Inhibition of sperm dilution damage by purified factors from hamster caudal epididymal plasma and by defined diluents.

Sperm dilution damage can be prevented by diluting hamster caudal epididymal (HCE) sperm in HCE plasma, a fluid which had been shown to contain sperm survival factors (SF). Dialysis and ultrafiltration studies demonstrated that SF consisted of both small-molecule and large-molecule components. Several known macromolecules and small molecules could substitute for these factors. Chemically defined diluents were designed that were able to substitute for HCE plasma in the prevention of sperm dilution damage under certain conditions. When the HCE plasma large-molecule component were fractionated by Sephadex G-100 chromatography, three bands of SF activity eluted. One appeared in the void volume ( is greater than 100,000 daltons), one with bovine serum albumin (67,000 daltons), and one at about 35,000 daltons. Two HCE plasma small-molecule components of less than 500 daltons eluted from both Sephadex G-25 and G-15 columns. Proteolysis studies suggested that both the small-molecule and the large-molecule components of HCE plasma may possess peptide bonds.