Bovine serum albumin, sperm motility, and the “dilution effect”

Abstract

Epididymal spermatozoa from rabbit and ram were washed either once or twice using an efficient washing procedure and were then diluted in various media to a final concentration of approximately 1.4 x 10(7) cells/ml and incubated at 30 degrees C for up to 12 hours. Bovine serum albumin (BSA), either untreated or defatted, was found to be better than polyvinylpyrrolidone, ovalbumin, or alpha-lactalbumin, both at stimulating and maintaining motility levels and at reducing the tendency of the washed spermatozoa to stick to glass. BSA was effective in all media tested, being independent of Ca2+, PO4(3-), HCO3-, and ionic strength). BSA has a reversible stimulatory effect on motility. If BSA was added to sperm suspensions 3 1/2 hours after they had been washed and diluted in protein-free medium, motility was stimulated to levels not significantly lower than those observed in samples that had been washed and diluted in the presence of BSA. However, samples washed into BSA and then washed free of it behaved essentially as though they had never been in contact with protein. The motility, survival, and response to BSA of twice-washed spermatozoa were the same as those of once-washed spermatozoa, showing that epididymal plasma factors are not required for survival in vitro. It was concluded that dilution is not essentially detrimental to rabbit and ram spermatozoa. However, severe dilution of semen may result in levels of male reproductive tract fluids insufficient either to stimulate motility or to prevent sticking of motile cells to container surfaces. Few motile spermatozoa are recovered from samples of such diluted semen.

rab3‐Peptide stimulates exocytosis of the ram sperm acrosome via interaction with cyclic AMP and phospholipase A2 metabolites

“…Both media also contained 1 mg poly(vinyl) alcohol/ml and 1 mg polyvinylpyrrolidone/ml, and had an osmolality of 305 mOsm/kg. Ejaculated ram spermatozoa were separated from seminal plasma by dilution and washing through sucrose medium (400×gm~ for 5 min, and 1000×gm~x for 10 min), as described [26].…”

Albumin is required to support the acrosome reaction but not capacitation in mouse spermatozoa in vitro

“…Although the specific mechanisms whereby albumin exerts its effects are not clearly defined, Lui, Cornett & Meizel (1977) have reported that albumin is required for induction of the acrosome reaction in hamster spermatozoa and that the fatty acid content of albumin can either enhance or inhibit acrosome loss . Albumin is also very effective in maintaining sperm motility during extended incubation in vitro (see for example Lui et ai, 1977;Suter, Chow & Martin, 1979;Harrison, Dott& Foster, 1982). Since motility is required for fertilization of eggs, at least those with intact investments, this may represent another facet of the albumin requirement.…”

Evaluation of swine fertilisation medium (SFM) efficiency in preserving spermatozoa quality during long-term storage in comparison to four commercial swine extenders

“…AeG and SFM possessed greater ability in preserving spermatozoa motility, which reached the 60% threshold at the end of the trial. These two diluents contain BSA, which has been shown to have a potent effect on the stimulation (Harrison et al, 1982;Waberski et al, 1989) and preservation of motility.For viability, we experienced the best results with AeG and SFM, which were able to preserve membrane integrity more efficiently and for more days as compared with the other extenders. AeG and SFM can provide better conditions with a more controlled pH and osmotic pressure.…”

“…AeG and SFM possessed greater ability in preserving spermatozoa motility, which reached the 60% threshold at the end of the trial. These two diluents contain BSA, which has been shown to have a potent effect on the stimulation (Harrison et al, 1982;Waberski et al, 1989) and preservation of motility.…”