (22), and glycerol, as well as ethylene glycol (EG), propylene glycol, and dimethylsulphoxide (DMSO), reduces the permeability of water (23).…”