COMPARISON OF MOTILITY AND MEMBRANE INTEGRITY TO ASSESS RAT SPERM VIABILITY

Rat sperm motility and membrane integrity were compared as endpoints f or viability, Sperm motility was measured by computer-assisted semen a nalysis (CASA), whereas membrane integrity was assessed by flow cytome tric analysis of sperm stained with two nucleic acid stains, SYBR-14 a nd propidium iodide, The two techniques were compared in experiments t hat examined sperm viability over time and by analysis of known mixtur es of control and freeze/thaw-killed sperm, Results from the two appro aches were quantitatively very similar, Sperm from rats treated with d ibromoacetic acid (600 or 1200 mg/kg) or alpha-chlorhyrin (100 mg/kg) were also analyzed. Neither technique detected a treatment-related eff ect with dibromoacetic acid, CASA identified a significant decrease in sperm motility in alpha-chlorhyrin-treated rats, whereas flow cytomet ric analysis did not find a measureable change in sperm membrane integ rity, Because decreases in sperm motility would be expected to directl y affect fertility, CASA may be a more robust endpoint for risk assess ment in reproductive toxicology studies than flow cytometric analysis of membrane integrity. (C) 1998 Elsevier Science Inc.